Who issues NPDES permits in Massachusetts?

US EPA Region 1 (with MassDEP) issues and enforces NPDES permits for wastewater discharges in Massachusetts. Klarifi tracks 66 permits held by publicly owned treatment plants in the state.

How many NPDES permits in Massachusetts are expired or administratively continued?

5 permits are administratively continued (the plant applied for renewal and the old permit stays in force) and 1 are recorded as expired, out of 66 permits tracked. 60 are effective.

How many Massachusetts wastewater permits come up for renewal soon?

31 in 2026, 17 in 2027 and 5 in 2028. Each year has its own renewal calendar with the plants listed.

How do I look up an NPDES permit number?

Enter the permit number (two letters and seven characters, for example TX0021873) or the plant name in the lookup on the NPDES page; each result opens the plant profile with status, expiry, design flow and the three-year violation count.

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NPDES permits in Massachusetts

Name: NPDES permits held by wastewater treatment plants in Massachusetts
Creator: Klarifi
License: https://klarifi.io/terms-of-service

66 permits held by publicly owned wastewater treatment plants · issued by EPA Region 1

Effective

Administratively continued

Expired

Total tracked

Massachusetts is not a delegated state: NPDES permits are issued by US EPA Region 1 (with MassDEP), with the state agency handling water-quality certification. Klarifi tracks 66 permits held by publicly owned treatment plants in the state, with status, expiry, design flow and three-year compliance for each. Agency website →

An NPDES permit runs for five years. To keep discharging, a plant must apply for renewal at least 180 days before the expiry date, and the renewed permit usually arrives with tighter effluent limits, new monitoring requirements or a compliance schedule. That is why the year a permit expires is the year a plant starts budgeting for upgrades: nutrient removal, disinfection, capacity or controls.

Permit renewals by year

2026: 31 permits →2027: 17 permits →2028: 5 permits →

2029: 2 permits

2030: 6 permits

Largest permit holders in Massachusetts

The 25 largest publicly owned wastewater treatment plants in Massachusetts by permitted design flow, with NPDES permit number, status and expiry. Source: EPA ICIS-NPDES via Klarifi.
Facility	City	Avg flow (MGD)	Design (MGD)	NPDES permit	Status	Expires	Violations (3y)
Deer Island Wastewater Treatment Facility	Winthrop	233.7	480	MA0103284	Administratively continued	Jul 2005	3
New Bedford Wastewater Treatment Facility	New Bedford	16.7	30	MA0100781	Administratively continued	Nov 2013	14
Upper Blackstone Wastewater Treatment Plant	Millbury	24.1	—	MAR053209	Expired	Feb 2026	15
Greater Lawrence Wastewater Treatment Facility	North Andover	21.7	—	MAL100447	Effective	Dec 2030	10
South Essex Wastewater Treatment Plant	Salem	17.57	—	MAL100501	Effective	Dec 2030	33
Pittsfield Wastewater Treatment Facility	Pittsfield	7	17	MA0101681	Effective	Oct 2026	84
Brockton Advanced Water Reclamation Fac	Brockton	9.9	—	MAL101010	Effective	Dec 2030	10
Northampton Wastewater Treatment Plant	Northampton	3.84	8.65	MA0101818	Effective	Nov 2028	40
Taunton Wastewater Treatment Facility	Taunton	5.36	8.4	MA0100897	Administratively continued	Jul 2020	52
Westborough Wastewater Treatment Plant	Westborough	4.17	7.7	MA0100412	Effective	Apr 2027	2
Amherst Wastewater Treatment Plant	Hadley	3.33	7.1	MA0100218	Effective	Jan 2029	42
Haverhill Wastewater Treatment Facility	Haverhill	6.58	—	MAL101621	Effective	Dec 2030	4
Hoosic Wastwater Treament Plant	Williamstown	2.04	6.5	MA0100510	Effective	Dec 2028	2
Westfield Wastewater Treatment Plant	Westfield	2.4	6.1	MA0101800	Effective	Nov 2028	0
Palmer Water Pollution Control Facility	Palmer (three Rivers)	1.2	5.6	MA0101168	Effective	Nov 2028	4
Billerica Wastewater Treatment Facility	Billerica	2.88	5.5	MA0101711	Effective	Feb 2029	52
Marlborough DPW Water Division East Plt	Marlborough	2.04	5.5	MA0100498	Effective	Mar 2027	13
Holyoke Water Pollution Control Facility	Holyoke	5.02	—	MAL101630	Effective	Dec 2030	4
Westerly Wastewater Treatment Facility	Marlborough	1.16	2.89	MA0100480	Effective	Dec 2026	26
Erving Wastewater Treatment Plant #2	Erving	1.72	2.7	MA0101052	Effective	Nov 2026	36
Gardner W W T F	East Templeton	2.28	—	MAG590013	Effective	Oct 2027	75
Rockland Wastewater Plant	Rockland	2	—	MAG590038	Effective	Oct 2027	32
Montague Wastewater Treatment Facility	Montague	0.54	1.83	MA0100137	Effective	Dec 2028	237
Newburyport Wastewater Treatment Facility	Newburyport	1.45	—	MAG590035	Effective	Oct 2027	0
Greenfield Water Pollution Control Facility	Greenfield	1.44	—	MAG590014	Effective	Oct 2027	31

All 66 plants in Massachusetts →

NPDES permits in Massachusetts: questions

Sources and methodology

Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.

Data refreshed September 11, 2026.

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