EPA mandates carcinogenic disinfectant must be checked in water supply

Joyce Kelly

Under mandate by the federal EPA, the state Department of Environmental Protection this year is requiring water suppliers check public water for carcinogenic disinfectant byproducts and cryptosporidium.

"Cryptospordium is one of the issues we and federal EPA are looking to address that's come up with the Federal Safe Drinking Water Act," said Ed Coletta, a spokesman for the the state Department of Environmental Protection. The state is required to work with local water suppliers to determine whether cyrptosporidium and disinfectant byproducts exist in the public water supply, he said.

Cryptospordium are microscopic parasites that cause a sometimes fatal diarrheal disease, and are most commonly transmitted by water, according to the Centers for Disease Control and Prevention.

The federal Environmental Protection Agency also is targeting disinfectant byproducts, created when natural materials interact with water treatment chemicals like chlorine. They are believed to cause cancer, Coletta said.

"It's an issue because we are finding that in source water, when you have organic materials such as leaves and natural brush, break down in source water like a lake, pond or reservoir, the material can react with treatment chemicals in a water distribution system and could cause a problem with byproducts," Coletta said. When certain organic materials break down, they release trihalomethanes and haloactetic acids - compounds that can interact with treatment chemicals to produce a contaminant, or "disinfection byproduct," he said.

The chemical most problematic is chlorine, he said.

"We want to keep an eye on that, we want to make sure the (contaminants) don't rise to a certain level. We want all the communities to monitor for these issues," Coletta said.

Every town and city in Massachusetts is on a schedule to monitor for both the parasite and contaminants, with larger communities having earlier deadlines for submitting reports, he said. If a water supplier has found a high level of disinfectant byproduct in the water, the supplier must also submit a plan to eliminate or reduce that, Coletta said.

Communities providing water to 10,000 to 50,000 resident must start monitoring for the parasites by April 1; those servicing fewer than 10,000 people have until Oct. 1, Coletta said.

Joyce Kelly can be reached at 508-626-4423 or

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