How many wastewater permits expire in Maine in 2027?

7 NPDES permits held by publicly owned wastewater treatment plants in Maine expire in 2027, covering a combined average flow of 0 MGD. The busiest month is Dec 2027 with 3 expiries.

What happens when an NPDES permit expires?

The plant must have applied for renewal at least 180 days before the expiry date. If the agency has not reissued the permit by then, the old permit is administratively continued and stays enforceable. The reissued permit typically carries updated effluent limits based on the latest water-quality standards, which is what drives upgrade projects.

Which is the largest plant with a permit expiring in Maine in 2027?

Ashland Wastwater Treatment Facility in Ashland, treating about 0.11 MGD under permit ME0101087, expiring May 2027.

How do I get contacts for the plants on this list?

Every plant links to its profile with flow, permit and compliance data. Treatment technology and verified decision-maker contacts for each plant, and the same list for every state and year, are available in Klarifi with a free account.

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Maine wastewater permits expiring in 2027

Name: Maine NPDES permits expiring in 2027
Creator: Klarifi
License: https://klarifi.io/terms-of-service

7 NPDES permits · 0 MGD combined average flow

7 publicly owned wastewater treatment plants in Maine hold NPDES permits that expire during 2027, issued by Maine Department of Environmental Protection. The table lists each plant with its permit number, expiry month, average flow, treatment technology and three-year violation count, in order of expiry.

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.

Other years:

2028 (9)All Maine NPDES permits →

Publicly owned wastewater treatment plants in Maine with NPDES permits expiring in 2027, from EPA ICIS-NPDES records. Refreshed on every release.
Facility	City	Avg flow (MGD)	NPDES permit	Expires	Violations (3y)
Grand Isle WWTF	Grand Isle	0.01	ME0102318	Jan 2027	58
Ashland Wastwater Treatment Facility	Ashland	0.11	ME0101087	May 2027	28
Subsurface Wastewater Trtmnt Discharge	Bridgton	—	MEU508273	May 2027	38
Whitneyville WWTF	Whitneyville	0.0021	ME0102687	Jun 2027	0
Bethel Wastewater Treatment Facility	Bethel	0.09	ME0101176	Dec 2027	43
Passamaquoddy Water Treatment Facility	Perry	0.02	ME0102211	Dec 2027	4
Ellsworth WWTF Sandfilter	Ellsworth	0.00068	ME0102593	Dec 2027	0

Maine permit renewals in 2027: 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 October 26, 2026.

Wastewater terms: NPDES permit · POTW · Biological nutrient removal · Tertiary treatment · Lift station · Inflow and infiltration · all terms

Cite this page

Journalists, researchers and educators are welcome to quote these figures. Please credit Klarifi as the source and link to this page.

Klarifi. “NPDES permits expiring in 2027: Maine wastewater plants.” Updated October 26, 2026. https://klarifi.io/facilities/maine/permits-expiring/2027

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