The Marshfield DPW Water Division — EPA/MassDEP Public Water System ID MA4171000 — draws its entire drinking water supply from sixteen active gravel-packed wells across six local aquifers, most prominently the Furnace Brook Aquifer and Little's Creek Aquifer. Every well sits within Marshfield's own borders, and the town buys no water wholesale from any neighbor for its own supply — a genuinely local, entirely-groundwater sand-and-gravel system.
Named well/pump stations, per the town's own 2023 report: in the High Zone, Union #1, Union #2, School Street, Fairgrounds, Furnace Brook #2, and Spring Street; in the Low Zone, Ferry #1, Ferry #2, Furnace Brook #1, Furnace Brook #3, Furnace Brook #4, Mount Skirgo, South River Street, Webster #1, Webster #2, and Church Street. All wells receive a pH adjustment (Marshfield's groundwater is naturally acidic); three of the Furnace Brook wells have additional activated-carbon filtration or aeration for volatile organic compounds, with sodium hypochlorite and/or UV disinfection before the water reaches the distribution system.
Population served: public sources disagree. The town's own 2023 Consumer Confidence Report states 28,000; EPA's federal SDWIS record (queried directly for PWS ID MA4171000) and independent trackers (EWG, TapWaterData) state 34,000. We report both rather than picking whichever sounds more precise — a gap this size between a utility's own stated figure and the federal record is common when populations are estimated on different bases (metered accounts vs. Census-adjacent methodology), but it's worth knowing about rather than smoothing over. Service connections: 10,948 accounts per the 2023 CCR; 11,000 per EPA's record — close enough to not be a meaningful disagreement.
Marshfield is also a modest water wholesaler: per its own 2023 report, the town supplies water to sections of Scituate's Humarock neighborhood, Pembroke, and Duxbury. Its own language is specific and worth quoting directly: "There are no interconnections to either Pembroke or Scituate. There is an emergency connection to Duxbury (hydrant-to-hydrant) if needed." See the callout box below for how that description compares to what Duxbury's own reporting says about the same connection.
The town's own 2023 Consumer Confidence Report lists no violations for any regulated or unregulated substance it tested that year. But EPA's federal Safe Drinking Water Information System (SDWIS) — which we queried directly for PWS ID MA4171000 rather than relying on a secondhand summary — shows a different, longer-running count:
| Period | Type | Status |
|---|---|---|
| Nov. 2005 – Dec. 2005 | Non-health-based (procedural/reporting) | Returned to compliance within about a month |
| Jul. 2015 | Non-health-based (procedural/reporting) | Returned to compliance within about two weeks |
| Aug. 2019 | Health-based MCL violation | Returned to compliance by Sept. 23, 2019 (about 7 weeks) |
The August 2019 entry is coded in SDWIS under the same rule family used for microbiological (Total Coliform Rule–type) monitoring, though we want to be precise about the limits of what we can confirm from the coded federal record alone: it doesn't spell out in plain language which specific contaminant triggered it, and we weren't able to independently pull the underlying corrective-action paperwork. It was resolved quickly and there's no coliform or bacteriological violation on record since. This lines up with independent tracker TapWaterData, which separately lists exactly one MCL violation for this system — consistent with the 2019 entry, while its methodology doesn't appear to count the two older non-health-based procedural violations at all. We're reporting all three because a federal record showing three counts and a tracker showing one aren't actually in conflict — they're just answering slightly different questions.
No PFAS-related MCL violation appears on the federal record. That tracks with the town's own testing: Massachusetts' PFAS6 standard only took effect in October 2020, and Marshfield's combined system-wide PFAS6 results have stayed under it since (see below).
Marshfield's PFAS story, like several of its South Shore neighbors, has two layers that shouldn't be flattened into one number:
Layer one — Massachusetts' combined PFAS6 standard (20 ppt): The town's 2023 Consumer Confidence Report reports combined PFAS6 (the sum of six specific compounds) at a highest detected amount of 11.1 ppt, with a range of ND–13.0 ppt across the system that year — comfortably under the state's 20 ppt limit, with no violation. By this measure, Marshfield's water is a genuinely clean, well-run result, consistent with its "highly reliable" reputation among South Shore systems.
Layer two — the federal individual PFOA/PFOS standard (4 ppt each), finalized in April 2024: This is where the picture gets more complicated, and where we have to be careful about sourcing. The town's own CCR reports PFAS as one combined system-wide figure and doesn't break results out well-by-well or compound-by-compound, so we can't verify individual-well compliance directly from Marshfield's own published report. Separate reporting fills in some of that gap:
| Source | What was reported | Applicable limit |
|---|---|---|
| Marshfield DPW 2023 CCR (combined, system-wide) | ND–13.0 ppt PFAS6 | 20 ppt (MA PFAS6 standard) — no violation |
| Furnace Brook #1A well (individual, PFOA) | 4.85 ppt (sampled July 30, 2024) | 4 ppt (federal individual limit) |
| Active town wells reported above the federal PFOA limit | 3 of 7 actively-tested wells | 4 ppt (federal individual limit) |
ppt = parts per trillion. The Furnace Brook #1A reading is cited by the Marin, Barrett & Murphy law firm's PFAS information page, which in turn attributes it to town monitoring data; we were not able to locate the underlying MassDEP sample record ourselves to independently confirm it, so we're citing it as reported rather than as our own verified finding. The "3 of 7 wells" figure comes from the Duxbury Clipper's reporting ("PFAS problems still on tap"), which describes Marshfield's individual-well PFOA results as part of its coverage of the regional PFAS picture; South Shore News' broader 22-community investigation ("What's in the Water") references the same regional pattern without naming Marshfield's specific wells beyond Furnace Brook. Neither outlet's underlying dataset was something we could pull ourselves, which is why we're presenting this as reported reporting rather than primary-sourced fact — a real limitation of what's publicly available, not a claim we're inventing.
