Investigation of Higher Than Standard Lead Concentrations in Drinking Water From Washington, D.C.

For over two years, the Washington, D.C. area has been plagued by the incidence of alarming concentrations of lead found in local drinking water. During this period, water with lead concentration levels above the U.S. Environmental Protection Agency's (EPA) action limit of 15 ppb has been found in approximately 66% of the homes tested. Because of the problems with lead in drinking water in the D.C. area, the EPA has begun the process of trying to determine whether or not this problem occurs nationwide by obtaining as much lead data as possible. However, it recently reported that no current information exists on lead levels from 78 percent of the nation's public drinking water systems, and that it has no data from as many as 20 states. In an effort to generate information that contributes to a greater understanding of the scope and nature of this real-world environmental health problem, we have begun collecting and performing lead analysis of drinking water samples from different parts of the country. As San Francisco Bay Area - based participants in the NSF-sponsored Environmental Science Information Technology Activities (ESITA) project, we began by establishing E-mail correspondence with children who attend elementary schools in the Washington, D.C. area two years ago, during the first year of the lead crisis. Since that time the elementary school children have sent over 150 water samples from their homes and schools, along with information on the locations from which the water samples were collected to the Bay Area. Upon receipt, we prepare and analyze these samples at UC Berkeley's Lawrence Hall of Science. Following analysis results are compiled, statistically analyzed, and used to create maps that aid in the interpretation of our data. The majority of samples collected from the D.C. area were obtained from schools and homes located in the central north-northeast section of the District. Of these samples, 72% contained lead in excess of the EPA action limit. Despite reports that lead levels have fallen significantly over the past year, 63% of all homes tested during the second year of our study still contained lead levels that exceed the EPA limit. In addition, drinking water collected from a well-used fountain at an elementary school site that a local government reported as lead free contained lead concentrations greater than 5 times the EPA action limit two years in a row. During the first year of our study, waters collected from this same fountain yielded values as high as 20 times the action limit! Our work over the past two years clearly shows that by working with students who attend schools in different parts of the country, we can contribute in a major way to the EPA's monitoring of lead levels in the country's drinking water. As a result, we intend to continue this work in the future, as well as continuing an investigation that includes the use of water delivery system models that enable us to assess how much water mains, service mains, and home piping systems contribute to the total lead concentrations measured in drinking water samples.