How Safe Is Arlington's Tap Water?

ARLINGTON, MA — As the temperatures stretch above the 80s in Arlington folks are drinking a lot more water. But how safe is the water from the tap? Should you be buying more bottled water?

A look at the annual MWRA state testing of the water coming from the Quabin to Arlington says the water tests well within accepted state guidelines and although the lead levels were higher last year than the two years before that.

"MWRA’s water system has been below the Lead Action Level for over a decade. Of the 2,300 samples taken in the last 5 years, 98% were below the 15 bpp level," according to the MWRA

The greatest concern in Arlington is lead leaching from the pipes within your own home if your home is old and has not had the pipes going from the house to the main lines replaced since the 1940s when copper lines became the norm.

If you think your pipes might be from before the 40s, the state has a couple recommendations to avoid lead exposure, including using cold water to cook and letting the water run til it gets cold if you haven't used the sink for six hours or more. (See more here). But chances are, they say, you're not going to get lead poisoning from drinking the tap water.

The Quabbin reservoir water goes through treatment at the John J. Carroll Water Treatment Plant in Marlborough. There it's treated with ozone, ultraviolet disinfection and fluoride is added and then mono-chloramine, a mild and long-lasting disinfectant combining chlorine and ammonia to protect the water as it travels through miles of pipelines to your home, according to the MWRA.

How reliable are the state's results? Pretty reliable, say experts.

"In general, the quality of local water straight from the tap is excellent and state water test results are reliable. There are high-profile cases where this clearly has not been the case -- most notably in Flint, Michigan -- but people in communities such as Newton and Brookline [and Arlington] have good reason to be confident in the quality of their tap water and that local officials will take action quickly if the quality is threatened," said Jim Salzman author of "Drinking Water: A History."

Here are the September 2016 Lead and Copper Results (ppb=parts per billion)

MWRA and local water departments test 300 to 500 water samples each week for total coliform bacteria. No EColi was found in any MWRA community in 2016