Warnings issued in 2 towns about perchlorate in water

The North Shore town of Hamilton has warned residents that their water may be tainted with a potentially hazardous chemical. And Millbury, in central Massachusetts, meanwhile, has shut down one of its wells after detecting unsafe amounts of the chemical.

John Tomasz, director of public works in Hamilton, said tests taken this month had found perchlorate in two locations. Tomasz warned that pregnant women, nursing mothers, children, and people with thyroid problems should not drink tap water. He also said residents should also discard any beverage or ice prepared with tap water in recent days.

In Millbury, the Millbury Avenue well was shut down on Thursday, according to a statement from Aquarion Water Co., which operates the well. Citing similar safety concerns as in Hamilton, the company also advised Millbury residents to discard ice and beverages prepared before Friday.

The Hamilton samples taken Aug. 13 at the School Street well and at the Idlewood water treatment plant contained as much as 22 times the state limit of 2 parts per billion. New samples taken Thursday and Friday returned clean, Tomasz said. But the no-drink order for children and pregnant and nursing women will be lifted only after six consecutive days of clean samples.

"We're taking samples every day until Tuesday just to confirm that the water supply on an ongoing basis is OK," he said.

Tomasz said warnings about the water had been sent to 3,200 households, most of which use the tap for water.

In Millbury, readings of perchlorate from Aug. 20 were 10.2 ppb, five times the state limit, according to Aquarion's statement.

The company has since received one safe sample from the well, said Town Manager Bob Spain, but will wait until Tuesday at earliest to reopen the Millbury Avenue well. In the meantime, residents will get their water from the Jacques well and from Worcester. He estimated 1,800 households, almost three-quarters of the town's homes, were serviced by the closed well.

A perchlorate contamination was discovered at the Jacques well in 2005, and a purification system was installed, Spain said.

Joe Ferson, a spokesman for the state Department of Environmental Protection, said the high readings of perchlorate are being scrutinized. "They suspect it might be part of the process" of testing, he said.

Perchlorate is used in explosives and rocket fuel. Exposure to the chemical can cause, among other things, impairment in physical development, behavior, movement, speech, hearing, vision, and intelligence, according to DEP.

While Massachusetts has set safety standards for perchlorate, the US Environmental Protection Agency has not ruled on what level of perchlorate is safe. It has set a nonbinding safety standard at 24.5 parts per billion.

The state issued its perchlorate regulation, the toughest in the country, in 2006 after high levels were detected in a Bourne aquifer.