Your Water System
The town of Littleton's drinking water comes from shallow sand and gravel deposits located within the Beaver Brook and Bennett's Brook watersheds. Four groundwater production wells are used to withdraw over one and a half million gallons per day of drinking water. The sand and gravel act as a huge underground reservoir, which is continually replenished by rainfall and snowmelt.
Once the water is pumped from the ground, it enters the distribution system, composed of over forty-two miles of water main and three standpipes. The standpipes, located on Newtown Hill, Cedar Hill, and Oak Hill store over two million gallons of water. This storage capacity helps maintain system-wide water pressure while at the same time providing sufficient amounts of water during periods of high water demand (i.e. fire flow protection). Water personnel not only service and maintain the existing distribution system but also provide assistance required for system growth and development.
Drinking Water Treatment
The chemicals Potassium Hydroxide (KOH) and Sodium Hypochlorite (Chlorine) are added to the drinking water system. KOH is added at very low concentrations to increase the ph of the water and reduce its natural corrosivity. Corrosive water is undesirable because it can cause service leaks, stains on plumbing fixtures, and even degrade the drinking water quality by leaching copper and lead out of private service lines. Chlorine is added at two wells for disinfection at the point of injection. A slight residual exists in the system which may present a slight taste and odor of chlorine.
Why We Treat the Water
We are treating the water from our Spectacle Pond Well to remove dissolved iron and manganese. Over the years, concentrations of iron and manganese in town well water have increased greatly. Because of this increase, what were once rare occurrences of "black water" have become common.
What is "black water"?
Iron and manganese that have come out of solution form a buildup on the inside of water mains. Occasionally, a piece of this black "stuff" breaks off and disperses into the water. This creates localized cloudy, gray/black water. Although perfectly drinkable, the black water can cause staining on fixtures and laundry.
Littleton Water Department Drinking Water Treatment Plant
(Simplified Schematic Diagram)
How it works:
 Step 1 - Well No. 5
Water from the Number 5 well is pumped into the water treatment plant. This water contains naturally occurring dissolved iron and manganese. Concentrations of these minerals have been increasing each year since 1981 when the well was first put into service.
 Step 2 - Ozonation
Ozone (O3) is created by sending electricity through very dry air. Thus created, the ozone is bubbled through the well water in the ozone contact chambers. Ozone causes the iron and manganese to form solids, which can be filtered out. Any remaining ozone is converted back to oxygen (O2) before being released.
 Step 3 - Filtration
Ozonated water is forced through filters, which block the solid particles of iron and manganese. Periodically, these particles are washed from the filters, dried and trucked away. The process has been designed to minimize the amount of water that is wasted.
 Step 4 - Corrosion Control
As with the other existing well sites, minute amounts of potassium hydroxide (KOH) are added to adjust the pH for corrosion control.
Step 5 - Distribution
The filtered water flows into a clear well and from there into water mains. The capacity of the plant is 1.5 million gallons per day, which could easily meet the water demand of the entire town.
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