Norton Water Treatment Plant
The Town of Norton, MA selected Weston & Sampson to perform pilot testing, design and provide construction services for a new water treatment plant. The facility was designed to provide treatment for the removal of iron and manganese for three of the Town’s existing groundwater wells.
During pilot testing, we determined that sodium hypochlorite was not adequately removing iron from the raw water. Potassium permanganate was tested and removed iron and manganese to acceptable levels.
The water treatment plant treats up to 2.5-million gallons per day using GreensandPlus™ media and six, twelve-foot diameter pressure filters. The treatment process includes potassium permanganate for oxidation, sodium hydroxide for pH adjustment, and an ortho/polyphosphate blend for corrosion control. Sodium hypochlorite is also added for disinfection and oxidation. The plant includes a 60,000-gallon in-plant clearwell for contact time and backwash supply. The clearwell provides 4-log virus removal to meet MassDEP GWR. A forced draft steel aerator is provided to strip carbon dioxide in the raw water and raise the raw water pH to approximately 7; a backwash recovery system is comprised of two backwash water decant/recycle tanks to increase the overall recovery of the plant.
Design elements of the treatment facility include a bathroom, laboratory area, fully automated SCADA system integration with the existing distribution system including two other active wells, site piping, and construction of a paved driveway and gravel access road along the perimeter of the residual sand drying beds. The design includes refurbishment of the well stations with new pumps, instrumentation, and demolition of the existing chemical feed systems.
A raw water transmission main was designed as a directional drill under the Canoe River to avoid environmental impacts and reduce overall costs.