How is My Water Treated and Purified?
The treatment process consists of a series of steps. First, raw water is drawn from the Allegheny River and goes to a mixing chamber where potassium permanganate, powdered carbon, polyaluminum chloride and lime are added. The addition of these substances causes small particles to adhere to one another (called 'floc') making them heavy enough to settle into a basin from which sediment is removed. Chlorine is then added for disinfection. Ammonium sulfate is added during warmer months to combine with chlorine. This reduces the formation of chlorine by-products, and the loss of chlorine residual as water passes through the distribution piping. At this point, the water is filtered through layers of fine coal and silicate sand. As smaller, suspended particles are removed, turbidity disappears and clear water emerges. Chlorine is added again at this point as a precaution against any bacteria that may still be present. (We carefully monitor the amount of chlorine, adding the lowest quantity necessary to protect the safety of your water without compromising taste.) Finally, caustic soda (used to adjust the final pH and alkalinity), fluoride (used to prevent tooth decay) and zinc ortho phosphate (used to protect distribution system pipes from corrosion) are added before the water is pumped to sanitized storage reservoirs, water towers and into your home or business.

2006 REPORT TO CONSUMERS ON WATER QUALITY
Water Quality Report   •    Continuing Our Commitment
Community Participation   •    Information on the Internet
Where Does My Water Come From?   •    Source Water Assessment
Substances that might be in Drinking Water    •    Is it Safe to Drink from a Garden Hose?
How is My Water Treated and Purified?    •    Sampling Results
New Arsenic Regulations    •    Important Health Information