D.C. Water Lead Levels Below Federal Limits
Wednesday, May 11, 2005
Lead levels in the District's drinking water have fallen substantially in recent months and dropped below the federal action limit for the first time in four years, the general manager of the D.C. Water and Sewer Authority said yesterday.
But the authority urged consumers to continue to take precautions, including using water filters.
The declining lead levels are proof that orthophosphate, a chemical added to the city's water system since last summer, is working, Jerry N. Johnson, the utility's general manager, said in an interview.
"We knew it would take six months to a year before we would start seeing the effects of it," he said. "We are starting to get down to the range we had hoped to be in."
Johnson said test results from 102 homes received since January will be sent to the Environmental Protection Agency, which regulates the utility, by the end of the month. If the next six months of test results are also low -- and Johnson said he is confident they would be -- the utility would drop its warning to consumers to flush their taps and to filter water if their households include children younger than 6, pregnant women or nursing mothers.
Two six-month periods of low test results also would allow the utility to escape the heightened scrutiny and regulatory requirements that kicked in with public disclosure last year that thousands of homes citywide had excessive tap water lead levels. That news triggered numerous hearings and investigations; a pledge by WASA to replace all lead pipes on public property by 2010; a proposal by Mayor Anthony A. Williams (D) to create a new Cabinet-level Department of Environment; and federal reforms in national drinking-water regulations.
Johnson said 90 percent of the homes tested this year had lead levels of 15 parts per billion or less; the federal action level is above 15 ppb. Last year, tests found 63 ppb in the first six months and 59 ppb in the last six months.
The homes tested this year included 71 that had been tested in the past; 28 of those had lead levels above the action level last year, according to test results supplied by WASA. In the recent round of tests, eight homes tested above 15 ppb.
Lead is a toxic chemical that can stunt growth and development, especially of babies and young children. Although lead paint is the main culprit, the EPA has estimated that tap water could account for 20 percent of exposure.
Erik D. Olson, an attorney with the Natural Resources Defense Council and frequent critic of the utility, said the test results -- if validated by the EPA -- "would be good news for consumers . . . although certainly we can't drop our guard."
Rick Rogers, chief of the water branch at the EPA's regional office in Philadelphia, received a telephone briefing yesterday on the test results and said his agency will do a detailed review. But at first glance, he called the news "a tremendous improvement over this period last year. The orthophosphate appears to have worked on schedule, as the experts said, maybe even ahead of schedule."
The city's water treatment plants, operated by the Army Corps of Engineers, began adding orthophospate in August to form a coating inside water pipes and prevent toxic lead from leaching into the water supply. The utility canceled its annual spring flushing with chlorine this year to allow the orthophosphate to do its work.
The water treatment plants and their customers -- water utilities in the District, Arlington County and Falls Church -- rejected proposals to use phosphate chemicals in the mid-1990s because of concerns over their cost and potential environmental impact.
Experts are not sure why lead levels rose in the District, but a leading theory is that it stemmed from a change in disinfectant chemicals at the water treatment plants. The plants switched from chlorine to a combination of chlorine and ammonia in 2000 because of concerns the chlorine byproducts could cause cancer.
The high lead readings triggered a federal requirement that the utility replace 7 percent of the city's lead service lines each year until results fall below the action level. WASA's board decided to replace all lead lines in public space by 2010, at a cost of $300 million.
The utility is not replacing the portion of the pipe on homeowners' property but is encouraging residents to do so themselves. WASA has set up a loan and grant program for low-income householders.