Conference Agenda

Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).

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Session Overview
Date: Saturday, 10/Sept/2022
12:00pm - 5:00pmPNCWA Board Meeting
Date: Sunday, 11/Sept/2022
9:00am - 12:00pmPNCWA Board Meeting
10:00am - 7:00pmRegistration Desk is Open
11:00am - 1:00pmWFP 5k run/walk

Starting/Ending Location: Forestry Shelter in Riverfront Park (run/walk will be a 5k out and back) 

1:30pm - 3:30pmService Project: River bank litter cleanup with Riverkeepers
4:00pm - 5:00pmMeet & Greet: First Time Attendees & New Members
5:00pm - 7:00pmMeet & Greet: All Attendees
7:00pm - 9:00pmPresident's Dinner (by invitation only)
Date: Monday, 12/Sept/2022
7:00am - 8:15amBreakfast—Monday Breakfast
7:00am - 5:00pmSpeaker Ready Room is Open
7:00am - 6:30pmRegistration Desk is Open
8:15am - 9:45amOpening Session Address

Be Like Water: Adapting with Purpose – A Call to Action

Phyllis A. Brunner

In keeping with the theme of the conference and setting the stage, the opening address will cover our changing and complex world today as it relates to the water sector. The goal of the presentation is to instill a sense of urgency in tackling the challenges we are facing but also with hope and confidence that we can creatively solve the issues ahead of us to benefit society and the environment.

We have faced challenges before in our past, and we have risen through innovation and working together. The spotlight on infrastructure is here with the federal spending bill and the issues we are facing with climate change. Examples of past accomplishments around wastewater treatment, advances in water regulations and compliance, technology, and how the human environment as adapted over time will be discussed historically. 

Turning then to today, we see a rapidly changing world focused on sustainability and resiliency. The terms will be defined, examples of how the water sector is adapting to the challenges and how we as engineers, scientists and operators can step up to address these global changes with our skills and experience. These times require us to think differently and look for solutions that address a range of scenarios because of the uncertainty. Approaches will be suggested for the audience to consider and explore during the rest of the conference.

Closing remarks will address the people side of the challenges we are facing professionally and personally. What should be considered at the organization level, how each of us can maintain our own resiliency individually and how to stay energized for a long and rewarding career. We each play a critical role in the sustainability of the future of our world, and we can inspire the next generations with what we do. This is our time!

9:45am - 10:30amMonday Morning Break
10:30am - 11:55amSession 01A: Water Reuse

Sustainably Protecting Local Water Supplies By Recharging Aquifers With MBR Effluent

Hiro Kuge1, Amber Mummert2, Allan Maas3, Larry Morris1, Yasushi Terao1

1Kubota Membrane USA Corporation, United States of America; 2Ilani Resort; 3Parametrix;

As water supplies dry-up around the country, potable reuse has become a sustainable option to replenish water supplies. In Washington state the Cowlitz Water Reclamation Plant (WRP) is utilizing membrane bioreactor (MBR) and UV treatment technologies to reclaim treated wastewater for recharging local aquifers.

To comply with standards for recharging aquifers, the effluent must meet primary and secondary safe drinking water MCL’s and Class A reclaimed water standards. This requires < 2.2 MPN/100 mL of total coliforms, an average 2.0 NTU for turbidity and < 10 mg/L total nitrogen.

Cowlitz WRP is located on the Ilani Resort site in Ridgefield, WA. The plant was commissioned in 2017 with an MMF of 195,000 gpd, expandable to 390,000 gpd. Wastewater is collected from the Cowlitz Casino and subjected to a screening process followed by MBR treatment. Flat sheet submerged membrane units separate the mixed liquor and bacteria from effluent, as well as provide most of the oxygen required for nitrification with scouring air. Prior to injection into the aquifers, the MBR effluent passes through UV.

The WRP has been operating for five years and the total plant effluent is achieving the Class A standards; total coliforms are < 1 MPN/100 mL and turbidity ranges from 0.05 to 0.15 NTU. Ammonia in the effluent falls below detection (less than 0.01 mg/L) and total nitrogen is < 5 mg/L.

Vadose zone injection is accomplished by pumping the disinfected effluent to 120-foot-deep injection wells where the water then percolates into the underlying water table replenishing the aquifer. This vadose (unsaturated soil) zone ranges from ground elevation to the top of the aquifer below. The wells operate under "Authorization by Rule" allowed by the federal Underground Injection Control Program.

It is possible to replenish local water supplies through sustainable reuse practices. At the Cowlitz WRP, wastewater is thoroughly treated to Class A reclaimed water standards with MBR and UV disinfection. The resulting treated wastewater is injected into vadose zone wells that recharge the aquifer and add to the local water supply. This presentation will be useful for municipalities exploring potable reuse applications.

Predicting Drainage in North Idaho Forest Water Reclamation Facilities

Madeline Clark, Mark Coleman, Robert Heinse, Erin Brooks, Eureka Joshi

University of Idaho, United States of America;

Wastewater is an unavoidable byproduct of populated communities. In northern Idaho, treatment facilities generate wastewater and are permitted by the Idaho Department of Environmental Quality (IDEQ) to apply it to areas of forest. Forests in the Inland Northwest experience annual seasonal droughts, and applying reclaimed wastewater is a way to replenish some of that soil water. Wastewater contains constituents such as nitrogen and phosphorous, two nutrients that are known to increase plant productivity. However, if nutrients are leached into groundwater sources, these constituents may reach nearby lakes and cause harmful algal blooms. One of the intentions of this land application is to avoid any runoff or drainage. To ensure this, the IDEQ has developed a hydraulic loading calculation. This calculation includes an estimation of the crop evapotranspiration rate. To estimate evapotranspiration for forests, IDEQ recommends a crop coefficient of 0.7 be applied to the reference crop evapotranspiration rate. It is important to assess whether this recommended value does avoid drainage during the irrigation season. In addition to collecting actual drainage with drain gauges, the potential drainage occurring in irrigated forests was quantified by estimated evapotranspiration rates for local trees using hydrological models (Hydrus-1D and WEPP). The Nash-Sutcliffe model efficiency coefficient (NSE) was used to assess the predictive capability of these models with observed drainage data. Results show that with calibrated input parameters, Hydrus-1D and WEPP are successful at predicting drainage acquired by drain gauges. While WEPP is more user-friendly, both models require site-specific soil data in order to accurately predict drainage. According to the models, the estimated crop coefficient recommended by IDEQ does not result in drainage during the irrigation season in this forest system, drainage only begins following the treatment season and the start of wet-season precipitation. According to the model with a crop coefficient of 0.7, at some locations irrigation could be increased by up to 140% before potential drainage occurs.

10:30am - 11:55amSession 02A: Social Equity

Advancing Equity Within Different Organizational Cultures

Nicki Pozos, Jessie Maran

The Formation Lab;

Social equity and justice seem to be everywhere these days, but that focus does not always improve outcomes for the underrepresented or disadvantaged. In some organizations, the intention is there, but the actions are unclear. While in other places, equity may face internal opposition. This presentation focuses on different value systems seen in our industry (based on a system called Spiral Dynamics), with a discussion of the challenges to and opportunities for advancing equity within each value system. Understanding and working effectively within different value systems can help organizations advance equity without alienating staff. This understanding can also help individuals who don’t match the dominant value system of their organization make greater progress in creating change. The point is not that one value system is better than another—we can learn to respect and work effectively with all of the value systems present in our organizations.

Getting Specific on Equity in a Project Plan and Aligning a Team: Why Common Language isn’t Enough

Brent Robinson1, Brenda Gardner2, Sam Keller2

1Murraysmith; 2Seattle Public Utilities; , ,

Seattle Public Utilities (SPU) has invested considerable time and resources in its staff to build capacity for racial equity, both as a value that is commonly shared, as well as a lens through which projects and programs can be shaped to better center the communities SPU serves. While many at SPU have embraced holding equity as a common value, understanding specifically how each project and program should proceed and eventually make decisions guided by equity is still a growing practice. The Longfellow Starts Here project is a combined sewer overflow reduction project that seeks to shape what an equitable planning approach could look like, especially one that is still heavily constrained by regulatory forces. While developing the planning approach, the project team struggled to align various staff groups and management on the approach specifics, even though everyone involved was aligned on the value of racial equity and the need to be community centered. This presentation will illustrate the approach the project team used to elevate and clarify the misaligned expectations and the framework used to guide hard conversations to align on a “north star” to better ground approach definition.

10:30am - 11:55amSession 03A: Treatment - Phosphorous

Online Phosphorus Stability Analyzer: Quantifying the Risk of BPR Upset

Adrienne Menniti, Skylar Watnick, Peter Schauer

Clean Water Services, United States of America;

Biological phosphorus removal (BPR) has been a cornerstone of the Clean Water Services (CWS) effluent phosphorus permit compliance strategy for decades. To reliably meet a stringent effluent phosphorus permit with limited chemical use, it is useful to have an early warning metric for detection of upsets in the secondary effluent. We have demonstrated the effectiveness of an online orthophosphate (OP) analyzer coined the ‘Stability Analyzer’ to better understand BPR Stability. The analyzer has been operating on aeration basin one (AB1) at the Durham Water Resource Recovery Facility since 2017.

The location of the stability analyzer was determined by repeated aeration basin orthophosphate profiling. We call its location at about 50% through the aerobic zone the stability point because generally phosphorus uptake is complete by this point during stable operation. Therefore, the stability analyzer reads zero during stable operation and becomes non-zero during unstable operation. We observe two types of conditions where the Stability Analyzer offers early warning of upset events:

  1. The daily average Stability Analyzer OP concentration has read zero for at least three days followed by an increase into non-zero daily average territory. This was found to have a 50% risk of upset 2-6 days in the future.
  2. The daily average Stability Analyzer OP concentration is already non-zero and the daily average concentration increases the next day. This was found to have a 77% risk of upset within the next 3 days.

A new aeration basin (AB5) recently came online at the Durham facility. AB5 is configured differently and has larger anoxic and anaerobic volumes. CWS repeated the profiling procedure for AB5 during its first summer of operation (2021) to determine the stability point. An online OP analyzer was installed at the AB5 stability point in February 2022.

The Stability Analyzer has proven useful in predicting BPR stability. The purpose of this paper is to review the profiling procedure used to locate the stability point, quantify the risk of an upset event using several years of historical stability analyzer data and summarize how the stability analyzer is used for routine process decision making.

Toward Reducing Nonpoint Phosphorus Discharges: A Novel, Commodity-driven Process for Recovering Phosphorus from Dairy Manure

Cody Peters, Erik R. Coats

University of Idaho, United States of America; ,

Excess phosphorus discharged to the water environment is increasingly scrutinized to prevent/minimize eutrophication and enhance overall water quality. To improve water quality, phosphorus waste load allocations (WLAs) into a given water body are regulated through the Total Maximum Daily Load (TMDL) process. Water resource recovery facilities (WRRFs) are acutely impacted by TMDLs and phosphorus WLAs; indeed, WRRFs in the Pacific NW are facing significant investments to either remove phosphorus in compliance with imposed WLAs or to divert reclaimed water away from impacted water bodies. However, WRRFs are often not the dominant source of phosphorus in surface water; nonpoint sources often are a bigger source. In Idaho, and to a lesser degree Washington and Oregon, dairy manure land application can be a significant source of environmental phosphorus – although commensurate treatment expectations do not align with those imposed on municipal WRRFs. Recognizing that financial incentives (i.e., revenue generation) will likely be more influential in achieving dairy manure treatment, research at the University of Idaho has focused on advancing a technology to capture manure carbon as a bioplastic (i.e., polyhydroxyalkanoate, PHA). Recently the research team has discovered that the PHA technology also removes nearly all phosphorus present in the influent wastewater. Of particular interest, preliminary data indicates that P is bacterially stored in a similar manner to that observed in enhanced biological phosphorus removal (EBPR) – yet the PHA reactors are operated fully aerobic, not consistent with EBPR theory. Ongoing research is establishing i) speciation/form of sequestered P, ii) the presence of phosphorus accumulating organisms in this atypical EBPR process configuration, and iii) the mechanism for excess P removal. Results from these investigations will be presented and discussed. This work will not only be potentially impactful to management of animal waste in the PNW region, but fundamentally may shed new light on the EBPR process. We believe the work well aligns with this year’s motto of “Be Like Water: Adapting with Purpose,” and will fit nicely into the “Treatment Innovation and the Future” category of this year’s conference.

10:30am - 11:55amSession 04A: Facility Operations & Maintenance

Why My Brand-New Equipment Shakes, Rattles, and Rolls

John Koch

HDR, Inc., United States of America;

Condition assessments have brought to the forefront many long term and ongoing issues with mechanical equipment. Finite element (FEA), modal, and vibration analyses has been employed during Level 3 and 4 stages of condition assessment to determine natural frequencies of the equipment, vibration frequencies, and amplitudes as well as how to increase equipment natural frequency to reduce vibration. Many vibration issues encountered during condition assessments can be attributed to equipment installation and anchoring.

There are many ”best practices” when it comes to mass and size of concrete equipment foundations that range from 3 to 5 times the mass of the equipment. With the sophistication and the ability to run FEA on desktop computers, the size and mass of concrete equipment pads can be determined. All of these design tools and best practices are for naught if the equipment is not properly secured and fastened to of the concrete. Sleeve manufacturers, individual/corporate standard details, textbooks, codes, You-tube videos, old gray-haired engineers, and contractors can provide examples of “how-to” anchor rotating equipment to concrete foundations. Many of these details are not applicable in today’s construction environment.

Equipment is not as “stout” as it was 40 to 50 years ago which means its stiffen and mass is less. The reduction in materials allows equipment manufacturers to thrive in this very competitive world. Older name-brand manufacturers have been taken over by big corporations where profit is often a top priority ahead of quality, reliability, and longevity. This overall philosophy has resulted in equipment that is more susceptible and prone to vibration.

API, PIP, and ANSI/HI have standard details that the industry should be following but trying to convince more seasoned engineers and contractors can be troublesome if not downright impossible. This presentation will examine photographs, details, and the results of using the “old” standards as well as what the current standards of installation should be for rotating equipment.

Focus on Affordability: A Creative Approach to Increasing Hydraulic Capacity

Gregory Humm1, Jue Zhao2, Steve Celeste2, Troy Thomson2, Maria Claudia Reed1

1Brown and Caldwell, United States of America; 2City of Salem, Oregon; , ,

The City of Salem (City) and Brown and Caldwell (BC) are working collaboratively to achieve affordable hydraulic capacity increases at the City’s Willow Lake Water Pollution Control Facility (WPCF). The joint efforts are on track to increase capacity by 32 million gallons per day (mgd) by identifying and resolving hydraulic bottlenecks.

BC used two modeling software platforms, Visual Hydraulics (VH) and InfoWorks, to estimate the peak hydraulic capacity of each segment of the WPCF and to identify hydraulic bottlenecks.

The models identified three flow bottlenecks. In the “north” plant, the VH Model confirmed that removal of existing weir plates originally intended to provide adequate submergence on the trickling filter pumps could be removed to increase trickling filter effluent flow to the south plant by 10 mgd without any cost. Increased flow conveyance to the secondary treatment process in the south plant reduces the need to put wet weather facilities into operation. The increased flow conveyance was confirmed through full scale testing by plant operations.

Further analyses of the north plant using the InfoWorks model concluded that an increase of 12 mgd could be achieved through the north plant by making physical improvements to eliminate bottlenecks. The benefit here is similar, a higher level of treatment of wet weather flow is achieved while simultaneously postponing the need to place wet weather facilities in operation. Those improvements were integrated into the design of a clarifier upgrade project at a cost of approximately $500,000.

The “south” plant hydraulic bottleneck was due to insufficient primary effluent conveyance capacity and constrictions created by Parshall flumes. By replacing the flumes with magnetic flow meters and adding a parallel conveyance pipeline, the bottlenecks were cleared, gaining 15 mgd of capacity. These improvements, estimated to cost $1,800,000, are currently under design.

In total, the City will invest approximately $2.3 million to eliminate the three major bottlenecks and increase plant capacity at a cost of less than $100,000 per mgd. Achieving an equivalent capacity increase by constructing additional unit processes would easily cost 10 to 15 times more than this amount.

10:30am - 11:55amSession 05A: Collection Systems - Pumping

Pumping to Greater Heights: BES' Collaborative and 3DBIM-Driven Pump Station Upgrades

Jen Murphy1, Huong Nguyen2, Robert Bacon2, John Welch II2, Stan Orr3

1Parametrix, Inc, United States of America; 2City of Portland, Bureau of Environmental Services (BES); 3Stettler Supply & Construction; , , , ,

In 2017 the City of Portland, Bureau of Environmental Services (BES) embarked on a project to upgrade and replace the Broadway and 94th pump station. The age of the existing facilities was approaching 40 years, it was not seismically resilient, and it was located at the end of a local drainage pathway leading to sediment inundation. BES engaged the Parametrix team to address these facility challenges. Additionlly, BES used this project to pilot project delivery via three-dimensional Building Information Modeling (3D BIM) software. This was the first time 3D BIM was used to design and construct a BES facilties project and this delivery approach is now BES’ standard for these project types.

Throughout design, the City-Consultant team navigated the challenges of implementing a new delivery method, which required modifying existing City standards and delivery models. The team was able to heavily leverage the 3D BIM model to communicate design alternatives, proposed details, and achieve rapid consensus of stakeholders within the organization. In addition, the design team collaborated with Operation and Maintenance staff, Construction Management staff, the Contractor, which enabled the City to complete the project with low change orders (approximately 2%) and high satisfaction of O&M staff. The new pump station meets O&M level of services and has improved seismic resiliency. This technical and delivery success reflects the cohesive team built throughout project delivery.

This presentation will discuss the specific challenges and associated solutions relating to station design requriements and the delivery method pilot. The speakers include the Consultant Project Manager, City Engineering Project Manager, City Construction Manager, City Operations and Maintenance Manager, and the Contractor Superintendent. This team will present their multiple perspectives and specific strategies used to build a truly dynamic and cohesive team that successfully collaborated to deliver this project.

Challenges of Installing a Wastewater Pump Station over an Artesian Aquifer

Erik Waligorski1, Tyler Whitehouse1, Ken Miller2, Fei Tang2, Rick Powell3

1Carollo Engineers, Seattle, WA; 2Lakehaven Water & Sewer District, Federal Way, WA; 3Robinson Noble, Inc, Tacoma, WA;

Lakehaven Water and Sewer District (District), located between Seattle and Tacoma, needed to design and construct a new 9.3 million gallons per day (mgd) submersible pump station (PS 33B) located on a constrained site surrounded by wetlands, a stream, and challenging subsurface conditions. This presentation highlights the unique design and construction elements, including lessons learned, of installing a large collection system pump station on a small site with unsuitable materials, pressurized aquifers, and adjacent stream and wetlands.

The project site for the new pump station is approximately 95-foot wide by 100-foot long located along a busy residential roadway and is bordered by Hylebos Creek to the east and wetlands to the west. Nine geotechnical borings were performed at the site and identified three different pressurized aquifers within 40 feet of existing grade, including a lower artesian aquifer encountered at 37 feet below grade that creates a water head extending 19 feet above ground surface if punctured. The subsurface soils from 0 to 30 feet depth included a slightly pressurized middle aquifer followed by an upper aquifer with groundwater at grade. It was also determined that the top seven feet of soil at the project site were unsuitable and would need to be removed and replaced.

The most critical design challenge was maintaining global stability of the site by ensuring that the lower aquifer would be protected and not punctured during all phases of construction of the new improvements. Design requirements implemented to protect the lower aquifer included:

  • Limiting open excavation volumes during removal and replacement of unsuitable soils.
  • Adding temporary fill to the site extending two feet above proposed grade during installation of the wet well.
  • Installing the wet well via a 28-step sink-in-place caisson method that included dewatering two separate aquifers, maintaining high water levels inside the caisson, and diver assistance.

The installation of the 21-foot deep rectangular sink-in-place caisson took approximately eight weeks to accomplish with multiple challenges encountered during construction, including slowed caisson sinking due to sloughed material, maintaining water levels in the caisson to prevent aquifer blowout, and swelled water stops requiring diver intervention.

10:30am - 11:55amSession 06A: Stormwater - Design

Stormwater Parks: A New Model for Regional Retrofits

Paul Fendt, Seth Sokol

Parametrix, Inc., United States of America; ,

Stormwater retrofits can protect impaired receiving waters from pollution from outdated legacy development while helping manage planned growth. However, too often these facilities are fenced-in “stormwater prisons” that fail to deliver a full range of public benefit. An emerging new concept explores the joint need for both public open spaces and stormwater retrofits that create new public spaces with multiple uses: stormwater parks.

The speakers will first talk through the planning and design of a stormwater park. This process starts with a needs assessment that identifies open space deficiencies and subbasins within the watershed that are most likely to benefit from stormwater management actions beyond current development requirements. After defining the multi-purpose project objectives and engaging stakeholders, the team develops stormwater park concepts, conducts preliminary engineering, seeks funds, acquires land, and completes design of the facility. At this point, the speakers will present several case studies and share lessons learned on recent stormwater parks such as the one soon to go into construction in the City of Marysville and several in Kitsap County. Finally, once the park has been built it is critical that the benefits of the facilities are distributed equitably by deciding who can buy in to the provided capacity and ensuring that public resources aren’t unfairly benefiting private development.

Throughout the presentation, the speakers will identify three key ideas for successfully planning and implementing stormwater parks: how space-making has evolved the stormwater facility from utility to broader purposes like providing desirable public spaces and educational opportunities; why the newest generation of proprietary filtration media has transformed the scale of what is possible in a given footprint; and what characteristics make a site optimal for such a facility.

Designing with Maintenance in Mind

Robin Kirschbaum

Robin Kirschbaum, Inc., United States of America;

The Washington State Department of Ecology requires all projects across the State to plan for and perform appropriate preventive maintenance and performance checks at regular intervals to ensure that stormwater facilities are adequately maintained and properly operated. However, the majority of project planning and implementation effort is often focused on the initial design and construction of the facilities, with less attention to optimizing the life cycle cost and feasibility of maintaining the facilities over the long-term.

The asset owner (i.e., private property owner or public asset manager) is typically not involved during the design and construction phases; but they inherit the consequence of decisions made by others. If factors such as access and ease of maintenance for each and every design component are not sufficiently assessed, the useful life of the facility may be less than expected, the intended benefits of the project may not be delivered, and the total life cycle project costs may be unreasonable.

This presentation will review three case studies, including the Seattle Public Utilities (SPU) Ballard Natural Drainage System Phase II, the SPU Capitol Hill Water Quality Project Retrofit, and the Kitsap County Suquamish Regional Stormwater Treatment Facility. These projects represent a wide range of contributing drainage areas, from 8 to 435 acres, and a broad mix of site settings, including ultra urban, residential, and rural/commercial. Each case study includes specific examples of how designs evolved based on available monitoring data and feedback from maintenance crews and community members. Lessons learned from these case studies are presented regarding how to design for successful long-term maintenance and operation.

10:30am - 11:55amSession 07A: Treatment - Biosolids

Design of Pocatello’s Biosolids Reuse and Recovery

Colter Hollingshead1, Skyler Allen2, Jared Richens1

1Keller Associates, Inc., United States of America; 2City of Pocatello; ,

The City of Pocatello has one of the largest liquid biosolids handling and land application practices in the Pacific Northwest. The City’s primary and secondary biosolids are treated in mesophilic anaerobic digesters and then held onsite in a sludge holding lagoon prior to seasonal liquid land application on farm fields. This type of operation requires a significant amount of effort, and the City is beyond their biosolids storage capacity. To improve the overall handling capacity and reduce operator effort, the City is now modifying its sludge handling process to incorporate mechanical dewatering. The City is implementing dewatering in a phased approach to balance project costs with the available capital budget, which will limit the financial impact on the community.

The transition to mechanical dewatering will provide substantial benefits to the overall capacity of the biosolids handling. One of the primary benefits of mechanical dewatering is that it will optimize the use of space at the treatment facility by eliminating the need for the large sludge storage lagoon. Also, because the liquid solids have historically been an important soil amendment on the existing fields, dewatered solids will still be land applied according to agronomic schedules, just in fewer loads. Additionally, the City is considering composting as a potential new commodity. Having a dewatering system will provide flexibility to allow composting to be tested since composting requires dewatered biosolids as raw material.

However, the transition to a mechanical dewatering system also provides some challenges to ongoing operations at the facility. Mechanical dewatering can negatively impact liquid stream treatment capacity due to increased nutrient recycling from the pressate stream, which is particularly difficult for the City, as their treatment has incorporated enhanced biological nutrient removal. With the additional nutrient recycle, there is also an increased potential for struvite formation. Each of these challenges will be discussed along with the creative solutions being incorporated into the design.

Is a Thermal Hydrolysis Process (THP) the Right Solution for Your Facility?

Majid Neyestani, Cameron Clark

Carollo Engineers; ,

Thermal Hydrolysis is a thermal conditioning treatment process used to enhance anaerobic digestion. A growing number of facilities are considering THP when evaluating solids stabilization technologies. THP is often viewed as a complex process. A typical THP system consists of solids screening, pre-THP dewatering, pre-THP dewatered cake storage, cake transfer pumps, THP reactors, steam boilers, and a solids cooling system.

The purpose of this paper is to illustrate how the key advantages and disadvantages of various technologies can be used to facilitate decision-making when evaluating solids stabilization technologies. This paper reviews the THP process in detail and summarizes the evaluation of three representative plants in which THP plus anaerobic digestion was compared to mesophilic anaerobic digestion only. The representative plants were evaluated using economic, environmental, social, and technical criteria. The results of this analysis show the following drivers for THP:

  • Producing Class A biosolids
  • Increasing volatile solids reduction
  • Producing more digester gas
  • Improving dewaterability of biosolids
  • Increasing the capacity of existing digesters or reducing the required volume of new digesters
  • Increasing community acceptance due to enhanced aesthetics and local product use
  • Reducing truck traffic
  • Reducing digester foaming concerns

Conversely, the drawbacks of THP include the following:

  • Many utilities have safety and staffing concerns about the need for steam boilers and certified steam boiler operators.
  • Potable water must be used for post-THP dilution to maintain Class A biosolids classification which could be problematic for utilities in water scarce regions.
  • Some facilities find that soil blending or other post-processing steps are necessary to produce a more valuable and acceptable biosolids product. Biosolids post-processing adds cost and infrastructure required to generate a desirable biosolids product.
  • Polymer consumption by Pre-THP dewatering can increase O&M costs considerably.

Because needs and priorities may vary significantly among facilities, a holistic analysis is required to understand tradeoffs of a THP process.

10:30am - 11:55amSession 08A: Innovative Stakeholder Involvement
10:30am - 11:15am

The City as a Stakeholder in Holistic Approach to Distributive Infrastructure Management

Mark Reiner, Shannon McElvaney

Jacobs, United States of America;

On February 9th, 2022, a massive 42-inch diameter, 100-year-old water transmission main burst and resulted in catastrophic flooding in Philadelphia. Deferred maintenance is a hazard. After every major infrastructure failure, there is a window of opportunity to create discourse of the benefits resulting from a proactive cross-sector (water, energy, communications, etc.) analysis of a city’s remaining risks and vulnerabilities. The ongoing barrier to effective bottom-up infrastructure planning by municipal senior staff is the lack of informed insights and information to be better informed advocates for improved maintenance and management of their infrastructure assets. Becoming effective stakeholders in utility management and CapEx prioritization with all utility providers requires a common language and KPIs.

The baseline of our Business as Usual is clear. At the national level, the – “US needs a new approach to invest in resilient infrastructure and communities.” (Brookings Institute, Dec. 20, 2018). On a household financial level in the United States – each household will have an average loss of $3,300 per year due to deteriorating infrastructure through 2039 (2021 ASCE Failure to Act). And, even at the water utility level, consider that the current paradigm has resulted in our water mains having an average life span of only 47 years – approximately only 60% of intended service life (material dependent). The path to the resilient city is not built on an infrastructure paradigm that fosters deferred maintenance and hurried construction. Rather, the city as a stakeholder needs information relevant for understanding existing vulnerabilities and the ability to communicate to the public.

This presentation will discuss Jacobs’ Kaleidoscope predictive analytics app and the Geodesign methodology that helps cities to assess vulnerabilities and threats across six key sectors of fixed horizontal infrastructure. Its cross-sectoral, approach provides a valuable, big picture view of infrastructure vulnerability that is complementary to traditional single sector asset management. And provides an aging infrastructure baseline for the outcomes of a city’s Hazard Mitigation Plan. Kaleidoscope uses the power of spatial analytics to identify exactly where infrastructure is most vulnerable so leaders can make informed, objective decisions on where to spend their limited budgets.

Promising Research on Eliminating PFAS and PFOA using Pyrolysis Process

Valentino Villa, Garrett Benisch, Elizabeth Bridges

Bioforcetech Corporation, United States of America;

Recent testing by the EPA that confirms the Bioforcetech system’s ability to destroy or reduce PFAS, PFOA, and other CEC’s to non-detectable levels from biosolids in our OurCarbon product. The research team published an article on February 14th, 2022 in the Journal of the Air and Waste Management Association outlining the process and the results. A summary of the project will be presented as explained below.

In 2019, Bioforcetech initiated testing of our process to determine our ability to eliminate CEC’s from biosolids. To do this, Bioforcetech isolated a single large batch of biosolids and tested samples of this batch for PFAS, PFOA, and PFOS at each step of our drying and pyrolysis process. An initial sample was taken of digested biosolids at 17% solids content, a second sample was taken of 91% solids content after the batch was dried in our patented BioDryer, and a third sample was taken after the batch was carbonized in our P-FIVE pyrolysis machine. The analysis of these samples, conducted by Vista Analytical Laboratory, showed the reduction of 38 PFAS, PFOA, and PFOS compounds from a significant presence in both of the biosolids samples to below detectable levels after pyrolysis.

In June 2020, Bioforcetech was approached by the EPA requesting to test the potential destruction of PFAS with their process. To test the system, the EPA designed a series of tests on the feedstock, the biochar produced, and the system’s scrubber water and exhaust gas. The resulting biochar was sent to Test America, Vista Analytical Laboratories, and the EPA Laboratories for multiple samples analysis. The results on the biosolids and Biochar confirmed that the Bioforcetech system reduces PFAS from Biosolids to non-detectable levels. It has also been demonstrated that the PFAS do not end up in the scrubber water. The flue gas was analyzed by Montrose Air Quality Services with an experimental method, which utilized 3 parallel FDIR. The results from these analyses have been peer reviewed by the EPA and do not show any PFAS in the analyzed exhaust gas, indicating that all PFAS compounds could be destroyed in the system’s combustion chamber.

12:00pm - 1:15pmLunch—Monday Networking Luncheon
1:15pm - 2:40pmSession 01B: Utility & Asset Management

The Evolved Water Professional: Leveraging Integrated Data to Address Megatrends

Guy Carpenter1, Pablo Calabuig2

1Murraysmith; 2GoAigua Inc.; ,

The water industry is collectively tossing and turning at night thinking about aging infrastructure, a maturing workforce without sufficient renewal, water scarcity, climate change, consumer activism, and funding gaps. Meanwhile, we use a variety of software tools and sources of data like meters and monitors to generate and collect data. On their own, the data sets are useful for a particular effort; however, through the power of machine learning, artificial intelligence, and digital twins, these disparate sources of data can be integrated in a way that produces insights not otherwise possible to help us more efficiently operate our utilities, maximize the capacity of existing assets, and right size new assets. Further, this sort of data integration and automated analysis can help us shore up operator training and responsiveness, develop strategies for addressing water scarcity and responding to climate variability, and anticipate asset failure so that repairs can be made before catastrophe ensues. All these outcomes help address the increasing scrutiny of rate payers regarding how their utilities are managed.

This presentation will provide an overview of the major trends the water industry is grappling with, and how SCADA systems, smart metering, GIS, CIS system, work order management, and other sources of data can be integrated to effectively respond to them. Engineers, operators, utility managers, compliance professionals, and laboratory staff will soon need to adapt to smart water systems that will fundamentally transform how we ensure high quality utility services. Mini-case studies will be highlighted to demonstrate the effectiveness of data integration, digital twins, and analytics in addressing today’s water megatrends. It is the authors’ intent to provide an overview of why smart water and digital twin technologies are appropriate for addressing today’s water challenges.

Selection and Development of a New Data Management Tool

Steven Rice

Clackamas WES, United States of America;

Clackamas Water Environment Services (WES) operates five water resource recovery facilities and eighteen pump stations in Clackamas County, OR, producing clean water for a service population of around 200,000 people. In 2021, WES completed the selection process for a new data management tool to improve manual field collection of data, increase access to various types of data, and streamline processes and regulatory reporting.

After a broad search of commercially available solutions, WES narrowed the selection process to four applications. Vendor demonstrations, user interviews, and demo systems were evaluated to determine the ability of each software to meet functional requirements developed by a cross-section of WES stakeholders that included operators, asset management staff, engineers, and IT staff. Following a competitive value-based procurement process, the group of stakeholders reached a consensus to move forward with procurement of eRIS. WES is the first utility in the Pacific Northwest to implement the software, which is a relatively new application in the data management field.

