Who issues NPDES permits in Maine?

Maine Department of Environmental Protection issues and enforces NPDES permits for wastewater discharges in Maine. Klarifi tracks 84 permits held by publicly owned treatment plants in the state.

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

32 permits are administratively continued (the plant applied for renewal and the old permit stays in force) and 9 are recorded as expired, out of 84 permits tracked. 43 are effective.

How many Maine wastewater permits come up for renewal soon?

3 in 2026, 6 in 2027 and 8 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 Maine

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

84 permits held by publicly owned wastewater treatment plants · issued by Maine DEP

Effective

Administratively continued

Expired

Total tracked

Maine Department of Environmental Protection (Maine DEP) runs the NPDES program in Maine under delegation from EPA Region 1, issuing and enforcing the discharge permits listed here. Klarifi tracks 84 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: 3 permits

2027: 6 permits →2028: 8 permits →

2029: 7 permits

2030: 16 permits

2031: 5 permits

Largest permit holders in Maine

The 25 largest publicly owned wastewater treatment plants in Maine 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)
Bangor Wastewater Treatment Facility	Bangor	4.38	18	ME0100781	Effective	Jul 2031	14
Anson Madison Wastewater Treatment Facility	Madison	0.6	7.84	ME0101389	Effective	Apr 2031	2
Westbrook Waste Water Treatmemt Facility	Westbrook	2.5	4.54	ME0100846	Administratively continued	Jul 2022	26
Sanford Wastewater Treatment Facility	Sanford	—	4.4	ME0100617	Administratively continued	Jul 2023	4
Old Orchard Beach Wastewater Treatment Facility	Old Orchard Beach	0.9	3.5	ME0101524	Administratively continued	May 2020	11
Old Town Wastewater Treatment Facility	Old Town	0.63	3.5	ME0100471	Effective	Sep 2029	2
York Wastewater Treatment Facility	York	0.67	3	ME0101222	Effective	Mar 2030	12
Lisbon Wastewater Treatment Facility	Lisbon	0.37	2.03	ME0100307	Effective	Oct 2029	4
Bar Harbor WWTF Main Facility	Bar Harbor	0.82	2	ME0101214	Administratively continued	Jan 2021	9
Livermore Falls WWTF	Livermore Falls	0.27	2	ME0100315	Effective	Oct 2029	14
Falmouth Waste Water Treatment Facility	Falmouth	0.7	1.56	ME0100218	Administratively continued	Dec 2023	3
Calais Wastewater Treatment Facility	Calais	0.34	1.5	ME0100129	Administratively continued	Nov 2021	11
Hartland Wastewater Treatment Facility	Hartland	0.08	1.5	ME0101443	Administratively continued	May 2023	0
Pittsfield Wastewater Treatment Facility	Pittsfield	—	1.5	ME0100528	Effective	Jun 2030	20
Belfast Wastewater Treatment Facility	Belfast	0.42	1.49	ME0101532	Expired	Feb 2021	0
Skowhegan Wastewater Treatment Facility	Skowhegan	0.31	1.44	ME0100625	Effective	Apr 2031	90
Yarmouth Wastewater Treatiment Facility	Yarmouth	0.44	1.31	ME0100765	Administratively continued	Aug 2022	3
Ogunquit Wastewater Treatment Facility	Ogunquit	0.54	1.28	ME0100986	Administratively continued	Nov 2023	8
Camden Wastewater Treatment Facility	Camden	0.32	1.21	ME0100137	Administratively continued	Dec 2023	6
Norway Wastewater Treatment Facility	Norway	—	0.98	ME0100455	Effective	Aug 2030	0
Dover-Foxcroft Wastewater Treatment Facility	Dover-Foxcroft	—	0.8	ME0100501	Effective	Feb 2028	5
Freeport Wastewater Treatment Facility	Freeport	0.23	0.75	ME0101036	Administratively continued	Feb 2021	4
Kennebunkport Wastewater Treatment Facility	Kennebunkport	0.26	0.7	ME0101184	Effective	Nov 2026	27
Jackman Wastewater Treatment Facility	Jackman	—	0.68	ME0100978	Expired	Oct 2024	0
Canton Wastewater Treatment Facility	Canton	—	0.62	ME0102067	Effective	Oct 2029	4

All 84 plants in Maine →

NPDES permits in Maine: 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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