General Description of the System
The Town of Needham's water distribution system is a single service pressure zone system supplied by two sources. The town's primary source of water is the Charles River Wellfield consisting of three groundwater water pumping stations. The water is pumped from the wells to the Treatment Plant before being pumped to the distribution system. This wellfield has been the major source of water since the 1930s.
The town's secondary source is from the Massachusetts Water Resources Authority (MWRA). The MWRA supply enters through a 36 inch diameter pipe that runs from the MWRA's Metro West Tunnel in Weston to a booster station on Central Avenue at St. Mary Street. This connection was constructed in the mid-1950's.
Water Treatment Process
Treatment processes include oxidation and removal of manganese with potassium permanganate via filtration, pH adjustment to raise the natural pH and alkalinity of Needham's water, thereby reducing the water's corrosiveness to household plumbing, disinfection via the addition of chlorine to kill any pathogens (germs) that may be present in the water, fluoridation which prevents tooth decay and cavities and finally injection of polyphosphate to minimize calcium from precipitating in homes. All components of the water treatment and distribution system are closely monitored by state certified operators through computerized Supervisory Control and Data Acquisition Systems (SCADA).
There are about 135 miles of street water mains that distribute our water throughout the town. This distribution system includes two large storage facilities that have a capacity of four million gallons. Each part of the water system needs routine maintenance in order to maintain a safe and dependable water supply. Listed are some of the projects undertaken by the Water Division in 2010.