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Massachusetts Water Resources Authority
July 16, 2014

Ria Convery, MWRA
(617) 788-1105,

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Commonwealth of Massachusetts
Executive Office of Energy and Environmental Affairs



Media Contact: Krista Selmi - 617-626-1109 or

MARLBOROUGH – Wednesday, July 16, 2014 - Energy and Environmental Affairs (EEA) Secretary Maeve Vallely Bartlett today helped celebrate the start-up of a new state-of-the-art ultraviolet (UV) disinfection facility at the John J. Carroll Water Treatment Plant, improving the quality of drinking water delivered to the Massachusetts Water Resources Authority’s (MWRA) customers. The plant serves 2.3 million MWRA customers in 43 communities in the metropolitan Boston and metro west areas.

“With this significant investment in treatment, along with well-protected reservoirs and extensive watershed protection efforts, MWRA’s customers can be confident that the water delivered is not just among the best tasting, but of the highest quality,” said Secretary Bartlett, who chairs the MWRA board of directors.

UV light is a more potent form of natural disinfection from sunlight that enables MWRA to inactivate the most difficult to kill pathogens that could potentially be in source water, without the use of additional chemicals and any associated disinfection byproducts.

The facility was completed in compliance with the U.S. Environmental Protection Agency’s (EPA) Long-Term 2 Enhanced Surface Water Treatment Rule, which requires the addition of a second primary disinfection process. This rule is intended to improve public health by reducing illness due to Cryptosporidium and other disease-causing microorganisms in drinking water.

“EPA applauds MWRA’s innovative efforts to meet requirements of the Safe Drinking Water Act by installing ultraviolet disinfection, thus providing an effective layer of drinking water protection for citizens of the Commonwealth,” said Curt Spalding, regional administrator of the U.S. Environmental Protection Agency’s New England office.

The Massachusetts Department of Environmental Protection (MassDEP), which regulates drinking water in the state, formally approved the start-up of the new facility. Construction of the $32 million UV project began in 2011. The new facility was designed and constructed to not only meet current treatment needs, but to provide flexibility to meet future changes in water quality or regulatory requirements.

Since 2005, MWRA’s water has been treated with ozone, which is produced by applying an electrical current to pure oxygen. Ozone has ensured strong protection against microbes and viruses, improved water clarity and has actually improved the water’s taste.

“In just a few short years, water treatment has gone from chlorine with its taste and odor issues, to ozone and now ultraviolet – with no additional chemicals and no disinfection byproducts,” said MWRA executive director Fred Laskey. “Just better, safer water.”

The Carroll Water Treatment Plant is a prime example of Governor Patrick’s commitment to innovate water technology. The state-of-the-art treatment methods employed at the plant, ozone and UV, ensure that MWRA’s customers are receiving some of the best drinking water in the country.

Secretary Vallely Bartlett
Energy and Environmental Affairs (EEA) Secretary Maeve Vallely Bartlett

More photos on flickr

MWRA - UV at John J. Carroll Water Treatment Plant
Ultraviolet treatment units

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Posted July 16, 2014