Marshfield's own 2023 Consumer Confidence Report describes its connection to Duxbury in narrow, specific terms: "an emergency connection to Duxbury (hydrant-to-hydrant) if needed." That's the only characterization we could find in Marshfield's own official reporting — a backup, not a routine supply arrangement.
Duxbury's own water-quality reporting (and its own independent Water Watch site) describes something that sounds more continuous: a purchased-water connection supplying roughly 150 homes in the Gurnet Road / Duxbury Beach neighborhood, sampled for PFAS by Duxbury's own water superintendent in April 2026, with reporting noting Duxbury has been billed at Marshfield's commercial rates for years despite no formal intermunicipal contract being on file. We are not restating the specific parts-per-trillion figure Duxbury measured at that connection as our own independently-verified finding here — we weren't able to independently verify it ourselves, and it's Duxbury's sampling, not Marshfield's. You can read the exact reading and full context on Duxbury Water Watch's water data page, and we've made sure nothing on this page contradicts what that page states.
What we can say plainly: Marshfield's own official description ("emergency...if needed") and Duxbury's own description (an ongoing, billed, sampled supply to ~150 specific homes) are hard to fully reconcile from public documents alone. We're reporting that gap honestly rather than picking whichever framing is more convenient. It's possible both are technically accurate from each town's own vantage point — an "emergency" connection that has, in practice, become a standing arrangement for one neighborhood isn't a contradiction so much as two institutions describing the same infrastructure differently in their own paperwork. We'll update this page if either town's DPW clarifies further.
Marshfield's own reporting documents one other contaminant story worth including precisely because it's an example of a problem that was identified, addressed, and resolved. Perchlorate — associated with fireworks and blasting agents — was first detected at the South River Street well, down-gradient of the Marshfield Fairgrounds, in 2004, with concentrations rising through a peak of about 2.20 ppb in early 2006. The Fair was asked to stop its fireworks displays in August 2005 and complied starting in 2006; concentrations declined afterward and have stabilized at roughly 0.33–0.5 ppb since 2009, with the 2023 report showing a highest detected amount of 0.21 ppb against the 2.0 ppb action level — well under the limit, and no violation.
How the rules around PFAS in drinking water have actually changed over the past several years — and where they stand right now.
MassDEP finalized an enforceable Maximum Contaminant Level (MCL) of 20 parts per trillion (ppt) for the sum of six PFAS compounds ("PFAS6") — PFOS, PFOA, PFHxS, PFNA, PFHpA, and PFDA. This is the standard Marshfield's own combined system-wide testing has consistently stayed under (ND–13.0 ppt in 2023).
The EPA's National Primary Drinking Water Regulation (NPDWR) set the first-ever enforceable federal limits for PFAS: 4 ppt each for PFOA and PFOS individually, 10 ppt each for PFHxS, PFNA, and HFPO-DA (GenX), plus a combined Hazard Index limit for mixtures of those and PFBS. Water systems were given until 2027 to complete initial monitoring and until 2029 to come into full compliance. This is the standard the Furnace Brook #1A well and reportedly two other Marshfield wells test above for PFOA — a limit Marshfield's own CCR doesn't yet break out compound-by-compound to confirm or refute system-wide.
EPA proposed two changes. The first (Docket EPA-HQ-OW-2025-1742) would keep the PFOA/PFOS limits at 4 ppt each but let water systems request a two-year compliance extension — to 2031 instead of 2029 — while requiring systems measuring 12 ppt or higher to take short-term mitigation action in the meantime. The second (Docket EPA-HQ-OW-2025-0654) would rescind the individual limits for PFHxS, PFNA, and HFPO-DA and the Hazard Index for PFAS mixtures, leaving the PFOA/PFOS limits untouched. EPA held a virtual public hearing on July 7, 2026.
The combined comment dockets closed July 20, 2026 — yesterday — after drawing well over 15,000 public comments. Neither proposal has been finalized as of this writing; EPA has indicated it intends to act on both before the end of 2026. For Marshfield, where the Furnace Brook #1A well and reportedly two other wells already test above the 4 ppt individual PFOA limit that these proposals leave untouched, the extension proposal (2029 to 2031) is the more directly relevant one to watch — the rescission proposal targets compounds and thresholds that don't appear to be Marshfield's current concern. Check EPA's site directly for the current status before assuming either change has taken effect.
Sources: Mass.gov — Massachusetts PFAS Drinking Water Standard (MCL); Federal Register — PFAS National Primary Drinking Water Regulation (April 2024); EPA — Proposed PFOA and PFOS Compliance Extension Rule; EPA — Proposed PFAS Rescission Rule.
We don't ask you to take our word for any of this. The underlying reports and data are public:
System-wide data only tells part of the story — which well serves your street, your home's plumbing, and how long water sits in your pipes can all change what actually comes out of your tap.
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