Some residents of a five-county area of West Virginia are now able to drink and bathe again after state health authorities decided Monday to lift some water bans that affected more than 300,000 people since a chemical spill last week.
But the accident illustrates some of the vulnerabilities of the nation's water supply and the fact that toxic chemicals are sometimes stored right next to water treatment plants. Experts say that it's much easier to prevent threats to sources of water rather than try to clean them up afterward.
"We really need to get a handle on things before they start," said Lynn Thorp, water program director at Clean Water Action, an advocacy group based in Washington. "If we wait to solve the problem in the drinking water plant, we've waited too long."
Each year there are more than 10,000 spills of oil and hazardous substances, according to federal estimates, many that get into water supplies. From raw sewage to rocket fuel, sometimes these spills evaporate or dissipate into the air or water. Other times, as in Charleston, W.Va., the results are disastrous to human health and wildlife.
The nation's worst municipal water contamination occurred in Milwaukee in 1993, when an outbreak of the Cryptosporidium parasite sickened 400,000 people and killed 69. A malfunctioning filter at the city water plant allowed the organism to spread throughout the city's entire public water system.
Thorp and others say the accident on the Elk River in Charleston was the result of lax regulation by both state and federal officials. Even though Charleston's water treatment plant has advanced carbon filtration systems, it wasn't enough to remove the 7,500 gallons of a chemical used to wash coal before shipment.
Across the country, communities have battled harmful runoff from animal feeding operations (North Carolina) naturally-occurring arsenic (New Hampshire, Ohio, Michigan and parts of California's Central Valley), acidic mine drainage from coal mines (Appalachia) and perchlorate from fireworks displays (Lake Tahoe, Calif.), former missile factories (Los Angeles), or seepage into the Colorado River.