Conference Agenda

Machine learning has been transforming many fields, including water resource management, where it has the potential to revolutionize how we collect, process, and analyze data to inform decisions. However, the field of machine learning can seem intimidating and out of reach for those without programming or data science backgrounds. In this presentation, we aim to demystify machine learning and encourage broader utilization of these tools by water resource professionals.

We will provide a brief overview of machine learning concepts and applications relevant to water resource management. We will also discuss recent developments in automated machine learning tools, which make it easier for people without coding experience to apply machine learning techniques to their data.

We will showcase an example of how machine learning has been used in CWS to generate effluent temperature predictions in the first clarifier process. In addition, we will highlight publicly available machine learning resources, including software packages and online courses, that are useful resources for learning and applying these techniques within the environmental engineering field.

Finally, we will discuss the future of machine learning in the water resource and utility sectors, highlighting the potential for improved accuracy and efficiency in decision-making, cost savings, and increased resilience to climate change and other stressors.

By the end of this presentation, attendees will have a better understanding of what machine learning is, its potential benefits for water resource management, and how they can start learning and applying these techniques to their own data.

High bacterial levels in ambient surface waters or stormwater can be a vexing problem to solve, as the traditional fecal indicators (typically E. coli or Enterococcus) give no indication of their source. Accordingly, many agencies have turned to PCR-based methods to determine the source of fecal pollution in various water matrices, a technique known as microbial source tracking (MST). The Sketa assay has been used in both research and regulatory contexts to quantify nucleic acid extraction recovery and/or environmental matrix inhibition in quantitative PCR water quality studies. The field of MST is moving to digital PCR, in which the variability from sample concentration and nucleic acid extraction exceeds the variability introduced from inhibition. Thus, a total workflow process control with an appropriate surrogate target is a more suitable approach to data quality assurance for digital PCR. Here we present a duplex Surrogate Process Control (SPC) assay for droplet digital PCR using a commercial spike-in whole-cell product at a cost of pennies per sample. This SPC measures the recovery of both gram-positive and gram-negative bacteria, which is important in contexts where both are measured for MST, e.g. Bacteroides and Enterococcus. This SPC was optimized, validated, then compared to the Sketa assay in seawater (n=5), freshwater (n=5), stormwater (n=5) and municipal wastewater influent (n=5) on the basis of percent recovery and percent inhibition. Sketa recovery (when added at the extraction step) ranged from 71- 139 percent for all samples. While inhibition was low (0% samples inhibited), the total SPC recovery varied greatly depending on environmental matrix. Average gram-positive percent recoveries were 22, 12, 9, and 1.6 for freshwater, marine beaches, stormwater, and wastewater, respectively. Average gram-negative percent recoveries were 11, 7, 4.4, and 0.4 for freshwater, marine beaches, stormwater, and wastewater, respectively. Measuring inhibition alone failed to identify samples that lost greater than one-log of material through sample concentration, especially in more challenging environmental matrices. Overall, this SPC is a robust and streamlined approach to quality control for digital PCR MST assays.

Increased dewatered cake solids will save approximately $1 million per year in biosolids hauling costs at the Columbia Boulevard Wastewater Treatment Plant (CBWTP). By 2045, CBWTP will thicken up to 724,000 pounds and dewater 260,000 pounds every day. The existing solids handling facility was built in 1970 on a foundation of wood piles, and the aging equipment was in need of replacement. The project presented an opportunity to upgrade primary sludge thickening in addition to WAS thickening to improve digestion performance.

Alternatives to rehabilitate the existing solids processing building were evaluated and due to desire for increased seismic resiliency and operation during construction, the decision was made to build a new solids treatment facility. There are site constraints at the CBWTP, ideally the new solids facility would be located near the existing facility, which is boxed in on multiple sides with existing infrastructure. This led to design of a unique multi-story triangular shaped solids handling facility, with a bridge across an existing channel and additional supports on the other side to allow trucks to pass underneath.

The co-thickening system design includes eight 3-meter-wide gravity belt thickeners, blend tanks, feed pumps, thickened sludge storage tanks and pumps, polymer facilities, and cameras for monitoring. The dewatering system design includes five 29-inch-diameter dewatering centrifuges, feed pumps, polymer facilities and conveyors to hoppers and the loadout facility. Operations and maintenance (O&M) staff were engaged at all stages of design to provide input on access and O&M needs. This led to multiple monorails, bridge cranes, and an elevator to allow for access to all of the equipment that is located on various floors of the new facility. The new biosolids storage and loadout facility provides redundancy and allows automated biosolids hauling 24-hours per day through monitoring/instruments including hoppers equipped with ultrasonic level sensors and weigh cells as well as full-length truck scales in each of the two loadout bays.

The presentation will walk through the decision process for this new state of the art solids handling facility, operations and maintenance considerations, and a live model fly-through of the unique multi-story solids facility.

Located between the cliff and a river, the City of Lewiston’s wastewater treatment plant had little room for expansion. The City’s dewatering system was undersized and required frequent maintenance. The City had a contract with a composting company to provide biosolids within an acceptable solids range. To compound the problems, the belt filter press was located on the second floor of a very small room in the center of the plant. The City was looking for an ideal solution that could fit into the existing space, reduce maintenance for the plant operators, and meet both the capacity and performance requirements.

As part of a performance-based evaluation process, the City selected HUBER Technologies, Inc.’s Q-PRESS 800.2 units. The new screw presses were among the first to include the high-capacity auger system, which consists of two design advances from previous models. The first design advancement being an elongated filtration zone in the inlet area which allows for a relative improvement in free water drainage. The second advancement is a more aggressive auger flight pitch which provides the unit with a higher solid conveyance capacity. These advances allowed the screw presses to dewater sludge 20% faster, reducing the required footprint and time of operation. This presentation will highlight the plant constraints, selection process, and also demonstrate the enhanced performance provided by the new screw presses.

WRFs using chemical disinfection with traditional means of control (e.g. flow pacing), typically overdose disinfectant by a factor of two. This overdosing can result in issues of excessive disinfectant cost, excessive quenching cost, disinfection byproduct formation, inconsistent performance, and inadequate public health protection. Advanced Dose Control (ADC) is a model-based disinfection control technology that seeks to account for the variables that impact disinfection performance (hydraulics, chemical background demand, and disinfection kinetics) and, regardless of process variability, to normalize disinfection outcomes while optimizing chemical dosages to avoid both over-dosing and under-dosing. Furthermore, in a complicated procurement environment, where disinfection chemical shortages and rising chemcical costs have become the norm, ADC provides a means by which to more tightly control chemical usage and for POTWs to hedge against supply volatility. ADC control technology has been included in the study matrix for WERF's most recently announced disinfection study, where bleach, PAA, and PFA will be compared under multiple control scenarios.

This presentation will highlight the foundations of the technology and present plant-scale pilot data, as well case studies from existing users demonstrating its performance vis-a-vis flow-pacing with both bleach, peracetic acid, and performic acid, and furthermore, will illustrate the implications of ADC's use at facilities using chemical disinfection, including significant cost savings (40%-50%), improved reliability, reduced discharge of residual disinfectant, reduction in dechlorination chemical, byproducts, and ultimately, reduced risk of permit violation.

Lake Stevens Sewer District (LSSD) and Columbia River Carbonates have worked closely since early 2022 to pilot improved RAS alkalinity and pH control at their Sunnyside WWTP operating in Lake Stevens, WA. This facility uses state-of-the-art membrane technology, designed to meet or exceed Washington State Department of Ecology permitted limits for contaminants in discharged effluent.

In January 2022, the two began replacement of 25% sodium hydroxide with MICRONA^TM AquaCal 70, a 70% solids micronized calcium carbonate aqueous slurry for alkalinity and pH control of mixed liquor at the 5 MGD MBR Sunnyside WWTP. While operating this pilot, wastewater quality and membrane permeability have been closely monitored while maintaining all standard operating conditions.

Results from the MICRONA^TM AquaCal 70 pilot for mixed liquor alkalinity and pH control and have been noted to a) decrease variability of alkalinity and pH in MBR mixed liquor, b) produce consistent pH control, allowing better conversion of ammonia to nitrates/nitrites and reduction to final effluent with a significant decrease in MBR mixed liquor alkali requirement, c) increased Suez membrane permeability and better operating conditions, d) decreased plant energy consumption, e) decreased overall alkalinity reagent chemical spend. These will be fully documented and presented.

LSSD also completed a 9-month pilot replacement trial of 25% sodium hydroxide added to MBR mixed liquor using 60% magnesium hydroxide from April through December 2021 and found improvement in some but not all operating and effluent quality parameters discussed above with respect to MICRONA^TM AquaCal 70.