Near the end of 2021, the software was deployed as a virtual appliance within the County’s server environment. The software’s functionality is delivered through direct connection to source data, so no data migration, duplication, or storage was required during deployment. The system was initially integrated with WES’ two primary sources of operational data: SCADA historian and the laboratory’s information management system. A new database was setup to store manually collected field data that is entered through the tool’s user interface. The system was later integrated with additional data sources including cloud-based collection system flow monitoring data and field precipitation data.

The implementation phase of the project is ongoing and has included development of the custom field data entry forms, reports, and dashboard screens with key performance indicators for each of WES’ five water resource recovery facilities. Ahead for WES is continued development of the system tools and rollout to a broader operational user base at the treatment facilities. Long-term goals include expanding the system’s capabilities to serve additional programs within WES, such as the biosolids management, watershed protection, industrial pretreatment, and field operations groups.

1:15pm - 2:40pmSession 02B: Collection Systems - Pumping

Can Companies Compute Cost Conscious CFD?

Brandon Moss, Jacob Stolle, Jen Murphy

Parametrix, Inc.; ,

Computational fluid dynamics (CFD) is rapidly becoming an important tool for designing, optimizing, and visualizing water infrastructure. Over the last few decades, commercial CFD software has entered the market with ever-increasing usability and workflows. However, the civil engineering field has yet to broadly adopt the software; it is often perceived as overly complicated and expensive. This presentation will show how CFD can be used cost-effectively to aid in design of a pump station retrofit.

The Sandy Pump Station, part of the Sandy Drainage Improvement Company, provides flood protection to homes, businesses, and public land to the northeast of Portland, OR. When the station was originally built in the early 1940s, the wet well included components to prevent vortices that create cavitation during pump operation. Condition assessments revealed that the anti-cavitation platform was partially rotted and in poor condition. Some anti-cavitation baffles had failed and been removed, and the remaining baffles were significantly deteriorated. Higher-capacity pumps had also replaced the original pumps.

In 2021, Parametrix began work to design wet well modifications that would reinstate components to minimize cavitation during pump operation. The design team used FLOW-3D CFD software to assess multiple design elements and configurations. The modeling consisted of larger scale simulations of the pump station and upstream channel to determine station influent flow characteristics and set appropriate model resolution. The modeling then focused on the pump station itself, using large eddy simulations (LES) turbulence model on numerous configurations to iterate design elements. Recent academic studies have shown LES turbulence models consistently identify flow patterns and vortex structures. Model results were evaluated against Hydraulic Institute standards for scale modeling such as swirl angle and turbulent kinetic energy to compare improvements provided by proposed components.

Instead of providing limited design alternatives based on Hydraulic Institute standards and best industry practices, using CFD software allowed quantitative evaluation of alternatives and configurations by comparing resulting model data. Furthermore, the CFD modeling provided an alternative to more costly scale modeling and provided a level of risk reduction and confidence that the proposed design would result in better flow characteristics for continued pump operation.

Adding Another Level of Redundancy to Influent Pumps at Vancouver Westside Wastewater Treatment Facility

Frank Dick1, Brad Eagleson Eagleson2, Matt Noesen2

1City of Vancouver, WA; 2Jacobs Engineering, United States of America;

Problem Statement: Aging infrastructure and community expectations for more resilient utilities prompted plant staff at Vancouver’s Westside Wastewater Treatment Plant to identify a vulnerability. The loss of both utility and emergency generator power caused loss of influent pumping, which resulted in raw sewage diversion to the Columbia River. The plant’s influent wet well and backup surge tank provide only a few minutes storage time before diverting influent flow to the Columbia River.


The City evaluated the following options to address this issue:

  1. Replace aging electrical distribution infrastructure and standby generator transfer controls.
  2. Install backup standby diesel pumps near the surge tank capable of transferring influent flow near though upstream processes.

The second option was selected to bridge near-term redundancy concerns and a turn-key project with Jacobs Engineering was constructed.

Unique features of the project:

  • Selection of two large diesel driven standby pumps capable of operating without plant power.
  • Computational fluid dynamics (CFD) modeling to guide engineering design to ensure vortices would not hamper pump performance within a surge tank not designed to Hydraulic Institute (HI) standards.
  • Project footprint and existing underground utilities provided challenges for design engineers and contractors to install the pumps and connecting pipes.
  • Limited response time required close coordination with the vendor to ensure pumps could prime and pump within the necessary timeframe.


  • The project provides for a completely independent powered influent pumping system to serve in both unplanned and planned events.
  • The CFD analysis identified the need for a complex vortex breaker to improve pump performance. Installation of an early warning level sensor at the influent wet well provided additional reaction time for the pumps.
  • The system was installed and commissioned in less than 12 months and has performed as designed during several start-up tests.
  • The backup pumps are tied into the influent pump discharge header, which allows isolation of the existing influent pump station for maintenance.


Diesel backup pumps proved to be an innovative, cost effective way of bridging the gap between aging infrastructure and reliability and can be installed with little or no disruption to plant operations.

1:15pm - 2:40pmSession 03B: Innovative Stakeholder Involvement
1:15pm - 2:00pm

Yikes! More Clogged Pipes? Using Social Marketing to Improve System Outcomes

Rachel Garrett1, Lynn Knapp2

1Brown and Caldwell, United States of America; 2Cascadia Consulting Group, United States of America; ,

Utilities are overwhelmed with competing needs, from system maintenance to capital projects. To compound the issue, system users often contribute to existing problems through detrimental behaviors such as rinsing FOG down drains and flushing wipes and trash. How can utilities not only increase awareness around problematic behaviors, but motivate behavior change?

In this session, Rachel Garrett of Brown and Caldwell and Lynn Knapp of Cascadia Consulting Group will explore how applying a Community-Based Social Marketing (CBSM) framework can help motivate behavior change. CBSM can be a useful tool in many scenarios that utilities commonly face. Here are a few examples of situations your utility may face that lend themselves well to a CBSM approach:

  • People are flushing more wipes than ever, especially since the pandemic began. Utilities are spending more to maintain equipment due to clogs.
  • FOG is clogging pipes in residential areas, contributing to “fatburgs”. Despite sharing outreach materials with customers, the problem seems to be increasing.
  • Businesses are not installing or maintaining grease interceptors. Enforcement crews issue fines and provide handouts, but in many cases, this does not increase compliance.
  • Potential stormwater challenges can also be addressed with a CBSM approach. To name a few: storm drains clogged with leaves, pet waste troubles, need for more green stormwater projects on private property, and businesses out of compliance with code-mandated stormwater BMPs.

In this session, we will define the practice of CBSM, where it originated, and its key elements. We’ll describe when to apply the CBSM approach, and how it differs from more widely used communications or public outreach tools.

We’ll share lessons learned from Seattle Public Utilities’ “What to Flush” student engagement campaign in 2018-2022, including choosing where to focus, conducting audience research, identifying values and behaviors of different audiences, changing course in response to audience feedback, and evaluating outcomes.

Finally, we’ll talk about the best way to learn more and access tools and resources, including national and regional communities of practice and trainings.

Building Support for a Clean Water Future

Shelly Parini-Runge1, Haili Matsukawa2

1Clackamas Water Environment Services, United States of America; 2Water System Consulting, Inc., United States of America; ,

Clackamas Water Environment Services (WES) provides clean water services to more than 200,000 people within Clackamas County. WES serves seven cities, plus urban and rural unincorporated areas. After the recent consolidation of sewer and surface water districts, we created a new brand to unify our services around our shared mission to protect public health and the environment, and the region’s economic vitality.

The regionalized story is complex, so in 2021 WES partnered with WSC to plan and deliver a robust community engagement and discovery process called the Clean Water Exchange. The three-component research approach included: Stakeholder Interviews, Virtual Focus Groups, and a Survey & Engagement Webpage.

Participants in the Exchange ranged from stakeholders vested in WES’ future, programs, and services to ratepayers with less existing familiarity with us and our services. To steer the process WES developed the following goals:

  • Strengthen customer and stakeholder understanding,
  • Create new clean water partnerships and advocates, and
  • Build trust through enhanced connections.

The data showed us there is deep appreciation for the work WES does to keep our waterways clean, but the district story is hard to understand. Moving forward WES needs to find creative and more inclusive ways to connect to its customers, stakeholders and service area communities to its work. Engendering understanding and support from stakeholders will be critical to WES’ long-term financial viability and its ability to sustain a high level of customer satisfaction.

The data also showed growing awareness for the clean water challenges ahead, such as climate change, affordability and equity, and a general sense that we can all work more closely together to address the complex issues.

In response four strategic initiatives were designed:

  1. Ensure educational materials are accessible for diverse audiences.
  2. Establish partnerships that leverage the strength of the community and shared goals.
  3. Invest in communication initiatives that support safe, reliable, and affordable services.
  4. Cultivate a generation of diverse watershed leaders.

These strategic initiatives were used to develop a 2022-2025 Communications and Engagement Roadmap which will help WES chart a course for continuous improvement with its customers and stakeholders.

1:15pm - 2:40pmSession 04B: Facility Operations & Maintenance

Flow Predictive Models Using Natural Intelligence and Human Learning

Chris Maher

Clean Water Services, United States of America;

The Water Environment Federation (WEF) and The Water Research Foundation (WRF) sponsor the Intelligent Water Systems (IWS) Challenge through the Leaders Innovation Forum for Technology (LIFT) program. The stated intent is to provide an “opportunity to showcase … innovation, with a focus on leveraging data using the best available tools to help utilities better understand the dynamics of complex systems and make better decisions”. In 2021 Clean Water Services (CWS) entered a project entitled “Intelligent Influent Flow Management”. The challenge was to “find, acquire, and leverage data to inform the operation of the Influent Pump Station (IPS) to maximize process and system efficiency, and inform risk knowledge when operating in a flow equalization (FEQ) mode.” The team placed third.

One piece of the challenge solution was to develop a prediction of influent flow. The Northwest River Forecast Center (NWRFC) issues a ten-day forecast for flow and gauge height for the receiving stream for the Rock Creek AWWTF, the Tualatin River. The team sought to leverage this forecast into a predictive model for IPS flow. Three years of daily river flow, gauge height, and IPS flow were used in calculating a multiple linear regression (MLR) model in Excel, verified with 2 years of data. The Solver function was used to find coefficients that would minimize the root mean square error (RMSE). The final model has an RMSE of 2.68. Finding the principal dependency of IPS flow on gauge height a simple logarithmic data fit between flow and gauge height was calculated with the same method for minimizing RMSE. This model returned an RMSE of 2.91, but proved to be slightly better at predicting the highest flows.

The Rock Creek AWWTF is subject to ammonia toxicity limits dependent on the daily and monthly average receiving stream flow. A monthly average river flow prediction was developed using actual, forecast, and 30 day running average data. This informs operations to better control nitrification rates for efficient compliance.

Both models are automated in Power BI, however, this project highlights a widely applicable, accessible flow prediction model, done with existing tools, and leveraging available data.

How Can You Manage Your Peak Wet Weather Flows with Treatment?

John Dyson

Aqua-Aerobic Systems, Inc., United States of America;

As our climate changes, we are experiencing more intense wet weather events resulting in an increase frequency in peak flow conditions in our collection networks and treatment facilities. These wet weather events are resulting in much higher instantaneous peak flow conditions and events are lasting for longer durations. These conditions are putting more stress on our treatment facilities to handle a larger range of operating conditions. Our industry has focused for decades on separating combined sewer systems (CSS), repairing sanitary sewer systems (SSS) or building storage to contain the excess volume during events. This work has made some major dents in reducing the discharge of untreated wastewater, but we continue to have untreated wastewater discharges because of climate change and the never ending collection networks repairs needed.

Generally, the first solution has been to build storage for the peak wet weather flow events and feed the stored volumes back to the treatment plant. This solutions works in some cases but not in all cases because the volumes to be stored can be very large volumes and not practical for all events.

How can we solve the issue of reducing or eliminate the discharge of untreated wastewater during peak wet weather flow events? The solution is the use of a combination of technologies to manage and control these peak wet weather flows and treat these volumes of wastewater.

This paper will cover the use of EHRT technologies with a focus on pile cloth media filtration (PCMF) to treat peak wet weather flow: This paper will cover the following items when using EHRT:

  • Use of PCMF for treatment
  • Application of PCMF within a treatment facility or remote sites

In summary, we have debated for decades about how to handle peak wet weather flows and legal issues regarding whether treatment of peak weather flows by auxiliary EHRT technologies is acceptable. While we have spent years debating how it should be done, millions, if not billions of gallons of untreated effluent have continued to flow into our waterways. Many EHRT technologies produce effluents close to or better than secondary treatment standards without biological.

1:15pm - 2:40pmSession 05B: Regulatory Challenges

Feasibility and Cost of Compliance with Washington Human Health Criteria Water Quality Criteria (HHWQC)

David Clark1, Michael Falk1, James Tupper2

1HDR, United States of America; 2Tupper Mack Wells PLLC;

Human Health Criteria Water Quality Criteria (HHWQC) for toxics in Washington have been a controversial, variable, unpredictable, and subject to litigation highlighted by the differences between the Department of Ecology and EPA. At the heart of the matter are new water quality standards driven by human health risk assessment and increased fish consumption rates (FCR). The resulting standards for nearly 100 toxics are extremely low concentrations. Compliance for wastewater discharges to surface waters for notable constituents such as Polychlorinated Biphenyls (PCBs), Arsenic, Mercury, and Benzo (a) Pyrene will be extremely expensive and perhaps technically infeasible.

This study has analyzed the technical feasibility of compliance with new water quality standards driven by human health to assess treatment processes and costs of compliance. Wastewater treatment targeted water quality standards for Total PCBs (0.000007 ug/L), Inorganic Arsenic (0.018 ug/L), Methyl Mercury (0.03 mg/kg fish tissue), and Benzo (a) pyrene (0.000016 ug/L). Elaborate treatment process trains comprised of microfiltration, reverse osmosis, carbon absorption, and advanced oxidation processes have been considered. The environmental impacts of employing these treatment processes include excessive energy consumption, chemical use, greenhouse gas emissions, reject brine disposal, and spent carbon regeneration have also been assessed.

Disagreements about Washington HHWQC have extended over a period of several years and two federal administrations. On August 1, 2016 Washington Ecology proposed state Water Quality Standards for Protecting Human Health following EPA’s proposed 2015 rulemaking for Washington. However, on November 15, 2016, as ordered by federal judge Barbara Rothstein, EPA decided on Human Health Criteria for Washington based on EPA’s 2015 proposed criteria, rather than what Washington Ecology had proposed.

In response to a February 21, 2017 petition, EPA reconsidered its previous Partial Approval/Partial Disapproval of Washington’s Human Health Water Quality Criteria and approved certain human health criteria that the Agency previously disapproved on November 15, 2016 from an August 1, 2016 Washington standards submission. On April 16, 2020, EPA finalized a rule to withdraw federal water quality standards for certain human health criteria as the final step resulting from the Agency’s May 10, 2019 approval of Washington’s human health criteria.

Occurrence of Per- and Polyfluoroalkyl Substances in U.S. Water Resource Recovery Facilities

Jennifer Hooper1, Charles Schaefer1, Laurel Strom1, Ibrahim Abusallout1, Jennifer Guelfo2, Gaya RamMohan3, Eric Dickenson4, Detlef Knappe5

1CDM Smith, United States of America; 2Texas Tech University; 3Gwinnett County Department of Water Resources; 4Southern Nevada Water Authority; 5North Carolina State University;

The presence of per- and polyfluoroalkyl substances (PFAS) in water resource recovery facilities (WRRFs) has been widely reported. However, comprehensive quantitative data on specific PFAS compounds, their fate and phase partitioning through WRRF treatment processes, and the factors that control PFAS distribution in finished biosolids, remain poorly understood. The goal of this research is to increase understanding on the occurrence, fate, and mass distribution of PFAS in WRRFs and determine the implications of these results for utilities. For this study, 34 utility partners representing 38 facilities participated spanning most US geographies and climates. In the first phase, these facilities collected 24-hour flow-weighted composite samples from WRRF influent and effluent, in addition to a single-point biosolid grab sample. For the second phase, 14 facilities continued to sample their influent and effluent monthly and their biosolids quarterly for 12 months. Finally, a detailed mass balance investigation was conducted at 9 WRRFs to characterize PFAS partitioning through various treatment processes. Aqueous, solids, colloidal and volatile PFAS samples were collected and analyzed for 40 target PFAS compounds, total oxidizable precursors, and/or extractable organic fluorine.

Results have been compiled from the first phase to assess overall PFAS occurrence in influent, effluent, biosolids, and mass loading. Results have also been compiled from the second phase to perform a temporal variability assessment. The detailed mass balance sampling has been conducted and data analysis is currently underway.

Initial results from this study showed that target PFAS were detected in the influent, effluent and biosolids at all the 38 WRRFs sampled within a relatively narrow range of 98±28 ng/L, 80±24 ng/L, and 160,000±46,000 ng/kg, respectively. Among WRRF treatment schemes, a decrease of PFAS precursors and increase in short chain perfluorocarboxylic acids (PFCAs) from influent to effluent suggests that perfluoroalkyl acid (PFAA) precursor transformation may be occurring. However further investigation is needed to characterize the extent of transformation and the implications for treatment. The results from this study provide a benchmark for comparison of PFAS occurrence in US WRRFs and ultimately may be used as the basis to develop appropriate methods and tools to decrease PFAS release to the environment.

1:15pm - 2:40pmSession 06B: Treatment - Phosphorous

The Impact of Anaerobic Mass Fraction on EBPR Performance and Robustness

Austin Carnes

City of Boise, United States of America;

On March 3rd, 2021, the West Boise Water Renewal Facility (WRF) suffered a prolonged power outage during which primary effluent was fed to the activated sludge process, but no aeration occurred. Prior to the power outage, the facility had been experiencing unstable enhanced biological phosphorus removal (EBPR), with daily average effluent dissolved reactive phosphorus (DRP) of 1.5 mg/L over the previous two weeks. Immediately after the power outage, EBPR stabilized, with no daily average effluent DRP value exceeding 1 mg/L for 45 days, and DRP for that 45-day period averaging 0.21 mg/L.

It was hypothesized that the increased anaerobic volume during the power outage boosted EBPR performance. A survey of the literature revealed key discussions around the relationship between anaerobic mass fraction and EBPR performance. First, an increase in anaerobic mass fraction can promote Accumulibacter PAOs to switch from the TCA-cycle to glycolysis for anaerobic reducing power which increases polyhydroxybutyrate (PHB) storage polymer production per VFA by roughly 1.5 times on a mass per mass basis. Second, increased anaerobic mass fraction can lead to a highly negative ORP (<-300mV) which favors the metabolisms of bacteria in the genus Tetrasphaera which are putative PAOs themselves, but can also ferment complex carbon molecules into VFA which can be utilized by Accumulibacter PAOs.

Based on this, the West Boise WRF’s Modified Westbank process was altered by discontinuing mixed liquor recycle in the Modified Ludzack-Ettinger portion of the process, making the second anoxic reactor anaerobic and increasing total anaerobic mass fraction from 11.8% to 28.5%. This resulted in plant effluent DRP of 0.048 mg/L during the period from October through December 2021. Plant effluent DRP was 0.927 mg/L during the previous October through December under otherwise similar operating conditions.

In addition to better phosphorus removal performance, increased anaerobic mass fraction resulted in a generally more robust process. A two-day interruption to the supplemental VFA supply was withstood whereas it would have led to an immediate upset under conventional operation. The process also tolerated increased return activated sludge nitrate mass loading which has historically been an inhibitor of EBPR at the West Boise WRF.

Achieving Low Level Effluent Phosphorous - Lessons Learned from Early Adopters

Jennifer Strehler, Laurel Strom

CDM Smith, United States of America;

Beginning in the 1990’s the US Environmental Protection Agency and state regulators began issuing NPDES permits with low-level total phosphorus (TP) limits to publicly owned treatment works (POTWs) to mitigate eutrophic conditions in sensitive watersheds. One of the first facilities to receive such a permit was the Charles River Pollution Control District (CRPCD), in Medway, Massachusetts. CRPCD received a seasonal monthly limit of 0.2 mg/L TP in 1996 and implemented provisions for chemical addition and the then novel cloth disk filtration technology. Shortly thereafter, in the early 2000’s, facilities discharging to the Sudbury, Assabet and Concord Rivers received seasonal limits of 0.2 mg/L and 0.1 mg/L. At the time, phosphorus removal to 0.1 mg/L was beyond the known limit of technology, and so existing technologies were pushed to their limit and new technologies were spawned to achieve these limits. Tertiary treatment technologies included cloth filtration (AquaDiamond®, AquaDisk®), ballasted flocculation (Actiflo®, CoMag®, BioMag®), upflow sand filtration (Dynasand®, BluePRO®), and dissolved air flotation (AquaDAF®), many of which were employed with or without biological phosphorus removal. As of today, there are 70 wastewater treatment plants in Massachusetts alone which have been operating to meet low phosphorus limits for a decade or longer.

The trend toward more stringent permit limits on phosphorous has expanded nationally. This presentation focuses on lessons learned from the early adopters - in the planning, design, construction, and operation of add-on technologies implemented to achieve the low-level total phosphorus (TP) limits (i.e. TP of 0.1 – 0.2 mg/L). The long-term performance and operation and maintenance of various systems, based on 10 to 20 years of experience, are shared that will help communities who are now just entering the world of low-level phosphorus removal.

1:15pm - 2:40pmSession 07B: Treatment

PowerBI and Piloting: Monitoring Micro-Aeration for H2S Control at Chambers Creek

Karina Woodland1, Vicky Hollingsworth1, Peter Zemke1, Chris Muller1, Karla Guevarra2, Amanda Summers2, Parisa Shahbaz2

1Brown and Caldwell; 2Pierce County;

The hydrogen sulfide (H2S) gas generated during anaerobic digestion produces corrosive condensates in the biogas stream that damage conveyance and handling equipment, resulting in increased operation and maintenance labor and costs. While in-situ chemical treatment and biogas cleaning technologies can mitigate high H2S concentrations, they are often accompanied by high operational costs, chemical handling considerations, and additional equipment. Micro-aeration is an alternative H2S treatment option that involves injecting a small amount of air into an anaerobic digester to oxidize the H2S. Micro-aeration has been thoroughly investigated in laboratory and research settings and is sucessfully used at full scale at several treatment facilities in Europe. However, it is less common in the United States with only a handful of full-scale pilots.

This presentation details the micro-aeration piloting effort at the Chambers Creek Regional Wastewater Treatment Plant located in Pierce County, Washington, which experiences high biogas H2S concentrations, often exceeding 2200 ppm. A pilot started in August 2021 on a full-scale submerged fixed cover digester to evaluate the ability of micro-aeration to reduce the H2S concentration in the biogas. A redundant digester was monitored under similar conditions but without micro-aeration to serve as a control. PowerBI data dashboards were created to monitor the pilot data and easily communicate results with stakeholders. These dashboards allow for near real-time monitoring to check the health of the anaerobic digester during micro-aeration. Key data was summarized in a clear and effective manner, which allowed the team to better leverage pilot data to execute process changes and explain the results of the pilot. This presentation will describe the setup, operating parameters, conclusions, and lessons learned from the pilot. Particular focus will be provided to how data communication and can improve piloting outcomes.

Full-Scale implementation of Membrane Aerated Biofilm Reactor (MABR) for process intensification of WWTP upgrades

Amit Kaldate, Jeff Peeters, Matthew Reeve, Daniel Coutts

Suez WTS;

Membrane Aerated Biofilm Reactor (MABR) technology is an attached-growth process in which autotrophic and heterotrophic biofilm growth occurs onto a dense gas-permeable membrane delivering oxygen by molecular diffusion. The advantages of the so-called counter-diffusion mechanism occurring in MABR result in a strong potential for process intensification, i.e. the increase of treatment capacity and/or achieving more challenging nitrogenremoval treatment goals within an existing biological process volume. Preferential growth of nitrifiers versus heterotrophs in a counter-diffusional biofilm is a key differentiator of MABR. MABR provides higher nitrification rates and oxygen transfer efficiencies as compared to conventional activated sludge and other biofilm technologies such as IFAS/MBBR. MABR zone can be operated as anoxic reactor, achieving simultaneous nitrification-denitrification. Since its early applications at pilot- and demonstration-scale, MABR has proved capable of providing process resilience and improved process performance, even under challenging conditions (e.g. low temperature, peak and variable loads, etc.).

The paper describes four full-scale MABR case-studies by focusing on (i) design challenges faced, (ii) the key-performances demonstrated at the existing WWTPs and (ii) the drivers which led to the selection of the technology against other options. Although each project has its own specificities, the full-scale installations confirm the value of MABR technology when upgrading and retrofitting existing plants. The key factors that make MABR preferred over other approaches include efficient process intensification within existing infrastructure and the associated benefits of fast implementation, no new civil construction and more competitive CAPEX and OPEX. In addition, the beneficial effects of counter-diffusion and bubble-less oxygen transfer have resulted in improved nitrification stability, enhanced operational flexibility (e.g. enabling bio-P removal and simultaneous nitrification denitrification) and lower OPEX mostly due to high energy efficiency.

1:15pm - 2:40pmSession 08B: Project Delivery

Neurodiversity in the Workplace: Applying Universal Design to Cultural Difference

Callan Wood. PE1,2, Carlyle King2,3, Carolyn Golden. PsyD3,4

1Idaho DEQ; 2Autism Society of Treasure Valley; 3Boise State University; 4Northwest Neurobehavioral Health, LLC;

People with autism and disabilities face a staggering unemployment rate, even when they are fully qualified and may have a lot to bring to table. These individuals may face difficulty in the hiring process itself, due to communications issues, which can continue to be an issue in the workplace. Employers also often see accommodations as a waste of resources. After conducting a literature review and consulting with Co-Authors Carlyle King, fellow Autism Society of Treasure Valley board member and winner of the Commitment to Community Award for his advocacy work, and psychologist Carolyn Golden, several conclusions were made. People tend to assume that applying universal design, providing the design that is usable to the greatest extent possible by the greatest number of people, will necessarily result in a design that is over budget. But when you involve the disabled community in the process, an interesting thing happens. We are used to having to think outside of the box in order to come up with solutions that work for us, and in finding a way to avoid our obstacles, we often come up with a solution that nobody else did but is easier and more efficient for everyone involved. Furthermore, we found that the concept of universal design has never been applied to cultural differences before. For Autistics, certain things like mannerisms, slang, figures of speech, sarcasm, metaphors, allegory, etc. are difficult to understand. It’s as if we’re walking around with perpetual cultural shock. Often times when we ask clarifying questions, people think we’re playing dumb, are dumb, or are being argumentative. Applying universal design to this issue, the apparent solution is then to treat everyone as if they are a possible foreigner or immigrant, and to keep things a clear as possible and not assume a certain level of understanding. And when someone questions you, always assume the best intentions.

Implementation of a Community Benefits Agreement Brings Subcontracting and Workforce Diversity on the City of Portland’s Secondary Treatment Expansion Program

Muriel Gueissaz-Teufel1, Andre Baugh2, Bill Mariucci3

1City of Portland, Bureau of Environmental Services; 2Group AGB, LTD; 3Kiewit Infrastructure West Co.; , ,

People of color, women and disadvantaged businesses continue to face significant barriers to employment and opportunities in the construction industry and beyond. Public agencies hold tremendous economic power in issuing contracts; low-bid, good faith efforts have had limited success in meeting diversity goals. In a trend that is likely to continue, a backlog of capital improvement on public works is leading to the implementation of large projects of increasing complexity, lending to the selection of alternative delivery methods for risks, cost, and schedule management. With this trend also comes the opportunity to truly achieve diversity and inclusion goals on large construction projects and leverage an agency’s purchasing power and distribution of wealth in its own community.

This presentation will discuss the City of Portland’s Bureau of Environmental Services (BES) experience implementing a Community Benefits Agreement (CBA) on its $475M Secondary Treatment Expansion Program (STEP) at the Columbia Boulevard Wastewater Treatment Plant, delivered under a Construction Manager/General Contractor (CM/GC) delivery method managed by the BES’ Project Management Office. Successful implementation of a Community Benefits Agreement starts early in the life of a project; the presentation will provide lessons learned and best practices from the early stages of the project through construction so that other public agencies and contractors have a better understanding of the activities entailed and outcomes that can be expected.

2:40pm - 3:00pmMonday Afternoon Break
3:00pm - 5:10pmSession 01C: Planning

City of Spokane System-Wide Wastewater and Stormwater Risk Assessment

Marcia Davis1, Santtu Winter2

1City of Spokane; 2Jacobs; ,

The City of Spokane recently completed a system-wide risk assessment of their wastewater collection, wastewater treatment, and stormwater systems. The purpose of this assessment was to identify and prioritize risks facing these systems, with a focus on identifying mitigation actions that the City should implement.

The risk assessment used the classic risk framework: a risk register was populated with risks identified during workshops, the risks were evaluated for their consequences and likelihood, and mitigation actions were identified. The resulting risk register was then analyzed to identify key risks and mitigation actions that the City should advance.

This risk assessment was unique because of its comprehensive and system-wide nature. Often times risk assessments are focused on specific programs or projects, whereas this risk assessment evaluated the entirety of the City’s wastewater and stormwater systems. This comprehensive approach resulted in several important benefits:

  • Allows for systems-level comparison of risk profiles – for example, the risk assessment clearly showed the risk reduction in the City’s wastewater treatment and combined sewer system due to the massive investment in capital facilities over the past several decades. The higher-risk systems are those that have had less investment – stormwater and the separate sewer system.
  • Enabled cross-discipline collaboration around risk identification, evaluation, and mitigation by bringing planning, engineering, management, and operations and maintenance staff together.
  • Focus on mitigation actions identified cost-effective non-capital projects, programs, policies, and initiatives that the City can implement to reduce risk.
  • Serves as a key steppingstone for the eventual development of an integrated utility master plan that prioritizes efforts across very different systems.
  • Some mitigation actions that were identified were applicable to multiple risks – for example, completing calibration of the City’s sewer model was a key mitigation action for many of the wastewater collection system risks. This helps identify the highest value mitigation actions.

This comprehensive risk assessment sets the City of Spokane up for more detailed planning efforts, while also identifying near-term actions that should be implemented. The effort was completed very efficiently, and resulted in an actionable and high-value plan that could easily be replciated in other municipalities.

Getting to the POINT of Nutrient Limits: An Interactive Planning Tool

Katerina Messologitis, Sanaz Inmen, Art Umble, Mehran Andalib

Stantec Consulting, United States of America; ,

Across the globe today, over 400 water bodies are at risk of severe environmental degradation and economic loss from nutrient pollution (i.e. eutrophication and hypoxia). In an effort to improve the health of impaired water bodies, water quality limits on effluent nitrogen and phosphorus discharge are becoming more common throughout the Western US and in the Pacific Northwest. Complying with these limits can be very challenging for existing facilities, especially given limited timeframes for compliance. Having a straightforward tool to assess the scale of improvement needed and the benefit of different process technologies can help public agencies understand potential nutrient removal options and communicate information to decision-makers.

Stantec developed an interactive tool called Process Optimization and Identification for Nutrient Treatment (POINT) to rapidly compare alternatives for a given facility to implement various nutrient removal technologies and illustrate the gap between current operation and the required level of performance. POINT was developed using more than 250 GPS-X process model simulations to evaluate performance under various influent characteristics, solids retention time, and COD/N Ratios. POINT can show both the potential and the limitations of nutrient removal technology. The tool offers valuable information through:

  • Powerful visualization backed by extensive biological process analysis
  • Illustration of the gap between existing treatment capabilities and potential future limits
  • Clear indication of performance of different treatment processes
  • Simple graphical representation to communicate complex process considerations

This presentation will describe the process used to develop the POINT tool, review the data that provides the foundation for process model simulations, show how the simulation results are used to generate heat map visualizations for different treatment scenarios, and provide a demonstration of the POINT tool.

Tualatin River 2013-2020 Water Quality Model Development and Calibration

Bernadel Garstecki1, Scott Wells1, Chris Berger1, Scott Mansell2

1Portland State University; 2Clean Water Services;

Oregon’s Tualatin River originates as a fast-moving stream in the forested slopes of the Coast Range after which it becomes a low velocity, meandering river through farmlands. River resources are severely stressed during the summer months due to low flows and increased agricultural and domestic water demand. Significant flow contributions during the summer months are from Clean Water Service’s wastewater treatment plants. Clean Water Services initiated the development of a water quality model to help predict and regulate changes in water quality conditions in the river as a result of their wastewater effluent. The water quality model for the Tualatin River and Hagg Lake was set up using the public domain model, CE-QUAL-W2, to simulate water quality parameters from 2013-2020 continuously. This model is a 2-dimensional (longitudinal-vertical) hydrodynamic and water quality model capable of predicting temperature and many water quality parameters. The model was calibrated to eight years of data collected during 2013-2020 along the Tualatin River and at Henry Hagg Lake. To better understand the processes occurring in the river system, two separate models were developed: (1) zero-order and first-order SOD model and (2) sediment diagenesis model. The sediment diagenesis model is fully predictive to changing organic matter flux into the sediments, however it requires much more precision in initial and boundary conditions. The zero-order and first-order model is often able to calibrate closely to field data in systems that have achieved a steady-state. Most water quality predictions were very similar between the first-order model and the sediment diagenesis model, with both models closely matching field data for most parameters. In most cases though, the first order model did better at predicting water quality variations over the 8-year simulation period. The sediment diagenesis model was not able to capture the yearly loading of particulate organic matter to the sediments. Whereas in the zero-order model, the background SOD was fixed and seemed adequate for predicting year-by-year variations in dissolved oxygen and nutrient releases. Analyzing the results from both models side-by-side allowed for a comprehensive analysis of the primary factors affecting the water quality of the Tualatin River.

