How Water Gets to Your Home
By Daily Press, Newport News, Va.
Apr. 26–Newport News Waterworks is a regional water utility that provides drinking water to more than 400,000 customers in the cities of Newport News, Hampton and Poquoson, and in parts of York and James City counties. On an average day Waterworks treats and delivers between 45 and 50 million gallons of water to its customers.
Most of the water is surface water from the Chickahominy River in James City County. Waterworks pumps water from the river to one of five outlying reservoirs for storage: Lee Hall in Newport News; Harwood’s Mill in Newport News and York County; Diascund in New Kent and James City County; Little Creek in James City County; and Skiffe’s Creek in Newport News and James City County.
To make water safe to drink, it is treated. At the water treatment plants, Waterworks cleans its surface water using the following process:
Screening: Before entering the water treatment plant, water passes through a screen to remove logs, fish, plants and other large debris.
Rapid Mixing: When the water enters the treatment plant, it goes to the rapid mix chamber, sometimes called a flash mixer. There, a chemical called a coagulant is mixed into the water. Aluminum sulfate, or alum, is a chemical that is often used as a coagulant. A coagulant causes charged particles in the water become destabilized. This helps to promote coagulation, the process of transforming a liquid into a semi-solid.
Flocculation: Next, the water travels through a basin where very slow mixing occurs. Here, the small, destabilized particles are attracted to each other. They begin to stick together and form larger, heavier particles called “flocs.” This process is called flocculation.
Sedimentation: Once the flocs form, the water travels through another basin where no mixing occurs. The flocs settle to the bottom of the basin where they will later be removed. This process is called sedimentation.
Filtration: The water is then sent through filters to remove any remaining particles. Often these particles are invisible to the naked eye. Filters are usually made up of materials like sand, anthracite coal and granular activated carbon. Disinfection: Disinfection is the part of the treatment process in which bacteria and germs are inactivated or killed. Ozone, chlorine and chloramines are three chemicals that we use for disinfection.
Fluoridation: Fluoride is added to the water to prevent tooth decay.
After water is treated, it is pumped to Waterworks customers through a series of pipes, storage tanks and pumps. Waterworks’ distribution system has 12 storage tanks, more than 1,700 miles of pipeline, 9,100 fire hydrants and 35,000 valves.
SOURCE: Newport News Waterworks.
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Copyright (c) 2007, Daily Press, Newport News, Va.
Distributed by McClatchy-Tribune Business News.
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