Waltham Water Department

WHY YOUR WATER TASTES GREAT – HIGH QUALITY SOURCE WATER

Your municipal water originates from the pristine Quabbin and Wachusett Reservoirs, located approximately 65 and 35 miles west of Boston. These reservoirs, sometimes supplemented by Ware River water, serve as primary sources for 51 neighboring communities. Together, they supplied roughly 210 million gallons daily of high-quality water throughout 2016.

The watersheds surrounding these reservoirs enjoy exceptional protection, with over 85% covered by forests and wetlands. To ensure continued safety, the Department of Conservation and Recreation (DCR) conducts regular testing and daily patrols. Precipitation falling on these protected lands flows through streams before reaching the reservoirs, naturally filtering through soil, rock, and vegetation. While this process helps purify the water, it can also dissolve small amounts of materials.

WATER SAFETY AND TREATMENT PROCESSES

The Massachusetts Water Resources Authority ensures clean, fresh water reaches your tap through advanced treatment at the John J. Carroll Water Treatment Plant in Marlborough. Since 2005, your water has undergone ozone treatment derived from natural oxygen, which effectively eliminates microbes and viruses while improving clarity and taste.

In 2014, ultraviolet (UV) disinfection was added as an additional safeguard, working much like natural sunlight disinfection but more intensively. Fluoride is included for dental health benefits, and water chemistry is adjusted to minimize home plumbing corrosion. Finally, mono-chloramine (a mild disinfectant combining chlorine and ammonia) protects water quality as it travels through the distribution system to your home.

COMPREHENSIVE WATER TESTING

Test results consistently show minimal contaminants in reservoir water, all well below EPA standards. Turbidity (water cloudiness) serves as one quality indicator – all water must measure below 5 NTU, with readings above 1 NTU only acceptable if disinfection remains effective. Throughout 2016, turbidity stayed consistently below both thresholds, with the highest reading at just 0.8 NTU. Typical Wachusett Reservoir readings average 0.3 NTU.

MWRA also regularly screens for pathogens including fecal coliform bacteria and parasites that might enter water from animal or human waste. All test results have consistently met or exceeded state and federal standards.

INFRASTRUCTURE IMPROVEMENTS

MWRA has prioritized system redundancy in recent years, creating backup supply routes in case of primary pipeline failures. While significant progress has been made from the treatment plant to metropolitan distribution tunnels, those tunnels themselves currently lack redundancy. Plans include constructing new tunnels starting in Weston – one northward and one southward – though construction remains several years away. Meanwhile, smaller projects are underway to strengthen the system, including new redundant pipelines in northern service areas (Reading, Stoneham, Woburn) and southern service areas (Boston, Dedham).

MWRA continuously rehabilitates aging pipelines throughout the distribution network to improve reliability and water quality. Since 1998, the authority has provided zero-interest loans to communities for local pipeline projects. In 2016 alone, $17.3 million funded 18 projects, replacing over 17 miles of older unlined pipes with new cement-lined ductile iron water pipes.

1. How often is municipal water tested?
   Municipal water systems conduct daily testing for some parameters (like chlorine levels), while other contaminants are monitored weekly, monthly, quarterly or annually depending on regulatory requirements and system size.
2. What causes water hardness?
   Water hardness results from dissolved minerals, primarily calcium and magnesium, that naturally occur in source water. These minerals can cause scale buildup in pipes and appliances while reducing soap effectiveness.
3. Is fluoride in municipal water safe?
   The CDC, American Dental Association, and World Health Organization all recognize water fluoridation as safe and effective for preventing tooth decay at regulated levels (0.7 parts per million).
4. How do I know if I have lead pipes?
   Homes built before 1986 may have lead service lines or fixtures. You can check pipe color (lead appears dull gray and is soft enough to be scratched with a key) or contact your water utility for assistance with identification.
5. What home water filters are most effective?
   Filter effectiveness depends on targeted contaminants. NSF-certified carbon filters reduce many organic compounds and chlorine, while reverse osmosis systems remove a broader spectrum including heavy metals and some inorganic compounds.