MnTAP finds energy savings at wastewater treatment plants

March 2024

Let’s talk about sweet, sweet energy savings at wastewater treatment plants!

Minnesota Technical Assistance Program (MnTAP) is an environmental outreach and assistance program for businesses and organizations throughout Minnesota. When it comes to wastewater treatment plants, MnTAP staff coach municipal operators on finding no-cost/low-cost ways to save energy without disrupting the plant, then those operators go and "Sherlock Holmes" out those savings. Nifty!

We spoke with MnTAP Engineer Kira Peterson to learn more:

CERTs: Tell me a little bit about the work MnTAP does with wastewater treatment plants.

Kira: Starting in 2014 MnTAP conducted a series of grant-funded projects focused on energy efficiency at wastewater treatment plants. Each project built on the last, establishing that there were opportunities for wastewater operators to make no-cost operational changes at their treatment facilities that consistently resulted in significant energy and cost savings for their cities. This led to our organization developing a curriculum to teach wastewater operators to identify and implement energy saving operational changes at their own plants, without negatively impacting the process or effluent quality. The training is a series of four in-person trainings and two conference calls that cover benchmarking energy use, secondary treatment efficiency, biosolids efficiency, energy rebates, and next steps. MnTAP instructors deliver the training in person at a local location, like a town hall or wastewater facility conference room to small cohorts consisting of operators from five or fewer nearby wastewater treatment facilities. The goal is that by the end of the trainings each operations team will have a clear plan to implement the savings opportunities they identified.


CERTs: You all find some impressive savings! What are some of the more common ways people are finding to save energy?

Kira: It's the operators themselves who find these savings, we just help them learn how to choose and prioritize the opportunities that make the most sense for their unique plants. During the course they usually discover that their secondary treatment process is the biggest energy hog at their treatment facility, whether it's aerated with blowers or with rotors. From there, they get creative with ideas for how they could potentially reduce airflow and theWhite woman with light hair wearing a white hard hat and holding her thumb up. In the background is a mechanical warehouse environment. corresponding energy that goes into it. This can look a lot of different ways, for example they might be reducing dissolved oxygen setpoints, prioritizing an existing smaller blower over a larger blower, or simply changing a tank level.


CERTs: How did you get into this line of work?

Kira: I've had a fun career that started in analytical chemistry and then transitioned to environmental engineering and operations. I have a professional engineering license and a Class C Wastewater Operator license in both Minnesota and Colorado. Back in 2021 I happened to see a job posting from MnTAP advertising a position focused on instructing wastewater operators in energy efficiency and I knew I had found my niche!


CERTs: What is your favorite part of the job?

Kira: I enjoy getting to know my students and their treatment facility processes. It always feels good to see them come up with a great idea to reduce energy at their facility.


CERTs: If people want to participate in a local energy efficiency training with their nearby wastewater treatment plant, what should they do?

Kira: Please contact me at [email protected] or 612-624-4653.

Energy Efficiency Success

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