3:00pm - 5:10pmSession 02C: Facility Operations & Maintenance

Adapting to Rapid Growth at a Decentralized MBR Plant

Ann Dickey1, Tyson Schlect2

1Dry Creek Sewer Company; 2HDR; ,

Decentralized treatment facilities face unique challenges when adapting to migration changes arising from pandemic and associated trends. Rapid population changes cause disruptive flow and load requirements Small plants are difficult to operate in general, and that difficulty is amplified by current population trends.

Dry Creek Sewer Company (DCSC) owns and operates a membrane bioreactor (MBR) wastewater treatment plant that treats residential wastewater from homes in the Dry Creek Ranch development. Macro factors such as pandemic relocation and low interest rates led to record sales rates of homes in the development. For this decentralized WWTP, the flows increased from about 9,000 gallons per day in the spring of 2019 to over 50,000 gallons per day by the spring of 2022. The sewer company showed dramatic ability to adapt and overcome design, capacity and operational challenges by implementing significant improvements much faster than envisioned.

After reassessing baseline flow projections, the bioreactor volume and UV disinfection were identified as unit processes most likely to be impacted by unexpected flow increase. Secondarily, the study identified screening, pumping, and membrane capacity as processes vulnerable to continued heightened growth.

A parallel path design project included near-term capacity expansion (fast lane) and mid-term capacity expansion (less fast lane). The UV system was quickly expanded to augment process capacity. A new bioreactor was constructed with 20 percent anoxic volume and a pre-anoxic standpipe to provide better total nitrogen removal. Since implementation of this upgrade the effluent TN has averaged about 2.9 mg/L even during cold winter temperatures (95 percent removal). The unitized improvement strategy allowed management of low flows while providing higher capacity required for additional lot/phase development.

The local controls engineer and the manufacturer controls group collaborated to develop procedures to adapt quickly to small plant specific controls issues. DCSC implemented a unique organizational structure to overcome pandemic-related hiring challenges. Multiple part-time certified operators and in-house compliance and engineering oversight staff were a critical piece of successfully adapting to the rapid growth.

Chemical Contingencies for the Supply Chain of the Future

Chris Maher, Bruce Cordon, Heidi Blasingame, Justine Abrook, Erik Lorntson, Mike Gates, Logan Olds

Clean Water Services, United States of America;

Pandemic associated disruptions in manufacturing, shipping, and supply chains in general have led to delivery delays and increased costs of all goods. In a Water Resource Recovery Facility (WRRF), treatment chemicals are a critical good delivered on a regular schedule. Interruptions in these deliveries are a direct threat to permit compliance.

This presentation includes the experience of Clean Water Services (CWS) in three areas of chemical procurement.

Sodium Bisulfite Delivery Delay

In January 2022 a breakdown in shipping of sodium bisulfite resulted in the potential for CWS facilities to be unable to dechlorinate final effluent. CWS responded with operational changes, securing local supplies, and planning purchase and shipping of bulk supplies from an alternate manufacturer. This event precipitated the compliance question: In the event we cannot dechlorinate, should we continue chlorination and discharge total residual chlorine, or should we discontinue chlorination and discharge more E. coli? CWS analyzed and debated this question.

Price Increases

Over the past 12 months, CWS has experienced a 40% increase in the price of thickening and dewatering polymer. In negotiations, the supplier explained the root causes of the increases and what financial indices would be most indicative of the future market as well as being most applicable to price increase calculations. CWS purchasing staff and business analysts examined these indices and market forecasts to propose temporary price increase intervals and index averaging periods, weighing the odds that any index would trend up or down.

State of Practice in Chemical Procurement

While there has been an intense focus on reducing energy consumption in the wastewater industry in recent years, little attention has been paid to treatment chemicals. At CWS, chemical costs have outpaced energy, and are second only to labor. An effort was made to review current practice in specifications, bidding, and contracting involving a resource search into existing guidance, interviews with chemical vendors, and interviews with numerous other water and wastewater utilities in northwest Oregon. The project provides guidance in:

  • Specifications
  • Alternative products
  • Bidding
  • Competition
  • Format
  • Contracting
  • Length
  • Renewals
  • Adjustments
  • Operations
  • Other
  • Consortiums

Nitrogen Removal Optimization at Bellingham

Anne Conklin1, Steve Bradshaw2, Adam Klein3, Susanna Leung1, Tadd Giesbrecht1

1Carollo Engineers, Seattle, Washington; 2City of Bellingham, Washington; 3Brown and Caldwell, Seattle, Washington;

The City of Bellingham (City) provides wastewater service for over 100,000 people at the Post Point facility. As part of the Resource Recovery project, the City plans to replace the existing aging incinerators with a new anaerobic digestion process. The Washington State Department of Ecology (Ecology) recently issued a General Permit that requires treatment facilities identify strategies to optimize their process to limit their total inorganic nitrogen (TIN) discharge. Since the recycle stream from the new digestion process will effectively introduce a nitrogen load to the plant, the Resource Recovery project will include a side stream treatment process. However, this process is expected to reliably remove only 80 percent of the additional nitrogen in the digestion recycle. Therefore, additional optimization measures will need to be reviewed to comply with the General Permit.

Several optimization strategies were evaluated to help the City limit their annual effluent nitrogen load. These strategies focus on dentification during the summer months when flows are lower and wastewater temperatures are warm. The strategies evaluated include modulating the operation of pump stations within the collection system to limit peak flows at the plant and to maximize nitrogen return to the secondary process by increasing the existing RAS pumping. The viability of these alternatives was evaluated using the existing collection system model and the calibrated whole plant BioWin model. Preliminary results of these modeling efforts indicate that the City’s range of nitrogen reduction strategies is anticipated to achieve compliance with the annual TIN Action Level prescribed in the General Permit through the first permit cycle.

3:00pm - 5:10pmSession 03C: Construction & Alt Delivery

How Progressive Design-Build Revives 100+ Year-Old Water Mains

Dennis Sanschagrin1, Anna Pridmore2, Joseph Willich3

1Pullman SST, Inc.; 2Structural Technologies, LLC; 3Brown and Caldwell; ,

Great Lakes Water Authority (GLWA), Detroit Metro's largest supplier of drinking water, will decommission the Northeast WTP due to overcapacity yet will still need to deliver drinking water to the residents and businesses in the service area from outlying WTPs. The service area covers a portion of northern Detroit and nearby suburbs. A series of existing 48-inch water transmission mains will be repurposed to directly provide drinking water. The challenge for GLWA: How to procure multiple projects to renew the pipelines to a AWWA Class 4 long-service life solution in an urban area while minimizing disruption.

The learning objectives of this presentation are:

  1. Accelerating the procurement process with progressive design-build based on concepts
  2. Structuring a dynamic design-build team to address a multi-faceted set of challenges
  3. Adapting design-build to remote collaboration during procurement
  4. Risk assessment and management with limited information on 100+ year old pipelines

Mitigating Financial & Technical Risk through Energy Savings Performance Contracting (ESPC)

Kathleen Kelleher

Ameresco, United States of America;

Deferred maintenance, open-bid contracting let downs, and being short-staffed are all concerns we hear from municipal clients. I want to present another method of procurement available to both water treatment and wastewater treatment facilities meant to protect public funds and provide the needed upgrades for facilities: Energy Savings Performance Contracting (ESPC). This form of contracting has been around for decades and used heavily in the education and municipal space; it can and has been applied locally to our PNW WWTPs with great success to obtain needed equipment utilizing the resources of an Energy Services Company (ESCO), all under a performance guarantee.

Energy Savings Performance Contracting (ESPC) is an alternative delivery method that offers a project with guarantees. From the performance of the equipment to the overall cost of the project, this is all guaranteed through the ESPC process resulting in clients mitigating their financial and technical risk when undertaking projects. Through partnering with an ESCO, clients have an extension of their team focusing on the goals of the project together.

This presentation will review the mechanics of ESPC, how to determine if it is a good fit for your organization, and case studies of local success stories utilizing ESPC to complete projects.

That’s a Fact: Alternative Delivery Means Alternative Value Engineering Approaches, for Real Savings and Value Added

Dick Talley1, Muriel Gueissaz-Teufel2, Dave Green3, Mark Bertolero4

1Stantec Consulting Services, Inc.; 2City of Portland Bureau of Environmental Services; 3Jacobs Engineering, Inc.; 4Kiewit Infrastructure West Corporation; ,

The Bureau of Environmental Services (BES) owns and operates the Columbia Boulevard Wastewater Treatment Plant (CBWTP) and is currently making a series of significant capital upgrades to the plant through a single program referred to as the Secondary Treatment Enhancement Program (STEP). The program is delivered utilizing a Construction Management/General Contractor (CM/GC) project delivery model, where the contractor building the facilities is part of the design development process with the intent of providing constructability reviews for a best value construction project.

Large projects are required to go through a Value Engineering (VE) process, where the over-arching intent is to consider alternative design solutions to optimize the expected cost/worth ratio of projects at completion. Historically at BES, under design-bid-build deliveries, VE approaches and outcomes have more often than not led to scope cuts, which actually remove value, to the chagrin of operations and maintenance staff.

The collaborative nature the CM/GC model between the Owner, Designer, and Contractor provides a greater opportunity to realize the true intent of VE. In this model, VE is not restricted to just the design phase, where even in the CM/GC construction phase, contractors are encouraged through shared savings to draw on their special expertise to propose changes that cut costs while maintaining or enhancing quality, value, and functional performance.

The presenters will summarize lessons learned while delivering a significant capital project ($475 million) during a pandemic, social unrest, drought, fires, supply chain disruptions, material and labor shortages and overall market volatility not experienced for decades. The presenters will provide an overview of how BES utilized the CM/GC delivery model and a rigorous approach to establishing and maintaining an interactive, participatory, and contributing role in an ongoing VE culture where rolling VEs and healthy “competition” was promoted between the team members to propose value added alternatives and vet them as a team. The result of BES’s VE process resulted in maintaining the forecast total budget at completion within 13% when compared to the 30% design forecast established before COVID and other disruptions surfaced.

3:00pm - 5:10pmSession 04C: IMW / Funding

Innovative Strategy and a Case Study for Implementing Watershed Nutrient Management: The Full Scale Program

Natalie Lenz1, Jeff Smudde2, Erin Houghton2, Brent Brown1

1Jacobs; 2NEW Water; ,


Wisconsin enacted legislation that allows regulated point sources to partner with stakeholders to implement watershed-wide strategies to reduce nutrient and sediment loadings to surface waters. The options include a “multi-discharger variance”, water quality credit trading, and watershed adaptive management. Each of these options allow more than one implementation strategy with each having unique advantages and disadvantages. The presentation will provide a summary of the phosphorus permitting framework in Wisconsin along with a case study. The case study highlights key decision criteria for the utility selecting adaptive management and the innovative, technology-driven approach to program implementation.

Case Study

NEW Water, the brand of the Green Bay Metropolitan Sewerage District in Green Bay, Wisconsin, discharges near the Bay of Green Bay to the Lower Fox River in the Lower Fox River Basin which is impaired for phosphorus and sediment (TSS) and has an approved TMDL. Several evaluations were completed which demonstrated that a watershed approach for meeting phosphorus and TSS permit requirements would be low-cost and provide additional non-monetary benefits. The State approved NEW Water’s permit application that includes adaptive management in 2020.

The adaptive management program, titled the NEW Watershed Program (Program), is anticipated to span four, five-year permit terms. The Program is partnering with several entities to install agricultural and urban conservation Best Management Practices (BMPs) to reduce phosphorus and TSS nutrient loading, with the goal to achieve TMDL reductions and water quality standards in the Action Area.

Several digital solutions were developed to address the complexity of executing and managing a large program with a diverse team. By efficiently leveraging data and utilizing tools like GIS, custom mobile applications, real-time dashboards, and automated workflows, managing a program of this size is more attainable than before. Using digital solutions has allowed personnel at all levels to effectively contribute to the overall project successes, including workload planning with key staff, collaboration in the multiple facets of BMP implementation, budget management, contracting, and monitoring progress against regulatory requirements, all in real‐time.

Funding 101: How to Navigate the Process and Develop Strategies to Secure Funding

Shelby Smith

Brown & Caldwell, United States of America;

Securing funding is a mission-critical component of any capital project or program. In today’s water market, municipalities are facing a nexus of challenges such as rising inflation, pricing and worker availability uncertainty, supply chain disruptions, and construction cost increases. These market-driven challenges coalesce with a national crisis around aging infrastructure, environmental justice, resiliency, and climate change that keep the pressure on local and state entities to act now instead of delaying project delivery. The recent Bipartisan Infrastructure Law (Infrastructure Investment and Jobs Act) passed by Congress is momentous evidence that the federal government sees the significant gap between capital needs and available funds and is taking action to help.

There is a wide variety of state and federal funding programs available to the water sector, however it can be difficult to decide which opportunity to pursue or know how to develop a compelling application that results in securing funding. This presentation will cover the overall funding process and it will focus on two specific funding programs at the state and federal level – State Revolving Fund Loan and Water Infrastructure Finance and Innovation Act (WIFIA) – providing best practices and guidance for how to develop a strategy for understanding funding eligibility requirements, preparing the funding application, and demonstrating how the capital project aligns with the funding programs’ priorities.

For each funding program, case studies will be shared to tell the story of how different utilities rose to the occasion and navigated the funding process to secure critical infrastructure funding. These stories are intended to help illustrate how other interested Pacific Northwest agencies can accelerate capital infrastructure delivery, alleviate financial burden to ratepayers, support underserved communities, and deliver the essential water infrastructure needed to support a vibrant, resilient community of the future.

Financing City Of Boise Water Renewal Facilities: A Case Study On One City's Experience With Capital Funding Strategies And Options For The Community

Scott Lester1, Matt Millis2, Paul Quinn1

1FCS GROUP; 2City of Boise; , ,

Since 1949, the City of Boise Water Renewal Services (WRS) is responsible for renewing more than 10 billion gallons of used water (commonly known as wastewater) per year. From the shower to the kitchen sink and toilet, from homes to businesses, large industry to hospitals and schools, every drop of used water travels through some of the more than 900 miles of underground pipes to one of two water renewal facilities. In the coming years, significant capital improvements will be needed to address WRS’ aging infrastructure, meet regulatory requirements, provide for capacity needs, and meet citizens’ service level expectations. A financial plan was created to address these capital needs, as well as help execute on the utility’s strategic plan, which includes the following elements:

- Enhance the health and use of the Boise River

- Reinvest in our existing infrastructure

- Support our local economy through industrial reuse

- Combat the pressures of climate change by adding recycled water to the aquifer for future use

- Balance affordability for our community

Using the collective work of WRS, FCS GROUP, and Brown and Caldwell as a case study, this presentation will discuss the challenges faced by the WRS, and how the utility worked in partnership with FCS GROUP to develop a customized financial solution to successfully execute the utility’s strategic goals and vision. The presentation will include discussion of the financial framework used, the challenges faced when trying to implement a capital funding plan, and how the WRS used the results of the financial analysis to support stakeholder communications including a successful voter-approved ballot measure for a long-term revenue bonding strategy.

Learning Objectives

Participants will take away information and perspective on:

- Infrastructure challenges faced by the City of Boise to ensure continued delivery of quality services to the community

- Policy and financial planning considerations for capital funding strategies

- Communicating capital funding and rate impacts to elected officials and stakeholders

- The strategies and public policy framework utilized to successfully support WRS’ long-term initiatives

3:00pm - 5:10pmSession 05C: Collection Systems - I&I

Crossing the Line: I/I Impacts After Lateral Improvements on Private Property

Chris Horgan1, Holly Ellis2

1J-U-B ENGINEERS, Inc., United States of America; 2City of Sandpoint, Idaho; ,

How much inflow and infiltration (I/I) can be eliminated by improving sewer laterals on both sides of the property line? This presentation discusses recent results from the City of Sandpoint’s attempt to answer this question based on a combination of flow monitoring and collection system improvements.

The City has long believed that I/I sources on private property, like sump pumps, roof drains, and laterals, contribute a significant amount of flow to the collection system. Despite cured-in-place pipe (CIPP) rehabilitation of almost all the oldest mainline in the collection system, peak flows at the WWTP are still 10 times higher than average flows. Reducing flow from private sources could therefore be a key component in reducing the scope of upcoming WWTP upgrades from 10 mgd to the City’s goal of 6 mgd.

However, undertaking City-wide lateral improvements was an expensive proposition and, with no sense of the expected efficacy, was a difficult concept for City leaders to support. Therefore, the City’s Infrastructure and Development Services Department devised a plan to provide a data-driven answer to this question and direction for future collection system work. The City identified two micro-basins in their collection system – a demonstration basin that would receive lateral improvements and a control basin that would receive no improvements. Flow monitoring was performed pre- and post-improvements to quantify I/I reduction.

The presentation will include results from the City’s approach to improving laterals in the right-of-way and on private property, the public outreach efforts used to obtain permission for lateral improvements on private property, flow monitoring results before and after lateral improvements, and challenges faced during construction.

The goal of this presentation is to provide information on the potential I/I reduction via improvements to sewer laterals and provide insight to how critical work on private property could be to a system’s overall I/I reduction. Public out-reach efforts and lessons learned during construction discussion will likely be useful for other entities with similar I/I reduction objectives.

Correcting Infiltration and Inflow in the Colfax, WA Sanitary Sewer System guided by Temperature Monitoring

Erik R. Coats1, Simon Smith1, Matt Hammer2

1Mountain Waterworks; 2City of Colfax, WA; ,

Infiltration and Inflow (I&I) in the City of Colfax, WA sanitary sewer collection system is well-documented, with I&I studies dating to the 1970s. Annually the I&I volume of wastewater flow received at the water resource recovery facility (WRRF) is 20-30 million gallons, representing 25-30% of the total annual flow, yet the source of I&I is poorly understood. Smoke testing did not reveal significant sources of inflow; conversely, analysis of precipitation-flow data indicates infiltration dominates. Identifying sources of infiltration is more challenging than inflow, ultimately requiring CCTV investigation to guide a capital improvement plan (CIP). System flow monitoring is a conventional approach to identify sewer lines for subsequent CCTV investigation. However, flow monitoring is expensive – in time and money – and thus can only be conducted in a limited manner both in time and space, particularly for small to mid-sized cities. Cost-effective methods that can be deployed more comprehensively in the sewer system are needed to guide targeted CCTV investigations.

In May 2021 Mountain Waterworks initiated a field investigation to monitor Colfax’s sewer system for I&I. Specifically, we deployed 16 temperature probes at strategic locations in the sewer system, with monthly data downloads. Temperature data was obtained in one-minute increments, providing excellent resolution for I&I interpretation. We collected data over an extended period that covered dry-, inflow-, and infiltration conditions to identify the sewer sections that contributed most I&I. Temperature data were analyzed using a simple rule-of-thumb approach coupled to a statistical-based interrogation to identify probable sources of infiltration; CCTV investigations were strategically guided from these analyses. The end result was a prioritized system-wide CIP to help the City tackle the “worst offender” areas of the sewer system and cost-effectively reduce I&I. Results from this study will be presented and discussed, along with guidance on how cities can implement their own temperature monitoring system.

The Sewer Whisperer: "Listen Carefully, Your Sewer is Talking to You"

Brogan Quist

SmartCover Systems, United States of America;

This presentation reviews how customers can adopt unique and patented monitoring technology, which gives them data in the field that they did not have before. The monitors mount directly on the manhole covers – thereby eliminating the need for a confined space entry - and use ultrasonic sensors to monitor water levels. The remote monitors send data to a secure customer website, as well as sending out alarms, advisories, and maintenance alerts directly to the customer.

Real-time remote water level monitoring can identify locations where a possible sewer system overflow is developing and alarm these conditions before the overflow, allowing field staff to visit the site and perform corrective actions. Locating these problems prior to an SSO actually occurring has enabled users to pinpoint the causes of these blockages.

By placing the remote monitors at sites which are cleaned multiple times a year (due to FOG, roots, etc), water levels are wirelessly transmitted in real-time to the collection system operator, and the knowledge of these water levels and the lack of problems at these sites has enabled re-deployment of staff to other problem areas. This yields both ROI in time and money within one year of utilizing the system.

Remote real-time level monitors also provide a means to detect and correlate rain events with I&I. The ability to identify, quantify and track down sources of I&I is critical to minimizing problems with overflows during significant precipitation events. This system now uses automatic tools to track WHICH locations are experiencing higher levels, based on the rain event. The system can also monitor the TOTAL dynamic range between the bottom of the pipe to the very top of the manhole.

Utilities can also utilize these monitors to provide additional information before, during, or after large Capital Improvement Projects. This application can also yield high levels of ROI, or the chance to delay, defer, or eliminate costly CIP projects.

Finally, by utilizing this same set up, agencies can now monitor H2S levels in their sewer systems as well. This new feature can assist in odor studies, dosing, and overall health of the pipe/manhole.

3:00pm - 5:10pmSession 06C: Treatment - Nutrient Removal

Maximum Wastewater Operation -Total Inorganic Nitrogen Tools to streamline and data for success

Austin Carnes1, Brandon Pechin2, Adam Jennings3

1City of Boise Water Renewal Facility; 2City of Boise Water Renewal Facility; 3HACH COMPANY, United States of America; , ,

To minimize RAS nitrate for the benefit of the EBPR process, the operation of anoxic/aerobic swing zones were optimized. Plant personnel began performing specific ammonia uptake rate testing and calculating nitrification capacity in pounds per day, which was translated into alarm setpoints from Hach AN-ISE probes. Swing zone aeration would be initiated if the probes indicated that basin loading was exceeding capacity and then was terminated when loading fell below capacity. This allowed for the facility to operate the swing zones in the anoxic mode for the greatest amount of time to maximize total nitrogen removal.”

Connecting the operator view, maintenance and management roles for permit compliance and wastewater optimization can increase success, bolster staff knowledge and save expensive resources using technology. This talk will focus on some fresh thoughts connecting operations, compliance and technology to maximize wastewater treatment. Information and material presented by the City of Boise Wastewater Process Analyst team will show how consolodating process data and using online insturmentation can bring visibility for more successful process control and Total Inorgainc Nitrogen removal.

Learning Objectives:

  • Gain perspective on NPDES compliance and operating in a traditional manner from a management view to an operators.
  • Understand the impact to treatment when preventative maintenance on equipment and individual unit processes go down.
  • Will cover how technology and specific data management can help with future wastewater strategic planning, staff, plant upgrades, etc.
  • Connecting real world operational examples of online instrumentation, process control lab and data management for improved Total Inorgainic Nitrogen removal at the City of Boise

Guidelines for Optimizing Nutrient Removal Plant Performance

Bryce Figdore, JB Neethling, Dave Clark, Pat Roe

HDR, United States of America;

The proposed sessions will present findings of Water Research Foundation (WRF) project 4973 “Guidelines for Optimizing Nutrient Removal Plant Performance.” The goal of the project is to develop guidance on approaches to optimize existing plants for nutrient removal, utilize full scale examples of how it is done, and to produce a guide on how to do it.

Two PNCWA sessions are proposed to cover this material, but alternative arrangements can be considered such as only a single session focused on the Nutrient Removal Optimization Decision Guidance Tool. The first session will present the fundamentals on conventional and emerging approaches for nutrient removal optimization. The second session will present case studies and “decision tree” guides for optimization. This session will provide unique learning opportunities for attendees regarding opportunities to optimize the process and achieve some nutrient removal at existing WRRFs that currently only provides secondary treatment for BOD and TSS removal. Optimization opportunities to reduce cost and improve performance will be discussed. Finally, these sessions will also allow feedback from the audience to shape the research for the Water Research Foundation project 4973 in developing practical guidelines for optimizing WRRFs to improve nutrient removal more efficiently and more reliably.

Three key learning objectives for this session are:

  1. Participants will comprehend the fundamentals of nutrient reduction and the focus areas to optimize the process (for example, while conventional thinking is to maintain a DO above 2 mg/L in biological treatment, lower DO concentrations can be used under appropriate conditions to achieve both nitrification and denitrification).
  2. Participants will learn how to identify opportunities for optimizing WRRF operation to reduce operating costs and to improve process performance (these two may be mutually exclusive in some instances).
  3. Participants will learn about new and emerging strategies and their development status.

Which Ones Do You Need? Nitrogen Removal Optimization Ideas and Case Studies

Miaomiao Zhang, Jeff Moss


The Puget Sound Nutrient General Permit (PSNGP) that was issued by the Washington State Department of Ecology at the beginning of the year, categorized 58 publicly owned domestic wastewater treatment plants (WWTPs) into three types—dominant, moderate, and small Total Inorganic Nitrogen (TIN) loads. All WWTPs under these three categories are required to perform a nitrogen optimization and submit the report annually or per permit cycle. This nitrogen optimization process will provide wastewater utilities the opportunity to identify and implement reasonable strategies from the perspective of operations and maintenance, process control, and unit process improvements. With this process, utilities will be able to meet the TIN action levels or optimization goals while not imposing a significant financial burden on wastewater utilities.

This presentation will provide the audience a whole suite of nitrogen optimization ideas and a few real-world examples from Kitsap County, City of Bainbridge Island, and LOTT Clean Water Alliance. Some of the topics will include:

  • Instrument/Equipment Maintenance, i.e.,

- Calibrate and repair DO, ORP, and ammonia/nitrate probes

- Calibrate and repair flow meters

  • Operational changes, i.e.,

- Optimize wasting and RAS return to maintain a consistent and desired biomass inventory, thus sludge retention time

- Increase mixed liquor recycle rate

- Optimize methanol addition to promote denitrification

- Adjust dewatering operation hours to even out ammonia load from recycle stream

- Optimize the aeration cycle for simultaneous nitrification and denitrification

  • Process control optimization, i.e.,

- Implement control strategies

- Flow pacing instead of manual operation

- Fine tune process control setpoints, DO, ammonia, etc.

  • Process upgrade:

- Upgrade aged aeration system with blowers and diffusers with automation

- Reconfigure existing aeration basins for improved flow pattern and biological nitrogen removal

- Optimize the division of aerobic and anoxic zones in the aeration basin to balance between organics removal and TIN removal, as well as reduce filamentous bacteria

3:00pm - 5:10pmSession 07C: Treatment - Nutrient Removal

Fermentation or Chemical Feed? Evaluating Carbon Addition at the Meridian WRRF

Zach Dobroth1, Clint Dolsby2, Tyson Glock2, Rick Kelly1, Rick Murray2

1Brown and Caldwell; 2City of Meridian, Idaho; ,

The City of Meridian, Idaho, is undergoing a series of upgrades to its Wastewater Resource Recovery Facility (WRRF) to meet stringent effluent nutrient limits that begin in 2027. Raw influent to the facility is carbon-limited, meaning supplemental carbon must be added to drive the WRRF’s biological nutrient removal processes. Part of that carbon can be provided in fermentate from the WRRF’s primary sludge fermenter (Fermenter 1), which was retrofitted from an unused digester in 2013. A second digester was designated as future Fermenter 2 but has remained mothballed.

In 2020, the City began operating a chemical feed facility capable of providing acetic acid and methanol to the WRRF’s aeration basins. These chemical feeds can provide all the necessary supplemental carbon required for treatment. However, the quantity and cost of chemicals will continue to rise with increasing influent nutrient loads and lower effluent limits in the future.

What will be the most cost-effective solution? To help determine a path forward, the City tasked Brown and Caldwell with:

  1. Evaluating fermenter operational data to determine the ability of Fermenter 1 to meet future carbon demands.
  2. Examining fermenter performance at West Boise (full-scale) and Central Valley, Utah (pilot-scale) to find potential performance improvements that could be gained through operational or design modifications at Meridian.
  3. Completing a 20-year life cycle cost analysis (LCCA) to evaluate upgrading and/or expanding the existing fermentation system in comparison to solely using external chemical addition to drive nutrient removal.

The LCCA showed the most cost-effective solution would be upgrading Fermenter 1 (including the addition of sludge heating) to optimize carbon output in the fermentate and offset chemical use. It also showed the addition of Fermenter 2 would not deliver enough value in additional carbon production to warrant the capital expense.

This presentation will summarize the fermenter evaluation and provide insights for other facilities using (or considering using) fermentation for carbon supplementation.

Process Intensification Using Low Dissolved Oxygen Biological Nutrient Removal

Jose Jimenez

Brown and Caldwell, United States of America;

Current manuals of practice and historical understanding of operations assume that low DO operation creates process performance challenges. For example, low DO operation has historically been linked to poor settling sludge and lower microbial rates (e.g., low nitrification rates), which results in the design of larger volumes for treatment and undermines intensification outcomes. This traditional understanding has persisted from systems with complete mix activated sludge, but the application of metabolic selector zones and active carbon management affect biological kinetics and population selection, enabling low DO operation while maintaining good settleability and nutrient removal. Ideally, the implementation of low DO BNR results in a decrease energy demand while maintaining PAO activity, enhancing SND and maintaining good mixed liquor settling rates which are all key factors to achieve process intensification. As an alternative to new technologies for low energy BNR, many facilities have focused on developing new process control and operational approaches with their existing infrastructure to reduce energy use. Application of low DO BNR in activated sludge facilities has led to many success stories where energy has been reduced, effluent nutrient concentrations have been lowered, and capacity has increased by "simply" lowering the DO setpoints. In order to advance the understanding about low DO BNR, key research questions will be discussed in this presentation. . What setpoints represent low DO? . How are nitrification, denitrification, and phosphorus removal kinetics impacted by low DO operation? A comprehensive understanding of the ecology, and thus kinetic rates, is critical for engineering design. . What role does carbon cycling play in successful low DO BNR system? . How do we maintain good settleability in low DO BNR systems? This presentation will cover the impact of low DO operation on biological nutrient removal, settling and microbial selection in the activated sludge process. It will help accelerating and enabling successful application of low-energy BNR, which will be a major step toward advancing wastewater facilities becoming energy positive resource recovery centers of the future.

3:00pm - 5:10pmSession 08C: Project Delivery

From Chaos to Control: Boise’s New, Robust Project Delivery Model

Evan Carpenter1, Emily O'Morrow2, Tiffany Torres2

1City of Boise; 2Brown and Caldwell; , ,

Boise’s Water Renewal Services (WRS) must more than double its project execution rate to meet the goals of the recently completed Water Renewal Utility Plan increasing both the number and size of projects. Like many utilities, the city previously managed its Capital Improvement Plan (CIP) and prioritization based on the immediate needs of WRS and lacked a way to balance the long-terms goals of the utility with short-term facility needs. WRS recognized that a robust business process would be needed to deliver on the Utility Plan and increase efficiency and transparency (both internal and external) in project execution.

WRS built a cross-functional team of utility employees, called the Capital Projects Staff Advisory Team (CP SAT), to identify gaps in the current CIP process. This resulted in a list of 32 opportunity areas for improvement. CP Sat developed a streamlined business process to address each of the gaps identified.

Key outcomes of the project delivery business process include:

Right Solutions come from Defined Problems: City staff at all levels in the organization are encouraged to define problems. Teams then investigate the problem and understand the consequences of not fixing it before developing a solution.

Right Budget Detail at the Right Time: City teams identify projects to solve the problem and conduct an appropriately complex alternatives analysis. Teams must analyze solutions based on life-cycle cost considering risks and benefits. Once a solution project is identified project managers develop a comprehensive cost estimate to create a budget ceiling for the project.

Transparency in Delivery: Standard form project management plans document scope, schedule, and budget, including resource allocations and other interagency coordination needs. Future projects are better understood by WRS staff at all levels increasing operator buy- in. WRS Leadership can more effectively plan resources and community messaging for projects on the horizon.

By engaging city staff in the development of a standard project delivery model, WRS is moving toward greater control of capital planning and increasing transparency and efficiency in project delivery.

Permitting Expectations And Strategies For Efficient Project Development

Sean Thomson, Leslie Hurley

Stantec, United States of America; ,

Permits have a direct impact on project design and construction. Without appropriate planning, the permitting process can delay construction, increase costs and generally place those involved under stress. This presentation will include a general overview for those new to the permitting process and provide effective strategies and tools which can help to streamline project development and reviews. Lessons learned from two recent case studies in Oregon; one small water utility and one very large municipal wastewater utility, will compare the right and wrong ways to go about project permitting. The presentation will also include brief introductions to permit team development and their use of SharePoint document management. From this presentation, utilities, consultants and agencies alike will see how more effective permit coordination is the key to efficient project development, lower costs and happier people.

