Tests have found excessive levels of lead in water from drinking fountains at 10 District public schools, including three schools where lead levels were more than four times the proposed new federal safety standard.

Water samples from fountains at Orr Elementary School in Anacostia and at Sharpe Health School and McFarland Junior High, both in Petworth, showed lead levels of more than 90 parts per billion, said Shelton Lee, the school system's director of security and safety.

The U.S. Environmental Protection Agency has proposed a standard of 20 parts per billion as the maximum safe level for lead in water; the current standard is 50 parts per billion.

"This is a matter for concern, but it is not a health hazard at this time," Lee said. The test results are based on one sample taken from every water fountain at each of the city's 169 public schools. Lee said water will now be retested at schools with high lead levels.

"We have to find out if these are real levels or just one-time readings," he said. "We have to get several samplings from each fountain."

The other schools with lead levels of more than 50 parts per billion from at least one fountain were Eaton, Seaton and Montgomery elementary, Garnet-Patterson Junior High and Dunbar High schools in Northwest; and Eliot Junior High and Mamie D. Lee Special Education schools in Northeast.

School board member Linda Cropp (Ward 4), chairman of the board's Buildings and Grounds Committee, said her committee has asked administrators to develop plans to correct the lead problem.

"These results are not bad for every school in the system," Cropp said. "There have been no reports of illness among children from lead."

The D.C. public health commission has said that children ages 9 and younger are at greatest risk for lead poisoning because their smaller systems retain lead in higher concentrations.

Lead is a potentially lethal toxin that accumulates in the body, especially in the bones and kidneys. At low levels, it causes fatigue, stomach pain, appetite loss and irritability. Large accumulations can poison the nervous system or stunt growth.

Health Commissioner Reed V. Tuckson said earlier this year that lead in water has not been found to have caused sickness in any of 17,000 children whose lead levels are tested each year.

Lee said the affected fountains were shut last week and will remain off until further tests determine how high the levels are and where the lead comes from.

Lead in water from the fountains could come from old plumbing pipes in the schools, pipes leading into the schools or pipes far away in some portion of the city water system, Lee said. The source of the lead will determine how extensive repairs must be.

Discoveries of lead in drinking water have plagued the city for the past year. The D.C. health and public works departments have said that buildings constructed before 1940 commonly used lead pipes to connect to city water mains. More than half the dwellings in the District -- about 71,000 buildings -- contain lead pipes.

City residents who have questions about the presence of lead in their water supply may call the Housing and Environmental Regulation Administration of the Department of Consumer and Regulatory Affairs, 727-7395.