Somerville Water Department (MWRA)

Support Local and Be Environmentally Conscious! Tap water is delivered directly to your residence without trucking or plastic waste. Bottled water produces over 10,000 times more greenhouse gases than municipal water. More than half of our energy requirements for water treatment and distribution come from renewable sources including hydroelectric generators and solar panels.

The DEP report commends DCR and MWRA for their current source water protection plans, noting that the "watershed protection programs are highly effective and significantly reduce the risk of contamination." MWRA follows recommendations to maintain pristine watershed areas.

Investing In Water Infrastructure

Currently and in coming years, MWRA continues to focus on ensuring redundancy for each water service area. This means providing secondary water access points in case of primary pipeline failures or breaks. Progress has been steady with ongoing work in northern communities like Stoneham, Reading, and Woburn, as well as southern areas including Boston and Dedham.

A new emergency pump station in Marlborough will ensure sufficient water reaches treatment facilities during system problems. MWRA has also begun strengthening main pipelines serving large system areas, with design work underway for the 11-mile Weston Aqueduct Source Main No. 3 improvements across Weston, Waltham, Belmont, Arlington, and Medford.

Pipeline Rehabilitation Efforts

MWRA continuously rehabilitates and replaces aging pipelines throughout the distribution network to enhance reliability and water quality. Since 1998, MWRA has provided interest-free loans for local pipeline projects. In 2017, communities borrowed $25.8 million for 18 projects, replacing over 15.4 miles of older, unlined pipes with new cement-lined ductile iron pipes or rehabilitating existing lines with cleaning and new cement coating.

Water Conservation

Conservation has proven effective. Customers in the MWRA service area have reduced daily demand from 340 million gallons per day in the 1980s to less than 200 million gallons today. These conservation efforts must continue, especially during dry periods.

Superior Water Quality Sources

Your water comes from the Quabbin Reservoir (approximately 65 miles west of Boston) and the Wachusett Reservoir (about 35 miles west of Boston). The Ware River can also supplement supplies when needed. These pristine reservoirs provide wholesale water to local departments in 51 communities, delivering about 200 million gallons daily of high-quality municipal water in 2017.

The Quabbin and Wachusett watersheds enjoy natural protection with over 85% of watershed areas preserved as forest and wetlands. The Department of Conservation and Recreation (DCR) conducts regular testing and daily patrols to ensure continued protection.

Natural Filtration Process

Precipitation falling on the watersheds flows through streams to the reservoirs, undergoing natural filtration as it contacts soil, rock, plants, and other materials. While this process helps clean the water, it can dissolve and carry small amounts of substances. Minerals from soil and rock typically don't affect water quality, but water can transport contaminants from human and animal activities, including bacteria and pathogens. Test data confirms these contaminants aren't problematic in your reservoir watersheds.

Advanced Treatment Technology

UV light treatment provides enhanced disinfection—similar to but more potent than natural sunlight disinfection—ensuring any pathogens in reservoirs are neutralized. Additionally, fluoride promotes dental health, and water chemistry adjustments minimize household plumbing corrosion. Finally, mono-chloramine (a mild, long-lasting disinfectant combining chlorine and ammonia) protects water as it travels through miles of pipelines to your home.

Comprehensive Water Testing

Test results show minimal contaminants in reservoir water, with any detected substances present at levels far below EPA limits. Turbidity (water cloudiness) measures overall quality and must remain below 5 NTU, with readings above 1 NTU only permitted if disinfection isn't compromised. In 2017, turbidity consistently remained below both standards, with peak levels at 0.92 NTU and typical Wachusett Reservoir levels at 0.35 NTU.

MWRA also tests for pathogens like fecal coliform bacteria and parasites such as Cryptosporidium and Giardia, which can enter water from animal or human waste. All results met state and federal standards.

Water Treatment Excellence

MWRA has invested in cutting-edge treatment at the John J. Carroll Water Treatment Plant in Marlborough. Since 2006, ozone treatment (produced from pure oxygen) has ensured robust protection against microbes and viruses while improving water quality and taste. In 2014, ultraviolet (UV) disinfection was added to further enhance water purity.

Lead Awareness

While most lead poisoning cases stem from deteriorating lead paint and dust, water exposed to lead can increase total exposure—particularly concerning for young children and pregnant women. Lead can enter tap water through home plumbing, lead service lines, lead solder, and certain fixtures. Corrosion of lead-based materials can introduce lead to tap water, especially when water sits stagnant for extended periods.

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