Conference Agenda

Session 04B: Collection, Pump Stations and Conveyance: Pump Stations
Monday, 09/Sep/2019:
1:15pm - 2:45pm

Session Chair: Jason Morse, Whitney Equipment;
Location: D137-138

1:15pm - 2:00pm

To Pump or Not To Pump: How Dynamic Models Help Facilitate Quality Design Decisions

Alex Yoffie1, Bhargavi Ambadkar2, Auburn Mills2, Tyler Nading1

1Jacobs, United States of America; 2City of Portland; ,

The City of Portland is increasing secondary process capacity at the Columbia Boulevard Wastewater Treatment Plant (CBWTP) to optimize biological wet weather treatment capacity and increase operational resiliency. The expansion includes two new secondary clarifiers, which the City is committed to provide with predictable hydraulic performance and at a minimized cost. The challenge is to identify the best way to integrate the new clarifiers into the existing plant hydraulic profile and facilities.

Five alternatives were developed in collaboration with the City, including gravity flow options and options which add a new intermediate pump station. This presentation will demonstrate how dynamic simulation was used during the conceptual design phase to develop and compare the alternatives and select the alternative that best meets the design hydraulic capacity, minimizes life cycle cost, and achieves system control objectives. Specific analyses performed included:

  • Creation of a hydraulic model of the existing system using plant drawings and of each of the proposed alternatives using conceptual design concepts.
  • Integration of the pump station control strategy based on plant process control narratives to create a realistic “flight simulator”.
  • Calibration of the model against historical plant data to verify model accuracy.
  • Evaluation of maximum gravity and pumped capacity for each alternative to confirm each alternative meets the design targets.
  • Comparison of operational costs and effectiveness using a full year of flow data for each alternative.

The presentation will illustrate how this project and dynamic hydraulic modeling helped facilitate the decision-making process by:

  1. Bridging gaps between hydraulics and controls design teams by facilitating discussion during the conceptual design phase.
  2. Bringing design clarity by visually demonstrating how the CBWTP system will operate for each alternative.
  3. Providing recommendations for the most cost-effective hydraulic solution with the lowest operational risk.

2:00pm - 2:45pm

A Triple Bottom Line Approach to Maximizing District Assets - Lift Station 23

Brian Casey1, Brigitte McCarty2

1Murraysmith; 2Alderwood Water & Wastewater District;

The District implemented a program to redirect flows within their collection system to take maximum advantage of their existing wastewater treatment plant asset. As part of this program, a new lift station and force main was needed to intercept gravity flow and pump to an adjacent drainage basin. Three primary characteristics guided the development of this project:

  • Triple bottom line analysis for pump station siting and downstream alternatives;
  • District willingness to align projects with infrastructure assets that already have a limited remaining life; and
  • Active engagement of Operation and Maintenance (O&M) staff.

First, the District/Consultant team needed to answer the weighted question, where can the greatest amount of flow be collected for the lowest impact? The team used a triple bottom line analysis to evaluate possible sites, and ultimately chose a location that aligned with District, operational, and community goals.

Critical to any wastewater pumping project, the team performed a downstream analysis to understand capacity and condition improvements necessary to accommodate the pumped flows. The District carried the triple bottom line mindset to this stage of the project as well - emphasizing not only capacity, but the service life of the existing infrastructure.

Operation and Maintenance (O&M) staff were actively engaged throughout the design process, most directly through several interactive workshops. The station configuration was selected largely by the O&M staff after reviewing alternatives and taking them on a tour of several wastewater pump stations in the local area. Ultimately, this project was defined as a 2.8 million gallon per day, wet pit/dry pit lift station with a 1,100-foot long force main.

Attend this presentation to gain insight into the triple bottom line approach used. Learn tips and tricks to actively engage O&M staff in the design process, which is the key to any successful project.