Based on the 2021-2022 evaluations of magnesium hydroxide and calcium carbonate, LSSD is moving forward with converting from usage of 25% caustic soda to the continued use of 70% calcium carbonate aqueous slurry because of its cost-effective, non-hazardous and easy to handle qualities as a wastewater mixed liquor alkalinity and pH control product. Additionally, the selection of calcium carbonate aqueous slurry at the Jacobs run Spokane County Regional Water Reclamation Facility and Sunriver Utilities Co. build confidence in the use of CaCO₃ for required alkalinity and pH control during secondary stage aerobic biological treatment by LSSD.

The Sand Island WWTP is the largest treatment plant in Hawaii, serving Honolulu and surrounding areas and treating an average flow of 65 MGD. The facility currently provides preliminary treatment, chemically enhanced primary treatment, and UV disinfection prior to discharge through a 2.4-mile outfall. The WWTP is located on a highly constrained site adjacent to public recreation facilities, industrial facilities, and the primary access road from the island of Oahu to Sand Island located in Honolulu Harbor.

The City and County of Honolulu entered into a Consent Decree to upgrade the Sand Island facility to secondary treatment standards, and recently began construction of a 20 million gallon per day (MGD) membrane bioreactor (MBR) facility as Phase 1 of the secondary expansion. Phase 2 of expansion will provide the additional 90 MGD of secondary treatment capacity required to meet full secondary standards and support future growth. Phase 2 will also add peak flow equalization, upgrade preliminary and primary treatment, and expand solids treatment processes to treat the additional waste activated solids generated by the new secondary process.

Previous planning evaluated a wide range of secondary treatment technologies for the Phase 2 expansion, however since the site was not intended to support full secondary treatment, only intensified processes including MBR, biological aerated filters (BAF), and aerobic granular sludge (AGS) are able to provide the full secondary treatment capacity required within the footprint available. The 90-MGD Phase 2 expansion would represent one of the largest facilities in North America using any of these technologies, therefore the City conducted extensive investigation including detailed process evaluation and site visits to nine large facilities in the United States and Europe. A large group of City stakeholders evaluated the secondary process alternatives based on qualitative and quantitative criteria, relying on technical information from the design team and operational experience and performance shared by utility peers during site visits.

This presentation will describe the evaluation conducted to assess the large-scale intensified treatment processes considered for the Phase 2 expansion, review the City’s selected process, and describe how the technology is being implemented.

A major barrier to quantifying the true cost of grit is these costs are typically accepted as routine maintenance assigned to different parts of the plant so the root cause may not be identified as the common denominator. If grit is not managed by removal in the headworks it will continue onto downstream processes and must be managed throughout the plant. Grit deposits in downstream process tanks, taking up space, reducing retention time and increasing velocity which impacts treatment efficiency. Grit deposition in the aeration basin can increase energy requirements needed to achieve proper treatment. Accumulation in digesters can create unstable operating conditions by reducing volatile solids destruction, impairing mixing, and reducing gas production. To remove deposited grit basins must cleaned. Digester cleaning is expensive, dangerous and time-consuming, requiring taking the basin offline, exposure to toxic gasses, confined space entry, repairs and recommissioning, not to mention removing, handling and disposing of the deposited material. Grit is also responsible for abrasive wear to virtually all mechanical equipment.

All plants are interested in improving efficiency, reducing O&M costs, improving plant performance and reducing energy requirements or moving towards energy neutrality. If plant staff could monetize the cost of bypassing grit process improvements could be justified.

The purpose of this paper is to provide tools to understand effective design points for grit removal systems and assess the true cost of grit while shedding light on why the grit removal process is important.

Water and Wastewater Membranes need to be protected against fibrous & sharp debris. This not only protects all downstream systems & monitoring equipment, including water & wastewater membranes from premature surface abrasion & clogging, but site studies have shown that 1.0 mm & 0.5 mm aperture membrane pre-screening significantly reduces the annual number of membrane desludging/cleaning cycles by up to 3-fold. It also reduces the labor intensity of each cleaning cycle while eliminating clogging of aeration manifolds that scour membrane surfaces. Fine Pre-screening has become extremely important in protecting both membrane warrantees and lifespans. Laboratory & field experiments prove the vast majority of debris is caused by chopping & maceration equipment installed at pump stations or inside plants to protect downstream equipment from disposable wipes & plastics flushed into our sewer systems. The presentation will emphasize the importance of fine screening with data showing how short, fine cotton-wool-polyester fibers, human hair, as well as filamentous algae will pass through 6.0 mm, 3.0 mm and 2.0 mm aperture screens and “Recombine” downstream into larger rag type debris that increases the operating maintenance & cleaning cycles of all downstream systems and monitoring equipment. The Presentation will also include supporting pilot plant & field data that focuses on why velocity & headloss are the two most important operational characteristics in understanding how screens are properly sized, maintained & operated. Computational Fluid Dynamics Analysis (CFD) with (SCR) Screening Capture Ratio data will reveal the direct relationship velocity & headloss have on a screen’s capture efficiency & performance. It will also emphasize the aperture requirement for removing 2 dimensional versus 3 dimensional solids. A screen’s effluent quality affects the lifespan, operation & maintenance of all downstream systems & monitoring equipment. Headworks and membrane protection screens share the same velocity and headloss limitations that affect their performance and debris capture. Both lab and site test data will demonstrate and support the shared conclusions of this presentation. Whether the drivers are regulatory, reuse or to improve downstream process efficiencies, the trend has been to remove non-biodegradable debris, algae & aquatic remains from influent flow.

In 2022, the City of Spokane Valley was operating its stormwater utility with the lowest monthly stormwater rates for residents in Washington State. Osborn Consulting partnered with the City to develop a proposed stormwater rate structure that encourages the City to proactively operate the utility. A key to success was utilizing an engineering-led team of experts in stormwater management, coupled with FCS Group’s knowledge of rate development. The resulting success was when City Council voted to raise stormwater fees for the first time in close to 15 years.

Stormwater comprehensive planning – maybe you do it every year, maybe the dust is starting to collect on your latest plan. Either way, planning for adequate funding and practical stormwater capital improvement projects (CIPs) can often make you feel like you’re drowning (pun intended). This presentation will throw out the life preserver and share how the City of Spokane Valley achieved this incredible investment in their stormwater utility program and how other agencies have approached CIP planning.

Spokane Valley has experienced significant population increase in recent years and is subject to increasing regulatory requirements for stormwater. Having not increased their stormwater utility fee in close to 15 years, the City hired Osborn Consulting to lead a consultant team in developing a proposed fee increase and a stormwater utility program master plan. Our goal was to establish a plan for the City to efficiently manage the capital improvement programs, operation and maintenance, retrofits, and level of service for the stormwater utility.

The presentation will cover key concepts utilized by the team in developing the City’s Stormwater Utility Program Master Plan and other stormwater comprehensive plans. This includes 1) how to approach identifying and planning for implementation of new Ecology requirements, 2) strategizing CIP development and long-term phasing, and 3) identifying programmatic needs. Finally, we will review the team’s approach to aligning all the “new initiatives” over the long term to develop a sustainable rate structure for the community with a focus on balancing growth and environmental stewardship.

Utilities throughout the United States are facing unprecedented challenges including aging infrastructure, water supply insecurity, prolonged drought, uncertainty, water quality improvements, and more stringent environmental regulations. Customer rate increases are needed to protect our vital infrastructure and build a resilient future for our communities. While conversations regarding rate increases are rarely convenient, they are necessary to build political and community support.

How do we make responsible investments that meet the needs of our systems and communities? How do we communicate the complex drivers for rate increases? How do we facilitate conversations in which customers feel heard and respected? These questions are top of mind for local leaders and decision-makers as they explore creative and adaptable solutions.

As a uniquely integrated engineering and communication firm, WSC has extensive experience working collaboratively with clients to build understanding around vital infrastructure investments amongst their rate payers and building community trust.
Our strategic communications professionals will share strategies and best practices for effective rates outreach and engagement, including the following:

• Considering community values and priorities when making infrastructure investments and structuring rates
• Leading a transparent and thoughtful process that results in defensible decision-making
• Leveraging data and storytelling to showcase investment needs
• Proactively engaging key stakeholders including high-users, influential community members, fixed-income customers, and more
• Centering tactics in empathy and understanding
• Directly addressing tough questions and key concerns
• Communicating the risk of deferred maintenance and investment to our vital water and wastewater systems

Attendees will walk away with the following skills and tools:

1. A framework for building community trust and support for rate adjustments
2. Lessons learned -- a collection of case studies
3. Tools and resources to consider in developing your “rates outreach toolset”
4. An appreciation for two-way engagement when considering infrastructure investments.

