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John J. Carroll recognized for his dedicated public service

MWRA's new John J. Carroll Water Treatment Plant,
located at Walnut Hill, Marlborough
MWRA's new John J. Carroll Water Treatment Plant, located at Walnut Hill, Marlborough
More details on the plant >link


Over the last ten years, the Massachusetts Water Resources Authority has made an enormous investment - almost $2 billion - in improving the water system that serves 2.3 million people in eastern and central Massachusetts. This has included the 17.6-mile MetroWest Water Supply Tunnel and the 115-million gallon Norumbega Covered Storage tank in Weston. The last major construction project, a state-of-the-art water treatment plant in Marlborough that uses ozone instead of chlorine for primary disinfection, has now been completed. The transition to the new system began on Wednesday, July 27, 2005.

Ozone is a highly-charged oxygen molecule and a powerful disinfecting agent. It is bubbled through drinking water to destroy potentially harmful organisms and also to reduce unpleasant tastes and odors. Ozone has been used for disinfecting drinking water since the 1800s. 

With a peak capacity of 405 million gallons per day, the John J. Carroll Water Treatment Plant will be one of the largest facilities in the country to use ozonation.

According to Frederick A. Laskey, MWRA’s executive director,“Using ozone as for disinfection allows us to use less chlorine, reducing the amount of potentially harmful chlorine by-products.  It also makes the water taste better!”

Carbon dioxide and sodium carbonate are added at the plant for corrosion control to prevent copper and lead from being released from home plumbing. Fluoride is also added to promote dental health. 

The $340 million plant is an investment by the ratepayers in 41 communities to ensure the safe and reliable delivery of the highest quality water to their taps.

In June, the MWRA Board of Directors voted to name the plant after John J. Carroll, the only original member of the MWRA Board of Directors, appointed in 1985 as a representative of the MWRA Advisory Board and still serving today as its Vice Chairman. Mr. Carroll, a Milton resident, has dedicated his career to public service, as the Commissioner of Public Works for the Commonwealth, as the Lexington Superintendent of Public Works and Town Engineer, and as the Norwood Town Manager for the past 26 years.

The dedication is being held on August 18, 2005.


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