Washington, DC - Drinking Water

The District's drinking water supply system allows parasites to enter into the drinking water supply. Cryptosporidium and giardia are two parasites that live in the District's raw water sources and may affect the city's drinking water quality if filtration is compromised. In 1995, the District's drinking water violated EPA's health standards on three occasions for bacteria and for turbidity.

In May 1996, the city's drinking water violated EPA standards for coliform bacteria. The city-wide "boil water alerts," as well the more recent incidents involving elevated levels of bacteria/turbidity, caused EPA to take a more active role in the District's drinking water distribution. In July 1996, EPA requested that the District produce a plan to improve the quality of its drinking water system within 60 days. The District agreed to flush and disinfect its pipes, improve storage tank maintenance, prevent sewage leaks into water pipes, and improve public involvement. After the city released its plan, it began flushing the drinking water system with chlorine to eliminate the bacterial contamination.

On August 7, 1996, the city reduced its chlorine levels slightly, but they were still above the normal level. Then on August 20, 1996, the city's drinking water again failed inspection; for the third month in a row unhealthy levels of bacteria were detected in the District's public drinking water supply.

EPA states that in order to control the harmful bacteria in the District's drinking water system, chlorine disinfection will continue and the system should be cleaned and upgraded. District officials estimate that it will cost between $200 million and $400 million to modernize its drinking water system over the next six years., Discussions are underway to create a new city agency that will take charge of the District's entire drinking water system.

serves as the primary source for drinking water for both households and

From:  THE UNIVERSE OF ENVIRONMENTAL PROBLEMS,Section 3.2 -  Drinking Water by:
Resources for the Future
1616 P Street NW
Washington, DC
20036-1400 USA
http://www.rff.org

businesses. The District's source for drinking water is the Potomac River. There are no wells (public or private) in the city that serve as a drinking water source. Approximately 63 percent of the city's population (about 364,200 residents) rely on the public drinking water system as their primary source of drinking water; the remaining 37 percent of the DC population (about 213,800 residents) use bottled water. The quality of the city's drinking water also affects non-residents, however, as the area employs thousands of commuters who also consume the city's drinking water.

The city's drinking water is treated by the U.S. Army Corps of Engineers (COE). COE maintains the treatment plant's operation and the DC Department of Public Works, Water and Sewer Utility Administration, distributes the water to city residents. This unique collaborative effort of separate treater and distributor complicates the process to modify and improve the system because of multiple authorities and jurisdiction.

The quality of the District's drinking water is a serious public health concern. Since 1993, the city has issued several "boil water alerts," to maintain public health. The city issued the alerts because officials detected unsafe levels of coliform bacteria in the drinking water system. Other contaminants in the District's drinking water include heavy metals such as lead from older pipes and trihalomethanes, which are byproducts of chlorine disinfection.

The city's drinking water also suffers from turbidity. Turbidity is cloudiness in water and results from ineffective water filtration. Parasites typically resist chlorine disinfection and can only be removed through filtration processes. An ineffective filtration