The Minnesota Buildings, Benchmarks and Beyond (B3) database automatically records DMR data the city submits to the MPCA and places it on the city's B3 web page. B3 then allows cities to routinely enter and track energy use at waste water treatment plants and receive an official (or unofficial for flows under .6 MG/D) Energy Star Portfolio Manager score from 1-100 that compares the performance of your plant to those nationwide. B3 can also be used to track lift station and drinking water data. Note that in Twin Cities the Met Council offers cities a customer portal for viewing metered waste water flow data and I/I program-related information.
The MN Auditor's Infrastructure Stress Transparency Tool reports 5 years of data on the sewer and drinking water fiscal performance of city enterprise funds for sewer and water plants. Additional information also available.
For facilities paying a demand charge for electricity, installing power factor correction equipment and/or storing methane from anaerobic digestion to generate peaking power will yield cost-savings due to lower energy demand charges.
Ductile iron pipe for drinking water mains has stronger walls, allowing a larger inside diameter, reducing friction and thus saving energy. According to St. Cloud’s Pumping Cost Study (July 2014), the city's use of ductile iron pipe (certified under the SMaRT standard ) results in an annual savings of $210,530 compared to competing pipe, measuring power cost, pump efficiency, and head loss.
Calculate your waste water plant's benchmark by dividing average daily energy use by typical flow in MGD (millions of gallons per day); report energy use for drinking water produced and delivered in kWh per 1,000 gallons (typically between 0.25 to 3.5 kWh). Report water system losses under action 20.3; report protection efforts that sustain facility function during extreme weather under action 29.7
Use B3, Portfolio Manager or the like to report several years of historic data; note how your water and waste water facilities compare to similar plants; report awards for plant excellence.
Report that the Sewer, and Drinking Water, Enterprise funds (using data from https://www.auditor.state.mn.us/maps ) have had 5+ years Positive Net Income; rank in the best 25% of Upper Midwest peer plants.
Who's doing it
Duluth - 3 star
Date action report first entered:
Date of last report update:
Year action initially completed: 2010
The Duluth Water Treatment plant has electricity and natural gas data entered from 2016 to the present.
Per the state auditor's tool, the city's Water and Sewer Enterprise Funds have had positive net income for the last 5 years.
The City has entered energy use data into B3 Benchmarking for purposes of monitoring and managing energy use and for comparison with peer water production facilities. Energy use in a water treatment plant varies with weather and can be significantly affected by drought years. However, the treatment facility has invested in variable frequency drives on its high service pumps and has been able to reduce pump use to one pump for the majority of its needs. This has produced a saving in demand charges when starting up additional pumps to meet daily demand.
Outcome measures/metrics/money saved:
In comparing kWh per 1000 gallons in 2008 with 2016 there was a 7 percent decrease in energy consumption. During both years, the facility pumped 2.43 billion gallons and saw an approximate increase in electric rates of 15 percent over the intervening 8 years. The treatment facility is on a peak shaving program with Dakota Electric Association and receives a reduced commercial electrical rate.
The City is a member of the Joint Water Commission (JWC) along with the cities of Crystal and New Hope. The JWC purchases drinking water from the City of Minneapolis, which draws its water supply from the Mississippi River. The JWC owns two water storage reservoirs from which water is pumped to three above-ground water tanks and through pipelines that serve all three cities. One of the reservoirs is located in Golden Valley and one is located in Crystal. Golden Valley provides financial services for the JWC and therefore receives and pays all energy bills. Golden Valley uses the B3 benchmarking database to compare the energy usage of its water reservoir to peer plants.
Outcome measures/metrics/money saved:
The average daily flow for the three cities that make up the JWC is 4.75 MGD. Between June of 2016 and June of 2017, the average daily electric usage for the Golden Valley reservoir was 2,043 kWh per day. During that same time, the average daily electric usage for the Crystal reservoir was 2,834 kWh per day. Therefore, the JWC pumps and delivers drinking water at a rate of 1.0267 kWh per 1,000 gallons.
The City has utilized B3 Benchmarking, internal data tracking programs, and has communicated energy usage results with local peer plants in an effort to gauge our efficiency. The tools available have proven the best measuring stick is your own plant due to the wide range of treatment technologies, flow, loading variables, differing regulatory requirements, etc. By actively benchmarking our operations by in-line data collection and daily data assessments we have been able to implement improvements that save energy, chemicals, water, and time.
MPCA recognizes North Branch wastewater facilities for operational excellence. The Minnesota Pollution Control Agency (MPCA) is recognizing 334 Minnesota wastewater treatment facilities for maintaining outstanding permit compliance from October 2017 through September 2018.
Utility billing data has been entered into B3 for the City's drinking water and wastewater treatment facility. B3 just added data that allows wastewater treatment facilities to be benchmarked against others for peer review.
The City's Comprehensive plan (see link Chapter 9) requires the water distribution system to complete an engineering study and CIP every 5 years (see attached report cover) to look for water losses, flow and pressure evaluations, and infrastructure improvements to improve efficiency of the system.
The Engineering Department does compare energy use of Crystal facilities with peer facilities on an on-going basis. Crystal volunteered to be one of the guinea pigs for automatic reporting of city buildings.
The City has received a report on emissions for City Operations through consultant Michael Orange as part of the development of our Climate Action Plan. This included energy use for the WWTP operations.