How many wastewater permits expire in Oregon in 2027?

19 NPDES permits held by publicly owned wastewater treatment plants in Oregon expire in 2027, covering a combined average flow of 7 MGD. The busiest month is Aug 2027 with 4 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 Oregon in 2027?

Oak Lodge Water Reclamation Facility in Milwaukie, treating about 1.74 MGD under permit OR0026140, expiring Mar 2027.

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

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

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Oregon wastewater permits expiring in 2027

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

19 NPDES permits · 7 MGD combined average flow

19 publicly owned wastewater treatment plants in Oregon hold NPDES permits that expire during 2027, issued by Oregon Department of Environmental Quality. 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:

2026 (10)2028 (10)All Oregon NPDES permits →

Publicly owned wastewater treatment plants in Oregon with NPDES permits expiring in 2027, from EPA ICIS-NPDES records. Refreshed on every release.
Facility	City	Avg flow (MGD)	NPDES permit	Expires	Technology	Violations (3y)
Ashland WWTP	Ashland	1.71	OR0026255	Jan 2027	Clarifiers, Carrousels / oxidation ditches, Biogas silos	15
Glendale WWTP	Glendale	0.07	OR0022730	Jan 2027	—	4
Rainbow Rock STP	Brookings	0.0036	OR0030945	Jan 2027	—	1
Arch Cape STP	Arch Cape	0.08	OR0027499	Feb 2027	—	0
Maupin STP	Maupin	0.06	OR0022608	Feb 2027	Uncovered lagoons	128
Oak Lodge Water Reclamation Facility	Milwaukie	1.74	OR0026140	Mar 2027	Clarifiers, Uncovered lagoons	3
Monroe STP	Monroe	0.04	OR0029203	Apr 2027	Uncovered lagoons	14
Cave Junction Wastewater Treatment Facility	Cave Junction	0.19	OR0028339	May 2027	Clarifiers, Uncovered lagoons	8
Aurora Sewage Treatment Plant	Aurora	0.08	OR0043991	May 2027	Aerated lagoons, Uncovered lagoons	11
Independence STP	Independence	0.47	OR0020443	Aug 2027	Uncovered lagoons	10
Hubbard STP	Hubbard	0.17	OR0020591	Aug 2027	Clarifiers	10
Dundee STP	Dundee	—	OR0023388	Aug 2027	Uncovered lagoons	1
Harrisburg Lagoon Treatment Plant	Harrisburg	—	OR0033260	Aug 2027	Uncovered lagoons	0
Creswell STP	Creswell	0.35	OR0027545	Sep 2027	Aerated lagoons, Uncovered lagoons	42
Stanfield STP	Stanfield	0.15	OR0026972	Sep 2027	Clarifiers	25
Rockaway Beach STP	Rockaway Beach	0.19	OR0023302	Oct 2027	Clarifiers, Aerated lagoons, Uncovered lagoons	0
Canby WWTP	Canby	0.99	OR0020214	Nov 2027	Clarifiers, Uncovered lagoons, Biogas silos	0
Twin Rocks WWTP	Rockaway Beach	0.08	OR0023493	Nov 2027	Clarifiers, Uncovered lagoons	2
Umatilla STP	Umatilla	0.72	OR0022306	Dec 2027	Clarifiers, Carrousels / oxidation ditches	0

Oregon 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 September 11, 2026.

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