4:30pm - 5:45pmWomen’s Networking Reception
5:10pm - 7:00pmExhibitors Opening Reception
7:00pm - 10:00pmNetworking Night
Date: Tuesday, 13/Sept/2022
7:00am - 8:00amBreakfast—Tuesday OPERATORS Breakfast (ticket required)
7:00am - 8:30amBreakfast—Tuesday Breakfast
7:00am - 5:00pmSpeaker Ready Room is Open
7:00am - 6:30pmRegistration Desk is Open
8:00am - 9:25amSession 09A: Treatment - Nutrient Removal

Using Kenaf for Densification and Winter Nitrification

Eric Roundy, Marvin Fielding

Keller Associates, Inc., United States of America; ,

The City of Rigby's Wastewater Treatment Plant received a new ammonia limit of 0.65 mg/L during the winter. With Rigby located on the eastern side of Idaho, wastewater temperatures can be extremely low in the winter, making it more challenging to remove ammonia. Expansion of the existing facility was an option; however, the City could realize significant cost savings by enhancing the current treatment. New densification technologies, such as Mobile Organic Biofilm™ (MOB), which utilizes kenaf plant material as a carrier for biofilm growth, can increase treatment capacity without the need to add basins.

The City of Rigby completed a full-scale MOB performance trial in their existing oxidation ditches, and with over a year of data, the trial demonstrated the capacity could be significantly increased. The trial primarily focused on effluent ammonia; however, total nitrogen, total phosphorus, and total suspended solids were also monitored. Additionally, process optimization such as aeration performance, solids retention time, clarifier settling, and solids dewatering was investigated. Since kenaf is commonly used as an absorbent, a toxicity test was also performed as part of the trial. This presentation will provide a summary of the results and observations from the full-scale MOB trial.

Compounding Interest: Building Your Way To Better Nutrient Removal Performance

Jeffrey Zahller1, Bryce Figdore1, Chris Sheridan2, Miaomiao Zhang3

1HDR, United States of America; 2Kitsap County, United States of America; 3Murraysmith, United States of America;

With the introduction of the Puget Sound Nutrient Genera Permit (PSNGP), utilities in Western Washington are looking for ways to leverage existing facilities to further reduce total nitrogen discharges. The Central Kitsap Treatment Plan (CKTP) began a process of nutrient optimization in 2020 to achieve three primary goals:

1) Find new ways to optimize operation of an existing secondary process with short-term improvements and operational changes.

2) Collect full-scale data during various operational scenarios to determine the real-world capabilities of the both the baseline and optimized plant design.

3) Determine long-term projects that could be implemented to further enhance nutrient removal as Kitsap County continues to see strong population growth.

With these goals in mind, Kitsap County began a two-fold evaluation process: (1) detailed field sampling and desktop modeling to develop a series of potential improvements (both small and large) for nutrient removal operation, and (2) implementing the most promising short-term improvements for operations staff to test at full-scale to prove the reliability and value of the improvements. The desktop modeling evaluation was conducted in 2021 and the full-scale trial work began in the first half of 2022.

This presentation will provide a summary of the key lessons learned from the initial full-scale testing process that included the following optimization options:

- Improved aeration control through most-open-valve (MOV) blower control and refurbished diffusers.

- Installation of new ammonium and nitrate probes at key locations throughout the secondary treatment train to allow for ammonia-based aeration control (ABAC).

- New control programing to allow for automation of internal mixed liquor recirculation (IMLR) in response to anoxic zone denitrification capacity.

- New control programing to automate methanol (carbon) addition in response to denitrification efficiency.

Additionally, long-term improvements were also evaluated in context of the full-scale testing results:

- Improvements to mixed liquor and return activated sludge (RAS) mixing to better distribute biomass between treatment trains and avoid solids short-circuiting.

- Development of centrate storage to equalize return rates of ammonia rich recycle streams.

- Expansion of methanol storage facilities to better support consistent, automated operation.

8:00am - 9:25amSession 10A: Regulatory Challenges

Developing An Alternative To A Point Source Based Approach To Regulating Nutrients In Puget Sound

Amanda McInnis, Ryan Dunne, David Austin

Jacobs; ,

The abstract will present the work to date in developing the science to support the impairment of the Sound, the SSM and the current draft of the general permit. More importantly, it will propose complimentary pathways that include realistic timeframes and represent responsible stewardship for the utilities’ rate payers.

About 5 million people in Puget Sound are served by municipalities. Those agencies are interested in responsible stewardship and protection of the Sound based on well-developed science that produces multiple measurable benefits.

Several stakeholders have considered development of alternative approaches to addressing water quality concerns in the Sound as alternatives to the current point source based approach. Some those alternative approaches include:

  • Improved data collection/modeling of bays
  • Integrated planning
  • Adaptive Management
  • Oxygenation of the deep anoxic zones

In addition, urban drainage water quality approaches and projects that more directly improve habitat are being considered.

The stakeholders will work toward development of a comprehensive menu of both natural and engineering-based options for managing nutrients across the Sound. These results will assist with making informed decisions for the best approaches to address the DO issue.

This approach, which is to use science to evaluate the health of the Sound ecosystem coupled with strategies for nutrient optimization at the municipal wastewater treatment plans, has the potential to provide a more effective roadmap for improved water quality than the general permit as it is currently proposed.

As nutrient regulation continues to move forward across the county, more and more watersheds will be facing the type of challenges that Puget Sound is facing. This work is an attempt to provide alternative pathways to improving water quality and keep a broader view of watershed management.

Water Sector Federal Cybersecurity Legislation 2022

Mark McKinney

Tetra Tech, United States of America;

The U.S. energy and water sectors now account for up to 80 percent of reported cyber incidents and data breach investigations, second and third only to financial services. Attempts to compromise critical infrastructure systems and services are up more than 400% since the beginning of 2020, according to cyber security officials at the ICS-CERT, a division within Homeland Security that tracks and investigates attacks against ICS networks.

Recent cyber incidents directed at water system operators have prompted federal, state, and local authorities to re-assess current regulations governing security controls for community water systems, to address evolving threats against cyber assets that could jeopardize water safety, availability, and quality.

On 27 January, the White House issued guidance related to enhancing cybersecurity requirements for the water and wastewater sector, directing the EPA to establish a governing council to work with water sector leaders to develop plans to improve the resilience of water system operators to potential cyber and physical security threats. This 100-day initiative, coined the Water Sector Action Plan, signals a significant expansion of the President’s Industrial Control Systems Cybersecurity Initiative to the Water and Wastewater Sector. Federal primacy agencies including the EPA, the Department of Homeland Security Cybersecurity and Infrastructure Security Agency (DHS-CISA), and the Water Sector Coordinating Council (WSCC) will coordinate with water systems across the U.S. to develop comprehensive security strategies and identify controls designed to improve water security resilience. A pilot program will be launched with select water utilities to evaluate effectiveness of these strategies that will form the basis for water sector security.

This session will discuss proposed legislation designed to enhance the security and resilience of the water and wastewater sector, as well as peer sectors that rely on industrial control system architectures, including energy oil and gas, maritime vessel and terminal, dams and levees, and critical building automation. Changes under review include enhancing federal oversight for water security, shortening AWIA recertification timelines, allocating more funding for system improvements, mandatory reporting of cybersecurity incidents, and implementing mandatory cybersecurity standards for water and wastewater operators similar to those required for electric utilities.

8:00am - 9:25amSession 11A: WateReuse

National Water Reuse Action Plan

Purple Pipe Public Playfields - Cheney WA Case Study 

8:00am - 9:25amSession 12A: Stormwater

Advances in Infiltration Testing for Stormwater Management

Scott Kindred

Kindred Hydro, Inc., United States of America;

This presentation summarizes the results of an infiltration study to develop improved methods for measuring bulk hydraulic conductivity (Kb) in the vadose zone and using that information to estimate the capacity of stormwater infiltration facilities. The methods rely on the borehole permeameter method and are suitable for sizing and design of shallow infiltration facilities such as ponds and bioretention facilities and vertical facilities such as drywells. The study includes both numerical simulations and field studies to validate and demonstrate the methods.

Shallow infiltration testing was conducted at four sites, with two test pits and three shallow test wells at each site. This testing demonstrated a high degree of variability over distances of 15 to 70 ft. These results, combined with numerical simulations, demonstrated that shallow well tests can be used to design shallow horizontal infiltration facilities by applying a correction factor to account for layering and differences in flow dynamics.

Deep infiltration testing was conducted in eight deep test wells with sandpack lengths of 15 to 30 ft and total depths ranging from 20 to 90 ft. This testing demonstrated field techniques necessary to conduct accurate deep well tests given the high flow rates and potential for air entrainment. In addition, these results provided further evidence that test wells drilled using hollow stem auger methods are prone to clogging and may not provide accurate results.

Numerical simulations were conducted to determine the effects of stratigraphic layering and groundwater mounding and to evaluate the field testing results. These simulations demonstrate that six-hour steady state tests can effectively capture the effects of perching layers and shallow groundwater for most infiltration facilities and groundwater mounding analyses are only necessary for larger infiltration facilities. The study also provides methods and correction factors for using measured bulk hydraulic conductivity estimates to size and design infiltration facilities.

The grant is funded by EPA and managed by the Dept. of Ecology. The City of Tacoma is the municipal lead.

Sharp Avenue Permeable Pavements - A Stormwater Treatment Study

Trey George, Mark Papich

City of Spokane, United States of America; ,

The Sharp Avenue Permeable Pavements project is part of the City of Spokane’s larger effort to reduce the amount of stormwater runoff and associated pollutants that discharges to the Spokane River. In addition to removing some discharges to the river, the project was designed to serve as an effectiveness study for the treatment of typical roadway pollutants, and to provide durability and maintenance information to assist with long term planning. The project consisted of installing porous asphalt and pervious concrete and associated road base along four blocks of a City arterial adjacent to Gonzaga University that include vehicle, bike and parking lanes, and full intersections. The permeable pavements capture arterial street runoff from Sharp Avenue that previously drained to the Spokane River untreated through three separate MS4 outfall pipes The project constructed multiple cross sections which varied the permeable pavements, surface slope, and placement in travel and parking lanes to evaluate the durability and maintenance implications across the seasons through the freeze and thaw cycles of Eastern Washington winter. In order to monitor the treatment effectiveness of the different permeable materials, the City installed three monitoring stations, where one collects surface runoff to provide a background, and the other two consist of underdrains, conveyance piping, manholes, and composite sampling equipment. The underdrain monitoring stations capture stormwater that has infiltrated through the permeable pavements and base materials, prior to interaction with native soils. Data and observations have been collected for almost three years, and the early data is providing analytical trends and pavement behaviors.

8:00am - 9:25amSession 13A: Collection Systems - Condition Assessment

Utilizing Acoustics To Enable Condition Based Maintenance In Gravity Sewer Systems

Gene Hallum

InfoSense, Inc., United States of America;

Effectively deploying resources to reduce sanitary sewer overflows (SSOs) is a tricky challenge. If cleaning resources are deployed to pipes that are functioning properly, then time and money are wasted. But if a blocked pipe is overlooked, SSOs may occur. For the average utility, determining where the 10-35% of pipe segments with blockages in the entire network is difficult and results in cleaning already clean pipes.

For this reason, hundreds of utilities have started using transmissive acoustics to rapidly screen small diameter gravity-sewer lines before deploying cleaning resources. The technology called the Sewer Line Rapid Assessment Tool, or SL-RAT, uses sound waves to quickly assess for blockages. The SL-RAT can provide an assessment in three minutes or less, meaning a two-person crew can inspect 10-20,000 ft/day.

This very fast and low-cost method of assessment is a powerful tool for wastewater collection system managers to gain understanding of their entire system. The quick insight helps focus resources to segments with identified need. Therefore, rapid acoustic assessment has become a helpful and economically attractive tool in helping utilities to stop cleaning clean pipe and transition to a condition-based maintenance program.

This presentation will examine numerous utilities that have effectively implemented acoustic inspections and discuss implementation strategies, cost-savings analysis and program results to demonstrate application. Furthermore, limitations of the technology will be discussed to give a comprehensive overlook of acoustic inspection technology. This presentation will be based on operator training courses performed around the country and will summarize a recently published ASTM Standard developed for acoustic pipe inspection.

Smart Pigging of Sewer Force Mains for Condition Assessment

Bob Jacobsen

Brown and Caldwell, United States of America;

The City of Bellevue (COB) provides wastewater collection for Bellevue and other communities in its 37 square mile service area located between Lake Washington and Lake Sammamish in Washington. The collection system consists of approximately 525 miles of sewer mains, 36 pump stations and associated force mains. COB retained Brown and Caldwell to design improvements to the Wilburton Pump Station and to assess the condition of the force main.

The Wilburton force main consists of approximately 1,600 linear feet of 8-inch ductile iron pipe that was installed in 1978. Brown and Caldwell subcontracted with SFE Global to provide pipeline pigging and inline condition assessment of the force main using i2iPipelines SmartFoam™, which is multi-sensor inspection tool with electromagnetic sensors embedded in the pig.

The Team performed planning, technical services and coordination, including providing equipment for pig launching and retrieval. Progressive pigging was performed to clean the force main prior to deployment of the inspection tool. The Team successfully pioneered the use of the SmartFoam™ tool in wastewater pressure pipelines, in which quality data was obtained for the entire length. The tool identifies joints, bends, fittings, and detects anomalies in metallic pipelines and identifies areas with pipe wall loss and other defects. The force main was inspected in a single day and data was analyzed and presented in a detailed report which was used to assess the condition of the pipe. The tool also captures x,y,z positional data and a record of the force main alignment can be developed.

Traditionally used in the oil and gas industry, this was the first known application of the use of the SmartFoam pig in the wastewater market. The SmartFoam pig can cost effectively inspect metal force mains that previously required complex bypassing and large installation points.

8:00am - 9:25amSession 14A: Facility Operations & Maintenance

Improved Filterability and Energy Savings with Mg(OH)2 Addition

Carol Nelson, Samayyah Williams

King County, United States of America;

The Brightwater Treatment Plant has been operating with a full scale pilot of magnesium hydroxide [59% Mg(OH)2] to supplement alkalinity demand in the aeration basins since June 2020. Activated sludge characteristics improved during the trial resulting in increased plant capacity and energy savings. Other observed benefits include reduction in chemical usage and safer handling conditions. Initial data also shows a five to ten per cent reduction in chemical costs.

Brightwater WWTP provides preliminary, primary, and secondary treatment of domestic wastewater prior to disinfection and discharge to Puget Sound. Secondary treatment includes a modified MLE process followed by Zeeweed membranes. To date, full nitrification is regularly achieved while denitrification is incomplete. Low influent alkalinity, lack of denitrification, and fluctuations in ammonia load contribute to the requirement for chemical addition. Continuous dosing of an alkalinity source is required to ensure permit compliance for pH. Sodium hydroxide (25% NaOH) was previously used to supplement alkalinity.

Secondary treatment capacity is determined by the “filterability” of the activated sludge. Prior to the use of Mg(OH)2, poor filterability resulted in reduction of plant capacity by more than 50%. During the pilot, plant capacity was either at design peak hourly flow capacity (44 MGD) or adequate for the plants influent flow (nominally 38 MGD or less). In addition to better filterability, better floc structure and reductions in foaming events were observed since continuous use in July 2020. Results for soluble COD analyses of the activated sludge were found to be well correlated with filterability prior to and during the study. Improvements in filterability also resulted in energy savings due to the reduction in scour air and backwash of the Zeeweed membranes of as much as 4,000 kWhd.

The plant plans to continue using Mg(OH)2 for alkalinity addition, with continued improvements for the installation and operation of this system.

8:00am - 8:45am

Research-Informed Operations & Maintenance Practices for Stormwater BMPs

Aimee Navickis-Brasch, Taylor Hoffman-Ballard, Kaela Mansfield

OCI, United States of America; , ,

Ensuring the success of a stormwater best management practice (BMP) does not stop once construction is complete. Ongoing maintenance is essential to ensuring stormwater BMPs are properly functioning. However, most stormwater BMP maintenance practices are based on engineering judgement. Researching and refining approaches to maintenance practices for stormwater BMPs advances the current state of knowledge, providing jurisdictions with proven and cost-effective techniques to manage their stormwater infrastructure. Optimizing operations and maintenance for stormwater BMPs allows stormwater programs to better plan and allocate resources, saving time and money.

This presentation will explore recent research into maintenance practices for stormwater BMPs. Three case studies will be presented demonstrating how research is being used to refine maintenance practices for BMPs such as sand filters, bioinfiltration ponds, and street sweeping. The presentation will also include discussion regarding how the results from these studies are being used by jurisdictions to support the MS4 permit compliance.

8:00am - 9:25amSession 15A: Treatment - Industrial Pretreatment

Effectiveness of Targeted Monitoring and Outreach Programs to Reduce PFAS in Influent

Scott Mansell, Joy Ramirez, Marney Jett, Bob Baumgartner, Kenneth Williamson

Clean Water Services, United States of America;

PFAS are a contaminant of increasing concern for wastewater utilities. The EPA will issue nationwide regulatory guidance on PFAS in the next few years which will affect NPDES permits of many wastewater utilities and may potentially threaten beneficial uses such as reuse and land-applied biosolids. While the EPA has provided some guidance on the potential sources of PFAS in influent to treatment plants, and many utilities around the country have begun sampling influent for PFAS in the last few years, results have been very site-specific. The dominant type of PFAS as well as the PFAS concentrations have varied widely driven primarily by the types of industries in the sewershed, often governed by a single industry even in large sewersheds.

In the next few years, wastewater utilities with industries in their sewershed will most likely be required to monitor for PFAS and work to minimize sources through source control. Several utilities in the upper Midwest have reported successful reduction of PFAS in influent and biosolids by requiring treatment of industrial effluents prior to discharge to the treatment plant. However, such treatments are expensive. For industries with less PFAS-rich discharges, it may be possible to achieve similar reductions using product substitution, process adjustments, and other less expensive means. However, the effectiveness of these programs for PFAS reductions has yet to be demonstrated.

Over the last several years, Clean Water Services (CWS) has been conducting regular PFAS monitoring at the treatment plants, throughout the collection system, and at specific industries. These data have been used to identify the main source(s) of PFAS to each of the treatment plants. Based on the monitoring data, CWS has been conducting outreach to specific industries as well as the general industrial, commercial, and domestic sectors to help them find ways to reduce their PFAS. CWS has focused specifically on six industries identified as sources of PFAS in our sewersheds as a case study for measuring the effectiveness of outreach efforts on reducing PFAS concentrations over time. This talk will report the findings from the monitoring results and what we’ve learned about the effectiveness of ongoing outreach efforts.

Two Decade Evolution of Industrial Stormwater Treatment at Vigor Shipyards, Seattle

Johnathan Cook1, Kate Snider2, Scott Stainer3

1Vigor Shipyards; 2Floyd|Snider; 3KPFF; ,

The Vigor Shipyard’s (Vigor) Seattle facility is one of the largest private shipyards in the nation and has been operation for more than 100-years. The shipyard consists of 27-acres of upland area, 4-acres of drydocks, and 20-acres of in-water area located on Harbor Island. Surface water discharges are regulated under an individual NPDES permit by the Washington Department of Ecology. This permit regulates flows from rooftops, drydock floodwater, and light industrial areas with restrictions on production activities. Each of these area types has a different flow path to numerous points of discharge. Vigor is required to construct new collection systems for surface water discharging areas and remove stormwater from an industrial wastewater discharge to a treated NPDES discharge. This presentation focuses on facility master planning and design for stormwater infrastructure retrofits and upgrades that are being implemented to meet Vigor’s changing stormwater regulatory landscape and environmental ethic.

In the early 2000s, the Vigor discharged stormwater through dozens of outfalls directly to surface waters. In 2003, due to tightening stormwater discharge limits, Vigor retrofitted the facility to discharge under an industrial pretreatment permit to King County’s sanitary system. Industrial stormwater is separated from other process water and pumped to 450,000 gallon detention tanks, allowing Vigor to discharge stormwater to the county sewer.

Nearly 20-years after this retrofit, the County is requiring Vigor to discontinue discharging stormwater to their sanitary sewer system (previously up to 1 MGD combined process, drydock, and stormwater). The new treatment system and discharge includes all stormwater flow from the facility, eliminating light industrial areas.

Concurrently, a CERCLA cleanup and habitat restoration is under construction. The new system’s point of discharge is adjacent to the habitat area. We will discuss the type and levels of treatment to allow this discharge near the habitat including pilot testing and mixing zone analysis. Design for these systems included retrofitting and installation of multiple pump stations, tanks, treatment system (siting, sizing and type selection), connection to City infrastructure for discharge and methods taken for validating the existing system for reuse. Construction began in May 2021 and continues through early 2023.

8:00am - 9:25amSession 16A: Risk Assessment & Emergency Response

Cyber-Resilience Through Manual Operations - Engineering and Operations Lessons Learned

Mel Damewood, Murphy Altunel, Andrew Ohrt

West Yost Associates, United States of America; ,

Automation is an essential part of many utilities' operations. However, our collective reliance on it has introduced new risks to our operations. As advised by recent Water ISAC and Department of Homeland Security, Cybersecurity and Infrastructure Security Agency, issued in response to increased cybersecurity risks, critical infrastructure operators need to maintain manual operation capabilities. Through West Yost's experience working with numerous utilities on the West Coast, we have observed that these capabilities are being engineered out of our systems and staff are no longer retaining the skills needed to operate manually.

This presentation will explore West Yost's observations from the field and what utilities can do to maintain or recover the ability to operate their systems manually, in the absence of automation. Broadly, this includes 1) ensuring utility staff have the skills and knowledge to operate manually, 2) the system is engineered to allow for manual operations, and 3) maintaining regulatory compliance.

In 2016, NPR noted that the U.S. Navy had realized their over-reliance on the global positioning system (GPS) system. They decided to once again teach officers how to navigate by the stars using manual methods and tools. Each organization needs to determine what their version of celestial navigation is and pursue it through better staff training and engineering practices. For many organizations in our sector, manual operations is our version of celestial navigation.

This presentation will give attendees examples of how to build and maintain staff and engineering capabilities to ensure that they can continue to serve their customers even in the instance of a loss of automation.

Monitoring Spatial and Temporal SARS-CoV-2 Burden via RT-ddPCR

Hannah Ferguson1, Blythe Layton1, Scott Mansell1, Andrea George1, Devrim Kaya2, Matthew Geniza3, Dana Alegre3, Christine Kelly2, Tyler Radniecki2, Kenneth Williamson1

1Clean Water Services, Hillsboro, OR; 2School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR; 3Center for Quantitative Life Sciences, Oregon State University, Corvallis, OR;

Clean Water Services (CWS) is a water resources management utility serving approximately 620,000 residents in Washington County, OR. In response to the SARS-CoV-2 pandemic, CWS initiated wastewater-based epidemiology (WBE) in April 2020, using reverse transcriptase droplet digital polymerase chain reaction (RT-ddPCR) to quantify SARS-CoV-2 RNA semiweekly at each of the district’s four water resource recovery facilities (WRRFs). Samples were extracted and quantified in-house at CWS’s molecular biology laboratory starting in December 2020, and sequenced by partners at Oregon State University (OSU). A total of 591 WRRF influent samples were analyzed from 4/1/20-3/1/22. SARS-CoV-2 RNA concentrations in influent varied spatially and temporally, with three major waves observed at each WRRF (11/20 – 2/21; 7/21 – 10/21: Delta surge; and 12/21 – 2/22: Omicron surge). These waves preceded increases in COVID-19 cases reported by the Oregon Health Authority (OHA) by 1-2 weeks, serving as a leading indicator. Spatially, SARS-CoV-2 RNA concentrations had greater peaks at the Forest Grove WRRF during the first two surges, while Hillsboro and Rock Creek WRRFs had greater peaks during the third, or Omicron surge. This trend was mirrored in reported case data, where cases during the Omicron surge were 1.5 – 3x greater in zip codes that make up large percentages of Rock Creek and Hillsboro influent flows compared to zip codes contributing to Forest Grove influent. During the Delta and Omicron surges, the respective variant dominated SARS-CoV-2 composition, contrasting to periods of low COVID-19 burden, where variant composition was diverse. These findings demonstrate the ability of wastewater surveillance to inform our understanding of COVID-19 burden across urbanized portions of Washington County. By investing in equipment necessary for in-house SARS-CoV-2 quantification (i.e., ddPCR technology), CWS continues to have flexibility in adapting to county-specific needs identified in collaboration with county public health partners. Furthermore, outfitting the molecular biology lab provided tools necessary for various research areas such as testing for viral or bacterial pathogens (other than SARS-CoV-2) in reuse waters, monitoring microbial communities involved in key biological treatment processes at the WRRFs, assessing the benefits of habitat restoration projects on biotic communities, and tracking sources of fecal indicator microbes in stormwater.

9:30am - 10:15amBreak on Exhibit Floor Tuesday Morning
9:30am - 10:15amExhibit Tours
10:15am - 11:40amSession 09B: Treatment - Nutrient Removal

Using IFAS at the Bend WRF to Provide an Effluent TN less than 3 mg/L

William Leaf1, Chris Miccolis2, George McConnell2

1Jacobs, United States of America; 2City of Bend, OR; , ,

The City of Bend needed an expansion of the Water Reclamation Facility (WRF) to accommodate growth within the service area, meeting both domestic and industrial demands. The Secondary Expansion project started in 2010, with selection of the integrated fixed-film activated sludge (IFAS) process to provide the basis for process capacity expansion. The key drivers for selection of the IFAS system were ability to meet the City’s total nitrogen limit, increase process capacity, provide operation and maintenance resilience, and allow for ease of future expansion. In October 2020 all IFAS system unit processes were placed into service followed by performance testing in early 2021. Performance of the IFAS system has been exceptional in meeting the annual total nitrogen limit (of 10 mg-N/L), with an average effluent total nitrogen of 2.8 mg-N/L in 2021. The effluent total nitrogen value, which is among the lowest of any treatment facility in the Northwest, is achieved with just the secondary treatment process and no need for supplemental carbon.

The presentation will review the implementation of the IFAS system at Bend WRF and highlight how the system is able to achieve the low effluent total nitrogen values. Details of the IFAS system will be presented, showing both the advantages and disadvantages of the process. Key design and operational drivers for selection of the IFAS system have been realized and will be discussed. The IFAS process has achieved the goal of meeting the total nitrogen limit, providing an increase in process capacity. Wastewater characteristics have changed in the Bend service area which have impacted the capacity of the WRF, in that the limiting unit process is no longer the IFAS system. The Bend WRF influent wastewater is considered “high strength” by industry standards, with high levels of soluble carbon, providing both benefits but also challenges for operation of the secondary treatment process. Lessons-learned throughout the startup of the IFAS system, together with findings from operation of the process over the last two years will be provided.

Streamlined Process Selection Helps Utilities Meet Stringent Nitrogen Limits

Brian Graham1, Anne Conklin2

1Carollo, United States of America; 2Carollo, United States of America;

On January 1, 2022, the Washington State Department of Ecology issued a General Permit to control nitrogen discharges to Puget Sound. This permit caps the annual effluent total inorganic nitrogen (TIN) load from the dischargers to current values. Additionally, the permit requires that discharges conduct a Nutrient Reduction Evaluation to determine what it would take to reduce their effluent TIN concentration to 3 mg/L.

While this is a big change for the Puget Sound dischargers, other parts of the Country have been dealing with limits as low as 3 mg/L for decades. In 1976 dischargers to Tampa Bay needed to reduce their effluent total nitrogen to concentrations less than 3 mg/L and since then there has been general adoption of these low nitrogen limits to other parts of Florida.

Through our experience in meeting these stringent limits in Florida, we have developed a streamlined approach to credibly and efficiently move from the “universe of alternatives” to a shortlist of alternatives for more detailed evaluation. The alternatives are divided into groups according to the process type. Representative technologies are selected from each group and a fact sheet is developed. These technologies are scored on non-economic factors such as treatment effectiveness, technology establishment, operability, construction sequencing, footprint and flexibility for future upgrades by an independent group of experts. The staff of the owning utility select the criteria that are most important to them using a pairwise comparison technique which results in a weighting for each criterion. The scores and the weights are combined to produce two to three alternatives for in-depth evaluation including process modeling and costing. The benefit of this approach is that it provides a clear roadmap and documentation for the processes selected for the detailed evaluation and allows the detailed evaluations to be focused on the most suitable alternatives.

This presentation will show how this methodology was applied at one utility in Florida that needed to upgrade their process to achieve an effluent total nitrogen concentration of less than 3 mg/L and how this approach allowed for a streamlined selection and ultimate design of the preferred treatment technology.

10:15am - 11:40amSession 10B: Risk Assessment & Emergency Response

Improved Cyber-Defense for the Water/Wastewater Sector

Andrew Ohrt1, Dan Ervin2, Mel Damewood1, Murphy Altunel1

1West Yost Associates, United States of America; 2Varius, Inc., United States of America; , , ,

Utilities are under constant attack from malicious actors intending to disrupt operations. With the invasion of Ukraine, the awareness of this reality has increased and Water ISAC and the Department of Homeland Security Cybersecurity and Infrastructure Security Agency have issued numerous alerts and advisories imploring critical infrastructure operators to improve cybersecurity practices. This is despite extensive cybersecurity investments by many organizations.

Utilities must consider how their SCADA and physical asset systems are resilient by design in the face of cyber-incidents. The escalation of control system-based cyber-incidents coupled with the natural evolution of engineering practices which have removed cyber-physical protections from our water and wastewater systems has created a widespread risk to our physical assets and people.

Developed by Idaho National Laboratory (INL), Consequence-driven, Cyber-informed Engineering (CCE) is an emerging methodology specifically designed to improve the security and cyber-physical resilience of critical infrastructure systems. The presenters are licensed by INL for the methodology and have worked with utilities to conduct CCE-related assessments, emergency preparedness exercises, and design improvements.

This presentation will summarize the four phases of CCE and illustrate examples of how a utility can implement CCE to improve resilience. Examples will include 1) how to better protect existing equipment and processes, a part of our systems that has received too little attention; 2) how to configure and operate physical equipment like pumps, pipes, relays, and valves; and 3) identifying system vulnerabilities due to engineering practices (like a chemical injection pump that can inject dangerous amounts of chemicals), and 4) how to mitigate those vulnerabilities through better engineering practices (like matching pump curves to the actual process needs).

The presentation is fast-paced and offered by leaders in this emerging methodology; West Yost Associates and Varius Inc. Attendees will be able to take lessons learned back to their utility and an understanding of the resources available through AWWA.

Wastewater Surveillance as an Emergency Response to Infectious Disease Outbreaks

Michael Harry, Devrim Kaya, James Gallagher, Casey Kanalos, Shana Jaaf, David Mickle, Tyler Radniecki, Christine Kelly

Chemical, Biological, and Environmental Engineering, Oregon State University, United States of America; ,

Wastewater surveillance can provide helpful information to public health practitioners and epidemiologists in a timely and cost-efficient manner. Although the COVID-19 pandemic has recently brought wastewater surveillance into the public eye, the Global Polio Eradication Initiative has used wastewater surveillance in many countries for decades to supplement clinical surveillance. Now that the US and many other countries have expanded wastewater surveillance systems to quantify and sequence SARS-CoV-2 (the virus that causes COVID-19), local, state and national public health authorities are gaining experience and confidence in interpreting wastewater data. In response to early success, primarily by researchers at universities across the globe, the CDC has implemented the National Wastewater Surveillance System to coordinate national wastewater surveillance efforts. As such, wastewater surveillance is expected to become a common tool to complement clinical data in response to infectious disease outbreaks.

In September, 2020, the Oregon Health Authority and Oregon State University initiated a statewide COVID-19 wastewater surveillance program to monitor the spread and severity of SARS-CoV-2 infections in over 40 Oregon communities. In addition to measuring the SARS-CoV-2 viral concentrations at the influent of wastewater treatment facilities, the Oregon Health Authority and Oregon State University have engaged in sewershed sampling in several communities to further localize outbreaks to neighborhood-scale hot spots. In this presentation we will describe our experiences and lessons learned in localized short- and long-term sewershed sampling for SARS-CoV-2. The process includes identifying appropriate manholes for sampling using sewer network maps, setting and collecting samplers for 24-hr composite samples, and analysis of wastewater samples for viral concentrations and genetic sequencing. We will describe the correlation between wastewater viral concentrations and variant detection with clinical case rates. Results of our sewershed studies in Newport, Bend, Corvalis, Oregon State University campuses, Redmond, Hermiston, Eugene, Woodburn, Astoria, Grants Pass, and Dallas will be highlighted. Finally, we will discuss the emerging field of interpreting the wastewater viral concentration data for public health and how the approach could be used in emergency responses.

10:15am - 11:40amSession 11B: Stormwater

Where Does Deep Infiltration Make Sense In The Northwest?

Kathryn Thomason

Oldcastle Infrastructure;

Many different solutions can and should be used to meet stormwater volume reduction goals, but have you considered deep infiltration? This presentation will focus on how deep infiltration can reduce CSO events, get past low infiltration till soil layers, and reduce costly infrastructure upgrades.

During the presentation I will:

- Identify where deep infiltration is a preferred solution based on OR and WA geology and groundwater elevations.

- Evaluate the benefits of reducing stormwater volume using deep infiltration.

- Discuss deep infiltration construction methods and how deep drywells can be installed quickly in areas like existing roadways.

- Review several case studies where deep infiltration was used to manage stormwater in the Northwest.

