The Cambridge water supply has turned slightly brown in the past two weeks because of a combination of increased manganese levels and old pipes, John H. Seites, Cambridge water superintendent, said yesterday.

The situation "Poses no health problems," George Coogan, director of water supply for the Massachusetts Department of Environmental Quality Engineering, said yesterday adding that although Cambridge has twice as much manganese in its water supply as the normal state level, "it is nothing really unusual."

The Cambridge City Council Monday discussed the problem of water discoloration after several council members reported receiving phone calls on the subject.

More Than a Feeling

Bernard Flynn, administrative assistant to Cambridge Mayor Thomas W. Danehy, said yesterday he had talked to many residents who complained about the dirty water. "We know that it is more than an isolated situation," Flynn said.

The waste problems may clear up within two or three weeks when manganese levels return to normal, Seites said, adding the waste department had not started any special testing or treatment programs in reaction to the discoloration.

"We haven't gotten any more calls than usual," Thomas Monahan, water superintendent for the Department of Buildings and Grounds, said yesterday.

Old News

A survey of Harvard students yesterday showed, however, that some had noticed the discoloration. "It started getting brown about four or five days ago," Jack Callahan '82, a Straus Hall resident, said yesterday.

The manganese level in the water in one-tenth on a part per million, about ten times the level earlier this summer and double the state standard of one-twentieth of a part per million, Seites said.

Increases in the manganese levels "are due to the water in the reservoirs turning over," said Seites. "When the water temperature reaches 59 degrees Fahrenheit, it starts to mix." The warmer water from the bottoms of the ponds carries manganese up to the top, he explained.

The city has never received so many calls about the water supply as it has this year, Flynn said. "Temperatures go down every fall, and this is the first time that this has happened."

Seites added "there may be systems problems in some of the water mains. Pockets of manganese that have collected over the years may add to the problem."