It’s National Drinking Water Week and MWRA customers have a good reason to celebrate: our tap water quality is excellent, year in and year out.

Here’s why our drinking water is among the best in the country.

We aggressively protect our water sources

MWRA’s water comes from the Quabbin and Wachusett Reservoirs in Central Massachusetts. These naturally pristine water sources are surrounded by miles of protected land. MWRA and the Department of Conservation and Recreation constantly patrol the watersheds to make sure they stay safe.

We use the safest and most effective treatment processes available today

At our Carroll Treatment Plant in Marlborough, water is treated with ozone gas and ultraviolet light.

Ozone is a natural, renewable disinfectant that “zaps” germs out of the water and leaves fewer disinfection byproducts (DPBs) than other treatment methods. Since MWRA started using ozone in 2005, DPB levels have dropped to an all-time low.

In 2014, we have added facilities to treat drinking water with ultraviolet light. UV light is essentially a more potent form of the natural disinfection from sunlight. UV enables MWRA to inactivate the most difficult to kill pathogens - which could potentially be in the source water - without the use of additional chemicals and any associated disinfection by-products. The UV process and MWRA’s high quality source water allows MWRA to meet new regulatory requirements cost effectively.

We protect the treated water, too

Once the water is treated, it goes to covered storage facilities across the MWRA service area. Covered storage protects water from being contaminated by airborne sources (such as birds) and keeps a back-up supply of treated water on hand near each community.

We test the water at every step on the way to your tap

MWRA and its member communities perform hundreds of thousands of tests on drinking water from the source to the tap. Testing covers over 120 compounds regulated by the Environmental Protection Agency and many other compounds that are not yet regulated.

We share all of our test results with our customers

Water test results are posted on our website monthly and annually. We also mail an annual report on drinking water test results to each household within our service area every year. Keep your eyes out for our latest Annual Water Quality Report, due to be delivered to homes this June.

Our water is the "Best Water in the Country"

MWRA's source water took home the 2014 award for "Best Water in the Country" at the American Water Works Association's annual conference in June 2014.

Check out our website for more information on our water system. MWRA has great confidence in the water we deliver to your home and wants you to have the same confidence.