The Mansfield Water Treatment Plant receives a daily blend of raw water from both a surface reservoir and 10 wells. Clearfork Reservoir is a 4.5 billion gallon lake, located southwest of the treatment plant. The intakes at the gatehouse permit water to be drawn from 4 levels within the lake, based on seasonal affects on water quality. Lake water flows to a lowlift pumping facility, which can deliver up to 25 million gallons per day (MGD) of surface water to the plant. Potassium Permanganate is added at the intake for zebra mussel control. In addition to the reservoir, there are ten wells, located within a two mile radius of the plant, capable of supplying up to 10 MGD to the plant. Five wells north of the plant, designated by Ohio EPA as under the influence of surface water, enter the plant at the same location as the reservoir water and receive full treatment. The remaining five wells, designated by Ohio EPA as not under the influence of surface water, are blended at the plant, ahead of our 16 rapid sand filters.
The reservoir and north well water are first treated at the plant with activated carbon, for taste and odor control, and alum polymer for coagulation. The water then flows into four primary mixing basins, with a total capacity 500,000 gallons, then into four secondary settling basins with a total capacity of 2.5 million gallons, for settling and clarification.
When the water leaves the settling basins, it is blended with the south well water, and flows to the 16 rapid sand filters. Pre-chlorine is added just ahead of the filters for disinfection. The water is filtered through a combination of anthracite coal, sand, and a mixture of support gravel. The filters remove any remaining suspended matter in the water. After the water passes through the filters, final chlorine is added for disinfection, and sodium hydroxide is added for stability. At the end of treatment, a phosphate silicate corrosion inhibitor is added for further stabilization.
The water flows into two pump houses where it is pumped to the City of Mansfield. The pump houses can deliver up to 25 MGD, if needed. The finished water is stored in two elevated tanks, Straub (2 million gallons) and Shaker (500,000 gallons), and in a 12 million gallon under ground concrete reservoir.
Our plant operators monitor and control the system using a programmable logic controller (PLC) based computer system. PLC’s are also used to monitor the reservoir system, wells, and finished water storage.
- The water plant is classified by Ohio EPA as a Class IV system, based on plant size, types of treatment, and population served.
- The water plant has an Ohio EPA approved chemical and bacteriological laboratory.
- The water plant owns and maintains all power lines, poles, transformers, and substations throughout the treatment system.
- The plant has an Ohio EPA approved corrosion control plan.
- The plant has an Ohio EPA approved wellhead protection plan.
Water Quality Reports