Lead Under EPA Limit, WASA Says
Wednesday, January 11, 2006
The D.C. Water and Sewer Authority announced yesterday that it has satisfied federal requirements for reducing lead in the city's drinking water after tests showed that lead levels have remained below the government's limit for a full year.
Tests in the past six months found that 95 of 103 samples, or 92 percent, were within the federal lead limit of 15 parts per billion, WASA said. Under federal law, water utilities are in violation if excessive lead is found in more than 10 percent.
It was the second consecutive six-month period during which WASA met federal standards, meaning the agency is eligible to be removed from the stricter oversight established by the Environmental Protection Agency two years ago.
Richard A. Rogers, chief of drinking water for EPA's Region III office, which oversees the District, said the office is reviewing the data and has not confirmed the findings.
But Rogers said previous data indicate that treatment to combat corrosion and prevent lead in pipes from leaching into the water "is working because lead levels have drastically dropped from beginning of treatment."
In a letter to customers, WASA General Manager Jerry N. Johnson called the test results "a very clear indicator that the drinking water treatment process is succeeding in controlling the potential for lead to leach from lead service lines and plumbing fixtures that contain lead inside the home."
WASA discovered excessive lead in 2002 and reported it to the EPA, but the extent of the contamination was not disclosed to the public until a Washington Post story in January 2004 revealed that tap water in 4,075 out of 6,118 homes tested by WASA had excessive lead. Many homes had lead levels above 300 parts per billion.
Lead can cause serious health damage, particularly in fetuses and in babies and other children. However, blood tests on more than 6,000 residents showed no immediate link between high levels of lead in tap water and lead levels in the blood, Johnson said.
Once a water utility discovers excessive lead, the EPA increases oversight. Under EPA orders, WASA embarked on a multi-pronged plan to correct the lead problem and protect consumers.
The agency distributed free water filters and began replacing lead service pipes. Meanwhile, engineers at the Washington Aqueduct, a federal agency, added a chemical, orthophosphate, to the water to coat the pipes with a film that prevents lead from leaching. Engineers believe that the chemical has reduced the lead levels.
"The orthophosphate addition was key in getting the levels down and getting the biofilm in the pipes so they would not have direct contact with the water," Johnson said in an interview yesterday.
WASA and the EPA had issued an advisory cautioning residents to use filters and to flush their taps before drinking the water.
Johnson said that although the advisory might be lifted, customers should continue to flush lines that have been stagnant for more than six hours. WASA recommends that customers run cold water for 60 seconds to flush the pipes and that they use cold water for cooking and drinking.
The EPA has required WASA to increase its lead testing from 50 samples a year to 100 every six months. EPA also required WASA to conduct testing to ensure that the orthophosphate did not have an adverse side effect.
Rogers said that no side effect was found and that WASA may be allowed to reduce its monitoring once the lead test results are confirmed by the EPA.
But Johnson said WASA will continue to take aggressive action to replace all lead service pipes by 2010, as mandated by the authority's board of directors in 2004.
"The board has taken a very responsible position in which we want to eliminate the [lead] problem from public perspective once and for all," Johnson said.
WASA replaces pipes on public property, but customers have to pay to replace pipes on private property. Johnson said about 29 percent of customers have elected to replace the pipes on their properties so far. He added that he has developed a proposal that he will make to WASA's board to increase that percentage, but he declined to elaborate.
Residents can continue to get free water tests from WASA if the agency's records show that their homes have lead service lines or the type of service line is unknown, Johnson said.