Norfolk County, Massachusetts: drinking water report. Norfolk County serves about 710,000 residents in suburban communities south of Boston, including…
Norfolk County serves about 710,000 residents in suburban communities south of Boston, including Quincy, Brookline, and Weymouth. Water sources are mixed – some communities receive MWRA water from the Quabbin and Wachusett Reservoir system, while others operate independent surface water or groundwater systems. The split creates significant quality differences between neighboring towns.
MWRA communities benefit from one of the cleanest municipal water supplies in the country. Independent systems face more variable quality. Massachusetts regulates PFAS as a sum of six compounds with an MCL of 20 ppt – one of the stricter approaches nationally.
According to the Massachusetts DEP's 2024 monitoring data, four public water systems in Norfolk County reported PFAS above the state MCL, all operating independent groundwater systems. These exceedances triggered mandatory treatment installation. UCMR5 data confirms the pattern – MWRA-served communities show minimal PFAS detections, while independent groundwater systems show higher levels.
Determine whether your town receives MWRA water or operates independently. The answer shapes your entire risk profile.
Check your water to identify your provider and see data. For independent groundwater systems with PFAS detections, a reverse osmosis filter adds household protection. Our water filter guide covers which systems work. Pull your detailed report, and visit our Massachusetts page for statewide patterns.
Drinking water is one exposure route. These federal datasets also cover Norfolk County, MA.
The EPA places Norfolk County, MA in Zone 2 - a moderate-risk category, with a predicted average indoor radon level between 2 and 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
68% of homes in Norfolk County, MA were built before 1980, and 33% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Norfolk County, MA averages 6.8 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide
Across 42 public water systems serving Norfolk County, MA with EPA lead testing on record, 5 (11.9%) reported a 90th-percentile lead result above the EPA's 15 ppb action level, and the median is 5.2 ppb. 27 water systems serving Norfolk County, MA carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Lead and Copper Rule | 18 |
| Revised Total Coliform Rule | 4 |
| Total Trihalomethanes (TTHM) | 3 |
| Perchlorate | 1 |
| Ground Water Rule | 1 |
Source: EPA Lead and Copper Rule 90th-percentile tap sampling and EPA SDWIS Safe Drinking Water Act enforcement records, aggregated from the public water systems serving this county. Figures are counts of water systems, not a test of any individual home or tap.