Provenance

Sources

Every filing on this site is transcribed from a public MassDEP record. Where we are uncertain, the page says so.

Primary sources

Watershed application table — MassDEP, snapshot dated 11 June 2026. Every filing, transmittal number and filing type on this site comes from it.
310 CMR 15.000 — Title 5 of the State Environmental Code, amended 7 July 2023 to add the Nitrogen Sensitive Area provisions. The disclosure duty in 15.215(4) and the Best Available Nitrogen Reducing Technology provisions in 15.215(2) have been checked, word for word, against MassDEP's final rulemaking redline (dated 21 July 2023) — a tracked-changes record of the actual adopted amendments, and a stronger source than the informal "clean version" summary this site relied on for that check until 22 August 2026.
314 CMR 21.00 — Watershed Permit Regulations.
Nitrogen Sensitive Area address lookup — MassDEP's public map, which determines whether a property is inside a designated area.
NSA disclosure template form — MassDEP, published in twelve languages.
Implementation Q&A — MassDEP, source of the designation dates and the five-year window dates.
MassDEP, direct written confirmation, 25 August 2026 — Andrew (Drew) Osei, P.E., Environmental Engineer, Wastewater Management — Cape & Islands, MassDEP, 20 Riverside Drive, Lakeville. In answer to our enquiry, MassDEP confirmed that towns can apply for watershed permits covering areas that are not designated Nitrogen Sensitive Areas; that Halls Creek, Rushy Marsh and Barnstable Harbor are not designated; that Barnstable included them because it is approaching nitrogen abatement comprehensively, to town boundaries as well as watershed boundaries; and that a watershed permit application does not imply an impaired watershed, the permit being the only mechanism through which MassDEP reviews alternative nutrient-abatement approaches such as permeable reactive barriers and cranberry bog reactors and restoration.
Pleasant Bay Revised Watershed Permit 01-M1 — MassDEP, issued 10 February 2026, running to 10 February 2046, on application 24-WP96-0001-AMD and signed by Brian D. Harrington, Deputy Regional Director, Bureau of Water Resources, Southeast Regional Office. Read from the permit document published by the Pleasant Bay Alliance. It replaces the 2018 Pleasant Bay Watershed Permit — the first issued in Massachusetts — and MassDEP describes the changes as minor modifications under 314 CMR 21.06(4), aligning the 2018 conditions with 314 CMR 21.00 and the 2023 Title 5 amendments.

Why that one matters. The watershed application table is titled as a list of towns with designated Nitrogen Sensitive Areas, which reads as though every row in it is designated. It is not — it is a record of what towns filed. We had this on the site as an open question with the explanation marked unverified. It is now answered, in writing, by the MassDEP office responsible for the Cape.

How this is maintained

The watershed application table changes as towns file and as MassDEP acts on applications. Transmittal numbers carry the filing year, so the record visibly moves. We re-check the table and date every page from the version we read.

What we do not know

Whether any town is behind on the milestones in its approved schedule. This is the single most consequential unknown on the site: missed milestones can restart the upgrade clock.
The Dennis / Herring River row carries no designation date in the source table.
MassDEP states 31 designated watersheds. We record 35 rows from the application table, of which 32 are designated areas and 3 are confirmed not designated; those 32 rows correspond to 23 distinct areas on MassDEP's address map. The remaining difference between 32 and 31 is spelling — the table writes some watersheds more than one way — so any single count depends on how variants are merged. We publish all four numbers rather than choose one.
Whether any watershed outside Barnstable's application is also undesignated. Every row on this site has now been checked against MassDEP's address map, and Barnstable's three are the only ones that came back undesignated — but the map is a live layer and coverage can change.

Corrections we have made

On 25 August 2026 we corrected the treatment of Barnstable Harbor, Halls Creek and Rushy Marsh. The site previously told a seller in one of those areas that the answer needed checking on the map and offered our own unverified explanation for the discrepancy — that designation follows an EPA-approved nitrogen TMDL under 310 CMR 15.214(1)(b)1. That reasoning was our inference and we have removed it. MassDEP's explanation is administrative, not regulatory, and the site now states the confirmed answer: those three are not designated, and box 4 applies.

On 27 August 2026 we corrected the Pleasant Bay permit. The site described permit 001-0, issued in 2018, and said that a granted permit does not revert barring revocation. That permit has been superseded: the permit in force is 01-M1, issued 10 February 2026 and running to 10 February 2046. The determination did not change — a seller in Pleasant Bay ticks box 2 either way — but the document we pointed at was the wrong one, and a permit with a term is a different thing from one described as open-ended. MassDEP's own watershed application table dated 11 June 2026 still lists 001-0, so the site now names the permit in force and says why the two differ.

Corrections you can send us

If something here is wrong — particularly if you work for a Board of Health or a town's wastewater programme — tell us and we will fix it and say what changed.

Not legal advice. This is an independent guide, not affiliated with MassDEP or any town. The official regulation governs, and your Board of Health is the authority on your property.