A multi-agency team of water treatment experts has scheduled two public meetings to outline plans for implementing its recommended corrosion control measures designed to reduce levels of lead in drinking water in the District of Columbia.
The meetings will be held:
o Tuesday, April 27, 6 p.m. at the Pennsylvania Avenue Baptist Church Harmon Hall, 3000 Pennsylvania Ave., SE; and
o Thursday, April 29, 6 p.m. at the Metropolitan United Methodist Church Great Hall, 3401 Nebraska Ave, NW.
The group of experts, known as the Technical Expert Working Group, has presented its recommendation to EPA's mid-Atlantic Region, which is reviewing it.
During the public meetings, representatives from the working group will be available from 6 p.m. to 7 p.m. to answer questions, and a formal presentation will run from 7:30 p.m. to 8:30 p.m. Representatives will explain the recommended treatment that would be introduced in a limited area in the district beginning as early as June 1.
If the treatment is successful, it could be rolled out as early as July 15 to the entire Washington Aqueduct distribution system, which includes Washington, D.C. and parts of northern Virginia.
The working group includes representatives from EPA, the Washington Aqueduct, the Centers for Disease Control and Prevention, D.C. Water and Sewer Authority (WASA), D.C. Department of Health, Virginia Department of Health and a variety of independent experts and contractors.
The recommendation focuses on adding the chemical zinc orthophosphate to the finished drinking water before it leaves the district's two water treatment plants – Dalecarlia and McMillan. Zinc orthophosphate is expected to reduce the corrosiveness of the water supply, and thereby reduce the amount of lead that wears away from inside the pipes in households and other buildings.
The partial distribution of zinc orthophospahate would begin around June 1 in the area known as the 4th High Pressure Zone in Northwest Washington. This area was chosen because it is a manageable size, isolated from the rest of the distribution system, and is a good representation of water mains used throughout the district. Using a limited area at first will allow experts to closely monitor changes before expanding treatment.
Residents in the pilot area may temporarily see rust-colored water from their taps during the monitoring period. Residents should not drink or cook with rust-colored water.
During this period, residents should run the water to make sure it is clear before they use it for drinking, cooking or doing laundry. The discolored water can stain clothing if it is used for doing laundry.
Experts do not expect lead levels to drop immediately after treatment begins. It will likely take six months or longer to see measurable reductions in lead levels.
Throughout the monitoring period, the distribution system will be closely monitored for bacteria and discolored water. A special flushing crew will be available to respond to complaints of the rust-colored water.
Monitoring of the water in the pilot area will last about six weeks, and if successful, will immediately be followed up by application to the entire Washington Aqueduct service area.
Until further notified, consumers should continue to use water filters and follow flushing recommendations and the D.C. Department of Health's advisory for children and pregnant women who live in homes with lead service lines.