These tools can support districts and agencies of all sizes in creating effective communication and engagement strategies for needed utility rate increases.

Clackamas County’s Water Environment Services (WES) has embarked on a project to build one of the largest new outfalls in the Northwest. Once constructed, this project will provide enhanced dilution performance to meet river water quality standards, protect beneficial uses in the Willamette River, and convert the existing outfall for use during peak wet weather events.

Designed to meet projected 2087 buildout flows of 168 mgd combined hydraulic capacity, the project benefited from early contractor input to successfully address challenging design criteria; rigorous permitting requirements; construction risk; and careful sequence of schedule constraints to work concurrently in the water with a nearby bridge widening project led by others.

The new mile-long 90-inch outfall construction requires installation of a 109-inch-diameter tunnel for half of its length in challenging ground conditions with a wet recovery in the Willamette River to install the 18-port 150-ft long diffuser at channel depth. For the remainder of the alignment, the outfall pipeline will be installed in a tight corridor between an old landfill and two of WES’s major 72-inch-diameter pipeline assets that require uninterrupted use during construction.

This presentation will give an overview of how the team successfully navigates construction risks and increasing costs in a volatile market while maintaining the ability to provide design input by using the Progressive Design-Build (PDB) delivery approach. WES also hired an Owner’s Agent to assist in the design/cost review, risk management, and permitting. The PDB contract started in 2022 after careful selection of a qualified Design-Builder, allowing WES to validate the project path forward while refining the construction approach to meet permit requirements and achieve greater cost certainty. The PDB approach has also allowed WES to collaborate more effectively with major stakeholders along the corridor (ODOT, City of Oregon City, multiple regulators) regarding project impacts and opportunities. Finally, WES has been able to gain increased cost certainty with estimates prepared by the Design-Builder that account for well-defined construction risk and contingencies and design opportunities.

More public agencies are considering collaborative delivery to deliver major capital projects for water and wastewater facilities. In 2017, Silicon Valley Clean Water (SVCW), in Redwood City, CA, chose Progressive Design Build (PDB) to deliver all three of the projects making up the $580M SVCW Regional Environmental Sewer Conveyance Upgrade (RESCU) raw wastewater conveyance rehabilitation program. RESCU has stayed on schedule through the pandemic, and is in the commissioning phase concurrently on all three projects, with final completion anticipated by mid-2024. This presentation highlights the importance of Owner involvement in the entire PDB delivery process, from contractor team procurement, through design and construction, to start up and commissioning. Why PDB was selected, how PDB has been implemented over 6 years, and current status will be presented.

RESCU consists of three projects that cover the entire conveyance system:

• Front-of-Plant: new 75-foot deep 80MGD lift station, new headworks with screens and degritting, new 1000LF 63-inch HDPE transmission pipeline to the plant influent;
• Gravity Pipeline: 3.5 miles of 16-ft diameter conveyance tunnel in low strength soils and high groundwater, under a regional airport taxiway and busy residential thoroughfare. Tunnel concrete segment ring excavation support has a finished diameter of 13-ft and is lined with 11-ft diameter fiber reinforced polymer (FRP) raw wastewater conveyance pipe;
• Pump Station Improvements: decommissioned two of four existing conveyance pump stations, rehabilitation of one existing pump station, and replacement of one pump station with a new combined screening facility and wet weather pumping facility.

SVCW leadership championed the early adoption of PDB for wastewater infrastructure, including the first large-diameter wastewater tunnel to be constructed in the US using PDB. RESCU started prior to the Covid pandemic, and, thanks to the effort of the Owner’s program team working remotely using MS Teams (Teams has been used on the Program since mid-2017), and the contractors’ focus on safety, no time was lost through two years of pandemic shutdowns. RESCU is on schedule and within budget expectations, demonstrating the value of Owner involvement in supporting collaborative delivery using PDB.

New and expanded facilities must respond to a full range of future conditions and operating scenarios to ensure system performance and regulatory compliance over their design life. Operators’ perspectives are an essential part of the design process, especially to provide guidance on system controls. Jacobs engaged with the Bureau of Environmental Services’ (BES) operations staff during early design of two new secondary clarifiers which resulted in more certainty with complex control schemes and the potential to reduce cost and risk during startup and commissioning. Presentation includes viewpoints from Jacobs, BES engineering, and BES operations staff.

The Secondary Treatment Expansion Program (STEP) includes the addition of two new circular 145-ft diameter secondary clarifiers at the Columbia Boulevard Wastewater Treatment Plant (CBWTP) that will be the largest clarifiers in the state of Oregon. CBWTP treats up to 450 million gallons per day with the combination of a wet weather treatment system and a secondary treatment system. STEP is increasing capacity through the secondary treatment system and changing the flow split between the two systems.

Early design workshops highlighted the complexity of the flow split scenarios (multiple flow streams and multiple control points) and effectively communicating how control decisions impacted hydraulic performance was challenging. Jacobs developed a design-level digital twin of the CBWTP secondary treatment system, so operations staff could engage with the flow parameters using the same visual interface and control logic as the constructed facility. The digital twin combined a detailed, dynamic hydraulic and simplified solids model, database structure, and instrumentation and controls narrative to simulate plant performance under a range of flow scenarios. Once the scenarios and control logic were developed, the design was stress-tested, using the tool, in an efficient and low risk environment. The operators’ input during design refined control logic and narratives which will allow for more intuitive operation and smoother startup and commissioning to meet regulatory compliance goals.

The Puget Sound Nutrient General Permit (PSNGP) became effective on January 1, 2022 and requires larger dischargers implement optimization to maintain nitrogen discharge below action levels established by the permit. The Wastewater Treatment Division (WTD) of King County operates three large treatment facilities, South Plant, Brightwater, and West Point. As allowed by the PSNGP, WTD elected a bubbled action level for compliance flexibility, instead of individual action levels for each facility. This presentation discusses actions taken by WTD under its bubbled action level in 2022 to comply with the PSNGP.
This presentation will describe the optimization planning work that HDR Engineering, Inc. (HDR) conducted with WTD staff and discuss lessons learned from optimization strategy implementation. HDR used WRF 4973, Guidelines for Optimizing Nutrient Removal Plant Performance, as a guide for screening optimization strategies. HDR led a collaborative process with WTD staff to assess current influent and effluent nitrogen loadings, identify, model and screen potential optimization strategies, and engage staff in reviewing and selecting strategies.
Previous testing at South Plant indicated that the facility could be operated in Ludzack-Ettinger mode during dry weather conditions to accomplish partial nitrogen removal, and this was selected as the initial optimization strategy as it could be implemented immediately with limited to no capital improvement. At Brightwater, a construction project is underway which will allow the plant to operate at low dissolved oxygen levels and increase nitrogen removal while improving process stability.
The PSNGP requires continual planning and adaptive management to respond to optimization challenges and maintain discharges below action levels. Both South Plant and Brightwater leveraged flexibility in implementation. They used trials and troubleshooting to maximize their success, and identified several potential strategies to improve outcomes, including an interim alkalinity feed system at South Plant.
As a result, WTD complied with the PSNGP in 2022 by staying more than 10 percent under the action level. Lessons learned from the first year optimization planning will be shared, along with a discussion of how WTD is planning to build and operate under an adaptive management framework for optimization planning and implementation.

Much has been publicized in the industry about the potential for digital or “smart water” technologies to address modern challenges. Some impressive successes have been demonstrated by digital technology providers that are leveraging sensors, data systems and machine learning to optimize systems and backstop operator transitions. A digital roadmap to complement renewal, replacement and upgrade plans for physical infrastructure can help a utility access the value of digital tools, increasing resilience and allowing more to be done with fewer resources. To implement digital technologies, the water utility manager must navigate a myriad of different technology providers and products to evaluate, prioritize and select the right solutions, and then figure out how to implement, integrate, and manage through the associated changes necessary to realize the benefits of the new digital technology products.

This presentation will offer an overview of digital water technologies and their potential benefits, explain the scope and importance of a digital roadmap within the master planning context for utility infrastructure, and review methods for selecting and implementing technologies. Case studies will be reviewed including the following:

1. Deploying sensors in collection systems establishes historical data for use in planning activities while enabling conditions-based maintenance. Olathe, Kansas suffered from high I&I. They needed dependable sensors for data collection backed by software with analytical capabilities so they could assess their basins and determine where to achieve the highest impact in reducing I&I.
2. Leveraging sensors, data and machine learning can help manage collection systems and avoid overflows. Houston, Texas experienced frequent dry weather SSOs due the accumulation of FOG in random locations in their collection system. Sensors, a digital twin and machine learning were utilized to identify forming obstructions prior to overflows occurring so that crews could be dispatched to clear the obstructions.
3. Implementing a digital twin for a WRRF can improve communications between stakeholders and optimize sub-systems for less consumption of energy and chemicals. The utility needed to unify their team around data-driven decision making and capture institutional expertise ahead of expected retirements. A digital dashboard of the 70 MGD CAS WRRF was implemented for these purposes.

