03-14-2022 Council Packet - Laserfiche WebLink

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CITY COUNCIL AGENDA ITEM 1E STAFF ORIGINATOR: Michael Grochala, Community Development Director MEETING DATE: March 14, 2022 TOPIC: Consideration of Resolution No. 22-32, Accepting Water Treatment Pilot Study VOTE REQUIRED: 315 INTRODUCTION Staff is requesting council acceptance of the Water Treatment Pilot Study. BACKGROUND In 2019, the Minnesota Department of Health tested the City's manganese levels in each of the City's wells as part of the EPA Unregulated Contaminant Monitoring Rule 4 (UCMR4). The water quality testing data from MDH indicated that five of the City's six wells exceed the maximum recommended manganese level for infants, and three of the wells exceeds the maximum recommend level for adults and children. A Water Treatment Plant feasibility study was completed in June of 2020 to evaluate options for addressing the manganese issue. A Utility Rate study, evaluating funding for the improvement, was completed by Baker Tilly and accepted by the City Council on May 10, 2021. On June 14, 2021, the City Council authorized WSB to complete the Water Treatment Pilot Study to verify the effectiveness of biological filtration to remove manganese, iron, and ammonia from the City's well water. The purpose of the study was to provide the City with critical information required to design and size a water treatment plant to address the manganese and iron levels in its drinking water. The attached report recommends construction of a conventional gravity filtration system using biological filtration with an initial treatment capacity of 6,000 gallons per minute (gpm). Biological filtration is promoted by the Minnesota Department of Health and is currently being used by the cities of Minneapolis, St. Paul, St. Cloud, and other communities in Minnesota to effectively treat their drinking water. Biological filtration could potentially save the City almost $1 million in chemical costs and save millions of gallons of water over the first 20 years of plant operation. With the completion of the Pilot Study the City is in a position to move forward with design of the Water Treatment Plant should the City Council decide to do so. Staff is planning to bring forth discussion on next steps at the April 4, 2022 work session.