Harvard yesterday released results of tests on the water supply, indicating that levels of potentially cancer causing chemicals in the Cambridge water supply have dropped below the maximum level allowed by the federal Environmental Protection Agency (EPA).

The Harvard tests, conducted last Thursday by New England Chromochem, confirmed earlier tests by Cambridge officials which showed that the levels of trihalomethanes (THMs) in the water posed no danger to city residents. Levels of THMs--which are known to cause cancer in certain laboratory animals--in the water had exceeded the EPA maximum from July, 1988 to December, 1989.

The THM levels in the water during the last two years do not constitute an "acute or even chronic health hazard," said University Health Services Director David S. Rosenthal, in a statement released yesterday.

The results of Harvard's tests, which were collected at five different locations around the campus, revealed THM levels ranging from 26 to 36 parts per billion--significantly lower than the city's most recent findings, which recorded levels ranging from 65 to 75 parts per billion.

The Harvard results were also well below the historical average for the city, which ranges from approximately 45 to 65 parts per billion, according to city Water Superintendent John J. Cusack, Jr.

"That [the low THM level] makes sense because we've been making some changes in the water system," said Cusack, "We are happy to hear those results."

Cusack said Cambridge has recently modernized its water system to cut the level of THMs, which form when chlorine added to water to kill dangerous bacteria reacts with organic material, such as leaves and wood. Recent changes to the system include adjustments in the filtering process and a switch to non-chlorine based chemicals, Cusack said.

Officals at Harvard's Environmental Health and Safety office said that the testing would not continue on a regular basis.

"At this point we plan to keep an eye on the water with the Cambridge Water Department," said Peter M. Bochnak, a Harvard senior safety specialist. "As far as testing on a regular basis, we have not been asked to do it."

But Leverett House Master John E. Dowling '57 said that "it wouldn't hurt" the University to begin regular water testing.

Dowling said he was upset over that Harvard did not begin the testing process when it was first informed of the EPA violations last January.

"If Cambridge water continues to be marginal Harvard should do its own testing," Dowling said.

In January, the city Water Department sent letters to customers telling them that levels of THMs in water exceeded EPA limits from July, 1988 through December, 1989. But last month, dean of the College L. Fred Jewett '57 told house masters that Harvard had already tested campus water and found it safe, according to Dowling.

At that time, tests had been scheduled but not yet conducted. Because Jewett and the house masters believed that the water quality had been tested, they did not tell students about the Cambridge letter, Dowling said.

According to a statement released yesterday bythe University the water was not tested until lastweek. The statement attributed the delay inconducting the tests to problems finding anEPA-certified laboratory, the necessity offollowing EPA protocols and proceduraldifficulties.

State Senator Michael J. Barrett '70(D-Cambridge), the sponsor of a state bill tosafeguard the city's perennially plagued watershedsystem, said that he was pleased that the Harvardtests confirmed the Cambridge tests.

"As the father of nine-month-old twins whodrink formula made with Cambridge water, I amrelieved," said Barrett.

But Barrett criticized the continuing highsodium content in the water and called for renewedlegislative action to protect and improve theCambridge water.

"The effort has just begun," Barrett said. "TheCambridge water still needs to be improved. Thecritical issue is are we going to protect thereservoir."

Barrett currently has a bill in the stateSenate that would create a "zoning overlay" overthe Cambridge water reseviors. Barrett'slegislation would supersede local zoning andprevent development near Cambridge's water supply