A new report from the Centers for Disease Control shows that water in almost 15,000 D.C. homes may still be contaminated by lead.
DC Water replaced water lines serving thousands of homes from 2004 to 2008, but homeowners were responsible for replacing any lead pipes on their side of the property line. Those who didn't may have increased their risk of lead contamination.
The study found that children living in homes with partial lead pipe replacement had elevated lead levels in their blood.
General Manager of DC Water, George Hawkins, says his agency knows that the partial pipe replacement along with the use of a water treatment chemical did not solve city's problem of lead contamination.
"Lead did leach into pipes due to a water treatment change, which was made by a federal agency called the Aqueduct in the mid-2000s. That lead in the water can, in some cases, lead to lead in the blood which is a great concern to all of us," Hawkins says.
He says his agency knew lead contamination could be a problem and has been taking precautionary measures to reduce risk.
"We've been acting as if everything that has been found by the CDC has been true for several years," Hawkins says.
The CDC says partial pipe replacement can sometimes cause more harm than good, and that residents should test their water and should drink bottled water until their homes can be tested. The lead can be especially dangerous for pregnant women and children.
The federal government banned the use of lead pipes more than two decades ago.
This post has been updated.