The Environmental Protection Agency’s (EPA) Lead and Copper Revision Rule (LCRR) requires utilities to submit a service line inventory for all services including the public and private side of the line in October of 2024. Many water agencies have invested time and resources over the past two years to establish an initial inventory, but many are faced with a daunting number of service lines with unknown materials. Physical inspection is the most reliable way to determine if a service line is lead, but often requires excavation and these inspections can be costly, ranging between $500 - $1,500 or more per property. Many communities are turning to digital methods such as Machine Learning to reduce costs and streamline the removal of lead service lines.

Collaborative Intelligence is a process in which Machine Learning is paired with human intelligence to enhance each other’s capabilities. Models excel at analyzing vast amounts of disparate data and identifying patterns; however, they need to be told which data should be included and how the output can be used.

This presentation will focus on the strategy and approach for training, using, and explaining Machine Learning to predict service line material with the goal of reducing the number of unknowns in the service line inventory in a cost-effective way. An initial model can be built using available field verification data, but if no verifications have taken place (or there are not enough to effectively train a model), data collected from historical records can be used to train the initial model. The initial model will be beneficial for targeting locations to perform further field verifications, and it can then be iteratively improved with additional field data from targeted and opportunistic inspections and replacements. We will look behind the scenes of this collaborative human and machine modeling process, highlighting techniques and approaches that help to boost model performance, ensure model reliability, and explain the outcome in terms homeowners and regulators can understand. We will present two case studies highlighting the differences in outputs due to quality and availability of model features and volume of training data (inspections).

Erratic climate patterns coupled with aging sewer infrastructure has caused many utilities to worry about their wet weather management strategies. One of the major contributors to wet weather flows is Infiltration and Inflow (I/I) which is a function of pipe material, pipe age, groundwater level and precipitation. In some cases, when groundwater level is above the invert elevation of the sewer collection pipes, I/I can also result in increased dry weather flows. With many utilities across the country planning major infrastructure sewer network upgrades due to ageing infrastructure, areas with highest I/I are usually a low hanging fruit to minimize wet weather flows. However, quantifying the benefits of such sewer upgrades is often difficult due to limited flow measurements typically available across sewersheds where upgrades are performed. The lack of flow measurements coupled with climate variability year over year render the use of simple ‘before’ and ‘after’ comparisons ineffectual. To avoid the bias and uncertainty due to climate variability, a different methodology is required to compare data and quantify impacts. This study investigates an alternate methodology of using pump station energy consumption data in lieu of flow measurements for quantifying the benefits for approximately $20 million in investments made by a utility¹ for rehabilitation of 210,000 linear feet of sewer pipe across six (6) sewersheds. This paper will review the approach of using a “control sewershed” i.e. a sewershed not having undergone any repairs, with similar characteristics as that of the sewershed undergoing rehab, to eliminate bias and using this alternate approach to quantify reduction in flows as a result of the I/I repairs. This paper will also review the approach for quantifying the return on investment for the rehabilitation as well as cost savings as a result of deferred treatment capacity expansions for the receiving wastewater treatment facility.

Note: 1. Approval to disclose the utility name is anticipated to be received ahead of the conference presentation.

This presentation will dive into a case study from Gresham, OR where deep infiltration was used to reduce the strain on an overwhelmed MS4 system. This site had shallow perched groundwater but beneath the silt layers were permeable sands and gravels that were perfect for infiltration. By drilling deeper, the stormwater can infiltrate and reduce the burden on the existing MS4 system.

This deep infiltration system was also installed in an existing residential street, which had tight existing utilities. By minimizing the footprint of construction and surgically targeting the location of the drywell, the construction timeline is shortened, and the risk of damaging existing infrastructure is reduced.

These deep infiltration systems are designed to protect groundwater quality by having a minimum of five feet of vertical separation between the bottom of the drywell and the high seasonal groundwater level. Results from monitoring this deep infiltration system will also be shared.

Clean water agencies, regulatory agencies, and watershed stakeholders are searching for innovative approaches and best practices to address water quality challenges due to nutrient enrichment and a changing climate. A key component of such improvements is to take advantage of existing assets through optimization. While potentially attractive, optimization is a daunting task and a comprehensive guide on implementing optimization has been lacking.

This presentation is part of the Water Research Foundation project 4973 “Guidelines for Optimizing Nutrient Removal Plant Performance” that developed a comprehensive guide on implementing an optimization strategy for water resource recovery facilities (WRRFs) with an emphasis on nutrient management (based on full-scale examples). The presentation focuses on a key component of the guide, the nutrient optimization decision trees that can assist WRRFs with navigating nutrient optimization.

The nutrient decision trees developed will be available on the Water Research Foundation’s website this calendar year as part of a web-based interactive tool. The decision trees ask the user a series of questions, whereby the responses inform the generation of a list of potentially viable optimization strategies for their WRRF. Each potentially viable strategy has a corresponding Fact Sheet associated with it to further assist the user as to whether such a strategy might work for their WRRF.

While more extensive detailed analyses will likely be required to verify/validate each potential strategy for facility specific applications, the decision trees expedite the optimization effort and help initiate the process. For example, the decision tools have been applied to satisfy the optimization planning requirements of the Puget Sound Nutrient General Permit (PSNGP). The decision trees benefit wastewater utilities by providing a comprehensive screening of optimization opportunities that efficiently narrow considerations to the most promising options. In this way, resources can be focused on the facility specific details of optimization.

As part of the presentation, the Water Research Foundation web-based interactive tool will be used in real-time to highlight the ease of using the tool. The audience should leave the presentation with an understanding on how to use the decision tree tool.

The City of North Las Vegas Water Reclamation Facility (CNLV WRF) uses a traditional Johannesburg process and a membrane biological reactor (MBR) aimed at removing phosphorus and nitrogen. During a recent capital improvement project to re-coat the MBR basins, the CNLV consolidated the number of basins in-service from 12 to 9 MBR trains. The basin consolidation impacted the stability of the biological phosphorus removal performance.

A study was conducted to identify and evaluate potential optimization opportunities to improve the stability of the biological phosphorus removal process. The study targeted key process parameters, such as chemical addition, solids retention time, hydraulic retention time, and oxidation reduction potential, all of which can also impact MBR performance. Seven optimization scenarios were developed focusing on three themes: peak flow management, solids loading in the MBR (chemical and biological), and dissolved oxygen concentration in the MBR and recycle streams.

All optimization opportunities were evaluated using a wastewater process modeling software with the intent of shortlisting several optimization alternatives to test on the full-scale process. The simulation results were used to estimate process performance, such as MBR permeate phosphorus, ammonia, and nitrate concentrations, under varying operational conditions.

This presentation will highlight the impact of peak flow management with the use of an equalization basin and the importance of balancing solids loading by optimizing chemical addition and dissolved oxygen concentration in the return streams by optimizing recycle rates.

Conventional design and operation of enhanced biological phosphorus removal (EBPR) focuses on providing volatile fatty acids (VFAs) from the collection system and sometimes from primary sludge fermentation to phosphate accumulating organisms (PAOs) in an influent anaerobic zone. Alternately, sidestream EBPR (S2EBPR) diverts a portion of the RAS to a longer hydraulic retention time (HRT) sidestream reactor where biomass and particulate COD is fermented endogenously to generate the VFAs required. Successful S2EBPR operation hinges on the sidestream zone producing enough VFA to support healthy PAO populations in the HRT available.

Clean Water Services incorporated S2EBPR into a recent secondary expansion but did not observe the process to improve EBPR stability over conventional EBPR operation. In order to investigate possible reasons, the apparent fermentation rate (AFR) at three CWS facilities was measured. The results showed that there is variably in the AFR across time and season in the same facility, between different facilities and based on the method used. The CWS testing also highlighted an integral parameter used to estimate the AFR from batch testing results: the ratio of VFA removed to orthophosphate released (the P-release ratio). Long term measurements of the P-release ratio show that it is also highly variable over time.

Polyhydroxyalkanoate (PHA) measurements were also performed during the bench scale AFR testing and during full scale S2EBPR operation. The goal is to determine if shifts in carbon storage may impact S2EBPR process performance. The results indicate strong differences in the type of PHA stored between conventional EBPR and S2EBPR. The possible reasons for this shift will be explored but it is as yet uncertain how carbon storage changes relate to differences in process performance.

This presentation will provide an overview of how apparent fermentation rate testing fits into design and operational decision making and will discuss the overall methodology and approach. CWS results will be compared against original design assumptions and against wider industry results. The importance of the P-release ratio and possible sources of variability over time will also be summarized.

