The Hanson Water Department, a town DPW division created in 1916, serves an estimated 9,400–9,950 residents (public trackers vary slightly on the exact figure; Hanson's total 2020 Census population is 10,639). Water comes primarily from four active groundwater wells at the Crystal Spring Well Field off Main Street — Wells #1, #3, #4, and #5 — with a single backup interconnection to the Brockton Water Department (surface water drawn from Silver Lake) used only when needed, not as a routine blended source.
Before Hanson developed its own wellfield in the early 1980s, the town purchased its entire water supply from Brockton and the Abington/Rockland Joint Waterworks. That history is why the Brockton connection still exists today, strictly as a backup.
MassDEP's Source Water Assessment Program (SWAP) report, completed in 2003, found that Hanson's wells sit in an aquifer with high vulnerability to contamination — the recharge area (Zone II) lacks a confining clay layer that would otherwise slow the movement of surface contaminants down into the groundwater. The primary recharge area is mostly forest and wetland, with smaller pockets of residential, commercial, and industrial land use nearby. Susceptibility is a measure of potential risk based on surrounding land use, not a statement about current water quality.
The groundwater itself is naturally corrosive (a pH below 7.0), so the Water Department adds sodium hydroxide to raise the pH and reduce corrosion of lead and copper from household plumbing, plus chlorine for disinfection.
According to EPA's Safe Drinking Water Information System (SDWIS) and multiple independent public trackers, the Hanson Water Department has no health-based Maximum Contaminant Level (MCL) violations on record. That means the utility has stayed within its legally required limits for regulated contaminants.
Legal compliance is not the same as zero risk, and it isn't the same as "nothing to know." Hanson's most notable water quality story isn't a violation at all — it's a secondary (aesthetic) standard for manganese, detailed below.
Manganese is a naturally occurring mineral, not a manufactured contaminant, and EPA regulates it only as a Secondary Maximum Contaminant Level (SMCL) — a guideline aimed at taste, odor, and staining, not an enforceable health-based limit. Hanson's Crystal Spring wells have shown manganese levels that repeatedly exceed that secondary guideline of 50 parts per billion (ppb):
| Sample date | Manganese level | EPA secondary guideline | Status |
|---|---|---|---|
| 2024 CCR reporting | 162–257 ppb | 50 ppb | 3–5x guideline |
| November 19, 2025 | 407 ppb | 50 ppb | ~8x guideline |
| May 6, 2026 | 549 ppb | 50 ppb | ~11x guideline |
EPA notes that manganese becomes a short-term health consideration (not just aesthetic) above 1,000 ppb, and recommends infant formula not be prepared with water above 300 ppb for more than 10 days. Hanson's recent readings sit between the aesthetic threshold and that higher short-term guidance — worth knowing, especially for households with infants, even though it isn't an enforcement violation. Source: Hanson Water Department Consumer Confidence Reports (2023–2024) and MassDEP monitoring data via EWG's Tap Water Database.
Sodium tells a similar, smaller story: a 2022 sample measured 35.6 parts per million (ppm), above the Massachusetts Office of Research and Standards Guideline (ORSG) of 20 ppm used to flag levels worth knowing for sodium-restricted diets. It is not an enforceable limit, but it's the kind of detail that doesn't always make it into the CCR's summary language.
Unlike some neighboring systems on Massachusetts' South Shore, Hanson's PFAS picture is genuinely clean relative to legal standards. State PFAS monitoring data (compiled by the Environmental Working Group from MassDEP records, 2013–2024) shows the following detections:
| Compound | Detected level | Applicable limit |
|---|---|---|
| PFOA | 2.58 ppt | 4 ppt (federal individual limit) |
| PFOS | 2.47 ppt | 4 ppt (federal individual limit) |
| PFHxS | 0.794 ppt | 10 ppt (federal individual limit) |
| PFNA | 1.04 ppt | 10 ppt (federal individual limit) |
| PFDA | 0.208 ppt | No individual federal MCL |
ppt = parts per trillion. Every individually detected compound sits below its applicable federal limit, and the combined total of the detected PFAS6-family compounds (roughly 7 ppt) is well under Massachusetts' 20 ppt combined PFAS6 standard. Some of these readings (PFNA and PFDA specifically) are attributed to the Brockton backup interconnection rather than Hanson's own wells. We're not going to manufacture a PFAS scare where the data doesn't support one — this is a genuinely different picture than towns where PFAS has turned up above limits.
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. At the time, Massachusetts was among the first states in the country with a legally enforceable PFAS drinking water standard; there was still no federal one. This is the standard the Hanson Water Department is required to meet today, and its wells currently test well under it.
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. Hanson's most recent PFOA and PFOS readings (2.58 and 2.47 ppt) already sit below the 4 ppt limit.
On May 18, 2026, EPA proposed keeping the PFOA and PFOS limits at 4 ppt each, but allowing water systems to request a two-year compliance extension — to 2031 instead of 2029. In a separate proposal, EPA moved to rescind the individual limits for PFHxS, PFNA, and HFPO-DA and the Hazard Index for PFAS mixtures, citing procedural requirements under the Safe Drinking Water Act. The PFOA and PFOS limits themselves were not proposed for rescission. EPA held a virtual public hearing on July 7, 2026, and the public comment docket (EPA-HQ-OW-2025-1742) remained open through July 20, 2026 — check EPA's site directly for the current status before assuming either proposal is final.
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 are public:
System-wide data only tells part of the story — your home's plumbing, fixtures, and how long water sits in your pipes can all change what actually comes out of your tap.
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