A clean water story, with a real question mark over its future
Plymouth is a different kind of Water Watch town: it's one of the largest towns we cover, and its water doesn't come from a single reservoir or a handful of wells you can count on one hand. The Town of Plymouth Water Division, part of the Department of Public Works, draws 100% of its supply from groundwater — 12 to 13 gravel-packed wells spread across the town, all tapping the Plymouth-Carver Sole Source Aquifer, a regional groundwater resource so large the EPA designated it a federally protected sole-source aquifer back in 1990.
The most recent testing data backs up that reputation: the highest PFOA reading found anywhere in Plymouth's system is 2.39 parts per trillion, comfortably below both Massachusetts' 20 ppt combined PFAS6 standard and the federal government's 4 ppt individual limit. Lead levels are similarly reassuring. But Plymouth's size and growth trajectory raise a different question than most of the towns we've covered: with no alternate water source and a single aquifer supplying the entire town, local reporting has raised real concerns about whether gravel mining, tree clearing, and development pressure near the aquifer's recharge areas could erode that clean record over time.
| Issue | What the data shows | Status |
|---|---|---|
| PFAS6 (combined, per-well) | Highest single-compound reading: 2.39 ppt PFOA (Wannos Pond Well); all other regulated PFAS non-detect at every tested well | Well below MA's 20 ppt limit; no violation |
| Lead (90th percentile, most recent round) | 0.0035 mg/L (3.5 ppb) — about 23% of the federal action level | Well below the 15 ppb federal action level |
| Historical SDWA violations | 1–3 old non-health-based paperwork/reporting violations (2014–2022), depending on tracker and lookback window | All resolved; no health-based violation found in any source |
| Aquifer protection | Town officials and environmental advocates disagree over whether gravel mining and development near the sole-source aquifer's recharge areas pose a future risk | Ongoing local policy debate, not a current testing exceedance |
Sources: EPA SDWIS/ECHO (PWS ID MA4239000); Town of Plymouth PFAS results page and 2023–2024 Water Quality Reports; Plymouth Independent reporting; see the full breakdown with citations on the Water data page.
