Session 04B: Energy Recovery
1:15pm - 2:00pm
The Future of Meeting Permit with Energy Efficient Operations is Here
While energy hasn’t been on everyone’s radar in the past, thinking about energy use and ways to operate more efficiently is becoming more common. Many WRRFs have made no and/or low-cost operational changes to save energy without sacrificing water quality. Some have overcome barriers including the “this is the way we’ve always done it” thinking. Hearing success stories about facilities who have made small changes that led to significant energy savings might just be the help you need for your facility. Even folks who think their facilities are already optimized have found ways to save energy through strategic energy management. This presentation will focus on typical energy saving opportunities at WRRFs. Real world examples of projects implemented in the Pacific Northwest will be shared.
2:00pm - 2:45pm
Lewiston, Idaho Revamps their Aeration Basins to Save Energy and Improve Process Control
Keller Associates, Inc., United States of America; ,
Lewiston, Idaho's wastewater treatment plant dates back to the 1950s, and surprisingly several of the original components are still in operation today. Although the equipment had been maintained, several equipment failures, and the associated emergency repairs, opened the City's eyes to the need for additional investment. One of the largest expenses for the facility was the aeration basins. The City utilized coarse bubble diffusers and controlled the aeration using manual operator adjustments. Additionally, the aeration capacity was insufficient, leading to several process upsets.
Over the past few years, the City made several critical decisions to improve its aeration basin system. Their approach eventually led to the construction of a new treatment process configuration within the existing basins. Additionally, the mixing, aeration, and aeration controls were all replaced to reduce energy usage and improve process control. The improvements, including compressed gas mixing and ammonia-based aeration control, have recently started up on the approximately $35 million project. This presentation will discuss the steps the City went through, their decision-making procedure to select the equipment, and the process and energy improvements that have been observed.