The Southwest portion of the City of Tacoma’s (City) Central Treatment Plant (CTP) collection system is experiencing ongoing redevelopment that includes both large proposed projects and smaller projects from continued steady population growth. This portion of the collection system flows by gravity to the South Tacoma Pump Station (STPS) and is then conveyed to the CTP. STPS is due for rehabilitation based on equipment age in the coming years.

This presentation summarizes updates of Tacoma’s collection system hydraulic model and describes model use to answer questions regarding large redevelopment projects and pump station design optimization. Several possible development scenarios were projected and evaluated in the hydraulic model. A sensitivity analysis for different development types was conducted with respect to system performance criteria balancing flows, piping improvements, pump station capacity and operations.

The City provided the most recent field verified system GIS data, pump station settings, and local flow monitoring in the key basins. This information was added to Tacoma’s CTP model, making the model completely up to date. Projected flow scenarios were developed for an old Airfield that is being re-developed along South Tacoma Way. Re-development of a high density 400-unit development on 6th Avenue, and the Mall at South 48th Street were also included in the analysis. The model was used as a tool to recommend future pipe upsize and help size the new planned conveyance system to meet the City’s performance criteria.

Additionally, the hydraulic model was used to evaluate the STPS operations during both a large rain on snow storm in January 2022 and the City’s collection system design storm. Model results were compared against the system performance criteria when either 4 or 5 pumps are operating at the current STPS. This was completed for the existing system configuration and for the proposed piping changes identified for the Airfield development. Operational changes with the current pumps were tested to improve system performance during storms. Lastly, pumping capacity for pump replacement were recommended that balanced system performance both upstream and downstream of the STPS, based on the recent large January 2022 storm and the City’s design storm.

The Gothenburg region was able to address emerging challenges within its sewerage system by developing a digital twin. Gothenburg, located on Sweden’s west coast, faces many of the same challenges faced in the Pacific Northwest. Gothenburg, one of the rainiest cities in Sweden, experiences heavy rainfall causing large loading variations to its central Rya water resource recovery facility (WRRF). Approximately 25% of the sewers in the City are combined, increasing the risk of flooding and discharge of untreated wastewater into the surrounding ecosystem.

Gryaab AB, the regional wastewater utility serving Gothenburg and surrounding municipalities, owns and operates the Rya WRRF and the tunnel system transporting wastewater to Rya WRRF. Gryaab saw the potential and developed a digital twin to help better manage its sewerage system, including:

• Developing a detailed H&H model of the tunnel system and catchment area
• Incorporating all controllable devices (gates, pump, etc.) in the digital twin
• Incorporating weather forecasting in the simulation
• Development of Forecast-on-Demand features
• Development of operational strategies to mitigate the risk of urban flooding and minimize CSO discharges

Deployment of the digital twin allowed Gryaab to get better real-time information about events in the tunnels and accurate predictions of potential issues and peak pressure on the system. This allowed them to optimize the overall system performance. Simulations indicate that yearly CSOs may, ideally, be reduced by 65%, and bypass volume at the WRRF by 85% through dynamic operation of CSO sites and increased utilization of tunnel volumes. Simulations for years 2035, 2050 with various climate and population scenarios helped understand how and when to plan for expanding WRRF capacity.

The digital twin allows Gryaab to act proactively. Staff can make decisions based on comprehensive, real-time data and prognosis and even allow direct implementation of the digital twin’s suggested setpoints in the SCADA-system. The digital twin is used for training in various scenarios so that staff is better prepared for future critical situations and for making better informed decisions. In short, the digital twin is used for gaining better real-time control and improving the operation of the sewer system, both today and in the future.

The City of Boise’s (City) water renewal utility, Water Renewal Services (WRS), has used a Business Case Evaluation (BCE) tool to inform capital project alternative evaluation and selection across their facilities since 2016. Following significant updates to their Level of Service (LOS) goals and Capital Project Delivery Model (PDM) through their Utility Plan development and implementation, they recognized the need to update their BCE tool’s criteria and processes to align with these new organizational values and processes.

In June 2022, the City engaged Brown and Caldwell (BC) to update their BCE tool to better align their organization-wide goals and commitments. The team improved user experience and drive tool adoption by refining usability and standardization. As a result, the new BCE:

• Aligned BCE tool assumptions, risks, and benefits with LOS
• Translated LOS goals into risk monetization criteria for inclusion into the tool
• Updated existing monetization assumptions and improve data source transparency
• Improved ease of use and overall BCE tool accessibility
• Increased the efficiency and defensibility of the decision-making process

This presentation will discuss the approach and results of the BCE tool update, outline how to translate high-level LOS goal language into quantifiable and monetizable evaluation criteria, and highlight opportunities for scaled application across other organizations.

The presentation will also provide the opportunity for other utilities and municipalities to consider how a BCE may help translate organizational values into decision-making criteria to support consistent application of LOS or other priorities throughout projects related to climate goals, utility resilience, employee experience, and more.

Known as the Emerald City, Seattle is famous for picturesque views, coffee culture and rain. Located on the shore of the Puget Sound in Discovery Park, the West Point Treatment Plant (WPTP) is the largest wastewater treatment plant in the Pacific Northwest, providing treatment for up to 440 million gallons per day of combined storm and sanitary flows. Operated by King County’s Wastewater Treatment Division (WTD), it is relied upon daily to protect the environment and the public health of approximately 750,000 residents and businesses in Seattle and northern King County.

Constructed in 1966 and expanded to secondary treatment in the early 1990’s, the WPTP needs significant investment over the next 10 years to improve resiliency and replace aging asset. As the workhorse of WTD’s treatment facilities, any construction that could affect the plant’s ability to provide peak treatment capacity is limited to each year’s “dry-season,” between April and September. Also, the facility is on a 32-acre site with land, water, height and depth constraints limiting available space for construction activities.

In June of 2020, WTD started to develop the West Point Capital Program (WPCP) with the vision to deliver projects at the WPTP in a coordinated manner, improving schedule performance, fostering better relationships between operations and project delivery staff, elevating project delivery procedures and reducing risks.

Implementing a programmatic delivery approach for the WPTP helps WTD to manage dependencies between projects, and provide consistent and integrated tools and documents to all project teams in real time. The program also improved communication across project teams, and enabled a broader management approach to identify, anticipate and manage schedule impacts and overall risks. This presentation will describe some key tools and processes that have served the WPCP well and contributed to the results obtained to date. It will also identify the challenges and lessons learned that the team faced while setting up the program and running the initial 2 years of the WPCP, and where the program will go from here.

Good water policy is informed by experience and expertise of the practitioners who work with resulting rules and regulations every day. Setting a course towards good policy frameworks and enforceable requirements begins with connecting those policymakers with their constituents. Learn to effectively advocate to state legislators regarding bills which affect your entity or area of expertise.

State codes governs a significant portion of what utilities are allowed to do, cannot do, and must do. In the northwest, these laws are written by part-time legislatures comprised of representatives from all areas of the state and all walks of life. Knowing how to effectively engage can make a big difference in educating state lawmakers, who are responsible for important water policy but often do not understand how it impacts utility operations.

Advocacy begins far before the legislative session, at the local level and continues year-round. Once the legislative session is underway, many bills are already far along in the drafting process with substantial support of various groups and voting blocs. Attempting to get a new idea off the ground or to redirect a flawed bill once it gains momentum are both challenging tasks. Clean water industry professionals provide a vital service by supporting members in navigating this process. A few of the activities we can pursue more effectively as an organization include:

• Anticipating emerging legislation and understanding potential impacts.
• Educating lawmakers to enhance their ability to create quality legislation.
• Supporting lawmakers in advancing legislation that supports and protects clean water goals.

Presenters will share advice on how to engage local legislators outside the legislative session, how to engage during the session itself, tools for monitoring the legislative process, and provide considerations to be taken when commenting on behalf of a public or private agency. The presentation will include both theoretical guidance and real-world examples from Government Affairs Committee members.

Water professionals from across the country descended upon the nation’s capital for Water Week 2023 (April 23-29) for a full slate of in-person events and meetings, including on Capitol Hill, which is now fully reopened to the public.

This year’s Water Week provided professionals with the opportunity to directly learn more from key federal officials about the implementation of the historical policy achievements secured by the water sector over the past two years, and significant actions on EPA’s regulatory agenda that will directly impact the water sector. It also provides the opportunity to build on this momentum and come together on Capitol Hill to advocate to Members of Congress the importance of ensuring all communities continue to have access to safe, reliable, and affordable drinking water and clean water.