Quantifying the Accuracy of Rainfall Spatial Interpolation Techniques

Nathan Foged, Ayman Alafifi, Matt Davis

Brown and Caldwell, United States of America; ,

Rainfall data are crucial inputs for calibrating sewer and drainage models that are used to evaluate system capacity and size capital improvements. Engineers must carefully consider the accuracy of available rainfall data because a poorly calibrated model can lead to undersized or oversized infrastructure, and thus, excessive costs. One major source of inaccuracy is spatial variation. Rainfall is typically collected at a limited number of rain gauges that may or may not be located near the basin of interest. Measured rainfall at gauges must often be interpolated to get the data we need for basin-scale modeling. This presentation will discuss four different techniques for spatially interpolating rainfall data: (1) nearest neighbor, (2) inverse distance weighting, (3) ordinary kriging, and (4) gauge adjusted radar rainfall (GARR). We will describe the accuracy of each of the techniques based on a detailed study conducted for the Milwaukee Metropolitan Sewerage District and will also present the latest results from ongoing studies in the Pacific Northwest. Participants will learn about the error ranges associated with the different techniques, software, and level of effort needed to implement similar studies for their jurisdictions.

10:15am - 11:40amSession 12B: WateReuse

Advancing State Leve Reuse Policy with Grass Roots Efforts (OR)

Oregon Case Study - TBD

10:15am - 11:40amSession 13B: Collection Systems - Pumping

“Post-COVID-19 Modern Trash Loading Proves Sewage Pump Clog Resistance Can Not Be Predicted By Impeller Throughlet Size”

Robert Domkowski

Xylem, Inc., United States of America;


One leading result of the COVID-19 pandemic has been the significant increase in the mass loading of Modern Trash being experienced in municipal collection systems. Ratepayers have fully expanded the breadth of "items that should not be flushed" introducing near-any cleaning wipe, rag and paper towel into collection systems nationwide disrupting normal operations. This presentation reviews the current collection systems situation, examines the challenges that conventional solids-handling pumps cannot overcome, previews laboratory clog testing results and delivers successful solutions proven to minimize disruptions and reduce OPEX


The number one requirement of a solids-handling wastewater pump is its ability to pump unscreened sewage without clogging. The ever-increasing collection system loading rate exacerbated by the effects of COVID-19 further exposes the traditional multi-channel solids-handling impeller as unable to operate without partial to full clogging with soft solids.

A wastewater pump's impeller throughlet size has been frequently used to specify clog resistance, despite data that demonstrates the irrelevance of this measurement, especially when considering handling modern wastewater containing non-dispersibles and FOG. Several published guidelines recommend a minimum impeller throughlet size based upon decades-past ideas. Pump clogging is a critical and highly undesirable operational problem in wastewater pumping, which results in increased operational and maintenance costs (OpEx) necessitating emergency calls from the end user utility. Clogging drastically reduces pump efficiency, causing increased energy consumption while pump unit mechanical damage to the bearings, seal and shaft unit can result.

This paper will review the historical impeller design perspective as well as discuss the successful modern-day design concepts. The presenter will also establish how a pump's throughlet size has been shown to be a very misleading parameter in specifying solids-handling pump unit clog-resistance. The attributes of various traditional solids-handling impeller type will be reviewed. Finally, attendees will be provided with guidance regarding the importance of a modern solids-handling pump's wet-end design for achieving successful clog-free pump operation while enjoying sustained high hydraulic efficiency and low cost of operation.

Safety Is No Accident -- Pump Station Safety And Design

Joe Schmidt

Smith and Loveless, United States of America;

Municipal utilities are made up of many different types of equipment that create safety concerns for operation, and wastewater collection systems are no different. This course will discuss the various types of equipment employed by wastewater collection systems and the inherent safety concerns related to their operation that must be considered during the design phase. The discussion will focus on operator safety while working with equipment within wet wells, dry pits, valve vaults, or above grade enclosures. The course will demonstrate how to identify the safety hazards of different types of collection system and the safety steps and procedures that need to be addressed when operating different types of equipment. Safety concerns covered will range from confined space entry, falls, electrical hazards, pinch points, lifting injuries, noise injuries, and exposure through gasses, liquids, solids, wastewater debris and sharp objects. We will look at the different types of safety risks and how to protect our coworkers. This course will be a basic overview of safety in the workplace with emphasis on collection system equipment and PPE (personal protective equipment) that is involved in each activity. New administrators, operators and designers will be presented with how wastewater system design can mitigate safety concerns while still achieving the need for effective and affordable service.

10:15am - 11:40amSession 14B: Facility Operations & Maintenance

Chlorine Supply Challenges in the Portland Metro: Lessons Learned and Collaboration

Victoria Boschmans1, Anne Conklin1, Dan Laffitte1, Bhargavi Ambadkar2, Monica Stone2, Darren Eki3, Justine Abrook4, Noah Harvey4

1Carollo Engineers; 2City of Portland Bureau of Environmental Services; 3Clackamas Water Environment Services; 4Clean Water Services; ,

In the summer of 2021, chlorine production in the area of Longview, Washington was interrupted due to the failure of critical electrical equipment. As a result, challenging chlorine supply chain issues resulting from the pandemic worsened and had the potential to significantly impact drinking water and wastewater treatment agencies on much of the West coast. This disruption revealed supply vulnerabilities associated with routine chemical delivery for facilities and their treatment processes that are critical in keeping wastewater and drinking water clean and safe.

To address this unforeseen emergency, several water and wastewater agencies in the Portland Metropolitan area collaborated to share strategies for enduring the shortage and building chemical supply resiliency for the future. The purpose of this technical session is to illustrate the emergency chlorine supply shortage response of three Portland Metropolitan agencies including The City of Portland Bureau of Environmental Services, Clean Water Services, and Clackamas Water Environment Services.

This session will present on emergency coordination efforts and lessons learned by these three agencies. The following topics will be discussed:

  • Immediate impacts on treatment
  • Strategies implemented to temporarily mitigate impacts on treatment
  • Temporary solutions including alternative chemicals or changes in treatment strategy
  • Considered approaches to build chemical supply resiliency including changes in procurement strategy, treatment processes, and chemical inventory
  • How the collaborative emergency response effort provided agency support

At the conclusion of this presentation, attendees will understand how the 2021 chlorine shortage effected City of Portland Bureau of Environmental Services, Clean Water Services, and Clackamas Water Environment Services. In addition, attendees will have insight into how these agencies collectively approached the water quality emergency and developed best practices for chemical supply resiliency.

Making Your Microbes Work for You - The Automation of Anaerobic Digestion

Kathlyn Kinney

Biomethane, LLC, United States of America;

We look to change the way we operate biodigesters so that we can get more out of existing infrastructure. Most wastewater operators lack a visual window into their digester health, making it all but guesswork to resolve existing issues, let alone feel comfortable adjusting parameters to gain additional gas production from existing capacity. We will discuss the possibility of:

  1. Identifying and fine-tuning real-time monitoring technology to handle the high solids throughput of anaerobic digesters. This lets operators derisk the process of gaining digester efficiency and substantially reduce the cost of operating digesters.

  2. Making RNG (renewable natural gas) more available. By monitoring existing digesters more effectively, we can introduce food waste and problematic wastes like FOG which readily double gas production, fulfilling landfill diversion legislation such as California State Bill 1383 and Washington State House Bill 1114. This likewise opens the door to improve gas production simply by optimizing digester microbial health with the proper nutrients.

  3. Allowing municipal governments to better utilize their limited resources. Instead of designating dollars and labor toward rote measurements, we can direct them toward resource efficiency and recovery measures that bring in a net return long into the future.

The Valkyrie real-time monitoring system measures upwards of 15 parameters in a digester influent stream containing up to 20% solids content. The system is undergoing its first commercial installation at a food processing waste digester as of February 2022. In pilot tests on an operational dairy farm, the Valkyrie demonstrated measurement accuracy within a 5-10% margin of error on 12 key variables, and is being validated on seven additional variables.

A chief argument against replacing national natural gas consumption with RNG (renewable natural gas) is that it is not widely available. Yet many wastewater plants burn around half the gas they produce by flaring it to the atmosphere. Moreover, many wastewater digesters run at suboptimal efficiency, leaving 30-100% of potential biogas production untapped. Ineffectively-run digesters leave a substantial amount of methane emissions to be released from their biosolids output. Improving digester efficiency leads to the capture of these emissions, making digestion substantially more climate-friendly.

10:15am - 11:40amSession 15B: Treatment - Aeration

Full-scale Demonstration of Energy and Carbon-efficient BNR

Pusker Regmi1, Marty Johnson2, Caroline Nguyen2, Ahmed Al-Omari1

1Brown and Caldwell; 2WSSC Water;

Utilities like WSSC Water are looking to reduce the burden on customers and maintain the affordability of water services through innovative solutions. This paper details the demonstration of one such effective solution resulting in estimated energy and chemical cost savings of ~$500K/yr, decreased carbon footprint; and reduced economic impact to WSSC Water ratepayers. The results are very promising, and plans are underway to expand the operation to the whole plant and implement it at the rest of WSSC Water’s WRRFs.

The 26 mgd Seneca WRRF employs a 4-stage Bardenpho process with an anaerobic selector, secondary clarifiers, and filters to meet stringent nutrient limits (total N of 4 mgN/L, total P of 0.27 mgP/L). One of the five process trains was converted to a test train that included the following changes:

1) Pumping of mixed liquor recycle (MLR) reduced from 400% to 200% of the influent flow.

2) Providing Ammonia-based aeration control (ABAC) to maintain dissolved oxygen (DO) levels in all aerated zones based on real-time ammonia probe readings.

3) Discontinuing Methanol addition.

The ABAC operation uses real-time DO and ammonia measurements to adjust blower turndown and valve positioning to meet the setpoints for the system, and includes tracking of real-time DO, ammonia, and nitrate. Based on weekly profiles, the average test train effluent ammonia was less than 0.2 mgN/L, TIN was 1.9 mgN/L, and orthophosphate was less than 0.2 mgP/L. Simultaneous nitrification and denitrification and post-anoxic denitrification were responsible for enhanced nitrogen removal in the test train. A high degree of P uptake occurred even at low DO conditions, resulting in very low effluent P. The low DO operation (~0.3 mg/L) achieved by ABAC resulted in SND and significant aeration savings (~40%) compared to the other trains operated at higher constant DO (~1.5 mg/L). In addition, the test train removed > 4 mgN/L via denitrification in the post-anoxic zones without the use of any supplemental carbon.

The results obtained from this demonstration study will ultimately enhance the sustainability of nutrient removal to meet stringent effluent standards, making it accessible for many more utilities.

Solar Powered Floating Aerated Fixed Film Modules for BOD Treatment and Nutrient Removal in Wastewater Lagoons

Lauren Takitch, Wayne Flournoy

Entex Technologies, United States of America;

Thousands of wastewater lagoons across the U.S. require BOD and nutrient removal. Of those lagoons, especially those in remote or low funded areas, access to a power source and ongoing electricity costs pose challenges. Solar powered fixed film modules provide aeration, mixing, and biomass for lagoons without a blower building, air distribution manifold, or operating costs.

Solar powered WavTex™ modules feature proven EnTextile™ fabric media sheets and integral aeration. Solar panels reside on top of the floating modules. The blower also resides on the floats yet is protected underneath the solar panels. The system utilizes beneficial microbiology that attaches to the fixed media to digest waste, converting carbon waste into water and carbon dioxide, and ammonia waste into atmospheric nitrogen. During the day, the energy collected by the solar panels power the blower, providing the air to consume carbon waste and convert the ammonia waste into nitrate.

During the night, with no power to drive the blowers, the microorganisms are forced to strip the oxygen from the nitrate molecules generated during daylight conversion of ammonia to continue feeding on the carbon waste, leaving atmospheric nitrogen. The system continues providing treatment during the night, even with cloudy days.

Unlike other in-pond systems, this alternating daylight/nighttime process converts ammonia to atmospheric nitrogen, providing complete nutrient removal. The system provides BOD removal, nitrification and denitrification. Where denitrification is not required, this cycle saves energy by recovering oxygen plus restoring alkalinity for nitrification. Thus, the cycle maximizes the high efficiency and effectiveness of the process. It also provides excellent mixing and additional dissolved oxygen to the rest of the lagoon.

Modules can be used alone, or with additional modules depending on the treatment required. They can be readily moved within the pond. No regular maintenance is required for the media or aeration, and only standard lubrication maintenance is needed for the blower. These energy efficient modules are ideal for remote wastewater treatment lagoons, hog lagoons, winery lagoons and other applications. Clean water ponds looking to reduce algae blooms may also benefit from complete removal of nitrogen nutrients from the water.

10:15am - 11:40amSession 16B: Construction & Alt Delivery

Incentivizing Partnerships for Green Stormwater Infrastructure in Seattle

Dustin Atchison1, Brian Mickelson2

1Jacobs Engineering, United States of America; 2Seattle Public Utilities;

Seattle Public Utilities (SPU) is expanding the use of green stormwater infrastructure (GSI) approaches to meet community and system needs in the City of Seattle. Doing so requires building innovative, cross-sector partnerships that leverage investments, accelerate and amplify existing work, and support a broader set of community outcomes than SPU would be able to deliver alone. Partners may include community groups, other City departments, private development, or any party interested in delivering a GSI project. A foundational component for this work is the ability to financially incentivize potential partners to design, construct, and maintain GSI.

SPU’s ability to engage the broader community in GSI work requires greater certainty for potential partners around where SPU can partner, specifically where SPU can provide funding for GSI projects. Relying on results from past planning efforts, that indicate where system problems are likely to exist, SPU aims to create a searchable map to proactively engage potential partners and leverage collective investment to build GSI on parcels and public rights-of-way (ROW) across the City. This presentation will provide a high level overview of work to develop a webmap that shows geographic eligibility for GSI program partnering dollars, and associated the stormwater performance criteria, which include two funding categories: water quality and flow control.

In addition to establishing the geographic areas where SPU is willing to partner, SPU is also striving to establish a consistent unit cost basis that establishes what SPU will pay for managing a unit of stormwater. This policy was developed through a comprehensive review of DWW capital project costs, as well as a survey of existing partnering programs at peer municipalities.

This paper will present the approach and key findings from this effort to define the approach for measuring unit costs based on historical delivery of GSI projects, describing partnership delivery models and developing a range of incentive payments in consideration of different stormwater performance standards and bonuses for expanded benefits.

Finding the Silver Bullet

Vu Han1, Randy Mueller2, Jeff Maag3, Brent Cline4

1City of Portland, Bureau of Environmental Services; 2Jacobs Engineering Group; 3City of Portland, Bureau of Environmental Services; 4City of Portland, Bureau of Environmental Services; ,

A program to expand the secondary treatment process at the Columbia Boulevard Wastewater Treatment Plant is currently under construction. At the heart of the program are substantial and disruptive modifications and improvements to the Silver Tunnel, a pump/piping gallery built in the 1970’s. These modifications are critical to the construction of several new facilities at the plant that include two new secondary clarifiers, a RAS pump station, and a new solids treatment facility. In operation for fifty years, the Silver Tunnel is packed with existing process piping, mechanical equipment, electrical power and control cabling, and other ancillary systems necessary to support the secondary treatment process and other plant operations. Key modifications and improvements to the Silver Tunnel include the demolition of aging and/or abandoned piping and equipment, the installation of new process piping and equipment, and the relocation of major electrical gear to address resiliency issues, all while maintaining operation and permit compliance. Completing this work is complicated by complex constructability and sequencing issues, loss of institutional knowledge due to retirement and turnover of plant staff, the lack of consistent and complete record drawings, and most importantly the need to maintain an operational facility during construction activities. To overcome these challenges, the team utilized several strategies to support their design efforts which included coordinating with the contractor early and often (which included a two-day campout in the Silver Tunnel), taking full advantage of the CM/GC delivery platform, dozens of field walks to dissect and fully understand the myriad of both new and old process and utility piping present in the tunnel, three dimensional scanning and modeling to assist with pipe routing and clash detection, sequencing planning to build a robust construction schedule, and discussions with plant operations staff to confirm shutdown allowances and limitations. The planning and design tools utilized to develop solutions and coordinate with plant operations staff and the CM/GC team are representative of tools that would be valuable for any wastewater agency conducting complex upgrades within existing operating (and aged) facilities.

12:00pm - 1:15pmLunch—Tuesday Business Luncheon
1:15pm - 2:40pmSession 17A: Collection Systems - Planning

Preliminary Design & Outreach for Replacement of an Aging Wastewater Lake Line

Cheyenne Thompson1, Erik Waligorski1, Joe Stowell2

1Carollo Engineers, Seattle WA; 2City of Renton, Washington; ,

The City of Renton (City) owns and maintains the Kennydale Lake Line System (Lake Line), an 8-inch diameter line in Lake Washington that serves approximately 55 properties in a waterfront residential community. The 4,700-foot-long line begins at a flush station that intakes fresh lake water to “flush” the contents downstream to a separate lift station, which pumps flow to the City’s gravity wastewater network.

In 2018, under an emergency order, the City completed a significant cleaning and condition assessment project (including construction of temporary in-lake manholes). The information collected during this activity allowed an assessment of the remaining useful life of the system. While failure by corrosion/degradation is not imminent for the majority of the lake line system, the risk of complete failure caused by a blockage in the pipe or damage by outside factors (i.e. caught by boat anchor) and the complexity and associated timeframe of permitting and construction has prompted design of a replacement system.

An alternatives analysis for a replacement system was completed that evaluated the following options: 1) gravity sewer deeper in the lake, 2) gravity sewer on land, 3) replace in the lake in its current location, 4) vacuum sewer on land, and 5) grinder pump system on land. Based on technical feasibility, permitting restrictions and costs, the grinder pump system was selected as the preferred alternative to move forward into the preliminary design phase.

The grinder pump system involves installation of a small grinder pump station for each property currently served by the Lake Line. The grinder pump stations will intercept flow from the residential side sewer and convey it to a new force main located in the adjacent roadway. Due to the impacts of this project on the private properties within the service area, public outreach and education has been a significant part of the preliminary design efforts.

This presentation will review the alternatives analysis completed to select the preferred alternative and outline challenges, lessons learned, and next steps for project components including emergency storage, backup power, easements, property access requirements, constructability considerations, community feedback, and long-term operation and maintenance of the system.

Making Sense of It All: A User-Friendly Visualization Tool to Analyze Model Results

Ayman Alafifi, Thomas Suesser, Angela Wieland

Brown and Caldwell, United States of America; ,

Hydraulic models are instrumental in helping to identify system deficiencies and make capital investment decisions. These models often generate extensive and overwhelming outputs, making it difficult to summarize and communicate key insights to decision makers. Identifying new ways to present model results to non-technical users can increase model credibility and empower decision makers to make more informed investment decisions.

Brown and Caldwell (BC) and the City of Medford (Oregon) are completing a city-wide stormwater master plan project, which includes development of comprehensive hydrologic and hydraulic models to aid in identifying and prioritizing capital project needs. To facilitate efficient review and decision-making during model development, BC developed a modular, interactive dashboard tool using open-source technology (R and Microsoft PowerBI). The tool reads model results from multiple Stormwater Management Model (SWMM) output files and updates tables, maps, and graphs in a pre-configured PowerBI dashboard. This enables rapid compilation, presentation, and comparison of results from multiple model scenarios. The workflow seamlessly connects model outputs to dashboard visuals, which:

1) Significantly reduce review time during model development and interpretation, enabling users and reviewers to toggle between interim results under varied thresholds and design criteria;

2) Improve quality control processes, allowing for more flexibility and efficiency through multiple model revisions;

3) Deliver valuable insights to the client; and

4) Adapt to multiple SWMM platforms, creating efficient, reproducible workflows.

BC used the tool to organize and analyze results from a calibrated, city-wide stormwater model built using CHI’s PCSWMM. The model includes over 200 miles of modeled pipes, culverts, creeks, irrigation canals, and ditches, and 19 modeled storage facilities – all subject to varied design criteria. BC evaluated the system under eight scenarios representing four design storms and two land use conditions.

Processing model results using this tool enables in-depth discussion among stakeholders. The project team used the tool to organize flooding nodes into problem areas, filtering for different criteria such as design storm deficiency, flooding duration, or ponding depth to prioritize capital project needs. Adaptation of the tool continues to expand its potential utility to other hydraulic modeling applications beyond stormwater.

1:15pm - 2:40pmSession 18A: Utility & Asset Management

Doing More With Less: Adaptable Tools For Prioritizing System Repairs

Adam Donald, Scott Duren

Water Systems Consulting, United States of America; ,

Ongoing inspections and system data collection tools are rendering static master plans inadequate for utility planning. Additionally, inadequate historical spending in infrastructure has left a rising need for investment with limited budgets. Living toolsets that are continuously updated are necessary to meet the evolving needs. WSC has worked with Portland Bureau of Environmental Services (BES), the City of Milwaukie, Oak Lodge Water Services, and numerous other agencies on developing rehabilitation decision-making tools of varying complexity to meet each client’s unique system needs and help make the best capital improvement decisions each year that fit within the available budget.

Our presentation will showcase a range of prioritization tools, from simple GIS-based systems to more complex quantified risk comparisons to augment traditional master planning with tool sets that automatically adapt to updates in condition data. Common issues that we have encountered, along with different solutions that have been implemented, will include:

  • Data limitiations and gaps and how they can be overcome;
  • Identification of investments in data collection that maximize return on investment;
  • Standardiziation of condition information across long time periods and different methods of collection;
  • Ability to normalize risk across different types of assets to make CIP decisions;
  • Methods for defining criticality for use in prioritization and scheduling; and
  • Assessing in-house capabilities versus contracting needs to drive planning.

By the end of this presentation, attendees will understand what is needed to implement an asset prioritization program within their respective systems based on their goals and overall budget. Additionally, attendees will learn which data investments add the most value for optimizing maintenance decisions.

360-Degree Cameras: A New Vantage on Water/Wastewater Infrastructure

Mackenzie Capaci, Robyn Wilmouth

Kennedy Jenks, United States of America; ,

The operations and maintenance (O&M) of collection and conveyance systems and treatment facilities is challenging, especially as personnel encounter insufficient and/or inaccurate information from record drawings and O&M manuals. Often the sector faces the challenge of the loss of historical or institutional knowledge, which impacts our ability to ensure safe access into and out of our industry's infrastructure. As we move forward and continue to “Adapt with Purpose,” we must identifying new operational approaches while holding safety paramount. Beginning in 2018, the presenters incorporated 360-degree technology into project work with large municipal clients in the Puget Sound area. Initial uses included: planning for confined space entry into wet wells of pump stations and conveyance lines; minimizing personnel confined space entry during construction and inspection; post-construction documentation of facilities, and condition assessment for large and small spaces. The presentation will include discussion of two types of 360 camera’s used, a comparison of the pros/cons of the different technologies as they pertain to different needs of various types of system owners, and a look to the future for ways to expand the utilization of this technology.

This presentation will include a series of case studies of uses for 360-degree technology to address the needs of the water and wastewater industry. During the past two years, the need for virtual accessibility has been pivotal. The use of 360 imaging and the creation of 3D model spaces enabled key aspects of the design process to continue and enhanced not only consultant/client communications but improves the efficacy for field staff to communicate to remote team members to better understand a site or state of equipment. This presentation will also discuss and highlight the challenges, successes and lessons learned during the piloting of these technologies. Lastly, the presenters will provide a facilitated discussion of future uses of the technology with the audience. For example, topics may include how facilities can incorporate 360-degree technology into: asset management, condition assessment and predictive maintenance, confined space registers, and integration into Building Information Modeling and 3D virtual model spaces.

1:15pm - 2:40pmSession 19A: Construction & Alt Delivery

Strategies for Managing Supply Chain Issues and Cost Escalation

Mike Conn

J-U-B Engineers, Inc, United States of America;

In the current global economy, water and wastewater utility owners are facing an unnerving reality of supply chain and materials cost escalation issues and disruptions with nearly every project they undertake. Contractors are faced with bidding projects with unprecedented uncertainty in their bids for materials availability, lead times and extreme pricing volatility.

Over the past 2+ years since the beginning of the COVID 19 pandemic, owners, engineers, attorneys, and contractors have been sitting at the table facing these issues time and time again. This presentation will help Owners and Engineers to identify why these are occurring, the potential risks to projects, and share some strategies and resources for managing the disruptions and escalation that is prevalent in our current construction environment. Contracting approaches, procurement alternatives, and managing cost and risk allocation will be discussed.

In addition to Construction, this presentation will also review strategies that agencies are taking to manage supply issues for the water-wastewater industry operational consumables like chemicals, and services including pros/cons to various approaches and limitations with procurement laws.

The goal of this presentation is to foster a dialogue between industry leaders and professionals to discuss options to navigate the volatility of our current market.

Words every Engineer love, but Commissioning Managers dread… “Largest installation ever” / “Full System Integration” / “First of its kind”

Kiersten Lee1, Fred Brown2, Paul Mueller3

1MWH Constructors, United States of America; 2City of Spokane; 3Jacobs Engineers; , ,

The purpose of this presentation is to share lessons learned from installation through commissioning and start-up (C&SU) of a membrane filtration system designed to treat up to 75 MGD of secondary effluent.

The City of Spokane (City) completed a major facility upgrade to the Riverside Park Water Reclamation Facility (RPWRF) in August of 2021. The project, commonly called the Next Level of Treatment (NLT), included the addition of a new membrane filtration system, the largest single installation of its kind in the World.

Due to magnitude of the Project, all ancillary systems to support the operation and maintenance of the membrane system were the first of their kind, specifically the clean-in-place (CIP) system and corresponding CIP neutralization tanks. One example of lessons learned included the hydraulic challenges of upsizing the ancillary pumping systems, which are “normally” on across-the-line starters. When scaled up to meet the demand of the RPWRF, the project team observed significant water hammer on multiple systems, as well as capacity impacts to existing facility pump stations. Another unique challenge was chemical foaming in the CIP tanks. The foaming was initially observed during membrane flushing and persistent throughout C&SU. The foaming was a challenge the vendor, engineer nor construction team had ever encountered before.

In addition to the new infrastructure the City, in parallel, upgraded the entire RPWRF SCADA system. Typically, with vendor packaged systems the programing exists on external PLCs and limited I/O is integrated into the overall facility SCADA system. However, the NLT project included a full system integration of the vendor programming, as well as custom SCADA screens to match the existing facility system graphics. The full system integration created unique challenges between the vendor and the City’s programming standards and graphics.

Throughout the NLT Project, the team worked through numerous challenges to troubleshoot and optimize the RPWRF. The team’s objective was to ensure a seamless transition to the City’s operation staff, deliver a quality project on time and under budget that positively impacted the Spokane community. This presentation will explain how the team resolved each challenge, share lessons learned and C&SU best practices.

1:15pm - 2:40pmSession 20A: WateReuse

City of Boise Recycled Water Program - Start Up (Phase 1) 

Onsite Non-Potable Water System Rule (WA decentralized reuse)

1:15pm - 2:40pmSession 21A: Facility Operations & Maintenance

Developing a Bench Scale Test to Evaluate Operational Digestion Stability and Capacity

Ornella Sosa-Hernandez, Peter Schauer

Clean Water Services, United States of America;

Anaerobic digestion is a very robust process as long as feed composition, feed rates, and stable operating conditions (e.g. mixing and temperature) are maintained. However, digesters are often operated as “black boxes” when the ability to make visual inspections is limited and only grab samples and laboratory analyses can indicate the potential for upset conditions. At the Rock Creek Water Resource Recovery Facility (WRRF) owned and operated by Clean Water Services (CWS), the five digesters lack individual feed flow meters or gas production meters and this gap in operational data slows the identification of unstable conditions.

To improve knowledge of the digestion process, CWS is working on the development of an easily implementable bioassay that benefits Operations and the Capital Improvement Program to:

- Help identify conditions that can cause upset events or instability.

- Determine capacity limitations and/or requirements for future construction projects.

- Evaluate impacts from co-digestion of high strength waste.

The assay compares the initial rate of biogas production from acetate addition to batch reactors containing freshly collected digestate and the biogas production rate of digestate alone. The ratio of these rates can be tracked over time and used as an indicator of process upsets caused by volatile acids accumulation and additional capacity of the system to convert organic matter to biogas.

The following results have been obtained from the initial tests performed at the Durham WRRF with digesters that have individual feed and gas measurements:

- Reliable measurements are obtained within 3-12 hours, making this test valuable for operations to respond to critical conditions.

- Gas recovery from acetate has been repeatable indicating that recovery calculations from different feed sources can be evaluated.

- The bioassay results and the full-scale digester gas production are comparable, which helps in circumstances where limited gas flow data is available (e.g. individual gas flow measurements are not available at the Rock Creek facility).

This presentation will include additional results from the following evaluations:

- Implementation of the test at the Rock Creek facility.

- Comparison of results obtained from the two facilities.

- Gas recovery from additional co-digestion substrates.

Troubleshooting a Process Upset: Experience at Portland’s CBWTP

Scott Weirich1, Monica Stone2

1Parametrix, United States of America; 2Portland Bureau of Environmental Services;

The City of Portland’s Columbia Boulevard Wastewater Treatment Plant (CBWTP) experienced a filamentous bulking process upset starting in April 2021. This presentation is a case study of the investigation to determine the causes and the solutions to the issue.

Operational changes due to construction, plant repairs, a regional sodium hypochlorite shortage, and extreme temperatures all generally contributed to the process upset, but extensive investigation was necessary to determine the specific causes. Investigative methods included microscope analysis, extra field sampling, and historical data analysis. Key factors determined through these analyses include:

- Filament proliferation identified: types 1701 and 1863, which indicate high F/M and low DO

- Low PAOs for an anaerobic selector and poor selector COD removal

- Low Dissolved Oxygen (DO) levels in the aerated zones according to the Palm-Jenkins Curve

- Unequal clarifier loading reducing the ability to handle bulking

Thus, the immediate factors leading to the overgrowth of filaments are poor selector performance and high loading causing high F/M and low DO in the initial aerobic cells. The plant then had to mitigate the present process upset and develop a plan to prevent similar challenges in the future. The following key changes were recommended, and are currently being implemented as possible:

- Reduce loading to the aerobic zones

- Maintain a higher aerobic SRT

- Optimize the aeration system to provide higher DO levels to the first aerobic zones

- Utilize more proactive RAS chlorination and implement higher doses when needed

- Optimize clarifier flow split and RAS rates to even out clarifier blankets

Process upsets are challenging issues. Often a wide variety of investigative techniques are needed to narrow down the problem and to provide an effective solution. This case study shows many of the investigative techniques used and possible solutions to such an upset.

1:15pm - 2:40pmSession 22A: Resiliency

Hitting the Curve Balls - A Water Resiliency Framework that Integrates Utility Investments, Communications, and Decisions Making

Holly Tichenor1, Rachel Garrett1, Frank Dick2

1Brown and Caldwell, United States of America; 2City of Vancouver, WA; , ,

What do you do with a Utility Rate Study recommending major policy and rate changes, competing programs and messages, and a CIP that is doubling in a City with limited resources? In the City of Vancouver, Washington’s case, we seized the moment to work on strategy, communication and alignment before diving in deep into the turbulent waters of change!

Our utilities face a vast array of competing demands and uncertainties that require new approaches to creating alignment and pathways for resilient outcomes. The demands range from growth and development pressures, stabilizing rates while covering program costs, changing regulations, and managing aging assets to protecting the environment, responding to climate change, addressing equity challenges, and ensuring system resiliency. Addressing these issues requires well-thought-out planning and communication approaches that utilities can use to inform critical decisions, effectively engage with communities, and integrate with broader utility/city strategic planning processes. Brown and Caldwell (BC) and the City of Vancouver, Washington (City) will describe how the power of meaningful engagement and communications can prepare our communities and leaders to better address the complex needs.

The City worked with BC’s Strategic Communications team to develop a Water Resiliency Framework and Strategy to align communications internally and externally with City officials and stakeholders. This process brought together a cross-functional team of City department leaders ranging from finance, management, engineering, planning, and public information. The Framework has guided Public Works’ updated CIP, Strategic Plan, community engagement, Council communications, and more. The Framework has bolstered support for long-term investment needs and led to clear funding/financing strategies and rate stabilization recommendations. The Framework focuses on how all water connects to benefit community health, economy, infrastructure, and the environment.

The City of Vancouver’s water resiliency strategy recognizes the inherent connection between all water resources and related systems. Now is the time for transformative and integrated water solutions—combining water, surface water, and wastewater—that address holistic City goals.

This presentation will cover alignment across city departments, framework development with multi-department involvement, identifying and building financial support, workshop planning to keep elected officials informed, and development of a community engagement and strategy plan.

Implementing Resiliency – Moving from Aspiration to Reality

Bhargavi Ambadkar1, Dave Green2, Dave Brunkow2, Muriel Gueissaz-Teufel1, Vu Han1

1City of Portland BES; 2Jacobs; , ,

Portland BES has embarked on one of their largest ever upgrade programs at the Columbia Boulevard Wastewater Treatment Plant (CBWTP), the Secondary Treatment Expansion Program (STEP) which includes a collection of new facilities (designed to meet current codes) as well as upgrades to existing facilities (typically designed to older codes/standards).

Level of Service (LOS) goals were previously developed as part of the Bureau of Environmental Services (BES) Resiliency Master Plan, in alignment with the Oregon Resiliency Plan. These Levels of Service goals dictate minimum levels of treatment and recovery goals after a significant seismic event. For the STEP projects, these Levels of Service goals have been applied to not only seismic events, but also flooding events, power outages and structural failures.

