Tuesday, Jun. 08, 2004

The Plumbing Professor

Marc Edwards
Can you trust the water you drink? Marc Edwards, a Virginia Tech civil-engineering professor and water-corrosion expert, is determined to answer that question. In March 2003 he was working on a pinhole leak in the plumbing of a private home in Washington when he heard talk of elevated lead levels in the local water. He decided to test some samples, and the results shocked him. "One sample was so high it was off the scale of my field meter," Edwards says. "The only thing I know for sure is that it contained more than 1,250 p.p.b. lead." Five thousand parts per billion is classified as hazardous; a city's water supply is considered unsafe if lead levels in more than 10% of tested samples exceed 15 p.p.b. Worried that there was a widespread problem, Edwards — one of the world's leading authorities on corrosion in home plumbing systems — launched an investigation. He was the right man for the job because leaching of lead into drinking water is one of the major consequences of corroded pipes. Says Washington, D.C., Congresswoman Eleanor Holmes Norton: "[Edwards] is the brilliant go-to guy if you are looking for answers beyond the usual prescriptions."

In May 2003 Edwards began collecting more water samples. His research — unfunded by any official sources and assisted only by his dedicated students — reached the startling conclusion that chloramine, which is used to minimize the amount of disinfection by-products in drinking water, was causing lead to leach from lead pipes and brass plumbing materials. He also found that traditional lead testing was misleading. The District of Columbia Water and Sewer Authority used to test both first draw (the first water out of the tap) and 5-min. draw (the water that comes out 5 min. later) and advised consumers to flush the tap for 1 min. But Edwards tested 1-min.-draw samples and found that some contained more lead than the first-draw samples. Why? Because of its position in pipes, 1-min. draw tends to be in contact with the most corroded plumbing materials. Just as Edwards recommended, the agency now warns consumers with lead service lines to run the tap for 10 min. before using water for drinking or cooking.

Recently called to testify on lead problems before the House Government Reform Committee, Edwards said he felt "hugely relieved that for the first time people in authority were treating this problem with the utmost seriousness." Edwards, the father of two children, ages 2 and 4, says the thought of his kids drinking contaminated water is what scares him most. "It's a cause worth dying for," he says. "What's happened here is so bad that I felt I had no choice but to fight it with every ounce of energy I had."