PNCWA member visited Washington DC in-person furthering key water policy priorities such as sustained growth in federal infrastructure investment, addressing water affordability, supporting water research & development and advancing sound science-based solutions, and making our critical infrastructure more resilient.

Each states delegates will speak to who they met with, what they learned and how that impacts the Pacific Northwest. As your representative, the Government Affairs Committee member in attendance will provide vital information on federal legislative action and how you elected congress is approaching legislation and how we can better advocate for important water policy. We will talk about the individual meetings with legislatures and their staff, share information form keynote speakers like Radhika Fox, with the US EPA and how Washington DC is grappling with issues that impact us like PFAS, climate change and infrastructure funding and affordability.

Lake Ontario is the primary source of drinking water for approximately half the population of Ontario, with the majority of that population residing in the Greater Toronto Area (GTA). In 2013, Source Water Protection studies identified sensitive areas near the drinking water intakes where the risk of impacts from accidental spills is considered a credible threat to human health and safety. A spill causing an acute contamination event at one of the water supply intakes could have catastrophic impacts to the population. However, the ability of stakeholders to assess the potential impacts and develop an appropriate response is presently limited to static planning level studies and maps. These proved to be useful tools for identifying the potential locations where pollutants may show up, but they did not provide any indication of the potential risks due to the conditions in the lake at the time of the spill.

In 2019, the Ontario Clean Water Agency together with the City of Toronto, Region of Peel and Region of Durham hired DHI to develop the Lake Ontario Water Quality Forecasting System (LOWQFS). The LOWQFS assists in evaluating the likelihood of a pollution event originating from any discharge source within, and adjacent to, Lake Ontario being transported to any one of the water treatment plant intakes located along the Greater Toronto Area (GTA) waterfront. The system collects climate forecasts and uses it to update a 3D hydrodynamic model of Lake Ontario to predict the water level, currents and temperature throughout the lake. The system also includes a Spill Forecasting tool for on-demand creation of spill events that are run using the latest hydrodynamic forecast. The results are made available for plotting of spill concentrations on a map and in time-series plots, and impacted water intakes are identified and reported to relevant stakeholders.

The system is currently in operation and emergency response plans are being updated to integrate the use of the LOWQFS into the protocols and workflows.

Environmental DNA (eDNA) refers to DNA shed by organisms into the environment, and can be captured in water, soil or air samples. By identifying DNA captured in a sample, we can infer species present within a given environment. As such, eDNA is a promising tool for understanding spatial and temporal variation in biodiversity across a watershed. Clean Water Services (CWS) is a water resource and recovery district serving Washington County, Oregon. CWS discharges to the Tualatin River, a meandering, valley-floor river, sensitive to nutrient inputs and stream flow augmentation. Accordingly, our watershed-based NPDES permit directs CWS to monitor the biological characteristics of 15 sites within the watershed each permit cycle. This work is typically completed using macroinvertebrate surveys, which are costly and limited in biological scope, and therefore provide limited information. Given eDNA’s promise as a means for characterizing broader biodiversity between sites, we are piloting eDNA as a novel method for gaining detailed biological information, that could potentially be used in the future in-place of traditional macroinvertebrate surveys. The first phase of a multistep project has been to monitor nine sites representing diverse habitats within the Tualatin River Watershed, on a monthly or quarterly basis through a metabarcoding eDNA approach using water and sediment samples. This presentation will discuss the observed differences in biodiversity between sites over the course of a year, and whether eDNA metabarcoding data can be used to assess temporal shifts in species-use at a particular site or habitat area. Additionally, we will demonstrate how aquatic algae identification via eDNA compares to morphological identification via microscopy, and suggest how this comparison may inform future studies. Finally, we will discuss how we plan to use these data to develop a framework for regularly monitoring biological characteristics to demonstrate the effectiveness of our watershed enhancement actions and in fulfillment of our NPDES permit.

To address regulatory commitments, Seattle Public Utilities (SPU) launched the Natural Drainage Systems (NDS) Partnering program in 2017 by developing retrofits in the three major creek watersheds within the City. Due to topography, historical development, and economic factors, much of this area lacks formal drainage infrastructure.

Working with sister agencies, concurrent SPU programs, and community partners, the purpose of the NDS Partnering program is to deliver high-value improvements to over 60 blocks of neighborhood streets in Seattle’s urban creek watersheds. The purpose of the partnering in the NDS program is to develop shared projects within SPU programs and between SPU and other City agencies to offer multiple benefits to neighborhoods and the natural environment, including greener neighborhoods, reduced flooding risk, improved natural habitat for native plants and animals, healthier creek ecosystems, and calmer traffic patterns. This presentation will highlight the program goals and site selection process and share lessons learned in addressing the challenges and opportunities of partnering to retrofit underdeveloped urban right-of-way.

The current NDS program consisting of the Longfellow Basin (under construction), South Thornton Basin (construction starting summer 2023), and North Thornton and Pipers Basins (under development and design). This program leverages innovations developed under recently constructed retrofit projects to enhance the viability of green infrastructure in challenging site constraints and soils. These innovations include the use of weirs, underdrains, structural soil cells, and underground injection control wells.

The program’s innovative green infrastructure improvements are an example of how to successfully balance the needs of the right-of-way while improving quality of stormwater runoff. SPU strives for continual program improvement through delivery community-centered projects that economically improve service.

Oftentimes long term localized drainage issues require a root cause, basin-wide analysis to identify the truest source of the issues. Leaving no rock unturned leads to developing sustainable solutions. Issues from frequent roadway flooding, localized ponded water, high groundwater, poor water quality, and lack of conveyance systems can all be addressed through taking a big picture look at the existing systems and focusing on aligning solutions with current and future community needs and funding sources. A comprehensive plan can then be developed, breaking down the basin approach into bite-sized solutions that can be implemented over time.

Josh and Ronnie will discuss how they work with the full suite of stakeholders to get to resolution on sticky long-term drainage issues. They will examine four case studies to understand key lessons learned associated with creatively addressing multiple issues in route to developing an actionable basin plan. The resulting action plans are focused on optimizing and retrofitting existing regional facilities and existing conveyance systems to manage stormwater from current and future developments, in order to drive and maintain economic growth and meet environmental requirements. Aiming to steer conversations with the community through the implementation of innovate stormwater concepts, these case studies offer valuable methods for problem solving on a larger scale.

The root cause analysis performed by the team includes in-depth data reviews, field walks with O&M staff, review of maintenance records, on-site conversations with impacted community members, collection of detailed field information (geotechnical and flow monitoring data) and ultimately performing detailed hydraulic modeling to identify drainage areas of concern. All feasible alternatives to improve water quality and reduce flows to surface water by increasing stormwater infiltration, retention, and detention are considered and analyzed in terms of cost-effectiveness. Alternatives that are developed include a variety of projects from new storm drain systems, groundwater collection drains, hydraulic connections for disconnected areas, and new/retrofitted regional facilities. We will discuss our teams approaches to engaging with the community to assist in developing practical and creative solutions that minimize disruption to citizens lives, reduce the risk of flooding on private property, and provide sustainable solutions.

Clean Water Services (CWS) is a wastewater, stormwater, and watershed management utility serving the populous of Washington County, Oregon USA through implementation of a watershed based NPDES permit. CWS operates 4 water resource recovery facilities (WRRF) with biological nutrient removal (BNR) activated sludge configurations to achieve phosphorus and ammonia nitrogen removal to low levels.

The Rock Creek WRRF is comprised of East and West trains configured in an anaerobic-anoxic-aerobic (A2O) process. On the East side there are 4 activated sludge basins (AB 4-7) that exist as pairs of identical basins. AB 4 and 5 are single pass basins tending towards complete mix reactors. AB 6 and 7 are three-pass plug-flow style basins with three swing zones for denitrification. All basins receive an independently controlled dose of volatile fatty acids (VFA) from primary sludge fermentation to effect enhanced biological phosphorus removal (Bio-P). Differences exist between AB 4-5, and AB 6-7 in the ability to step feed primary effluent to different zones within the basin. The basins are operated as discrete units with independent and isolated biomass in each basin.

Nitrification and Bio-P are sensitive processes prone to upset conditions, particularly during the colder months. To increase the resiliency and reliability of the basins to perform this biology, CWS has installed a Cross-Basin Activated Sludge Seeding system (C-BASS). This system is capable of diverting a portion of the return activated sludge (RAS) from one basin to another. The plant is required to nitrify year-round to varying levels depending on receiving stream flow, so one basin is kept in a fully nitrifying condition. C-BASS is used to rapidly establish nitrification in other basins as permit limits change. The facility faces VFA limitations even with primary sludge fermentation. One or two basins may be heavily dosed with VFA for robust Bio-P, and C-BASS used to get the benefit of residual phosphorus uptake in the other basins. Waste activated sludge (WAS) remains an independent system and can be managed to retain biomass during C-BASS.

