Fluoridation:

Fluoride is a natural constituant of ground water and is typically 0.1 milligrams per Liter in our source water. We add sodium fluoride to raise the level to 1.0 to 1.1 milligrams per Liter to promote strong teeth and prevent tooth decay. The fluoride treatment is voluntary and is authorized by Town Meeting vote.

pH Adjustment:

Potassium Hydroxide is added to the water to raise the pH of the water from 6.5 or lower to 7.0 in order to reduce the corrosion rate of lead and copper home plumbing materials. This treatment is required by the Safe Drinking Water Act and was started in the 1990's. We add approximately one gallon of Potassium Hydroxide to each 20,000 gallons or water pumped.

Disinfection:

Sodium Hypochorite is used for disinfection. It is used as the primary disinfectent at the source and a chlorine residual is maintained in the distribution system to protect against contamination. One side effect of using chlorine is it forces more manganese out of solution which causes sediment to acculmulate in the mains. Disinfection of our water is required by the Massachusetts Department of Environmental Protection.

Sequestering:

This winter we hope to add a phosphate based sequestrant to keep manganese in a soluable form and prevent it from precipitating out of the water and accumulating as a sediment. The manganese concentration is relatively low in our source water but it can accumulate quickly because of the large volumes of water we withdraw.