Water tested in Bristol — at the southern end of the Bristol County water system — showed the higher than state health department-accepted levels of the chemical THM (trihalomethane), according to BCWA.

The authority said Thursday there is no "immediate risk" to the chemical's presence in the water.

Bristol County Water Authority Executive Director Pamela Marchand said today that two sites in Bristol tested at around approximately 90 and 100 parts per billion. Those levels are higher than the 80 parts per billion limit that is the new state standard.

The state has not issued any violations against the BCWA for the makeup of the water, which is provided by the Providence Water Supply Board from the Scituate reservoir but treated with additional chlorine here.

Because THM forms through the mix of chlorine and organic compounds found in water, Marchand said Barrington will probably have the lowest THM samples in Bristol County. The longer chlorine mixes with the organics, she said, the higher level of THM.

"This is not a violation, an emergency or an immediate risk," reads a water authority press release. "Surface water systems are required to treat the water with chlorine in order to inactivate bacteria that can cause disease. Trihalomethanes (THMs) are formed when chlorine is added to water containing natural organics. Water from surface supplies, such as reservoirs, contain natural organics from the decay of leaves and other vegetation."

The violations of the 80 parts per billion limit of THM (trihalomethane) came to light at the monthly meeting of the board of directors on Wednesday, Nov. 28, in Warren, according to a story on eastbayri.com.

Marchand told the board that previous requirements were an average of 80 to 100 parts per billion. Revised regulations, she said, limit THM levels to an average of the lower number.

Two tests of samples taken this year in Bristol showed levels that exceed this limit, she said. The BCWA had not received results on a third set of samples.

Long-term exposure to THM has been shown to cause kidney disease or cancer in lab animals. Anyone with questions or concerns — particularly preganant women and residents with very young children — should contact their doctors, the authority reportedly advised.