Water Treatment Plant Reclaim Improvements

After a water plant rehabilitation and ultrafilter (UF) membrane addition, the City of Mankato and Bolton & Menk identified a significant source of water being lost in the drinking water treatment process. UF membranes require frequent “backwashing”. The backwashing process, which uses treated drinking water from the distribution system, was consuming 450,000 gallons of useful water per day that could be re-treated and returned back to the drinking water supply. Instead, water was discharged directly to the sanitary sewer system. In realizing disadvantages, the city worked closely with the Minnesota Department of Health to develop a “reclamation” system to return water back to the treatment process. The amount of water saved is equivalent to the daily use of 5,000 residents.