MnTAP (Minnesota Technical Assistance Program), a free assistance provider at the University of MN, will help develop recommendations that might be fundable using utility rebates.
The Midwest Assistance Program focuses on communities under 2,500 in population (allowing them to bypass a full RFP contracting process), and the MN Rural Water Association provides services at no charge to community water and wastewater systems and rural water districts with populations under 10,000.
Inform residents about the ecological benefits of reducing water softener salt use; shift operation times of large pumps or activities so as to secure a cheaper electric rate; purchase cheaper 'interruptible rate' electricity; install a peaking generator for load shaving/cost savings as well as backup power. Report ductile drinking water pipe under BPA 15.8.
Report savings from reduced fluoride levels; evaluate pump efficiency, repair or upgrade to efficient ones and report on anticipated cost savings; launch a rebate program for residents to optimize, upgrade or remove their water softeners.
Implement other/longer payback period drinking water facility upgrades such as measurable reduction in chemical use, use of backwash water; soften drinking water and work to eliminate home water softeners.
Who's doing it
Apple Valley - 3 star
Date action report first entered:
Date of last report update:
Year action initially completed:
The city has completed an energy audit and backwash optimization improvements.
The City of Inver Grove Heights utilizes Xcel Energy's peak control program for the booster station and three of the city's wells. When Xcel experiences a high energy demand, the City can power the wells with our generators to receive a reduced energy rate.
To increase pumping efficiency, the City upgraded the water treatment plant's lift station with the financial assistance through an Xcel rebate. Operating pumps at the booster stations and well house have received annual variable frequency drive upgrades over the last 15 - 20 years.
In 2015, the Department of Health reduced the required concentration of fluoride in drink water. The City of Inver Grove Heights responded by reducing the concentration of fluoride added at the water treatment facility from 1ppm to 0.7ppm, which reduced the City's expenses on water treatment chemicals.
The City has upgraded their force main wastewater pumps to dual air release / air vac for better performance and efficiency.
The City utilized the allowed 10% of recycles backwash water in the water treatment plant operations.
By using the clarifiers in the wastewater treatment plant, the City has lowered the amount of Aluminum Sulfate by approximated 1/3.
The City has lowered the amount of hydrofluorosilicic acid used to fluoridate the city’s drinking water in response to the new fluoride level rule.
2019: The Minnesota Public Facilities Authority (PFA) announced $12 million in loan and grant funding for water infrastructure projects in Atkin, Dassel, Gibbon, Marshall. “These projects will increase access to clean water and protect the environment,” said Governor Tim Walz. “This represents a great investment in the health and wellbeing of our local communities.” “Water infrastructure continues to be a vital resource for Minnesota communities,” said DEED Commissioner Steve Grove. “These projects represent an investment in the future health and economic growth of Greater Minnesota.”
Outcome measures/metrics/money saved:
2019: Marshall, $7,000,000
This project consists of improvements to the drinking water treatment plant that will reduce discharge of chlorides to the environment. Funding for this project comes from a Point Source Implementation grant of $7 million. In addition $4,585,492 will come from local sources.
We have back-up generators and are already part of the Xcel Energy’s peak shaving program. We recycle all water used for backwashing and from the filter presses. This water gets pumped back to the head of the plant for re-treatment.
In late 2016, the City started construction on water treatment facility that contains a reverse osmosis membrane treatment. This allows for softer water coming out of the plant and for citizens to reduce their water softner or remove all together. We have seen a reduction in the amount of chloride in our wastewater system.
-The City of Burnsville pumps the majority of it's water at night, securing a cheaper electrical rate.
-The City has many natural gas pumps and motors, versus electric.
-Installed a peaking generator for load/shaving and cost savings in the 1990s.
The City evaluates pump efficiency in it's 10 Year Cycle Rehabilitation Plan. If a pump needs to be replaced, the city applies for rebates that usually make the most energy efficient pumps that most cost efficient.
A third party electrical company inspects the City’s water and wastewater pumps on a yearly basis to ensure all pumps are working to their maximum efficiencies. The City has installed a peak shaving generator in its pump house and has replaced two out of the four water reservoir pumps with newer, more efficient models. There are plans to replace the remaining two pumps by 2020.
Outcome measures/metrics/money saved:
The average daily flow for the three cities that make up the Joint Water Commission (Golden Valley, New Hope, and Crystal) 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.
In the summer of 2011, the Ciy hosted a MnTAP intern who researched process optimization options at the City's WasteWater Treatment plant. Following the recommendations of the study, the city has replaced its sludge pnd aerators with NEMA super premium efficient motors. In March 2012, the City began implementing the second round of recommendations, which includes installing dissolved oxygen sensors and VFD drives on rotors to optimize dissolved oxygen processes. This project has been budgeted and is expected to be completed by June 2012.
The attached MnTAP Intern report lists process optimization options and associated payback periods.
The WTP lighting was upgraded from high bay metal halide to LED high bay fixtures in the fall of 2015.
The metal halide lighting was never turned off due to the nature of the type of light. If the lights were powered off and we turned them on, it would take 5 minutes for the lights to become fully lit. Meaning we never shut these lights off due to how long the light took to power back on. This was a huge energy hog and most of the time no one was in the room. By changing over to the LED, not only were the lights lower in wattage, they were brighter, and we were able to turn the lights on with instant lighting. The lighting in these rooms today are normally off and have a motion sensor to turn back on when needed.
The improved wastewater plant has many implementations to provide longer payback for drinking water and other water uses. The new plant will get Gilbert below the dreaded mercury limit, as well as remove excess phosphorus from the water. Aerobic digestion will be used to alleviate and reduce waste. The new facility will remove many unnecessary chemicals that would eventually inadvertently end up in Lake Superior.
Outcome measures/metrics/money saved:
The hopes for the future are that Gilbert will meet the soon to be enforced mercury limit. Many people in Gilbert do not understand why there is a mercury limit, much less why they need to comply to it. This new facility will take the burden off their hands. The technology does the work for the people of Gilbert. Phosphorus and mercury do not belong in the St.Louis river, nor in Lake Superior.
We partner with Rich Prairie Sewer and Water for our City Sewer and Water. They test and monitor water and chemicals regularly to make sure that they are providing clean and healthy drinking water. They also have a generator in case of power failure that allows them to continue to operate.
Energy and chemical efficiency evaluations are completed daily at both the drinking water and wastewater treatment facility. These evaluations are used to make changes to the treatment process to be as cost-effective and energy efficient as possible.
The City uses SCADA (Supervisory Control and Data Acquisition) control panels system monitoring. The computer-based SCADA equipment provides information that makes it possible for utility personnel to more effectively monitor and maintain the sanitary (lift stations) and water distribution systems.
Water Treatment Plant Efficiency
The City of Savage standard operating procedure is to use state of the art equipment that is programmable logic controlled, scaled linearly to flow, and calibrated to an individual wells chemical makeup characteristics. This has resulted in immediate savings and chemical reduction to the City.