Where Contamination on Beaches Comes From
Editor’s Note: Recent water news has been filled with stories about polluted beaches in the US and around the world. Most of these report the bad news but do little to explain the causes. We’ve excerpted some information from an excellent article by Andrea Gelfuso Goetz that appeared in the Denver Post that gives a good explanation of the how and why of the nation’s dirty beaches. –Hardly Waite.
A study conducted by the environmental organization NRDS found that as many as 10 percent of U.S. beaches are unsafe for swimming, contaminated with storm-water runoff and sewage overflow that cause illnesses like “stomach flu, skin rashes, pinkeye, respiratory infections, meningitis, and hepatitis.”
How does raw sewage end up on U.S. beaches?
Every time it rains, water running over lawns picks up fertilizer, pesticides and animal waste. Water running over streets and parking lots picks up oil, gas and spilled chemicals. In cities, storm runoff is channeled into sewers that discharge polluted water directly into water bodies, including the river your dog likes to splash in.
While some municipal storm water is pumped into sewage treatment plants, they are overwhelmed by heavy storms, so storm water is discharged, untreated, into rivers and lakes. On the coast, storm water is discharged into the ocean, polluting U.S. beaches, sometimes making swimmers sick.
Doesn’t environmental regulation protect us from water pollution? The Environmental Protection Agency sets water quality standards for U.S. waters based on the intended use of each water body. For example, water used for drinking has to meet the toughest standard. Water used for swimming and fishing has to be clean enough so people don’t get sick.
The Clean Water Act regulates “point sources” of pollution (water pollution that comes out of pipes), but only weakly regulates “non-point” sources, pollution that is created when water runs over the ground. So we end up with polluted beaches.
But untreated storm water affects more than beaches. The EPA tracks water-quality data for all types of water bodies, including rivers and streams, lakes and reservoirs. Compared to other water bodies, beach water quality is just ducky. While 90 percent of U.S. beaches meet EPA standards, less than half of U.S. rivers and streams are safe for swimming and fishing. What’s worse, only 28 percent of U.S. rivers and streams have been assessed — so we don’t know whether 70 percent of U.S. rivers and streams meet the standards.
How about lakes and ponds? Nationally, only 43 percent have been assessed. Of those, 67 percent are “impaired” and don’t meet public health standards.
Most disturbing, of the U.S. lakes, reservoirs and ponds used to raise fish for food, 74 percent are impaired.
To see water quality information for all U.S. water bodies, go to the EPA’s website, click on the science and technology menu, and the waters tab.
Source : Denver Post.