Cambridge water has had its share of problems. In 1990, the Massachusetts Department of Environmental Protection fined the city $19,000 for exceeding the limits for Trihalomethanes (THMS), a category of carcinogens.

J. Kevin Reilly, a spokesperson for the federal Environmental Protection Agency, says that the Agency's water regulations are intended to reduce contaminant levels in the water.

"There's a one in a million risk of somebody coming down with cancer, but that depends on that person drinking two liters a day for 70 years," Reilly says.

Statistics from the American Water Works Association indicate that most people do drink about 2.4 liters of water per day.

According to Barnes, THMS form when chlorine, added to purify water, combines with organic matter, such as leaves.

Present levels of THMS fall far below these limits. Barnes attributes this decline to the covering of the Payson Park storage facility where treated Cambridge water is held prior to distribution.

The storage facility was covered in 1990, after concerns arose about the possibility of contamination to treated water, Barnes says. After covering the reservoir, the city was able to halve the amount of added chlorine, which then reduced the THMS.

Barnes says the occasional brown color of the water is due to a combination of water from underground sources and surface water from rain, lakes, streams, which results when Fresh Pond drops below a certain level, as it did this fall.

The high level of manganese in the ground water caused the brown color, says Barnes. She says manganese is not harmful at these levels.

Another perennial problem in the water supplies is high sodium content. Cambridge water repeatedly has more sodium than EPA guidelines recommend. Barnes says the sodium level is not harmful, and the EPA says its "guidelines" are only advisory, and do not have the force of law.

Barnes says the high sodium levels in the water are due to run-off from Route 128, which runs within 15 feet of the Hobbs Brook reservoir. The proximity of the highway to the reservoir has also caused concern over the possibility of chemical spills or other accidents.

City and water department officials worry that development in the area of the Cambridge watershed may endanger water sources.

City Councillor Francis H. Duehay '55 says he is a proponent of a legislative bill which would protect reservoir areas from the hazards of over development.

"One hundred years ago these were rural areas, but not any more," Duehay says. "Waltham has developed underground sewage and gasoline tanks in the area of the [Hobbs Brook] Reservoir."

In the past, city councillors and Cantabrigians have complained about a city ordinance which allows dogs to run free at Fresh Pond. Although dog waste have been known to spread disease in drinking water, there is no evidence of this occurring at Fresh Pond, Duehay says.