TASTE OF METAL: Modified disinfection methods may have changed the chemistry of drinking water in Washington, D.C., making it more likely to dissolve lead-encasing minerals in pipes. Image: PHILIP JAMES CORWIN Corbis
The public reporting last year of high lead levels in the drinking water in Washington, D.C., has led to a congressional investigation, the firing of a D.C. health official, and calls for a review of the 1991 law that is supposed to keep the neurotoxic metal out of drinking water. That law, however, may not contribute to the problem as much as the changes made to disinfection procedures resulting from another water safety rule. The conflicting regulations mean that other municipalities may also soon find too much lead coming out of their faucets.
To date, at least 157 houses in D.C. have lead levels at the tap higher than 300 parts per billion (ppb), and thousands more have exceeded the Environmental Protection Agency's limit of 15 ppb. Residents have received contradictory advice about whether tap water is safe to drink and whether replacement of lead service lines will solve the problem.
This article was originally published with the title Leading to Lead.