How many wastewater permits expire in Idaho in 2028?

7 NPDES permits held by publicly owned wastewater treatment plants in Idaho expire in 2028, covering a combined average flow of 4 MGD. The busiest month is May 2028 with 2 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 Idaho in 2028?

Rexburg WWTP in Rexburg, treating about 3.22 MGD under permit ID0023817, expiring Mar 2028.

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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Idaho wastewater permits expiring in 2028

Name: Idaho NPDES permits expiring in 2028
Creator: Klarifi
License: https://klarifi.io/terms-of-service

7 NPDES permits · 4 MGD combined average flow

7 publicly owned wastewater treatment plants in Idaho hold NPDES permits that expire during 2028, issued by Idaho 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 (6)All Idaho NPDES permits →

Publicly owned wastewater treatment plants in Idaho with NPDES permits expiring in 2028, from EPA ICIS-NPDES records. Refreshed on every release.
Facility	City	Avg flow (MGD)	NPDES permit	Expires	Violations (3y)
Rexburg WWTP	Rexburg	3.22	ID0023817	Mar 2028	41
Kamiah Regional STP	Kamiah	0.16	ID0028002	May 2028	11
Lava Hot Springs WWTP	Lava Hot Springs	—	ID0021822	May 2028	0
Moyie Springs, City Of - Moyie Springs WWTP	Moyie Springs	0.06	ID0030040	Jun 2028	232
Worley WWTP	Worley	—	ID0022713	Jun 2028	8
Culdesac WWTP	Culdesac	0.06	ID0024490	Sep 2028	58
Bovill Wastewater Treatment Facility	Deary	0.05	ID0022861	Nov 2028	14

Idaho permit renewals in 2028: 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 · Equalization tank · Centrate · 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 2028: Idaho wastewater plants.” Updated October 26, 2026. https://klarifi.io/facilities/idaho/permits-expiring/2028

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