C-BASS is a simple and effective system that many facilities could install in-house to improve resiliency and expand process control options.

Aerobic Granular Sludge (AGS) technology operates on an optimized batch cycle structure that creates the proper conditions to develop and maintain granules: large, dense microbial aggregates displaying as particles greater than 200 microns in diameter that perform biological nutrient removal and display exemplary settleability relative to conventional activated sludge (CAS). The layered microbial community of these granules enables simultaneous nitrification/denitrification and enhanced biological phosphorus removal to occur within the granular biomass. This technology therefore eliminates the need for clarifiers, carrier media, and return sludge pumping stations, as well as selectors or separate compartments for plants looking to achieve BNR. The enhanced settling properties allow the system to operate at a high MLSS in excess of 8 g/L without a loss in aeration efficiency due to the granular nature of the sludge. The AGS process can therefore provide a significant reduction in footprint requirements and energy demand compared to a conventional technology.

The AGS process has been implemented successfully for nearly years with over 100 plants either in operation or under construction globally. Introduced to the North American market in 2017, there are now over 10 plants operating or under construction in the United States. This session will present case studies of plants that selected the technology to prepare sites for future regulatory demands, population increases, and climate resiliency.

A major interceptor with 7MGD flow in Pierce County’s Chambers Creek Water Resource Recovery Facility (CCWRRF) collection system has historically been plagued by microbially induced corrosion (MIC) and odor problems, with gas phase hydrogen sulfide concentrations as high as 200ppm. The rate of concrete corrosion as measured by weight loss was 8-9 % annually based on a concrete coupon study.

The CCWRRF was expanded to provide biological nutrient removal in anticipation of nitrogen nutrient limit from the state, which in turn led to the requirement for industrial users to reduce nitrogen nutrient loadings. A wastewater characterization study revealed that an industrial user discharges a high-strength waste stream with an ammonia concentration as high as 2000 ppm and is a major contributor of ammonia loading to the interceptor. Armed with the knowledge that nitrate compound addition is one of the best solutions to control MIC, CCWRRF decided on a creative approach for nutrient removal by this industry. Instead of complete nitrogen nutrient removal through the full cycle of nitrification and denitrification, the industry is asked to nitrify only, generating a waste stream with nitrate concentration as high as 2000ppm which is discharged to the collection system. This strategy has been proven to be very successful and is mutually beneficial to CCWRRF and the industrial user: MIC and odor in this interceptor have largely been controlled, as evidenced by liquid phase sulfide concentration at less than 0.2ppm and gas phase hydrogen sulfide reduction by 90%, without incurring the significant cost of nitrate salt addition by CCWRRF; and the industrial user achieved significant costing savings by not having to add supplemental organic carbon to achieve denitrification.

EPA promulgated aluminum aquatic life criteria in 2021 for Oregon based on the 2018 nationally recommended criteria. Aluminum is traditionally measured in environmental samples as total and dissolved aluminum, and criteria were based on total aluminum. However, the method to measure total aluminum uses a very low pH digestion which aggressively dissolves aluminum bound in clays and other mineral forms. This overestimates the amount of aluminum that is bioavailable and potentially toxic to aquatic life. Using total aluminum would assess more water bodies as impaired than would be accurate, and the listing could require TMDLs to be developed. For NPDES permittees using alum, this could result in unnecessarily restrictive aluminum limits which may impact the ability of WRRFs to use alum to meet phosphorus limits. Therefore, in implementation efforts, EPA recognized a new analytical method (Rodriguez et al. 2019) that measures bioavailable aluminum and allowed its use for river measurements.

Clean Water Services (CWS) is committed to studying analytical methods that best measure the potential toxicity of aluminum. The CWS Water Quality Lab began using the bioavailable aluminum method in 2019 and analyzed total, bioavailable, and dissolved aluminum in concurrent effluent and river samples from the Tualatin River. Results consistently show that a low fraction of the total aluminum is bioavailable to aquatic life in the Tualatin River, with an average of 7% bioavailable. Bioavailable aluminum concentrations were always less than the instantaneous water quality criteria calculated from the water quality standard, while 50% of total aluminum concentrations were greater than the criteria. Data also demonstrated that aluminum from CWS WRRFs that use alum is almost entirely bioavailable, highlighting the importance of reducing tertiary alum and the implementation of alternative methods of phosphorus removal. CWS has collaborated with Oregon DEQ to monitor total, dissolved and bioavailable aluminum in a broader range of rivers. CWS plans to continue bioavailable aluminum monitoring efforts and collaboration with Oregon DEQ in support of this method. ASTM publication, as well as 40 CFR approval, are important next steps in wider acceptance of the method by EPA in future aluminum criteria updates.

Bacteria in biological nutrient removal (BNR) activated sludge treatment reactors uptake and metabolize wastewater nutrients to achieve effluent desired by operators and engineers. Induced metabolisms – i.e., the metabolic pathways by which the bacteria “digest” nutrients – are the backbone of biological wastewater treatment. However, little data is available to study and understand these metabolic pathways directly. Moreover, differences in metabolic activity at a molecular level between differing BNR systems and configurations are, at best, poorly understood.

Metabolomics is the scientific study of biochemical processes involving metabolites, which are the small molecule substrates, intermediates, and products of bacterial metabolism. Metabolomics is an emerging scientific field that holds promise to help fill the knowledge gap in BNR processes with an easy sampling and analytical process that can be used to study a broad range of intracellular compounds. Research at the University of Idaho is focused on applying metabolomic methods to better characterize and describe BNR processes, with the ultimate aim to generate new knowledge on process operation and control. This presentation will describe metabolomics and its potential application in research and activated sludge troubleshooting. Original research will be shared on developing a “metabolic fingerprint” for different full-scale, pilot, and bench-scale BNR configurations; employing metabolomics to troubleshoot EBPR failure; and a metabolomic investigation into the upset of a BNR culture associated with addition of elevated concentrations of emerging contaminants.

The City of Pasco has been one of the fastest-growing cities in the State of Washington and the nation for several years and keeping ahead of this growth has taxed the City’s water and wastewater utility infrastructure and associated fund balances. The City is actively planning for future improvements at their wastewater treatment plant (WWTP) which have included, fast-track short-term capacity modifications, a comprehensive 20-year facility plan, the acquisition of State Revolving Fund (SRF) loan project funds, design of the first two phases of high priority improvements, and construction of the Phase 1 liquids-focused WWTP upgrade that will roughly double the capacity of the plant to just under 10 million gallons per day.

This presentation will focus on the planning, design, construction, and start-up of the WWTP’s $22 million Phase 1 improvements which included the construction of an expanded and modified blower building with two new blowers and reuse of two existing blowers, two new aeration basins, the retrofit of two existing aeration basins, selector process considerations, aeration piping replacement, return activated sludge (RAS) piping modifications, mixed-liquor recycle (MLR) pump addition, over 1,100 LF of outfall piping upgrades, demolition of an existing trickling filter and associated appurtenances, and site work.

This presentation will:

• Provide a contextual overview of the existing facility and phased improvement planning
• Review unique Phase 1 design elements:

- Use of an intentionally flexible anoxic/anaerobic selector to maximize rated capacity
- Aeration basin FRP partitioning to convert from complete mix basin and create plug flow conditions to maximize capacity and aid foam removal
- Blower selection and reuse of existing blowers
- Probe selection, use, and location for operational control and data acquisition
- Diffuser process selection for improved capacity and O&M access
- Open Channel Mag Meter to maximize capacity
- Preparation for future phases incorporated into the design

• Discussion of bid procedures for contractor responsibility and qualification-based bidding specific to Washington State requirements
• Discuss construction and facility start-up lessons learned

Many water resource recovery facilities (WRRFs) in the Chesapeake Bay and mid-Atlantic region have completed improvements to address low effluent nutrient requirements over the last two decades. Many utilities in this region have to meet total nitrogen (TN) below 3 mg/L and total phosphorus (TP) below 0.2 mg/L.

The extensive experience in the Chesapeake Bay and mid-Atlantic regions uniquely positions utilities facing new effluent nutrient limits to learn from their peers’ experiences and adopt best practices and technology advancements for nutrient removal. This presentation will introduce key design considerations and best practices with a focus on nutrient removal experiences and introduce advances in nutrient removal technologies. Specific topics, including actual case studies, will include:

• Optimizing biological nutrient removal (BNR) Reactor Design – Providing flexibility in anaerobic, anoxic, and aerobic zones to address seasonal variations in temperature and loads allows fine-tuning of nutrient removal processes and can reduce overall volume. Providing deoxygenation zones prior to nitrified recycle pumping or unaerated zones optimizes carbon usage for nutrient removal. Proper baffle wall design to allow foam transport and surface wasting.