Although the new secondary clarifiers and the new solids treatment facilities are designed for seismic and flooding resiliency, the existing secondary treatment process facilities at the CBWTP (built on wooden piles in the 1970s) are susceptible to a number of failure scenarios. Three failure scenarios were developed as a means of identifying resiliency investments that would align with the Level of Service goals:

Failure Scenario 1 – Plantwide power loss

• Assume complete loss of incoming power with incoming power restored within 2 to 3 days

Failure Scenario 2 – Significant seismic event

• Assume long-term plantwide power loss (longer than 3 days), coupled with structural failure and/or significant damage to secondary process facilities

Scenario 3 – Flooding event in secondary process

• Assumes loss of secondary treatment for minimum of 1 week to several months’ duration

Wastewater utilities across the Pacific Northwest are facing unprecedented capital expenditures related to ensuring that treatment facilities are resilient to a wide range of disasters (climate change, flooding, seismic events, extended power outages, and failure of aged infrastructure). This presentation walks through the approach and decision process used to evaluate the impacts of these failure scenarios at CBWTP and how investments were strategically targeted to meet BES’ Level of Service goals.

1:15pm - 2:40pmSession 23A: Treatment - Nutrient Removal

Commissioning And Startup Of The First Full-Scale Sidestream Treatment System In The Western U.S.

Mike Falk2, Felipe Munoz1, Nikolaus Hlavacek1, Ameen Razavi1, Fatemeh Shirazi1

1Microvi Biotech Inc., United States of America; 2HDR Inc., United States of America;

Reliable nutrient removal continues to be a high-priority issue for treatment agencies facing stringent discharge limits, especially for those located adjacent to bays and estuaries. Reducing nutrient discharge without taking on large capital costs may be attained via treatment of sidestream (filtrate) flows coming from anaerobic digesters. In many cases, treatment of 1% of the total plant flow as sidestream can reduce up to 20% of the nutrient (Nitrogen) load entering the main treatment works. In 2021, Oro Loma Sanitary District (OLSD), in partnership with Microvi, commissioned the first sidestream treatment process in the Western U.S.

The process makes use of Microvi’s MicroNiche Engineering (MNE) technology. MNE “biocatalysts” are synthetic polymeric composites containing a high density of specific organisms capable of degrading inorganic and organic matter in water. The MNE biocatalysts for sidestream treatment are capable of oxidizing high levels of ammonia, converting it to nitrite and nitrate.

The deployment of MNE technology is highly suited to utilize existing assets. At OLSD, a 30,000-gallon sedimentation basin was retrofitted to retain the raw filtrate. A set of redundant diffusers, pipework and an air blower were repurposed to provide the necessary oxygen to an existing 90,000-gallon aeration basin. Supplemental alkalinity dosing was controlled automatically via a pH feedback loop. A stainless steel quiescent (settling) zone was installed to retain the MNE biocatalysts within the basin.

Results indicate that ammonia removal by MNE biocatalysts is optimal even at the lowest blower setting, thereby saving energy. The system can reliably remove upwards of 150 kg-N/day at steady-state.

The commissioning process found that the technology was robust. After process upsets (e.g., digester downtime) and routine flow shutdowns, the system’s performance recovered quickly. Further, the operational requirements of the MNE system are simple with no complex control systems or downstream solids management, thereby requiring minimal operator involvement.

The implementation of the MNE technology at OLSD is the first-of-its-kind in the Western U.S. with broad applicability across a number of use-cases where sidestream ammonia removal can reliably enhance nutrient removal while achieving cost-savings.

IFAS Media for Single Tank Nitrification/Denitrification

Lauren Takitch, Wayne Flournoy

Entex Technologies, United States of America;

A housing development in Powder House Pass, SD needed a 25,000 gpd treatment plant to meet effluent requirements of 10 mg/L BOD and < 1.0 mg/L ammonia-nitrogen. Entex supplied the internal equipment, controls, and instrumentation for the equalization tank, aeration tank, secondary clarifier, tertiary filtration, and sludge digestion tank.

Three WavTex™ moving media modules, containing a high surface area, three dimensional, EnTextile™ fabric media, were installed in the aeration tank. The media consists of buoyant sheets that are tethered to the bottom of the modules, allowing the sheets to stand and continuously wave freely when underwater. Because the media sheets are only tethered to the bottom of the modules, there is no chance of media breakage and there is no need for retention screens. The modules have integrated aeration that provide the dissolved oxygen for the treatment, provide biomass scouring, and enhance the mixing in the tank. The three-dimensional structure of the woven EnTextile media is designed to simultaneously promote both aerobic and anoxic processes within a single aerated tank. The biofilm that resides in the outer zones of the sheet, which are in contact with the aerated water, removes BOD and facilitates nitrification. The interiors of the media sheets are anoxic, allowing for denitrification.

As a result of this WavTex IFAS process, the plant consistently met or exceeded the ammonia-nitrogen and BOD removal requirements, even in the cold winters of the Black Hills of South Dakota. Furthermore, even though the tank was fully aerated, the effluent total nitrogen achieved was 0.2 mg/L, corresponding to nearly complete denitrification.

1:15pm - 2:40pmSession 24A: Treatment - Digital Tools

Sludge Characterization and 3-D Computer Analysis for Large New Secondary Clarifiers

Shinjiro Miyawaki1, Jeff Maag2, Stefan Chabane2, Bhargavi Ambadkar2, Corey Klibert1, Glen Daigger3

1Jacobs Engineering; 2City of Portland Bureau of Environmental Services; 3University of Michigan; , , , ,

Two new circular clarifiers at the Columbia Boulevard Wastewater Treatment Plant (WWTP) will expand the sustained peak secondary treatment capacity to 130 mgd. The primary objective was to maximize the peak secondary treatment capacity of the expanded system using limited available area at the WWTP. The two new clarifiers have a sidewater depth of 21.3 feet and a diameter of 145 feet, and are designed to achieve surface overflow rate (SOR) up to 1,800 gallons per day per square foot. Preliminary 3-D computational fluid dynamics (CFD) analysis identified that, due to the high SOR desired, characterization of the solids at low concentration, 500 mg/L or lower, was essential to properly optimize the clarifier configuration. Consequently, solids characteristics were measured in the field and the results were used in CFD analysis.

A batch-type test for flocculent settling was performed to measure the settling velocity and mass fraction of large and medium flocs. The height and diameter of the column were 6.0 feet and 6 inches, respectively, and five sampling ports were provided on the column at one-foot intervals. Three-dimensional CFD analysis was conducted to compare different types of energy dissipation inlets (EDIs), center wells, and peripheral baffle shapes. User-defined expressions were added to a commercial general-purpose CFD solver software package, ANSYS CFX, to model transport of water and solids in the clarifier.

Results from diluted flocculent settling tests showed that a larger fraction of flocs settled faster than expected based on literature and previous projects with medium to low sludge volume index (SVI). On average, 90 percent of large and medium flocs settled at 5,300 gallons per day per square foot, while 70 percent of large and medium flocs were expected to settle at 3,800 gallons per day per square foot. This difference agrees with general understanding of the difference between mixed liquor with lower and higher SVI. As a result of the CFD analysis, the optimal clarifier configuration consists of a Los Angeles-EDI, a 40 foot diameter and 11 foot deep center well, and a McKinney baffle.

Is The Northwest Ready For Digital Twins? Giving Operators One System With All the Information They Need to Make Real-time Operational Decisions And Optimize The Treatment Process.

Alex Puryear, Brian Vu

Xylem; ,

European wastewater treatment plants have been leveraging digital twins in their wastewater treatment process for years. With increasing regulations in our region, optimizing the treatment plant to give operations the ability to leverage data to improve processes and increase effluent quality is now more critical than ever. Are we ready?

Flows into the treatment plant are inherently variable, both in terms of flow rate and water quality, due to wet weather, seasonal changes, and diurnal patterns. The system enables the plant to continually adapt itself to provide the optimal treatment conditions at the lowest cost for the full dynamic range of flows. The power of leveraging digital twins does not come from simply integrating and collecting data, but from the ability to provide utilities with insights derived from that data.

Deployed as a real-time decision support system, the solution creates a digital twin of the plant process to simulate the complex biological and chemical processes taking place within sewage treatment facilities and model the optimal scenarios to improve operations. This provides utilities with data-driven recommendations to optimize plant performance — without new infrastructure. By combining cutting-edge digital intelligence with the operational expertise of plant operators, utilities can ensure regulatory compliance at less cost.

Utilities integrate historical and real-time SCADA and LIMS water quality data, weather data, and other relevant data points into one centralized system. This visibility to their treatment plant provides a simple, transparent and continuously updated view of current operations.

The data is used to create a digital twin of the plant that accurately forecasts operating conditions, and an optimization algorithm recommends the optimal treatment conditions for the current wastewater flow and composition. This is a feed-forward loop rather than a feedback loop.

These powerful analytic tools, give operators one system with all the information they need to make real-time operational decisions and optimize the treatment process.

To cost effectively meet new compliance regulations, wastewater treatment plants will need to consider new approaches. This presentation will explain how digital twins can be leveraged in a treatment plant and give specific examples from over 40 wastewater treatment plants worldwide.

2:45pm - 3:00pmBreak on Exhibit Floor Tuesday Afternoon
3:00pm - 4:25pmSession 17B: Collection Systems - Stakeholders

An Update on Bend’s Citywide Septic to Sewer Program

Susanna Julber

Barney & Worth, Inc., United States of America;


In 2019, the City of Bend, Oregon implemented a citywide septic to sewer conversion program for households still reliant on septic systems. The ultimate solution, crafted through extensive community outreach – including a community advisory committee and policymaker workshops, balances the needs of septic system homeowners and sewer ratepayers. This presentation recaps lessons learned from the decision-making process and provides an implementation update.

Introduction / Overview

Many communities have homes that still use septic systems. As unsewered neighborhoods are annexed and sewer becomes available, these homes need to connect to sewers. Bend has some 2,600 households still reliant on septic systems. Most of these homes were annexed years ago after being developed in unincorporated Deschutes County neighborhoods. The largest concentration of unsewered properties is in Southeast Bend where construction of the Southeast Interceptor (SEI), a major sewage conveyance pipe, was nearing completion. This triggered mandatory sewer hookups for many homeowners who were close to the interceptor.

Before the SEI was completed, Bend City Council appointed a committee to recommend solutions for a cost-effective plan to transition these homes to sewer. The City contracted with a team of engineering, financial and public involvement experts to develop a design for the sewer, a financial strategy, and lead the outreach process. The committee’s policy and financial strategies set the framework for Bend’s successful Neighborhood Extension Program (NEP).


Through the NEP, residents in areas that are currently unsewered can apply for funding to complete sewer projects. The program is funded through citywide utility rates and allows residents to apply for sewer funds. Up to $2.5M is available annually, balancing the needs of residents and sewer ratepayers.

The NEP has been popular with unsewered neighborhoods. In 2021, 17 neighborhoods applied for over $27 million in project costs. Surrounding Central Oregon communities – Madras, Terrebonne, and Tumalo – are looking at this program as a model, as their aging and failing septic systems can pose environmental and health risks, and limit redevelopment potential.

How to Put a Pipe Through a Nature Park: Partnership and Communication

Jadene Stensland

Clean Water Services, United States of America;

In early 2021, Clean Water Services (CWS) began a two- year utility construction project to replace the 40 year old sanitary pipe which runs through the popular Tualatin Hills Nature Park, a 220-acre “crown jewel” nature and wildlife reserve. The project will also enhance the environment and wildlife habitat around Cedar Mill Creek. Ultimately, the project team created a 360-degree Virtual Reality tool to allow the public to experience changes in vegetation growth during and after construction.

As part of the design planning process, CWS partnered with Tualatin Hills Parks and Recreation District (THPRD), to understand park users’ needs and create an alignment alternatives selection process. They met with THPRD, Friends of the Parks groups and held a public open house in July 2019. The open house produced input that helped shape the project and the communication strategy.

The area surrounding the park is owned by a complex mix of public and private entities. CWS worked extensively with these stakeholders to obtain easements and ensure access and permission to operate during construction.

CWS communicated the facts of the project using a variety of tools and tactics, and an equity lens, including:

  • A comprehensive communication plan
  • Fact sheets and FAQs in Spanish and English- in the park and online
  • Park signage, using images and icons, in Spanish and English
  • Detailed bilingual construction-related trail map. Printed versions were available in the park and digital versions were online
  • A PowerPoint presentation, used for online presentations with neighborhood groups.
  • Information provided to park advisory committees and volunteers, park users, four city neighborhood advisory committees and condo associations, light rail riders, nearby businesses, county road information, environmental organizations and elected officials.
  • Use of social media channels and targeted Nextdoor outreach
  • Public information staff presence on the trail at significant times
  • Three “Coffee with the Contractor” meetings: CWS staff and construction contractor were at the nature park entrance for three hours to talk with park users, offering donuts, coffee and project information
  • Development of a 360-degree Virtual Reality tool to allow the public to experience changes in vegetation growth during and after construction
3:00pm - 4:25pmSession 18B: Facility Operations & Maintenance

Your Other Permit: Air Contaminant Discharge Permits for Water Resource Recovery Facilities

Chris Maher, Jamie Hughes, Bob Baumgartner, Patrick Orr, Tom Stow, Chad King, Kevin Wegener

Clean Water Services, United States of America; ,

NPDES permits often receive the most focus at Water Resource Recovery Facilities (WRRF), but as industrial manufacturing facilities they are also subject to Air Contaminant Discharge Permits (ACDP). Understanding these permits is equally important from a compliance perspective, and air discharge should be thought of as equal to effluent discharge as a source of pollutants to be controlled. This is increasingly relevant as we as an industry develop processes to enhance and accelerate the transfer of organic carbon to gaseous carbon through biogas production.

Clean Water Services’ (CWS) Rock Creek WRRF has operated under an ACDP issued in 2008, expired in 2013, and extended until 2020 when CWS and Oregon DEQ began working together to reissue the ACDP. Given the time passed since the original permit was issued, CWS had lost institutional knowledge in ACDP’s across regulatory, engineering, maintenance, and operations disciplines relating to emission sources and pollution control equipment.

Oregon’s regulations pertaining to air quality are extensive and complex. Engine generator classification was challenging, depending on type, age, fuel mix, operation, location, maintenance, and date of major maintenance. A major rebuild of one of two engine generators meant different classifications and compliance requirements for two identical units. Determining compliance potential required equations and conversions uncommon to wastewater operators and process engineers. Mechanical engineering and maintenance technicians dealt with engine tuning, exhaust stack source testing, equipment obsolescence, and detailed review of rebuild costs.

Added to the internal CWS team, a legal expert was retained to assist with interpreting the complex regulations and a mechanical engineer was tasked to assist with testing and calculations. The future of gas utilization at the facility involves a choice between on-site co-generation and pipeline injection of renewable natural gas. This business analysis and project timeline also had to be debated. Other sources of airborne contaminants received equal scrutiny. The distribution of work and contributions of individual specialists across the team increased everyone’s subject knowledge expertise.

In sharing this experience, the audience will understand the basic components of an ACDP, units and calculations of emissions, in-house source testing, regulation outline, and permit negotiations.

Getting More for Less: The Benefits of Process Optimization

Richard Kelly1, Lance Mason1, Adam Klein1, Jessie Hartman2, Brandon Pechin2, Laurie Pierce3

1Brown and Caldwell; 2City of Boise, ID; 3Pierce County, WA; ,

While flows and loads to wastewater treatment facilities grow steadily with population, the ability of utilities to expand the facilities is not always able to keep up with these ever-increasing demands. This can be exacerbated as new regulations, such as the nitrogen limits currently being put into effect in the Puget Sound region, further reducing capacity of facilities and adding additional strain on utilities to expand sooner than originally planned.

Though strained, many facilities have untapped capacity that could help reduce these constraints, or the ability to meet more stringent effluent limits efficiently without the need for costly capital improvements. As an example, a review of Pierce County’s Chambers Creek Wastewater Treatment Plant (WWTP) systems resulted in several process optimization improvements, which included:

  1. Aeration control. Review of system resulted in implementation of cascade dissolved oxygen (DO) control, which stabilized the DO, improved process performance and stability, and reduced power demands.
  2. Sidestream treatment. Optimized the sidestream treatment process to remove more nitrogen made main-stream biological nutrient removal (BNR) more efficient and easier to control.
  3. Chemical flocculation. Chemical addition to the mixed liquor has provided an extra layer of reliability when faced with bulking and/or pinfloc conditions. Expected expansion of the secondary clarifiers has not been necessary due to chemical addition, resulting in capital savings.

The City of Boise realized similar benefits with aeration optimization at the Lander Street WWTP, with improved energy efficiency and an increase in overall system capacity for nutrient removal gained through reductions in aeration operating setpoints.

Using examples throughout the Pacific Northwest and the US, this presentation will show the benefits gained by utilities who completed process optimizations, which have included increased system capacity, improved or expanded ability to meet stringent effluent limits, and improved overall process efficiency.

3:00pm - 4:25pmSession 19B: WateReuse

LOTT Reclaimed Water Infiltration Study - Start to Finish

Reuse Regulator Session and Q&A (WA, OR, ID, TBD)

3:00pm - 4:25pmSession 20B: Resiliency

Using Elutriation to Calculate the Particle Size Distribution in Effluent

Justen Eckhardt, Scott Mansell, Steve Thompson, Bob Baumgartner, Kenneth Williamson

Clean Water Services, United States of America;

Particle size distributions (PSD) of wastewater treatment effluents are rarely measured, but can have important water quality implications because such distributions often control the settling and dispersion of the effluent particles in the receiving waterbody. This lack of data often limits a full understanding of the fate of particles and particulate-associated constituents in receiving waterbodies.

Clean Water Services (CWS) discharges about 30 MGD of tertiary treated wastewater from its Rock Creek facility to the Tualatin River and about 4 MGD of secondary treated wastewater from its Forest Grove facility to a natural treatment system (NTS). This study was initiated to gain an improved understanding of the PSD of each of these effluents in order to predict the potential removal of the TSS and associated organic carbon in the Forest Grove effluent in the NTS, and the potential contribution of the particulate organic carbon and phosphorus within the Rock Creek effluent to sediment diagenesis in the Tualatin River. The study used an elutriation apparatus to measure the PSD of the effluents and the organic carbon and particulate phosphorus associated with each particle size. The elutriation apparatus consisted of a series of small upflow columns with sequentially increasing diameters to produce settling environments of decreasing critical settling velocities. Effluent from the two treatment plants was passed through this apparatus to collect settled particles. TSS and water quality measurements were done for each column, and mass balances was used to determine the PSD and potential particulate organic carbon and phosphorus removals as a function of particle size. These experiments showed that the discharged TSS in the Forest Grove effluent would settle nearly completely in the NTS, but that less than half of the particles in the Rock Creek effluent were expected to settle in the Tualatin River and contribute organic carbon and phosphorus to the river sediments. This information was used as supporting information related to CWS’ NPDES permit renewal and will be used for future updates to the Tualatin River TMDL for phosphorus.

The Tools to Combine Co-digestion with Existing Infrastructure to Fight Climate Change

Tim Mills1, Christian Aristizabal1, Jacob Corum2

1Brown and Caldwell; 2City of Gresham, OR; , ,

Upgrading existing municipal anaerobic digesters (AD) provides the best pathway for your agency to meet commonly accepted global climate action goals. Prioritizing methane emission reduction is seen as a highly effective means of reducing near-term global warming, which was affirmed by over one hundred countries in 2021 when they entered the "Global Methane Pledge." The agreement aims to limit methane emissions by 30% by 2030 and creates potential eligibility of funding opportunities for municipalities endeavoring to take on resource recovery.

Co-digestion has proven to be valuable on many levels, and facilities plan to receive more organic waste and continue operation into the future. New governmental incentives and industrial partnerships are on the horizon. However, co-digestion is a significant change in operations and increases demands on aging systems and plant staff. AD designed over 30 years ago require upgrades to meet the challenges of co-digestion, including capacity for increased gas production, organics receiving stations, operational changes, and safety mechanisms and protocols.

This presentation will showcase upgrades of existing AD to address common condition issues, increased gas capacity, specific features of co-digestion, organics receiving, and operational safety. Work includes addressing the relatively new ANSI biogas code (B149.6) and aspects of the digestion systems for several Oregon facilities. Data was reviewed to understand digester performance under high organic loadings and exploration of dewatering impacts. Operation and maintenance provided input during the design process to make improvements to organics receiving facilities, including addressing the uniquely corrosive organic material received and screening needs. Design features include modifying digester gas system control to nearly double capacity with existing piping and adding overflow capacity to manage risks from rapid volume expansion.

New tools can be designed along with rehabilitation to modernize AD. The right tools simplify the adoption of new ways to operate, gaining support at all-levels for the important cause of fighting climate change

3:00pm - 4:25pmSession 21B: Constructions & Alt Delivery

Navigating Supply Chain Disruptions and Inflation with Estimating and Scheduling

Bob Griesinger


Public agencies are facing market volatility caused by supply chain disruptions and accelerating inflation. This presentation will cover how Murraysmith effectively navigates this volatility to bring best-value solutions to projects and municipalities.

By leveraging relationships with major equipment and building material manufacturers, our firm gains insight into the major supply chains feeding into the construction market, which is the foundation of our strategic supply chain monitoring process. Since the outbreak of COVID-19, we have been collaborating with partners to closely monitor construction supply chain disruptions and impacts on market prices for materials and equipment.

The sources and references utilized are AGC of America, American Institute of Architects (AIA), Bloomberg Markets, Department of Commerce, Engineering News-Record (ENR), Kitco (metals products retailer), Portland Cement Association, Producer Price Index (PPI), World Steel, US Pipe, Skanska, Mortenson, U.S. Bureau of Economic Analysis, U.S. Bureau of Labor and Statistics, and more. Some of the trends we closely monitor are lead times, material and labor cost, logistics, transportation impacts, bid results, and current construction market conditions.

This data is used to update project cost models utilizing software tools by HCSS, such as Heavy Bid and Preconstruction Services. Allowing us to download direct cost information into Microsoft Project and Primavera P6, these two tools enable us to provide accurate costs information tied directly to scheduled delivery dates. By integrating this data into our strategy, can provide more complete and accurate estimates to our municipal partners for all disciplines and project stages.

Equipped with the information resulting from this process, our municipal partners have been able to pre-order long lead items, allowing them to save on increased costs, avoid project delays, stage projects to take advantage of cash flow projections, accelerate the bidding process (on some projects) to take advantage of contractor availability, and postpone projects that no longer make financial sense.

This presentation outlines how public agencies and consultants can navigate the challenge of developing reliable cost estimates during these unprecedented current market conditions to minimize risk, increase efficiency, keep pace with project timelines, and stay on budget.

Carmel Area Wastewater District WWTP Rehabilitation and Replacement Projects

Ron Walz, David Kennedy, Nick Lazarakis

Kennedy Jenks, United States of America; , ,

The Carmel Area Wastewater District (CAWD) and its predecessor, the Carmel Sanitary District, have worked with Kennedy Jenks for almost a century to deliver design and construction support for the 10 MGD WWTP facility. In addition to protecting the environmentally important water environment in the Carmel California area, recycled water from CAWD WWTP is used by the iconic Pebble Beach Golf Course located nearby.

Ten years ago, CAWD looked forward to the next era of successful operations and requested Kennedy Jenks perform a WWTP facility-wide condition assessment and asset management update. This exercise identified rehabilitation opportunities and new improvements to the WWTP that were supported and funded in the subsequent Capital Improvements Plan (CIP). The CIP outlined a 15-year plan that is being accomplished in only 10 years using a two phased approach which bundles the smaller projects.

The $14M Phase 1 project completed construction in 2018 and incorporated energy management planning into the design and construction of the following replacement and new improvements.

  • DAFT mechanical components
  • Aeration blower
  • Stormwater pump station and forcemain
  • RAS and WAS pumps and piping
  • Dewatering screwpress
  • 1-water pump station
  • 3-water strainers and bypass
  • Anaerobic digester and associated control building
  • Sodium hypochlorite and sodium bisulfite storage and feed facility
  • Overhaul of main and standby power system, including a new switchgear

The $8M Phase 2 project is completing construction and included design and construction of the following replacement and new improvements.

  • Four influent pumps
  • Two automatic bar screens
  • Grit washing unit
  • Grit tank collector mechanism
  • Modifications to reduce grit buildup in channels
  • 3W system pressure controls and new pump VFDs
  • Sludge holding tank and associated mixing system
  • Four MCCs

The presentation will include an overview of both Phases with a specific focus on innovative permanent improvements, temporary systems, and construction sequencing to keep the WWTP operational during construction.

3:00pm - 4:25pmSession 22B: Utility & Asset Management

Programmatic Delivery of Pipe Replacement to Minimize Risk for Least Cost

Amy Carlson1, Shelby Smith2, Debbie Harris3

1Jacobs; 2Brown and Caldwell; 3City of Bellevue Utilities;

The City of Bellevue Utilities Department faced a backlog of over 1,000 storm and sewer pipe assets with significant structural defects in 2020.  As the City worked to develop long-term asset management tools to prioritize these repairs and replacements based on probability and consequence of failure, they also wanted to address the near-term, ever-growing backlog and capitalize on strong contractor interest and competitive bidding due to the COVID-19 pandemic.  Rather than wait until the asset management tools were ready and suffer market cost increases, the City initiated an annual program and entrusted Jacobs with prioritizing and developing designs for eighty (80) of those backlog assets.  Jacobs tapped their experience and tools to perform a rapid prioritization of the backlog of pipe assets, quickly recommending assets for inclusion in the City’s 2020 Pipe Defect Repair Project and efficiently developing fix methods understanding the pros and cons of trenchless vs. conventional technologies.  Once assets were identified for inclusion in the 2020 project, Jacobs and team streamlined design preparation and submitted a 60% design a month after assets were determined. Similarly, the permitting process was made more efficient by bundling individual pipe assets into fewer individual City permits.  The Jacobs team ensured that the City would get the best price for the work by setting up the bid packages to be attractive to bidders, using straightforward language and splitting the repairs into two bid packages:  trenchless vs. dig and repair.  The bids for both of the bid packages came back at less than the engineer’s estimate. As construction of the 2020 pipe defect repair project was nearing completion in Q3 of 2021, the City asked Jacobs to proceed with the 2021/2022 Pipe Defect Repair projects, this time including nearly 200 individual pipe assets.  This presentation will describe the delivery process, how inflation and anticipated market conditions informed the analysis, and how lessons learned from each year are leveraged to strengthen future iterations of the program.  

Resource Constrained? A Case Study on EconH2O for Capital Program Planning

Lanelle Ezzard1, Brian Landau2

1HDR Engineering, Inc, United States of America; 2City of Bellevue, Utilities Engineering Division; ,

Utilities are investing billions to solve their most pressing problems. Faced with dire water supply problems, some utilities envision becoming leaders in recycled water. Others faced with significant water loss and impacts to the utility’s revenue stream are charging ahead to become leaders in smart water. Considering the level of financial resources input to realize these benefits Utilities are required to ask, “Even if we encumber the necessary cash and/or can secure alternative funding, can we deliver a $xxx million or more annual CIP?” Furthermore, “What level of staffing is required to deliver a CIP of this size?”

Like most local government agencies, the City of Bellevue, Washington, is responsible for a wide variety of infrastructure assets, including water, sewer, and stormwater. Bellevue has developed a streamlined CIP budget planning process, a proactive asset renewal program, and initiates ongoing system assessments to continue to deliver quality service to customers. For Bellevue, development of a balanced CIP and meeting CIP accomplishment metrics is driven by an overriding factor: employee resources. Understanding and right-sizing employee resource requirements provides a basis to develop and prioritize capital improvement projects and potential programmatic mitigations.

To address full time employee (FTE) resource constraints, Bellevue is applying a HDR tool, EconH2OTM that incorporates established concepts for capital improvement capable of optimizing not only on financial and affordability conditions, but also on FTE resource constraints. The goals of adapting the tool for Bellevue’s CIP budget planning purposes are to fit the staffing needs of an implementable CIP, improve CIP accomplishment, reduce utility system and level of service risks, and comply with the fiscal limitations and obligations of the City.

Using a project completed in 2021 as a case study, we will discuss EconH2OTM development, identification of constraints, and determination of a prioritized CIP project list and associated resources requirements. The City of Bellevue, Utilities and HDR initiated the project for a customized capital planning prioritization tool for its 10-year planning horizon across water, sewer, and stormwater. HDR’s EconH2OTM is a decision support tool for planning prioritization, that can facilitate the entire CIP planning process.

3:00pm - 4:25pmSession 23B: Treatment - Energy

Hydrogen Fuel From Biogas – Future or Not?

Vanessa Borkowski, Pooja Sinha, Nicole Stephens, Dian Zhang, Dru Whitlock

Stantec, United States of America; ,

Hydrogen can be derived from Water Resource Recovery Facilities (WRRFs) through methane source. Hydrogen is a clean transportation fuel, identified as a Zero Emission Vehicle along with electric vehicles. Indeed, production of hydrogen fuel is currently being incentivized in California as recognized in the Assembly Bill 32 (AB32), since it offers the potential to reduce greenhouse gas emissions compared to other conventional fuel technologies.

Biogas which mainly consists of methane and carbon dioxide is being produced at WRRFs during anaerobic digestion process. Technologies such as Steam-Methane Reforming (SMR), converts biogas to produce hydrogen. SMR is one approach that can be implemented at WRRFs to recover hydrogen, represented by the following reaction:

Steam-Methane Reforming Reaction

CH4 + H2O (+ heat) à CO + 3H2

WWRFs are capable of producing methane on a consistent basis due to the constant influent wastewater flows. This potential hydrogen fuel supply from the methane is complemented by the global pledges to achieve net zero carbon emissions by 2050 through the Conference of Parties and Paris Agreement and State of California mandate to achieve the same by 2045. These commitments and current incentives are laying the foundation for clean energy production such as SMR for hydrogen fuel cells to become the resource of the future. The transportation industry has mainly benefited from hydrogen fuel as an alternative resource to conventional fuels. The State of California is aggressively accelerating towards building hydrogen fueling stations with the goal to achieve carbon neutrality. The new Las Vegas hydrogen production plant is being constructed to support demand in California, where the raw material of this plant is about 50% biogas.

This presentation evaluates the current landscape of WRRF-derived hydrogen for transportation fuel in terms of available incentive pathways, policies, and economic feasibility; identifying obstacles that would need to be overcome for hydrogen to become a more competitive fuel source; future developments required in this area; and evaluates how WWRFs can effectively produce valuable clean

Net-Zero WRRF Goes Carbon-Negative via Innovative Public Private Partnerships

Margaret Laub

Anaergia, United States of America;

Building upon the momentum of a public private partnership (P3) that delivered energy neutrality to Victor Valley Wastewater Reclamation Authority (VVWRA)’s Water Resource Recovery Facility (WRRF), VVWRA and Anaergia teamed to implement California’s first WRRF-based pipeline renewable natural gas (RNG) project. This initiative demonstrates the critical role WRRFs of all sizes can play to combat climate change, increase resilience, and create alternative revenue streams.

VVWRA operates a 14MGD advanced treatment facility in Victorville, CA. VVWRA sought to better utilize biogas, offset electricity costs, and achieve net-zero. To achieve these goals and mitigate risk, VVWRA partnered with Anaergia to design, build, and finance upgrades to increase digestion capacity and deploy cogeneration modules to achieve energy neutrality.

Following the project’s success, VVWRA sought to maximize co-digestion and expand on energy and infrastructure benefits realized thus far. At the increased levels of biogas achieved from Phase 2 co-digestion, analysis confirmed he highest-value beneficial use was upgrading to pipeline quality renewable natural gas (RNG) for pipeline injection. This approach has added benefit of generating carbon-negative fuel, an invaluable tool in achieving carbon-neutrality goals and mitigating climate change.

Completed in 2021, the P3 includes WRRF upgrades for expanded co-digestion (new liquids receiving, high-solids mixers in each digester) and biogas utilization facilities (biogas conditioning, RNG membrane upgrader, and utility interconnection). Ancillary upgrades (e.g., dedicated digester feed lines) were provided to support overall WRRF operations and address capital improvement needs. The project tripled VVWRA co-digestion and associated biogas production. Anaergia owns and operates the compact RNG facilities (less than one-quarter acre), so that VVWRA may continue to focus on its core mission. VVWRA continues to benefit from energy resilience and electric grid independence via cogeneration using natural gas (funded by the project). In addition, VVWRA receives new revenue streams via lease payments from Anaergia, additional tipping fees, and RNG sales revenue sharing.

Pairing existing public infrastructure with private investment provides an effective and responsible means to expand resource recovery capabilities, opening the door for ambitious and innovative initiatives. This partnership demonstrates a replicable model to expeditiously transform wastewater treatment facilities into energy-neutral or -positive resource recovery centers.

