Tests find water supply is drug-free

Two reservoirs that serve city, region checked

As New York, Chicago, and other US cities struggle over how to respond to reports that traces of pharmaceuticals exist in their drinking water, a first-ever test of the reservoirs that serve Greater Boston makes one thing crystal-clear: The water supply is drug-free.

The testing by an independent laboratory of the water pumped to the city and surrounding communities found no detectable levels of more than two dozen pharmaceutical products that have tainted water supplies elsewhere.

"We were guardedly optimistic, but you never say never," said Fred Laskey, executive director of the Massachusetts Water Resources Authority, which commissioned the study. "We wanted to do the test just to reassure the public, and ourselves, what we were convinced of - that our water is pristine at the source."

While the MWRA routinely tests the water supply for more than 100 contaminants including lead, chlorine, and disinfectant byproducts, state and federal governments do not require tests for pharmaceuticals such as acetaminophen, progesterone, and the insect repellent DEET.

A five-month Associated Press investigation, released in March, found that water supplies for at least 41 million Americans contained trace amounts of antibiotics, mood stabilizers, and other drugs, raising concerns about what impact the substances, even in minuscule amounts, might have on consumers' health.

The news service did not include in its investigation the MWRA, which provides drinking water from the Wachusett and Quabbin watersheds in Central Massachusetts to 2 million users in Boston and all the communities inside Interstate 95/Route 128 except Cambridge, along with a few other communities such as Framingham and Chicopee.

The MWRA decided to conduct its own tests, given the recent public concern over the issue, Laskey said.

Boston residents should be happy to hear the test results, said Amy Pruden, a professor of environmental engineering at Colorado State University who has studied the effects of antibiotics in drinking water.

"It sounds like, at least with respect to that particular water quality issue, they can rest fairly easy," she said. "It sounds like Boston's in good shape, especially for such a big city."

Unlike most of the water systems found to contain trace amounts of pharmaceutical products, Boston's water supply does not have a wastewater treatment plant upstream, Laskey said. The MWRA's two reservoirs are mostly protected from nearby development, which limits the introduction of human and industrial waste into the water supply.

"That certainly lowers the level of concern if there's no known sources," said Pruden.

The MWRA paid California-based MWH Laboratories $23,250 to test 31 samples of raw and treated water drawn on March 14 from testing sites at its reservoirs.

The only compound picked up in the testing was a softener commonly used for rubber gaskets, washers, and food containers called tris (2-butoxyethyl) phospate, or TBEP. It was found in a test of untreated water, and Laskey said officials believe the "minute trace amounts" of the compound actually came from the plant's testing spigot. The effects on humans of exposure to the chemical are unclear, but are believed to be minimal, according to data from the National Library of Medicine. Results of a follow-up test of water extracted directly from the reservoir, without contact with plumbing, should be available within three weeks, the MWRA said.

Given the small amount detected, and the fact it came from untreated water, officials are not concerned about it, Laskey said.

The tests of treated water came from a separate testing spigot at an MWRA plant, and not from the faucets from which residents ultimately collect their water. But an MWRA representative said that water "never sees the light of day" between the reservoir and the tap, so there would be no opportunity for foreign substances to enter the stream before it reaches consumers' homes.

Laskey said there are no immediate plans to institute regular screening of drinking water for pharmaceutical products, but he said it appears federal regulators may be moving toward requiring such testing. Advocacy groups and congressional committees have been demanding stricter federal monitoring of drinking water since the reports of the presence of pharmaceutical products surfaced.

John C. Drake can be reached at jdrake@globe.com.