• Optimized Aeration System Design – Oversized aeration systems increase energy and chemical costs to meet effluent nutrient limits. Aeration systems need to be designed for flexibility over a range of variable load and environmental conditions, with a focus on maximizing turndown to avoid overaerating and allowing adoption of advanced aeration control strategies such as ammonia-based aeration control (ABAC).

• Carbon Management for Chemical Reduction – Providing flexibility in BNR reactor design and low dissolved oxygen operation improves utilization of influent carbon for nutrient removal. Many WRRFs in the region were designed to meet effluent TN limits through both BNR and denitrification filters, which require methanol addition. As WRRFs optimized their BNR processes they have become less reliant on denitrification filters, and many have discontinued methanol feed to filters.

• Next Generation Nutrient Removal – New “intensification technologies” such as aerobic granular sludge (AGS) and densified activated sludge (DAS) reduce footprints and capital costs of nutrient removal improvements. Shortcut nitrogen removal approaches such as deammonification and partial denitrification-anammox (PdNA) to lower the carbon and energy inputs required for nitrogen removal.

Many coastal waters in the US and worldwide are adversely affected by excessive nitrogen loading; however, high costs and scientific uncertainties can impede stakeholder agreement regarding the degree of nitrogen control necessary. This paper presents a case study of how regulatory agencies, utilities, and environmental groups charted a path forward for reduction of nitrogen loads to the Great Bay estuary in New Hampshire. This network of tidal rivers, bays, and harbors has experienced historical declines in seagrass. In the mid 2010s, agencies attempted to impose a nitrogen criterion that would drive stringent limits on municipal wastewater treatment facilities (WWTFs). This attempt stalled after an independent expert panel found insufficient scientific evidence that the proposed criterion would achieve the desired ecological benefits. At this impasse, utilities preferred optimization and voluntary nitrogen reductions, whereas other stakeholders continued to advocate low, enforceable nitrogen limits.

Ultimately, the parties negotiated a resolution that culminated in USEPA’s issuance of the Great Bay Total Nitrogen General Permit in 2020. This permit currently covers thirteen WWTFs, with the option for additional utilities to obtain coverage in the future. The first 5-year permit term includes enforceable nitrogen load caps, intended to limit the aggregate nitrogen loading to 100 kg/year per hectare of estuary surface area. The general permit does not include nitrogen concentration limits, and the load limits are expressed as rolling seasonal averages. This approach provides operational flexibilities to the WWTFs and allows some utilities to postpone upgrades by staying under design flow rates.

A key element of the general permit is a utility-authored adaptive management plan that charts a course for future permit terms. Under this plan, the utilities support regional water quality monitoring and scientific studies to improve our understanding of the role of nitrogen and other stressors in the Great Bay. Brown and Caldwell serves as the technical representative to the municipal alliance, advocating sound science and reasonable regulatory interpretations of the ongoing studies. This paper will describe ongoing nitrogen-seagrass studies and how those results are being considered for future general permit terms.

Current Clean Water Act regulations affecting municipal wastewater and stormwater discharges inhibit collective efforts as individual stakeholders are forced to address rigid and narrowly focused regulations. EPA's Integrated Municipal Stormwater and Wastewater Planning Approach Framework that applies systems thinking based on a one water principle, coupled with local accountability. A more effective one-water regulatory framework can create more economical and sustainable outcomes that result in better overall water quality. Integrated planning is a concept that supports prioritization of capital investments in all forms of water infrastructure designed to protect human health and the environment, and to incorporate societal objectives in the most cost-effective, affordable way. Integrated planning also provides more coordination and up-front planning at the local level along with local stakeholder accountability. The result is less cost to achieve ultimate goals, compliance with regulations, and successful outcomes. While the framework has existed for a decade and is now part of the Clean Water Act, less than 0.5 percent of communities are taking advantage of it.

The Water Environment Federation established the Integrated Planning Task Force (IPTF) to provide effective and focused leadership about integrated planning through collaboration with WEF committees, WEF members, regulators, municipalities, and other stakeholders. A long-term goal for the IPTF is to increase incorporation of integrated planning in the development of municipal National Pollutant Discharge Elimination System (NPDES) permits and consent decrees in enforcement actions under the Clean Water Act.

The Roadmap for Integrated Planning purpose is educating this audience about integrated planning and helping utilities and regulators understand how integrated planning could benefit the utility, the regulatory agency, the community, and the environment. This session will provide an overview of the content of the Roadmap and the plans to help both utilities and regulators become more knowledgeable about integrated planning and to begin using it for NPDES permitting and enforcement actions. Participants will learn about when integrated planning is likely to be most successful, reinforced with case study experience, and how an integrated plan can be efficiently developed for a community.

The paper will summarize the IPTF's plans for taking the roadmap "on the road."

There’s never been a better time than now for utility leaders to examine and improve business processes throughout their organization. With many utilities experiencing on-going staffing and funding challenges, the Water Environment Federations’ (WEF) WISE program for Utility Management provides utility leaders with a framework and methodology to create greater value and improve performance. This comprehensive approach to improve management and performance in water sector utilities encourages full systems thinking. It provides greater value to stakeholders, improves senior leadership’s ability to make an impact, and increases employee engagement and thus their motivation to add value to the organization. It is a collaborative peer-to-peer effort that includes leading utilities from all over the U.S. including Charlotte Water, Louisville MSD, Great Lakes Water Authority, San Francisco, DC Water, the City of Portland and others in the US as well as utilities in Canada and the United Kingdom.

One of the greatest strengths of the WISE program is the collaboration among the participating utilities: the Utility Partners. Subject Matter Experts from the Utility Partners have created leading practice models for Capital Improvement Programs, Asset Management, Capital Project Business Case Evaluation, and several other business processes. The presentation will include an overview of the methodology and several case studies where utilities have successfully employed elements of the approach as well as the findings of current pilot projects. Participants will learn how they can become part of the consortium of utilities improving their business practices in meaningful and comprehensive ways.

Abstract Summary:

The purpose of this presentation is to share the issues, corrective actions, and lessons learned during the startup and commissioning of steam boilers that feed three thermal hydrolysis process (THP), designed to process 375,750 dry lbs/day.

Background:

The Achilles heel of the Thermal Hydrolysis Process (THP) system are the ancillary support systems (potable water, compressed air, steam etc.). The THP system cannot be tested, commissioned or started-up without steam. The boiler system and associated infrastructure is as crucial for facility operation and reliability as the THP system. Consequently, any delay in the testing can result in a day-for-day loss to the project schedule.

With an increase of THP systems across the country, the demand for industrial sized steam boilers at Wastewater Treatment facilities has also increased. The addition of large boilers can pose new and frustrating challenges that are unique to the boiler industry, and uncommonly encountered in municipal facilities. This presentation will delve into the challenges that arose during the commissioning and startup of three 16 million BTU Firetube steam boilers. Specifically, gas supply challenges, gas regulating valve placements, excess head loss and steam supply issues for injection into the Deaerator.

This boiler system case study consists of three boilers, a deaerator, three feed water pumps, a chemical dosing system, and a water softener system. Serving as the installing Contractor and the Commissioning Manager, MWH led the startup and testing of the boilers, troubleshooting and coordination between project stakeholders. Due to the criticality of boiler system reliable operation, MWH was responsible for collaborating with stakeholders to develop work arounds and final infrastructure corrections.

This presentation will outline the issues that arose, the troubleshooting steps taken to determine the route causes, steps used to ensure the boilers were ready to support the startup of the THP systems, and finally, review crucial lessons learned throughout the process.

Over the past 10 years I’ve had the unique opportunity to both write electrical and I&C testing specifications as a design engineer and execute those testing specifications in the field working as a C&SU manager on multiple water/wastewater projects.

It’s often we find the specifications to be lengthy and most owner’s and general contractors don’t understand the effort required to execute the testing in the specification, nor do they even know what the testing entails. Owner’s and general contractors become extremely reliant on their EI&C subcontractors to tell them when and how to execute the work. This typically isn’t a problem until the project team is up against the deadline to start-up the plant or the individual piece of equipment, and their subcontractor is holding them hostage. I often get asked, what testing really must be done to start a piece of equipment? How much time should be allocated in a schedule to account for this testing? How should all the testing predecessors be tracked allowing for a green light for the commissioning phase? In what order should the testing be conducted? All these questions have led me to spend the last several years of my career, looking at how to optimize this process and how best to communicate the requirements with owners and contractors who may not speak the EI&C language.

This presentation will cover testing requirements/types at a high level, then I’ll take a deeper dive into the order in which testing should be executed and where there might be opportunities to expedite testing in the schedule.