An independent system, for now
Weymouth doesn't buy finished water from a neighboring town or share a joint utility the way some South Shore communities do. The Weymouth Water Department, part of the Town's Department of Public Works, runs its own public water system — EPA/MassDEP Public Water System ID MA4336000 — built around two treatment plants: the Great Pond Water Treatment Plant, drawing mostly from Great Pond with a supplemental pumping station at the South Cove of Whitman's Pond (roughly 86% of supply), and the Arthur J. Bilodeau Water Treatment Plant, treating groundwater from five bedrock wells in the Mill River Aquifer (roughly 14%). In genuine emergencies only, Weymouth can draw backup supply from Abington, Rockland, Braintree, Hingham, and Quincy — this is emergency interconnection capacity, not routine blending.
That independence is set to change. The town is now pursuing a roughly 6.7-mile transmission main connection to the regional MWRA water system, driven partly by long-standing supply constraints (Weymouth's sources have operated under a state-ordered safe-yield limit since the 1990s) and partly by the redevelopment of the former South Weymouth Naval Air Station into the mixed-use "SouthField" community, which needs more capacity than the town's wells and reservoir can reliably provide.
| Issue | What the data shows | Status |
|---|---|---|
| PFAS6 (combined, town supply) | ND–11.4 ppt system-wide, 2025 | Below MA's 20 ppt limit; no violation |
| Lead (tap sampling) | 0–4.8 ppb, 90th percentile = 1 ppb | Well below the 15 ppb federal action level |
| Lead service line inventory | A few hundred of ~18,000 service connections still classified "unknown" as of Oct 2024 | Town says most are unlikely to be lead based on install-era standards; verification ongoing |
| Historical violation | One tracker (PlainEnviro) lists a Combined Radium 226/228 treatment-technique violation dated 1/1/1997 | Not shown in EPA ECHO's recent history or the current CCR; likely resolved decades ago |
Sources: Town of Weymouth 2025 Annual Water Quality Report; EPA ECHO/SDWIS; MassDEP; see the full breakdown with citations on the Water data page.
