We're kicking this off with a fact most of our neighbors don't know: a specific spot on Longwater Drive, right here in Rockland, near the Norwell town line, is the exact location tied to a set of MCL violations for disinfection byproducts — Total Trihalomethanes (TTHM) and Haloacetic Acids (HAA5) — recorded across four consecutive quarters in 2014 and 2015. It's a "low-flow" sampling point, meaning water sits there longer before reaching a tap, which is exactly the kind of spot where these byproducts (formed when chlorine reacts with organic matter) tend to build up. There's no public record of it recurring since 2015, but it's a genuinely Rockland-specific entry in a water record that, for almost everything else, belongs jointly to Rockland and Abington.
That's because Rockland doesn't have its own separate water utility. Every drop that comes out of a Rockland tap runs through the Abington-Rockland Joint Water Works (ARJWW) — one combined system, one EPA Public Water System ID (MA4001000), jointly governed by both towns since the 1880s. Rockland's own contribution to that system is substantial: the John F. Hannigan Memorial Reservoir and Water Treatment Plant off Hingham Street is one of the system's three treatment plants, and it's also where the utility's biggest recent story played out. Starting in March 2021, the Hannigan plant's source water tested above Massachusetts' 20 parts-per-trillion PFAS6 standard, with exceedances recurring into 2024. Rockland and Abington jointly borrowed roughly $26 million for new treatment, and the Hannigan plant's permanent system came online in March 2026, reducing PFAS6 to non-detect — a genuine, verifiable turnaround for a plant that sits inside Rockland's own town lines.
Add a July 2024 raw-water PFOS reading at Abington's Myers Avenue plant well above the federal limit, a May 2025 E. coli-triggered boil-water order that reached five towns, and a genuinely clean 2024 lead-service-line inventory, and you get a system that's had real problems and has been visibly working through them — which is exactly the kind of nuance we think deserves a plain-language home. See the full breakdown, including the Longwater Drive record, on our Water data page.
We're not going to soften this and we're not going to overstate it either: the Abington-Rockland Joint Water Works has a real, documented PFAS history at Rockland's own Hannigan plant, and it is actively, visibly resolving it. The Hannigan plant's source water exceeded Massachusetts' 20 ppt PFAS6 standard starting in March 2021, with exceedances recurring in 2024. A raw-water sample at the Myers Avenue plant in Abington measured PFOS above the federal individual limit in July 2024. Both towns responded with a joint $26 million investment in new GAC and resin treatment.
As of this writing, the Hannigan plant's permanent treatment system has been online since March 4, 2026 and is reducing PFAS6 to non-detect — meaning the plant physically located in Rockland is, right now, the one that's fully resolved. The Myers Avenue plant currently relies on an interim pilot system that keeps finished water below the 20 ppt limit while its own permanent system is completed. We'll update this page as soon as we can confirm Myers Avenue's permanent system is fully online — treat that specific detail as still in motion rather than settled.
See the full compound-by-compound and plant-by-plant breakdown on our Water data page.
Long before there was a federal PFAS rule, there was a Massachusetts one. In October 2020, MassDEP finalized an enforceable drinking water standard — a Maximum Contaminant Level, or MCL — of 20 parts per trillion for the combined total of six PFAS compounds, a grouping the state calls "PFAS6": PFOS, PFOA, PFHxS, PFNA, PFHpA, and PFDA.
At the time, this made Massachusetts one of a small number of states with any enforceable PFAS standard at all. For the Abington-Rockland Joint Water Works — and specifically for Rockland's own Hannigan plant — this is the exact standard that fell out of compliance starting in March 2021, and the standard the new treatment system is now built to meet. As of March 2026, Hannigan's finished water tests at non-detect for PFAS6, comfortably under the 20 ppt threshold.
Source: Mass.gov — Massachusetts PFAS Drinking Water Standard (MCL).
Until April 2024, there was no federal limit on PFAS in drinking water at all — only the Massachusetts state standard set in 2020. That changed when EPA finalized its National Primary Drinking Water Regulation (NPDWR) for PFAS: the first time PFAS compounds have been individually, enforceably regulated at the federal level.
The rule set limits of 4 parts per trillion (ppt) each for PFOA and PFOS, 10 ppt each for three additional compounds (PFHxS, PFNA, and HFPO-DA), and a combined "Hazard Index" limit for mixtures of those plus PFBS. Water systems nationwide were given until 2027 to complete initial monitoring and until 2029 to come into full compliance.
For the Abington-Rockland Joint Water Works, this rule wasn't an abstraction: a combined raw-water sample collected at the Myers Avenue plant in Abington on July 30, 2024 measured PFOS at 18.8 ppt — nearly five times the new 4 ppt individual limit. That reading, in raw source water ahead of treatment, is part of what makes the ongoing treatment project at both Myers Avenue and Rockland's own Hannigan plant a genuine compliance necessity rather than a precaution.
Source: Federal Register — PFAS National Primary Drinking Water Regulation.
On May 18, 2026, EPA announced two proposals that affect the federal PFAS rule described above. The first (Docket EPA-HQ-OW-2025-1742) would let water systems request a two-year extension — from 2029 to 2031 — to comply with the enforceable limits for PFOA and PFOS, while requiring systems measuring 12 ppt or higher to take short-term mitigation action during the extension. The second (Docket EPA-HQ-OW-2025-0654) would rescind the individual limits for three other PFAS compounds (PFHxS, PFNA, and HFPO-DA/GenX) and the combined "Hazard Index" limit for mixtures of those plus PFBS, on the grounds that EPA says the prior process didn't follow required Safe Drinking Water Act procedure.
What doesn't change: the 4 ppt limits for PFOA and PFOS individually are not part of either rescission proposal. That distinction actually matters here in a way it might not for a system with clean PFAS results: the Abington-Rockland Joint Water Works has recorded a raw-water PFOS reading well above 4 ppt at its Myers Avenue plant, so the extension proposal — and its 12 ppt mitigation trigger — is directly relevant to how quickly the treatment work gets finished, not just a policy abstraction. Rockland's own Hannigan plant already crossed that finish line in March 2026; Myers Avenue is the one still working toward it.
EPA held a virtual public hearing on July 7, 2026, and the comment dockets remain open through July 20, 2026, with more than 15,000 comments submitted as of mid-July. Nothing here is final; treat the 2024 rule as the current baseline until EPA actually finalizes a change.
See the full regulatory timeline for how this fits with the 2020 state standard and the 2024 federal rule.
System-wide data only tells part of the story — service lines, home plumbing, and private wells can all change what actually comes out of your tap.
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