3:00pm - 4:25pmSession 24B: Treatment - Sidestream

Ultra Fast Startup and Robust Operation of North America’s First Complete Granular Sludge Deammonification System

Mudit Gangal1, Cody Schoepke2, Willie Driessen3

1Ovivo USA; 2Fond du Lac WRRF, WI; 3Paques BV;

Sidestream Nitrogen removal via deammonification has been established as an accepted and efficient method of treating high nitrogen return streams at water resource recovery facilities (WRRFs) to optimize nutrient removal at the plant with minimal operational and maintenance (O&M) inputs. Complete granular sludge deammonification systems which optimize the deammonification process further, while popular in EU and globally, have only recently been introduced to North America. This paper discusses the startup and operations over two years, of a full scale complete granular sludge deammonification system in the United States including operational data and lessons learned.

The Fond du Lac WTRRF, WI selected the Ovivo-Paques AnammoPAQ complete granular sludge deammonification system to be implemented at their facility to treat the highly concentrated nitrogen rich stream produced after centrifugation of co-digested biosolids from their temperature phased anaerobic digestion system. The system was designed to treat the centrate with an influent concentration of 1,200 mg/l Ammonia-N to reduce the same to < 200 mg/l without addition of external alkalinity. Also as part of the performance guarantee, testing had to be carried out in peak Wisconsin winter to ensure operation under worst case conditions. The system was seeded in January with granular Anammox sludge and even in the depths of winter the system was able to startup within 1 week of seeding i.e. reach 90% Ammonia-N removal (far exceeding the performance guarantee goal). The system was further operated with varying operating flow and load variations including several shock treatments, under peak winter conditions and it was seen that the system maintained consistent treatment with effluent Ammonia-N values typically less than 150 mg/l, without addition of any supplemental alkalinity.

The data from the plant thus showed the complete granular sludge deammonification system proving itself as a quick starting and robust process along with being a compact and cost effective upgrade at the Fond du Lac WTRRF. The system helped substantially reduce the Nitrogen loads going back to the head of the plant, while significantly reducing the energy and chemical costs associated with the treatment, thereby helping optimize the overall O&M costs at the facility.

4:30pm - 6:00pmExhibitors Closing Reception
6:30pm - 8:30pmDinner—Tuesday Night Awards Banquet
Date: Wednesday, 14/Sept/2022
7:00am - 8:30amBreakfast—Wednesday Breakfast
7:00am - 11:00amSpeaker Ready Room is Open
7:00am - 12:00pmRegistration Desk is Open
8:00am - 10:10amSession 25A: Leadership

Utility Leadership: What I Wish I Had Known (Panel Discussion)

Jon Skidmore1, Haley Falconer2, Neil Jenkins3

1Murraysmith; 2City of Boise; 3Eagle Sewer District; , ,

As wastewater professionals, much of our time is devoted to addressing our most technical challenges. However, our world is changing and requires utility leaders to adapt and prioritize in the face of competing challenges. Our communities are becoming increasingly expensive, often outpacing our ability to recruit talent, we face climate-related challenges, and our technical training doesn’t prepare us for these issues. Successful utility management requires us to consider a broad collection of societal factors. At PNCWA we need to recruit members of our teams – city managers, finance directors, attorneys – to better understand and address the expanding water world. Like water, we need to adapt to changes with our non-technical teammates to assure we manage appropriately based on our changing world.

This panel will engage high-level managers of wastewater utilities and public works departments in our region in a discussion about how our business is increasingly influenced by items not related to the movement and treatment of water.

This discussion will:

  1. Advance meaningful non-technical discussions at PNCWA. To successfully manage our utilities and serve our communities, we need to discuss things outside the traditional scope of our roles. Topics will likely include housing affordability in the Pacific Northwest, and recruitment challenges, board and community politics, the role of our utilities in climate resiliency efforts and others.
  2. Exchange ideas, stories, and experiences to help address these challenges. Panelists and attendees will provide insight on various issues that we can use in our daily professional lives and perhaps create the basis for more formal PNCWA conversations.
  3. Recruit non-technical members of our teams into the conversation. As much as we like to discuss centrifuges and digesters, many teammates who help us address these issues don’t need that much detail. Strategically bringing in other professionals with different perspectives will allow us to address these items holistically.

This forum is an initial attempt to broaden the conversation at PNCWA to attract instrumental members of our teams by focusing on issues that need more than the engineering expertise to address.

Leadership Lessons in Unexpected Places

Allison Hornak1, Emily O'Morrow2

1HDR, United States of America; 2Brown and Caldwell, United States of America; ,

Engineers habitually talk about the technical innovations needed to complete our work, but often the equal hurdle is the capacity of the people charged with the work. Before COVID, the “grey-tsunami” flooded our industry, and now with “the great resignation,” work force gaps continue to be a problem at all levels of our organizations. However, these gaps also provide opportunities for emerging leaders within our industry. The question becomes, “How can young leaders develop the skills they need to prepare for new roles?” We have personally found that the biggest growth often comes from unexpected places: such as mentors outside our organizations, engaging in professional organizations, and from pursuing unique project opportunities.

Mentorship often leads to professional development inside an organization- a senior leader takes a junior engineer under their wing and help them grow. External mentorship can have equally beneficial outcomes. In 2019 we formed a mentor circle who get together for coffee once a month. This mentor circle is made up of an unexpected quartet: three consultants and one client; two rising professional women, two mid-level men; all with different technical focuses— committed to each other’s growth. We meet over coffee and bring our challenges and successes to share with the group. We’ve all gained additional conflict management and team building skills, learned to give candid and honest feedback, share our perspective (often differing) in a respectful way, and always find something to laugh about. Our lesson learned: take the risk to set up something that seems “awkward” and show up with your honest self to get the biggest return on investment.

In 2019, Haley Falconer asked us to join her in planning PNCWA 2020. We were empowered to set vision and were the responsible charges for all decisions. We were supported by a team of advisors and peers who challenged our ideas, safeguarded our decisions, and provided the opportunity and space to lead. Together we delivered a successful conference in Boise despite a global pandemic. Our lesson learned: Any experience, with trusting foundations built on shared outcomes and values can provide unexpected leadership opportunities.

Leadership Panel: Evolving Leadership in an Evolving World

Amy Dammarell1, Lara Kammereck2

1HDR, United States of America; 2Carollo Engineers, United States of America; ,

Over the past 2 years, the traditional work style has been interrupted with many organizations navigating in-person, virtual, and/or hybrid work arrangements. This panel will include discussion topics around change management, organizational and personal leadership. Specific topics will include the eveolving role of leaders; and mentoring, knowledge transfer, and building teams in a virtual or mixed environment.

A panel of up to 4 pairs of mentors/mentees (total of 8 individuals) will be developed with Conference Committee and Leadership Committee. This will include individuals just joining the workforce in the last 2 years along with those with longer tenure that are adjusting to this recent disruption.

Anticipate the panel will include diverse gender and age leaders at both private and public agencies from Washington, Oregon and Idaho.

8:00am - 10:10amSession 26A: Collection Systems

Breathing life into Retired Infrastructure for Wet Weather Storage

Steven Drangsholt, Casey Gish

Brown and Caldwell, United States of America; ,

In a continual effort to enhance the water quality of Puget Sound, the City of Everett (City) is working to reduce unplanned combined sewer overflows (CSOs) at four outfall locations along the shores of the Possession Sound. In 2012, the City acquired the decommissioned Kimberly-Clark pulp and paper mill wastewater treatment plant (KCWWTP) with the goal to retrofit the plant into a wet weather storage facility. Through site condition assessment, alternative design concept development, and creative thinking, the City and Brown and Caldwell (BC) developed a planning level design for reviving the KCWWTP into the Port Gardner Storage Facility (PGSF).

Following a site condition assessment, climate change resiliency evaluation, and alternatives analysis, planning level design of the future facility began. The condition assessment included a plant wide drone inspection and visual review of existing plant assets. The climate change resiliency evaluation considered how sea level rise may impact the site and capacity of the facilities’ existing deep water outfall. Using the findings of the condition assessment, BC collaborated with the City to develop four alternative site configurations to retrofit the KCWWTP infrastructure. Input from City engineering staff, utility leadership, and operations developed and refined the alternatives, culminating in a planning level design for converting the KCWWTP into a wet weather storage facility.

This planning level design of the future facility includes screens and grit separation for combined sewer solids removal, a retrofit of the existing aeration basin and secondary clarifiers into combined sewer storage, building an onsite stormwater equalization and treatment system, and constructing a new effluent pump station. This presentation will demonstrate how the City of Everett used creative problem solving to repurpose defunct infrastructure to meet current and future needs to protect the waters of the Puget Sound. This talk demonstrates how collaboration and incorporating perspectives from multiple stakeholders is critical to meeting the City’s current and future needs.

City of Bellevue Pipe Defect Evaluation and Trenchless Repairs

Craig Christensen

David Evans and Associates, Inc., United States of America;

Over the past two years, the City of Bellevue Utilities Department (City) has requested the assistance of the Jacobs Engineering Group (Jacobs) and David Evans and Associates (DEA) to address the City’s backlog of sewer and storm drain pipe (asset) defects. To address this backlog, Jacobs and DEA developed separate “dig and repair” and “trenchless” construction contract packages.

The scope of these projects is broken down into the following tasks:

  • Prioritization of assets in City’s database (Jacobs)
  • Evaluation of City-selected assets (DEA)
  • Design of repairs (trenchless - DEA and dig and repair – Jacobs)
  • Construction management of repairs (trenchless - DEA and dig and repair – Jacobs)

This presentation will focus on evaluation and trenchless repairs.

After the City identifies the assets to be included in the project, DEA was tasked with leading the evaluation phase. The first and most important evaluation step was to setup a large master spreadsheet and file folders to track all information for each asset. The second step was to review each asset’s closed circuit television (CCTV) video inspection from the City’s records. These reviews were done prior to looking at any of the City’s review comments or design recommendations so that a fresh perspective could be had. While watching each CCTV, first the asset location, diameter, material, and length were noted and then very detailed notes were taken on the type and location of any pipe defects. If additional CCTV was needed, that was requested from the City.

Either at a later date or concurrently to the CCTV review, a site visit was completed for each asset that included a topographic survey, structure measurements, and photos. All of the evaluation information was then used to determine if a trenchless repair or dig and repair was the most suitable approach.

For design of the asset’s defects using trenchless repairs, the evaluation information was then used to determine which method of repair(s) were recommended: cured-in-place pipe (CIPP) full length liner, CIPP spot repair liner, CIPP tee/lateral liner, or pipebursting. Once a method was selected, construction plans and specifications were prepared for City review and approval.

Teamwork Overcomes Challenging Site Conditions in Major Utility Replacement

Jeff Moss1, Marcus Byers2

1Murraysmith; 2Kleinfelder; ,

The City of Renton Downtown Utility Improvements Project included replacing City-owned water, wastewater, and stormwater utilities in preparation for major redevelopment and revitalization of the more than 100-year-old downtown area. Challenging factors required the project team to collaborate and adapt to deliver a successful project, including pipe inverts in excess of 20 feet deep; a tie-in to the King County Eastside Interceptor in excess of 30 feet deep; highly variable soil conditions; shallow ground water; areas of contaminated soil and groundwater; extensive existing and legacy utilities; and maintaining access to residences and businesses located along busy streets. The project included over 8,000 linear feet of 8- to 24-inch diameter sewer main and appurtenances, as well as the design of approximately 6,100 linear feet of storm drain, and over 3,300 linear feet of 12-inch diameter water main and appurtenances. Close collaboration between the City, design consultants, construction management team, and the contractor allowed adaptation to varying site conditions and led to successful completion of the complex and high-risk project ahead of schedule and under budget.

This presentation will focus on aspects of the project that presented significant risk to the City in the form of high bid costs, high change order likelihood, or damage to adjacent properties. Mitigation strategies considered for each will be presented, along with how they were ultimately addressed in the Plans and Specifications. Lessons learned will be shared on topics including construction dewatering; excavation, shoring, backfill, and asphalt patching; protection of and damage to existing utilities; traffic control and phasing; and subcontractor qualification for specialty construction. Participants will become better equipped to address similar risks on their projects.

8:00am - 10:10amSession 27A: Construction & Alt Delivery

Supply Chain Market Outlook and Risk Mitigation Strategies

Michael Fuss

Stantec, United States of America;

The global pandemic has produced unprecedented, once in a generation supply chain and market upheaval. The reality is we have experienced unrivaled short term increases in costs, difficulties in obtaining supplies, and limited supply alternatives. We will attempt to shed light on the significant cost and market impacts we have all experienced, the current trends, and share strategies to mitigate risk and market impacts going forward. We will present national and regional market trends focused on the water/wastewater industry, and expound on several price, delivery, and cost risk mitigation strategies from an engineering and vendor perspective. We are optimistic about the future and the market returning to something like near pre-pandemic standards, but it will take time and risks will continue. Market risks can be mitigated, and resources are accessible through pre-planning, pre-engineering, advance purchasing, effective contingency planning, engaging your market advisors and considering alternative delivery. Our seas have been rough but understanding the trends and options available for your projects will keep you afloat and help you find calmer seas.

Staying Ahead of Traffic – Fast-Tracking a Sewer Design in Advance of Highway Expansion

Hunter Bennett-Daggett1, Wade Denny2, Gordon Munro1

1Tetra Tech, Inc.; 2Clean Water Services; ,

Clean Water Services’ (the District’s) Fanno Creek Interceptor is a large-diameter sanitary sewer located parallel to Highway 217 in Beaverton, Oregon. In early 2021 the District learned that an imminent Oregon Department of Transportation (ODOT) project would construct new traffic lanes over portions of the interceptor.

A vault over the interceptor was identified by ODOT as a potential concern because it was not designed for traffic loading. The vault’s original flow monitoring weir had been removed once modern flow monitors were added to the system, and it now functioned only as a manhole to receive flows from two City of Beaverton sewer lines.

Tetra Tech and District staff evaluated the vault and identified options for modifying or replacing it. The vault was in poor condition due to corrosion, impeded laminar flow, and required frequent maintenance to remove debris. Modifying the vault to sustain traffic loading was evaluated, but the selected option was to replace the vault with a new manhole and modify the connecting sewers. This would simplify the complicated pipe geometry around the vault and alleviate the past maintenance difficulties encountered by the District’s maintenance department.

The highway project was due to bid within two months of the vault evaluation, limiting the time available to design and construct the sewer modifications. District, ODOT, Beaverton, and Tetra Tech staff worked together on the design process. Initially the work was planned to be bid separately and constructed by a District-hired contractor during the course of the highway project. However, during the sewer design, input from the highway project contractor led ODOT to decide to merge the sewer modifications into the existing project as a change order.

Additional challenges included:

  • Limited project work area between existing freeway and active railroad tracks.
  • Need to bypass existing sanitary flows—up to 25,000 gallons per minute during a five-year storm.
  • High groundwater due to nearby Fanno Creek.
  • Required excavation to a depth of approximately 30 feet.
  • Nearby waters of the state.

By working collaboratively and maintaining flexibility, the team met the required schedule. It is anticipated that construction will be completed during summer 2022.

Managing Large Storm Flows in Urban Spaces

Christa Lee1, Alan Lord2, Tina Hastings3, Chris Stoll4

1City of Tacoma; 2Seattle Public Utilities; 3Jacobs Engineering; 4Kennedy Jenks; , , ,

Municipalities are upgrading existing conveyance infrastructure or installing new infrastructure to build resiliency for large storm water and combined sewer flows. Designing and constructing systems that fit within existing urban spaces takes coordination and creativity. The presentation will discuss three different projects in Seattle and Tacoma related to stormwater and CSO conveyance and specific challenges related to project delivery in urban areas. The challenges that will be addressed include permitting, inadvertent discovery, public outreach, coordination with other projects, utility coordination/relocation, tunneling, property and alternative delivery. The presentations will focus on unique approaches and different approaches to address these challenges.

8:00am - 10:10amSession 28A: Innovative Stakeholder Engagement

Strategies for Engaging Residents in Private-Side Service Line Inventories

Samantha Becker

TruePani, United States of America;

The requirement of the new LCRR to inventory both public-side and private-side service line materials presents a unique challenge to water systems that have historically focused on maintaining the publicly owned and operated distribution assets. The identification of private-side service line materials can often be costly, disruptive, and resource-intensive and could benefit from early engagement with residents and homeowners. Building robust and resident-centered communication and education campaign can help water systems more easily comply with new LCRR requirements. By increasing private stakeholder participation in identifying service lines, sampling programs, and replacing service lines, a water system can more effectively plan to meet LCRR compliance dates and reduce lead exposure in their community from the private side of the water main.

Detailed communication and outreach workflows paired with educational materials specific to LCRR are important in collaborating and establishing credibility with the owner of the private side of the water main. The learning goals:

  • Learning goal 1: LCRR recap, how water systems will have to interact with private side
  • Learning goal 2: Communications workflow and educational materials
  • Learning goal 3: Methods for private stakeholder participation/engagement in identifying service lines, sampling programs, and replacing service lines

Bringing Everyone To The Table: Engaging Large Stakeholders Groups For Basin Planning

Clara Olson1, Jen Murphy1, Mackenna Bell2, Julie Matney3

1Parametrix; 2Multnomah County Drainage District; 3Portland Bureau of Environmental Services;

Effectively engaging stakeholders is a vital aspect of watershed and basin planning work, especially when it comes to managing public and natural resources equitably. The engagement process consists of three distinct tasks: communicating goals and project updates, collecting feedback from stakeholders, and collaborating with stakeholders establish the plan’s conclusions. In this presentation, the speaker(s) will review how project teams can couple emerging engagement tools with a straightforward approach that reaches each group of stakeholders to arrive at a consensus.

The Peninsula Drainage District No. 1 (PEN1) is a 900-acre subbasin located in the Columbia River floodplain of Portland, Oregon. A culturally significant area, the PEN1 basin includes the historic Vanport City that was flooded after a railroad berm collapsed in 1948. Today, the area is managed by the Multnomah County Drainage District (District), who partners with the City of Portland (City), Metro, and the Port of Portland to maintain and operate this flood control system. Parametrix is working with the District and City to develop a drainage and water quality master plan that will identify opportunities to improve habitat, water quality, and drainage system function in PEN1.

An important objective of this project has been to conduct inclusive, accessible, and authentic stakeholder engagement. Because the PEN1 district is comprised of many property types with unique needs – like the Portland Expo Center, Portland International Raceway, Heron Lakes Golf Course, Vanport Wetlands, and other businesses – conducting inclusive stakeholder engagement was a distinct and intriguing challenge.

In this presentation, the speaker(s) will detail the multiple approaches they took to involve stakeholders as much as wanted. Tactics included a one-day site visit for the entire PEN1 basin; a virtual stakeholder survey to gauge interest, concerns, and priorities; an interactive ArcGIS web map that documented feedback and compiled survey information; an open house style stakeholder meeting; and a dynamic story map with project information and survey for the broader public. We will review these tools and present some of the results of these efforts, which helped the team effectively collaborate to develop a multifaceted and adaptable master plan.

Indigenous Community Collaboration: An Investment in Our Collective Futures

Serina Fast Horse

Kimimela Consulting LLC, United States of America;

The City of Portland, Oregon Water Bureau has begun an exciting endeavor to build collaborative relationships with local Indigenous community members. The origins of this work are based in an acknowledgment of Indigenous peoples as the original inhabitants and stewards of the lands we occupy as well as a recognition of powerful potential of Indigenous traditional ecological and cultural knowledge to help restore balance to our shared ecosystems. Kimimela Consulting, an Indigenous women owned business, has been appointed to lead the collaborative process with the goal of collectively creating a plan for the future of an empty agricultural parcel located next to the bureau’s new filtration facility. With years of experience on land-based, community-led projects, Serina from Kimimela Consulting would like to share some important lessons learned and stories of hope for the future. Engaging in this work is inherently beneficial as it uplifts the perspectives and needs of a historically marginalized community. It is work that also benefits the land and water through land tending practices and planting plans that promote ecosystem harmony and balanced relationships to nature. Additionally, this work provides opportunities for reciprocal knowledge sharing that can create lasting synergies and connections for working together for healthy lands, waters, and communities.

8:00am - 10:10amSession 29A: Resource Recovery

The Challenges and Benefits of Renewable Natural Gas Production – An Oregon Story

Mark Van Eeckhout1, Steve Barnhardt2, Luke Werner3, Benjamin Bosse3

1City of Springfield, Oregon; 2City of Eugene, Oregon; 3Kennedy Jenks Consultants; , , ,

The Metropolitan Wastewater Management Commission (MWMC) Eugene/Springfield Water Pollution Control Facility (WPCF) in Eugene, OR is a 34 MGD plant that generates 400,000 to 500,000 cubic feet per day of biogas from 4 anaerobic digesters. For over 10 years the facility has operated a combined heat and power cogeneration facility, however changing priorities and the desire to fully utilize all biogas caused the plant to investigate alternative biogas utilization strategies.

The Renewable Natural Gas (RNG) Upgrades Project (Project), commissioned in December 2021, is the first RNG facility at a Publicly Owned Treatment Works to come online in the state of Oregon. The Project now receives close to 100% of the biogas produced by the WPCF and upgrades the biogas to RNG for injection into the gas utility pipeline. The Project includes H2S and moisture removal, Pressure-Swing Adsorption (PSA) technology to scrub the Biogas to a high-BTU, natural gas quality Product Gas, and compressors to meet the gas utility’s injection criteria. A Tail Gas stream comprised of carbon dioxide and trace amounts of methane and VOCs not captured by the PSA is conveyed to a Regenerative Thermal Oxidizer for destruction. A Receipt Point Facility operated by the gas utility, Northwest Natural, was constructed at the WPCF site to take transfer of the gas while simultaneously monitoring the quality, pressure, temperature, and quantity of Product Gas. The MWMC is working with BlueSource to register and broker the sale of renewable energy credits, including federal RINs and state carbon fuel standard credits.

The Project was designed to have the capability to run continuously in response to fluctuating biogas availability, and automatically adjust operations to consistently meet Project performance requirements. Plant staff have worked in collaboration with the biogas upgrading equipment vendor Greenlane Biogas to fine-tune operation and troubleshoot issues. This presentation will highlight technology selection, challenges with equipment procurement and construction, coordination with stakeholders and lessons learned along the way.

Gassy Decisions – Idaho Falls Wastewater Biogas Beneficial Use

Dru Whitlock, Madison Bertoch, Nick Smith

Stantec, United States of America;

The City of Idaho Falls, ID has been taking steps to move forward with expansion of the renewable energy portfolio within the City. Hence, the City initiated work with its engineering team to consider the biogas generated at its wastewater treatment plant (WWTP) for either potential power generation (engine generators or microturbines) to add to the existing renewable power portfolio or through upgrading the biogas for use as a renewable natural gas (RNG) for sale and potentially leveraging available incentives. The Team first reviewed existing capacity and conditions at the WWTP biogas and solids handling system. This assessment was followed by estimating future growth, evaluating similar facilities, and providing conceptual designs for the three alternatives of engine generators, microturbines or RNG to accommodate future capacity. Finally, the Team developed capital costs, operational costs and qualitative metrics to determine the feasibility of selecting one of these options for future development. The results are in and the City is in the final adjudication process for the future of their biogas resource. This study will be of any utility looking to make use of their biogas and of particular interest to smaller utilities and the options available to them.

When you have Too Much Digester Gas – The Role of Storage and Balancing Supply and Demand

Kelly Wood1, Shawn Spargo2

1Environmental Services, City of Portland OR, United States of America; 2Kennedy Jenks, City of Portland OR, United States of America; ,

The City of Portland Bureau of Environmental Services (BES) has constructed a Renewable Natural Gas (RNG) facility to beneficially reuse surplus digester gas. BES uses the new RNG facility to deliver cleaned digester gas to NW Natural. To maximize the amount of gas generated and to keep organic waste out of landfills, BES is constructing an Organic Waste Receiving Facility (OWRF) that will accept food waste in an agreement with Metro. BES also plans to increase primary digester capacity through co-thickening of primary and secondary solids. These two changes are expected to substantially increase the amount of gas produced by the plant’s primary digesters. However, the current gas storage facility is contained in an aging facility and solids are routed through a network of four digesters that date back to the founding of the plant in 1952. The focus of this effort was to evaluate the best use of the plant’s secondary digesters and provide adequate gas storage based on operational needs, while maximizing return on investment. This presentation will encompass the alternatives analysis process that resolved conflicting viewpoints on future digester gas and solids storage, addressed asset management considerations, and accounted for financial constraints through a net present value comparison.

8:00am - 10:10amSession 30A: Planning

Bellevue Watershed Management Plan Development

Amy Carlson1, John Lenth2, Jerry Shuster3

1Jacobs; 2Herrera; 3City of Bellevue Utilities; ,

The City of Bellevue is committed to improving and protecting the aquatic health of water bodies within its boundaries while supporting a vibrant and climate-resilient community. Urban development in Bellevue over the past 100 years has dramatically impacted the health of the streams within the City, resulting in widespread disruption in the ecological function of the City’s streams. To initiate its watershed planning efforts, Bellevue conducted a watershed assessment through which limiting factors were identified. Building on the watershed assessment, the Watershed Management Plan (WMP) directs investments to high-priority watersheds providing measurable environmental benefits to stream health within a shorter time frame than past or current approaches, maximizing the return on the City’s investment in stream health. The Jacobs team assisted the City in assigning management strategies of ‘protect’, ‘improve’, and ‘sustain’ to each of the City’s subbasins. These assigned management strategies, along with characterizations of the sensitivity to each subbasin to both climate change and to population growth/development, informed where investments in stream health will be made across the City. The WMP has an investment plan with recommended projects, policies, programs, and operational plans to meet performance goals for Bellevue’s streams. Integrating investments for watersheds with those of other City departments, including Transportation, Parks, and Community Development, maximizes overall benefit to the community and makes the most of limited public dollars. The WMP includes an adaptation strategy which identifies the investments in watershed and stream health that are necessary to adapt to a changing climate. The WMP includes a long-term strategy to protect the City’s watersheds from the impacts of the tremendous growth and re-development occurring currently in the City, leveraging partnerships with the business community and non-profits. These partnerships were identified by finding an intersection of purpose between restoring stream and watershed health and advancing economic growth and environmental conservation within the City of Bellevue. This presentation will focus on lessons learned and best practices in the City’s effort to protect and improve the condition of their water bodies through climate change and a time of unprecedented population growth and urban development in Bellevue.

A Decision Model for Resilient Communities: Flood Risk, Ecosystem Services, and Property Values

Doug McClintic

StormSensor, United States of America;

In the age of climate change, most communities are making plans towards resiliency. As these plans are developed, it is important to consider the tradeoffs needed to preserve the community while still allowing for growth.

We often hear about changing property values and the positive economic growth that new development—and redevelopment—can bring to a community. However, the goods and services that natural ecosystems provide, such as timber production, clean water, flood protection, and biodiversity support, are often left out of this conversation.

The services provided by untouched ecosystems often compete with property values and expanding development. Ignoring ecosystem services when making planning decisions could lead to the potential loss of important tools that could be used for climate mitigation and adaptation, making the goal of resilience even harder for a community to achieve. On the flip side, creating and restoring natural systems can help provide a first line of defense against flooding impacts.

To effectively plan for resilience, communities need to be able to visualize the value of the services their ecosystems provide in context with both appraised property values and the risks posed by climate change.

This session will explore by way of a case study how incorporating ecosystem services into the planning process could assist communities in making wiser management decisions optimizing existing natural systems to mitigate the risks posed by climate change. The results of these efforts may also inspire communities to restore ecosystems, such as coastal wetlands, to further mitigate climate risk.

Water Resource Recovery Facilities….It Isn’t Simply Wastewater Treatment and Disposal Anymore

James Clark

Black & Veatch, United States of America;

This presentation will look at water scarcity including pressure from population growth and distribution; provide statistics about how much usable water there is available and how it is being used; discuss the importance of reusing water to the maximum extent possible, and beneficially recovering and using other resources from wastewater including nitrogen, phosphorous, energy, and organic biosolids. Examples of how and where this is being done will be presented. Roadblocks to potable reuse, such as compounds of emerging concern and negative public perception will also be explored.

8:00am - 10:10amSession 31A: Treatment - 101

Coagulant/Polymer 101: Fundamentals of Sedimentation and Dewatering

Yong Kim

UGSI Solutions, Inc., United States of America;

Since the chemistry of coagulant and flocculant is different, the mechanism of coagulation and flocculation is fundamentally different. Various topics regarding coagulation and flocculation are discussed from the perspective of engineers and operators. It includes basic polymer chemistry, effects of dilution water and mixing profile, methods of achieving efficient polymer solution, and case studies of emulsion and dry polymer application.

Characteristics of polymer are discussed regarding physical form, molecular weight, charge density, and size distribution. Proper way of handling and storage of high molecular weight polymer is reviewed as well as the shelf-life of neat polymer and diluted polymer solution. Considering the increasing trend of utilizing reclaimed water for polymer mixing at wastewater treatment plants, the effect of dilution water on the quality of polymer solution must be checked. It includes chlorine level, hardness, temperature, pH, suspended solids, turbidity and TDS. Aging of polymer solution is seriously affected when reclaimed water is used for polymer mixing.

The concept of two-stage mixing and sufficient residence time in emulsion polymer activation is justified with theoretical study and lab data. Its benefit is clearly illustrated by pilot testing at F. Wayne Hill WRC of Gwinnett County, GA, which was performed by Jacobs Engineering. Different polymer mixing systems from three manufacturers were evaluated by monitoring polymer dose required, polymer solution concentration, cake solids, and TSS level of centrate. The results from pilot study demonstrated that an optimally designed two-stage mixing system was able to reduce polymer consumption by 25%, while produce better quality centrate.

Activation of dry polymer must follow the same principal, two-stage mixing and sufficient residence time. Since much longer mixing time is required for dry polymer than emulsion polymer, it is critical to provide uniform and low energy mixing in the mix tank. Non-uniform mixing energy will cause considerable amount of polymer chains to be broken. Dry polymer system developed based on this principle was installed at the Fairfield-Suisun Sewer District in northern California. The plant realized 42% polymer savings after one year operation of new dry polymer system and the increase of sludge throughput by 18%.

It Doesn’t Have to Stink: Wastewater Odor Control 101

Ian Watson

USP Technologies, United States of America;

When problems of wastewater odor arise, there are numerous solutions available to the wastewater utility, and yet determining which solution will provide best outcome is often extremely difficult. Appropriate for wastewater collections and treatment professionals of all levels, Odor Control 101 will examine the basic concepts of odor generation and emission, and what to do when odors become a problem. This presentation will additionally cover use cases and limitations of the majority of available aqueous and vapor phase control solutions, with the goal of empowering the treatment professional to select the best odor control solutions for their facility.

High Solids Digestion for Resource Recovery, Energy Resiliency and Revenue

Margaret Laub

Anaergia, United States of America;

Anaergia’s Omnivore high-solids digestion (HSD) AD platform triples capacity of existing digesters to maximize existing WRRF infrastructure. Anaergia’s sludge screw thickener recuperatively thickens digestate to decouple SRT from HRT, allowing digesters to operate at significantly higher solids content at similar SRT and greatly reduced HRT. Excess water separated from digestate is returned to headworks for treatment and/or nutrient recovery, while thickened solids (~12% TS) return to digesters. This allows operations at up to three-times solids concentration (6-8% TS) and organic loading rates up to 0.33 lb-VS/ft3/day. By decoupling SRT from HRT, Omnivore provides SRT well over 15-day regulatory requirements. With additional AD capacity, WRRFs can rapidly accommodate increased sludge loads, external high strength waste (HSW) for co-digestion, and improve resiliency.

South San Francisco-San Bruno Water Quality Control Plant (WQCP) capital improvement planning identified a need for additional AD capacity and initially prescribed construction of a new AD facility. Design by Carollo Engineers incorporated Omnivore digester retrofits to cost-effectively provide necessary capacity and avoid the need to build an additional digester. The retrofit also increases redundancy, improves digester performance, and provides flexibility for future co-digestion of HSW and increased biogas production. In late 2020, construction was completed to retrofit Digester 1 (0.83 MG) with one skid-mounted SST for recuperative thickening, three high-solids submersible PSM digester mixers, three mixer service boxes, and all ancillary equipment.

HSD system performance was validated through third-party performance tests. The WQCP realized these benefits:

  • Avoid major capital expenditure of additional digester
  • Address capital improvement needs
  • Redundant digester capacity
  • Reliable stabilized biosolids production
  • Improve digester and mixing performance
  • High-efficiency mixers with lowest lifecycle cost
  • Future-proofing for load growth and feedstock changes
  • Enable HSW co-digestion
  • Support increased biogas production for revenue and energy neutrality

Approach may be replicated to cost-effectively improve biosolids management while enabling municipalities to leverage existing infrastructure for resource recovery.

Session will discuss considerations, advantages, and applications of HSD at WRRFs. It will detail third-party acceptance testing data demonstrating successful operation of Omnivore, and achievement of new standards in high-performance mixing. Discussion will include agreement between in-field performance testing and modeled WQCP mixer performance, and implications.

