Douglas County’s drinking water comes primarily from the Authority’s 1.9 billion-gallon Dog River Reservoir. How does that water get from the river to your faucet?
We start with what we call raw water. At the reservoir intake station, debris such as fish or sticks that could damage plant equipment is screened out before water is pumped to the Bear Creek Water Treatment Plant.
As water enters the plant, it is treated with various chemicals, including chlorine, alum, and lime. They kill disease-causing organisms, adjust the water’s pH and prevent it from having any taste or smell. They also help get tiny particles in the water such as silt to stick together so that they become so heavy that they settle out in a process called coagulation.
Water then moves through a series of chambers, where it is stirred and directed over and under a series of boards. That evenly distributes the chemicals and enhances the coagulation process. As the tiny suspended impurities begin to stick together and grow heavy, water is held in a sedimentation tank so those particles, called floc, can settle out.
You’re almost through! Water then moves though a filter composed of coal, sand and stone that removes any remaining solids and ensures clarity of the water. The filtered water then gets one last shot of chemicals, including chlorine, for final disinfection; lime to adjust pH; phosphates to prevent corrosion of the pipes that carry water to your house; and fluoride which strengthens your teeth.
Your finished water is then held in the Authority’s two 3 million gallon clearwells at the plant so the chemicals can mix evenly before water is pumped into the distribution system and eventually your home. Water not used by homes or businesses goes into the Authority’s six water towers. Those reserves pressurize the system so that your taps run at full flow. They also make sure the community has water to fight fires and to meet demand in unusual circumstances, such as during a power outage or on a hot day when demand is extremely high.