8:00am - 10:10amSession 32A: Treatment

New Grit Management System Makes Immediate Improvements

Patrick Herrick1, Rick Murray2

1Hydro International, United States of America; 2City of Meridian Public Works Department/Wastewater;

First North American Installation of an Adaptive Clarifier Inlet

Mario Benisch

HDR, United States of America;

An Alternative to the SRT for Sequencing Batch Reactor Design and Operation

Nicholas Guho1,2

1Carollo Engineers, United States of America; 2University of Idaho, Moscow, ID, United States of America;

9:00am - 10:30amPNCWA Past Presidents Breakfast
10:10am - 10:30amWednesday Morning Break
10:30am - 11:55amSession 25B: Resource Recovery

Case Study: Improving Plant Performance by Eliminating Sidestream Phosphorus Loads

Nathan Brown1, Nicole Stephens1, Dan Freedman2

1Stantec Consulting Services - Denver, Colorado; 2Metro Water Recovery - Denver, Colorado;

Increasingly stringent nutrient limits have driven the development of various biological phosphorous removal (BPR) alternatives. While the resulting impacts to receiving streams are positive, unintended consequences have been realized at facilities operating in BPR modes. Anaerobic digestion of biological solids from BPR processes and the recycle of dewatering sidestreams to the main plant have been associated with detrimental impacts to BPR performance, increased nuisance struvite formation, and deterioration of digested sludge dewatering performance. These challenges, along with the industry trend toward a circular economy, prompted the development of phosphorus recovery technologies that break phosphorus recycles and generate marketable fertilizer products. This presentation will highlight a case study where implementation of BPR drove the comprehensive evaluation and complex construction of the world's largest pre-dewatering phosphorus sequestration and recovery system.

As part of the Metro Water Recovery (Metro) Phosphorus Initiative, a Nuisance Struvite and Dewaterability Improvements Project was implemented to evaluate technologies that address detrimental operations and maintenance consequences associated with BPR. The District evaluated pre- and post-dewatering recovery alternatives using process and thermodynamic modelling, pilot studies, comparable case studies, and a sustainable business case evaluation. The evaluation resulted in the selection and implementation of the MagPrex™ pre-dewatering phosphorus sequestration and recovery system manufactured by CNP.

The MagPrex™ reactor, commissioned in 2020, has successfully eliminated the biosolids train’s phosphorus recycle at the 220 mgd Robert W. Hite Treatment Facility (RWHTF) thus allowing the secondary BPR process to achieve lower effluent total phosphorus water quality. Metro Water Recovery has seen a 25%+ reduction in polymer addition since the facility began operation coupled with a dramatic decrease in the formation and deposition of nuisance struvite throughout the biosolids train. Furthermore, an existing anammox process downstream of the MagPrex™ reactor has seen no negative impacts to its nitrogen removal capabilities. The project at RWHTF was awarded the Water Environment Federation (WEF) Project Excellence Award in 2021.

Sustainable Solutions: Regional Resource Recovery in Central Oregon

Christina Davenport1, Brittany Parks2

1Brown and Caldwell; 2Leeway Engineering Solutions; ,

United Nations sustainability goals include finding innovative solutions for resource recovery as an alternative to waste disposal. Communities throughout the northwest increasingly turn to resource recovery solutions to manage wastes and nutrients. Multiple hauled liquid waste streams are a growing concern for the City of Bend in Central Oregon. Currently, millions of gallons of fat, oil, and grease (FOG) waste; high strength brew waste; septic system and portable toilet wastes are applied to agricultural land. This is not a sustainable practice and does not align with City goals of reducing the carbon footprint and greenhouse gas admissions. As one of the fastest growing regions in the United States, application sites are diminishing as the volume of waste is increasing. In addition, the City of Bend is losing the opportunity to generate revenue through tipping fees and resource recovery that may reduce overall utility rates for customers. There are many stakeholders interested in finding solutions to handle this regional problem including surrounding cities, breweries, restaurants, and waste haulers. Adequate engagement and education with community, industry and City leaders is necessary to shift the perception of these “wastes” to be recognized as “resources”.

Strategic analysis of alternatives for waste management helps determine the best course of action for handling the resources in a community. The goal is to find sustainable solutions that protect public health and the environment, benefit all stakeholders, and reduce costs to ratepayers, businesses, and industry. This presentation will provide an overview of the project, including stakeholders, communications, effective collaboration, public private partnership, and possible solutions/outcomes. Identifying alternatives that will give the stakeholders options to consider for future feasibility studies and master planning activities.

10:30am - 11:55amSession 26B: Stormwater Quality

Treating Phosphorus in Stormwater—Using Current Data to Design for Success

Jeremiah Lehman


Phosphorus (P) pollution from stormwater runoff is a well-documented cause of impairment in freshwater bodies, resulting in eutrophication, algae blooms, poor water clarity, and aquatic habitat degradation. Removing P can be difficult for many treatment BMPs, especially swales and bioretention systems which contain organic components in their composition and risk exporting P at higher concentrations than the influent. Current data compiled from the International BMP Database confirms limited effectiveness in P treatment by bioretention systems, especially in the dissolved form as measured by orthophosphate (OP). This is mirrored by several studies conducted for the Washington Department of Ecology, which recently modified its bioretention media soil specification to limit P export.

Performance is better for other BMPs, including manufactured treatment devices (MTDs) which utilize some sort of filtration mechanism to reduce P concentrations in effluent. However, these mechanisms differ in their ability to actively remove dissolved P concentrations through biological processes or adsorption, versus relying on physical removal of sediment and associated particulate P to achieve a reduction in total phosphorus (TP). With regulations taking a sharper focus on dissolved species of P such as OP due to their direct impact on algal growth, there is great interest in understanding which MTD design aspects optimize soluble P removal. For this study, ten different MTDs employing varying filtration unit operations were evaluated for removal of TP and OP. These included membrane filtration, chemically active media filtration, high-rate biofiltration, and hybrid systems. Data was collected according to the Washington State Department of Ecology’s program for field evaluation of MTDs (the Technology Assessment Protocol—Ecology (TAPE)), which each of the systems completed by successfully demonstrating 50% reduction of TP concentrations. The resulting analysis demonstrates that some conditions can lead to OP removal by systems that only utilize physical filtration; however, these systems may also require frequent maintenance. Better understanding of TP and OP field testing data will assist regulators and site designers in meeting TMDLs and other P treatment goals by selecting BMPs that are appropriate to site conditions and pollutant sources.

Assessing Water Quality Improvement At The Carli Creek Regional Stormwater Project

Christopher Desiderati, Ron Wierenga

Clackamas Water Environment Services, United States of America; ,

Stormwater management is an ongoing challenge in the United States. As state and municipal agencies grapple with conflicting interests like encouraging land development, complying with permits, and charges to steward natural resources for the long-term, some agencies may turn to constructed wetlands as functional natural analogs for attenuating pollution delivered by stormwater runoff. In 2018, Clackamas Water Environment Services opened the Carli Creek Water Quality Project, a 15-acre constructed stormwater wetland adjacent to Carli Creek, a small, 3500-ft tributary of the Clackamas River in Clackamas County, OR. The combined creek and facility drain an industrialized, 438-acre, impervious catchment. The facility consists of a linear series of a detention pond and three bioretention treatment cells, contributing a combined 1.8 acres of treatment area. This study evaluated pollutant levels against International Stormwater BMP database benchmarks, Oregon Water Quality Criteria, and pollutant removal performance. Concentration and mass-based reductions were calculated for 10 pollutants and compared to daily precipitation totals from a nearby precipitation station. Mass-based reductions were generally higher for all pollutants, largely due to runoff volume reduction in the facility. Concentration-based reductions were highly variable and suggested export of certain pollutants (e.g., ammonia), even when reporting on a mass-basis. Mass load reductions for total dissolved solids, nitrate+nitrite, dissolved lead, and dissolved copper were 43.3 ± 10%, 41.9 ± 10%, 36.6 ± 13%, and 43.2 ± 16%, respectively. E. coli log-reductions ranged from -1.3 — 3.0 on the terrace, and -1.0 — 1.8 in the creek. Oregon Water Quality Criteria were consistently met at the two in-stream sites on Carli Creek for E. coli, and for dissolved cadmium, lead, zinc, and copper. The precipitation record during the study was useful for explaining certain pollutant reductions, as several mechanisms are driven by physical processes, however it was not definitive. The historic rain/snow/ice event in mid-February 2021 appeared to impact mass-based reductions for all metals. Qualitatively, precipitation seemed to correlate closest with ammonia-nitrogen export. This study is useful in establishing a framework and baseline for understanding this one-of-a-kind regional stormwater treatment project.

10:30am - 11:55amSession 27B: Treatment - Biosolids

KIS Plan for Meeting Total Phosphorous Limits and Biosolids

Ken Windram


The Washington Department of Ecology, through a TMDL, set dissolved oxygen levels in the Spokane River requiring the wastewater treatment plant's effluent Total Phosphorous to be less than 0.05 mg/l. The Hayden Area Regional Sewer Board (HARSB) choose a 2-phase approach to meeting the TMDL limits. The first Phase was to improve Biological Nutrient Removel (BNR) for Nitrogen and Total Phosphorous. Then optomize Total Phoshorous Removal (BPR) to determine the best tertiary treatment design. The Phase 2 first step was to select a design team that were experts in their field. HARSB would pre-slect and pre-purhcase project equipment to meet the design requirements. A general contractor pre-qualification process was implemented to have only experienced contractors on the project.The overall result was that HARSB staying in control of the project, getting the best equipment and the best general contractor and staying within a tight project budget and schedule.

This presentation begins with a review of the plant's BPR Operation. Then explain the operational game plan to ensure compliance with the 0.05 mg/l Total Phosphorous effluent limit. The decision was to build a "water" treatment plant to treat the wastewater secondary effluent for Total Phosphorous should the BPR process shutdown. The tertiary water treatment system would be designed by an equipment manufacture that builds water treatment plants every day. Special HDPE storage tanks and pump station would be needed for the trertiary treatment system operation. The Total Phosphorous chemical coagulant would be selected based on the final biosoloids disposal plan. Speaking of biosolids, Total Phosphorous is only removed from the treatment plant with the biosolids. Since HARSB did not have a biosolids treatment system, a new biosolids plan and equipment would be designed for long term biosolids disposal including tertiary treatment solids.

Pivoting into a Sustainable Class A Biosolids Management Program

Mark Cullington1, Kristin Preston2, Katie Spilker1

1Kennedy Jenks Consultants; 2City of Albany; ,

The Albany-Millersburg Water Reclamation Facility is an activated sludge plant that is designed to treat a dry weather flow of 12.3 million gallons per day (MGD) and a peak wet weather flow of 68 MGD. The original plant was constructed in 1952 with many upgrades over the years. In 2009, significant improvements were made including a solids reduction process that failed to perform and resulted in undigested solids being sent to the landfill. This is unsustainable from both an economic and environmental standpoint, so the City began to look into alternative solids handling options. Additionally, the City’s dewatering equipment was aging, overused, and needed to be replaced.

The City engaged with Kennedy Jenks early on in the process to complete an alternative analysis, feasibility studies, and pilot projects. The City selected composting to a Class A biosolids product as the treatment process for its undigested, dewatered solids. Kennedy Jenks led the City through the design process and assisted in construction oversight of the new biosolids facilities, which will be completed in April 2022.

Equipment changes include two new FKC rotary screw presses, a dewatered solids conveyor system, and a new polymer addition system within the existing Biosolids Dewatering Building. The Biosolids Storage Building will be enclosed and have a canister system for treating odors. Composting facilities are being constructed to process solids and ground yard waste for beneficial use as a Class A biosolids product. This includes covered piles, with in-ground aeration utilizing Engineered Compost Systems technology, a biofiltration odor control system, and covered storage for amendments and finished compost.

This presentation will outline the project details, vision, and drivers. Attendees will learn about developing a biosolids management solution, including identifying key design criteria, selecting the best solids treatment alternatives, addressing important challenges like odor control and equipment selection, and working with staff and stakeholders.

10:30am - 11:55amSession 28B: Facility Operations & Maintenance

A New Standardized On-Site Capture Efficiency (SCR) Sampling & Testing Protocol for WWTP Screens

James Impero, Abner Aviles

Ovivo USA, LLC, United States of America; ,

For approximately two decades, consulting engineers have asked screen manufacturers to provide third party, independent test results documenting the capture ratios of their screen’s debris removal efficiency. Have these results truly been reproducible at your wastewater plant?

Decades of third-party capture testing of screens in the UK have been a good thing. However, the screenings capture data proved only the “Capability” of that particular screen tested and under those specific UK flow conditions. Expecting identical capture results from the same manufacture’s screen at wastewater facilities with differing hydraulics, variable wastewater velocities, TSS & FOG loading characteristics, let alone up-front grinders is neither practical thinking or proven in the field to be true for 40%-45% of the current installation history in the US. Why? It is the very subject of this paper & conference presentation. There are definite wastewater similarities from site to site; however, there are also many dissimilarities that require screening equipment modifications to achieve the true screenings capture capability of any manufacturer’s screen. This presentation will discuss an inexpensive upstream and downstream on-site sampling method & procedure, as well as a protocol and accepted test methodology that can be performed at any municipal wastewater treatment facility or local third party laboratory to measure solids capture efficiency of any newly installed screen(s) at startup, including older screen installations that have fallen short of owner expectations.

This presentation will reveal standardized sampling hardware, process & procedure, as well as simple bench-top test method for determining the screenings capture of any headworks or membrane protection screen. A single day sampling method & protocol will be described in detail that will provide a screen’s site-specific debris capture efficiency. This standardized sampling and testing protocol can be performed by screen manufacturers, plant operators, and/or third party laboratory technicians.

When incorporated into a consulting engineer’s screen specifications it will require all bidding manufacturers to meet a desired screen capture efficiency (±X%) in the bid spec. The awarded manufacturer will be responsible for meeting the specified screenings capture.

Protecting and Preserving a Concrete Jungle

Jeff Maag1, Muriel Gueissaz-Teufel1, Randy Mueller2, Rich Forrest2, Dave Brunkow2, Al Owens3

1City of Portland, United States of America; 2Jacobs; 3ACMS NW / Stantec; , ,

With the large investments in wastewater infrastructure dating back to the inception of the Clean Water Act in the 1970’s, and a focus that has been on treatment processes, many wastewater utilities are faced with the need to extend the life of aged and deteriorated concrete tankage that is critical to its operation. After more than fifty years of service, significant degradation of the Columbia Boulevard Wastewater Treatment Plant four pairs of aeration basins is visible, exposing the steel reinforcing and making it vulnerable to corrosion. The degraded concrete has a pH less than 10.0 and no longer provides corrosion protection for the steel reinforcing. Surface rehabilitation of the concrete was selected to restore the basins and extend their service life for another projected 25 years. Since the active basins provide critical capacity during wet weather events, rehabilitation of the basins was constrained to the short, dry-weather season, driving the schedule and key decisions. The rehabilitation process included hydro demolition of the outer concrete layer combined with the application of a new layer of mortar to seal and protect the exposed aggregate and rebar followed by an epoxy finish design to protect the mortar from abrasion and chemical attack. Due to the age and inconsistent makeup of the existing concrete, hydro demolition of the outer layer of concrete was a delicate procedure that required careful monitoring to prevent uneven removal. Only concrete with a pH less than 10.0 was removed and therefore required frequent testing. Application of the mortar was labor intensive and required multiple crews to stay on schedule. After applying epoxy to the cured mortar of the first two basins, it was determined that the stringent and time-consuming testing requirements along with some uncertainty regarding the expected service life extension was not worth the cost of the epoxy layer. Epoxy for the future basins was removed from the project scope. This presentation will present the approach and lessons learned – technical and contractual, used on the aeration basins at CBWTP and provides a roadmap for accomplishing these concrete rehabilitation projects, particularly during a constrained outage window.

10:30am - 11:55amSession 29B: Collection Systems - Planning

Collection System Yoga - How Post Falls Flexibly Balanced Growth and Budget Constraints

Kyle Meschko, James Bledsoe

Keller Associates, Inc., United States of America; ,

Post Falls, situated between Spokane, Washington, and Coeur d’Alene, Idaho, is among the fastest-growing cities in the Pacific Northwest. This amount of growth puts an immense strain on existing infrastructure, and it also creates unique challenges to pay for improvements within existing budgets. Post Falls recently completed a collection system planning study and associated improvements to help the City balance these demands. Through innovative and flexible solutions, the City has been able to position itself well for immediate growth with a balanced budget approach.

Suburban growth can cause a chain reaction that overwhelms the downstream collection system. For Post Falls, a long-term solution involved a regional pump station that could bypass the downstream bottlenecks, pumping directly to the Water Reclamation Facility (WRF). However, the cost of this was not financially feasible at the time. The City needed a solution to accommodate growth as well as give the City time to fund the long-term project. Also, the solution needed to accommodate substantial expansion, such as lift station flows that would be 20 times larger in the future.

To meet the growing demands in the area, an innovative lift station facility that utilizes equalization was constructed. The lift station operates by pumping the peak flows to the equalization basin and then discharging during low flows at night when the downstream system has capacity. The lift station was sized to incorporate several phases to increase the capacity as the continued growth occurs; in addition, controls and integration were also considered to occur in phases. The equalization storage fulfills the City’s long-term goals of providing emergency storage at key lift station facilities. Ultimately, the collection system improvements provided exceptional flexibility in funding, schedule, utilization of existing infrastructure, and long-term adaptability to the ever-growing City of Post Falls.

Maximizing Return on Investment by Optimizing and Prioritizing Capital Improvements

Katie Maschmann1, Julia Matton2

1HDR; 2WCS; ,

Johnson County Wastewater (JCW) is a regional service provider for over 400,000 customers in 16 municipalities in the Kansas City Metro area. JCW’s system includes 7 wastewater treatment facilities (WWTF), 31 pump stations, and a collection system containing over 2,250 miles of pipe. As the system continues to grow and age, investments in maintenance and renewal to continue to meet JCW’s high level of service and manage risk will continue to grow. Additionally, JCW is in the process of planning and executing multiple large WWTF capital upgrade projects and wet weather capacity enhancement initiatives to address upcoming regulatory drivers from state and federal agencies. These increasing investment needs, coupled with limited resources, has driven JCW to continuously improve service delivery while continuing to execute day-to-day work functions. Taken together, these programs result in over $2 Billion in upcoming investment needs that require an effective prioritization process that balances water quality, customer service, and program execution with regulatory and rate payer expectations.

JCW has adopted optimization as a tool to prioritize investment needs in the collection system. JCW retained HDR and WCS to develop and prioritize the long-term plans for the four oldest and largest basins in the system. Using JCW’s calibrated hydraulic model and Optimatics’ Optimizer software, the team identified the optimal combination of conveyance improvements, storage facilities, treatment plant improvements, and infiltration and inflow (I/I) reduction. Following identification of required improvements, a prioritized capacity improvement plan (CIP) was developed using Optimizer coupled with sound engineering judgement including construction phasing and staging alternatives. Through this process the team prioritized projects with low cost and high utility value and phasing to gain the highest immediate benefit for every capital dollar spent.

This presentation will focus on what it takes to achieve a successful optimization implementation based on the lessons learned from four successive projects with JCW.

10:30am - 11:55amSession 30B: Climate Science

Climate Adaptation and Combined Sewer Overflow Infrastructure: State of the industry

Drew Henson1, Amina Kedir2, Anna Marburg1, Janice Johnson2, Erika Schuyler1

1Murraysmith; 2King County - Wastewater Treatment Division (WTD); , ,

Incorporating potential climate impacts into wastewater capital planning is an emerging topic that is affecting utilities across the nation. To inform its own long-term planning, King County Wastewater Treatment Division (WTD), located in Seattle, Washington, sought to understand the state of these efforts. King County provides wholesale wastewater conveyance and treatment of flows from 17 cities, 16 local sewer utilities, and one tribal government. WTD and its consultant teams interviewed peer wastewater agencies and reviewed published literature to gather information on current strategies, methods, and findings related to climate adaptation and Combined Sewer Overflow (CSO) facilities. The strategies identified through this effort will assist WTD in preparing for and adapting to climate change in its capital program.

The project team gathered information on how peer agencies are incorporating climate change impacts into their capital delivery process via a questionnaire followed by a phone interview. Key topics explored in the interviews included quantifying climate change impacts and uncertainty, CSO reduction and sizing decisions for capital planning and design work, financing and costs, and equity and social justice (ESJ) and public involvement. These discussions revealed agencies are at various stages of considering climate change impacts on their sewer systems. Many agencies are still considering their approach to incorporating climate change projections into their CSO and wastewater programs.

Three main themes emerged from the literature review: real-world effectiveness of GSI in reducing CSOs, ESJ and public involvement impacts, and decision-making under uncertainty. Some modeling studies showed potential for volume reduction to CSOs using GSI, but real-world observations had difficulty quantifying volume reductions from GSI. The literature suggested that both the distribution of CSO outfalls and the financing of system upgrades can have equity implications. Finally, the literature suggested strategies to support decision-making for infrastructure investments even with large uncertainties about future conditions.

These findings have been shared via a public report and are being used within WTD to inform the long-term planning process, as well as develop adaptation and resiliency strategies using current climate data and modeling tools. This presentation will discuss the findings of this project.

Too Hot! Thermal Modeling for NPDES Temperature Mitigation

Jen Murphy, Chloe Nichol, Brandon Moss, Jacob Stolle

Parametrix, Inc, United States of America; , ,

NPDES permit requirements related to water temperature across the United States are becoming more stringent as climate change impacts increase and the impacts of excess thermal load on environmental systems are better understood. While there are several ways of reducing the excess thermal load of municipal resource recovery facilities (RRF) on receiving water bodies, the majority of programs with large scale thermal load reductions are either reactive (i.e., implemented through permit renewals for existing facilities) or are for new industrial discharges, where the thermal load is more predictable. As such, there is a need for a more accurate way to anticipate thermal loads of proposed plants.

Parametrix was recently part of a project with uncertainty regarding the ability of a future RRF to meet long-term effluent temperature permit requirements. To remedy this, the project team and internal Parametrix developers created a thermal model to estimate RRF effluent temperatures using key thermodynamic principals, environmental data, and various system configurations. Parameters considered were based on integration of several past studies on treatment plant thermal modeling and included:

  • Heat flux from external sources including:
    • Solar and atmospheric radiation
    • Aeration
    • Conduction and convection
    • Evaporation
    • Mechanical equipment
    • Biological reactions
    • Advective and diffusive mixing
    • Humidity
    • Ambient air temperature
    • Air speed
    • Process basin configurations (e.g., FRP or concrete covers; footprints and depths; primary, recycled, and secondary process flows, etc.)

Specifically, the developed model utilizes five years of historic environmental data from the National Energy Research Laboratory climate data repository. Preliminary Biowin process model results, and SWMM collection system data predicting collection system flows over the next 20 years. The model can also be used to forecast the effects of various cooling methods such as additional shading, addition of heat exchangers, and different discharge pipeline configurations on the discharge temperatures.

It is anticipated that this type of modeling is going to increase in frequency and importance as the impacts of climate change increase. This presentation will cover the academic basis for the modeling approach, specific considerations and complications of implementation, model results and findings, approaches to mitigate excess thermal loads, and potential future developments.

10:30am - 11:55amSession 31B: Treatment - Industrial Pretreatment

Using FTIR Technology to Quantify Gas Emissions in Conveyance Systems

Justen Eckhardt, Steve Thompson, Scott Mansell, Kenneth Williamson

Clean Water Services, United States of America;

Gaseous emissions are common within both sanitary and storm sewers. These emissions can result from particular industrial discharges or from biological or chemical reactions. Many of these can be health and safety hazards which can be avoided by appropriate use of handheld gas monitoring instruments. These instruments commonly check for concentrations of oxygen, hydrogen sulfide, carbon monoxide, and other combustible or volatile organic gases.

Clean Water Services (CWS) personnel commonly use such gas monitoring instruments before opening and when working in manholes or other potentially hazardous areas as part of required safety protocols. Recently, we have experienced a number of occurrences of handheld gas monitoring instrument repeatedly detecting hazardous gases within particular portions of the conveyance system in an industrial area. This has prevented personnel from performing maintenance and other essential functions on the sewer infrastructure in this area. Facing unknown gases that triggered hazardous alarms, we initiated a comprehensive sampling and analysis study that utilized grab and continuous sampling methods and analyzed the samples off-site using standard EPA gas analysis methods. The study was unable to identify the gas(es) responsible for the alarms, but did help narrow down potential source locations.

To expand our ability to increase monitoring both spatially and temporally, we have initiated the use of Fourier Transform Infrared spectrometry (FTIR) to identify offending gases. FTIR is unique in that it can simultaneously identify multiple compounds in real time by analyzing absorbance spectra across a band of infrared wavenumbers. While most FTIR instruments are made for benchtop use, CWS purchased a portable FTIR instrument designed specifically for gas analysis in the field at low PPM to PPB detection levels. The instrument identifies gases using a spectrum library of over 350 individual gases.

In this presentation, we describe the results of our use of FTIR spectrometry to identify and quantify harmful gases within our sewer system and trace them to their source. In addition, we discuss the role of FTIR in our future efforts to monitor greenhouse gases from our facilities, aid in air quality permitting, and help to identify gases from digestion and other processes.

Aeration & Mixing in Industrial Wastewater

Brad Eberspecher

IPEX, United States of America;

Many industrial customers generate substantial volumes of high strength wastewater that can create problems when discharged to municipal wastewater collection and treatment systems. As a result, cities are recognizing the impacts to their systems and are increasingly issuing significant surcharges based on waste strength and volumes, sometimes even requiring pretreatment to lower the strength of their wastewater before discharging it.

Vortex Force™ aerators are well suited for aeration and mixing in the pretreatment of industrial wastewater before it is discharged to municipal systems. These aerators utilize unique hydraulics and the kinetic energy of flowing wastewater to efficiently add dissolved oxygen and maintain completely mixed conditions. Aeration systems that utilize Vortex Force™ aerators can help industrial wastewater producers overcome several challenges.

  • Reduction of waste strength (BOD, COD, etc.)
  • pH neutralization
  • Eliminates offensive odors
  • Solids can be kept in suspension

Vortex Force™ aerators have no moving parts, with each aerator requiring only a single pump to provide the recirculating flow. The unique hydraulics draws in air and creates intense turbulence that breaks up the incoming air stream into small bubbles that are carried downward to the bottom of the tank. The recirculating flow creates currents in the tank maintains completely mixed conditions. The flow exiting the aerator can also be directed to aid in the removal of suspended solids.

Existing installations and laboratory performance testing that has been completed to date show that Vortex Force™ oxygen transfer performance is more than adequate, while the costs of both electricity and operator labor for maintenance are a small fraction of other options.

Municipal applications also exist currently, but are currently limited to collections and conveyance applications due to a lack of adequate performance data for process aeration applications. But as the use of Vortex Force™ aeration expands, more performance data will be documented and made available, and eventually Vortex Force™ aeration will replace existing technologies in process treatment of industrial and municipal wastewater.

10:30am - 11:55amSession 32B: Social Equity

Supporting a City for Everyone with DEI and Recycled Water

Haley Falconer1, Andrea Hall2, Erin Cox2

1City of Boise, Water Renewal Services; 2Brown and Caldwell, United States of America; , ,

The City of Boise is striving to uplift the community by incorporating diversity, equity, and inclusion (DEI) into the fabric of how it operates and provides services to its residents. Boise’s motto is “creating a city for everyone,” and it takes that adage seriously as it endeavors to be a community that supports equity and access for all through thoughtful policy and intentional action. Public works in many places have inadvertently created inequality through their policies and decision-making processes. Boise is an innovative city that is embedding DEI into how public works projects are planned, prioritized, and executed in the community.

Boise has embarked on developing a Recycled Water Program to enact the concepts and outcomes set forth by the Water Renewal Utility Plan. This program will shift how Water Renewal Services (WRS) uses and manages water. It will enhance water resiliency and environmental outcomes while protecting economic development and public resources. The Recycled Water Program will combat future water shortages by recycling water within Boise’s service area through aquifer recharge and industrial reuse. Diversifying industrial water supply sources will relieve pressure on groundwater and preserve water resources. WRS plans to incorporate DEI into each element of the Recycled Water Program, developing a framework that identifies equity goals, objectives, processes, and measurable outcomes to incorporate community-centered equity considerations into each program element.

To accomplish its DEI goals, WRS will perform a community analysis profile to better understand the community, equity circumstances, and challenges to inform the Equity Framework. The team will conduct listening sessions to align city and department level equity priorities and equity levels of service. WRS will also hold workshops with city staff to develop a community-centered and outcome-based equity framework that will establish goals, procedures, and priority actions to be enacted through the Recycled Water Program. Additionally, DEI considerations will be embedded into major decisions and policies of the Program, in particular policy making, land acquisition, and workforce development.

DE&I: Where Are We? Where Can we go from Here?

Emily Flock1, Nicki Pozos2

1Keller Associates; 2The Formation Lab; ,

The Racial and Social Justice subcommittee (RSJ) surveyed PNCWA members to collect information and insight on current diversity, equity, and inclusion (DE&I) programs and practices in their organizations. This presentation will summarize and discuss organizations’ current DE&I practices based on the survey responses, establishing a general overview of where we, as PNCWA organizations, are in our DE&I journeys. The sharing of the survey results aims to facilitate knowledge and experience sharing between our member organizations, recognize that we are all in this journey together, and we can help each other strive to do and be better. Additionally, we will present potential next steps and practices organizations could explore and implement, as well as tips for how someone could go about beginning conversation and promoting change for these practices within an organization.

12:00pm - 1:00pmLunch: Workshop Participants
1:00pm - 5:00pmWorkshop 1: The Future of Facility Operations: Stories from the Front Line

In late 2021, members of the POMC identified recognition and development as two areas that can provide support to plant operations and maintenance personnel.  Recognition is intended to inform rate payers and decision makers of the import role of these positions. This includes both health, safety and environment as well as understanding the increasing complexity of the technology, regulations, and operation of water resource recovery facilities. Development focuses on technical training, certification, and retention.

The POMC is sponsoring the development and execution of this workshop to share information across organizations and garner feedback to guide this initiative.

1:00pm - 5:00pmWorkshop 2: Preparing for the energy shift - how to prime your WWTP for RNG and solve your infrastrucutre issues while you are at it!

Wastewater plants represent a large untapped source of renewable methane energy, and our best hope of diverting organics to better destination than landfills. Often, plants miss the opportunity to make the most of their biogas resources, because of limited knowledge on how to doing so may in turn solve issues with infrastructure, biosolids, labor shortages and more.

1:00pm - 5:00pmWorkshop 3: Find the Leader Within You

Discover your leadership potential! Whether you’re an aspiring leader or one who’s been there, join us for an exploration of leaders at their best. This workshop is based on the five leadership principals outlined in the book “The Leadership Challenge” by Kouzes and Posner. The workshop includes breakouts and table discussions to encourage shared learning. Participation in this workshop will help improve performance of operators, project coordinators, and/or current and aspiring supervisors and managers by helping them work effectively with peers. With a firm understanding of the five practices of exemplary leadership, participants will be valued employees, supervisors and managers, understanding what it takes to help lead truly outstanding performance.

        Learning Objectives:

        Understanding of the five practices of exemplary leadership and how anyone can be a leader right where they are.


We will follow up with a survey to gauge both how much the participants have learned as well as how much they have been able to apply the five practices.


The curriculum is highly interactive with the material presented followed by specific activities at tables of six to eight to incorporate the learning. Participants will walk away with ready-to-implement skills to become compassionate and inspiring leaders within their organization and in their community.

1:00pm - 5:00pmWorkshop 4: Hope for the Future: Using Envision to Improve Sustainability

Infrastructure is at the heart of addressing this key challenge of the 21st century, and the standards and methods of the past will not be adequate to meet the needs of the future. A new paradigm is required. 

But how do infrastructure developers know whether their decisions are contributing to sustainability or not? How do they bring attention to the need for more sustainable infrastructure? How do they communicate around a shared understanding of what sustainability means? Envision provides a consistent, consensus-based framework for assessing sustainability and resilience in infrastructure. Envision:


  • Sets the standard for what constitutes sustainable infrastructure;
  • Incentivizes higher performance goals beyond minimum requirements;
  • Gives recognition to projects that make significant contributions to sustainability; and
  • Provides a common language for collaboration and clear communication both internally and externally.


Envision is a framework that includes 64 sustainability and resilience indicators, called ‘credits’, organized around five categories: Quality of Life, Leadership, Resource Allocation, Natural World, and Climate and Resilience. These collectively address areas of human wellbeing, mobility, community development, collaboration, planning, economy, materials, energy, water, sitting, conservation, ecology, emissions, and resilience. These indicators collectively become the foundation of what constitutes sustainability in infrastructure.

1:00pm - 5:00pmWorkshop 5: Asset Management – Advancing Practices and Outcomes from Your Current State of Maturity

Objectives: the intent of this workshop will be to provide very concrete and specific ideas and examples for action by various positions or groups in the organization to advance that organization’s practices and outcomes within the broad topic of asset management. We will make this huge complex topic simple by focusing on clear vision and unpacking pain points for the participants. We will provide practical, ready-to-use ideas and practices that will make a positive difference and advance organizational outcomes.


Message to Potential Attendees: Every asset intensive organization in the water/wastewater sector is doing some asset management, but no organization is a top performer in all aspects of asset management. What this means is that everyone is at a different level of maturity and everyone has an area where they should improve. Assuming the workshop chair and vice-chair can obtain a list of attendees, a pre-workshop survey will be sent to attendees prior to the workshop in an effort to identify themes of their current needs so that we can design content (including exercises) to address those specific challenges. Each module will focus on engaging attendees to help them to identify actionable next steps they may take to advance their organization.


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