How many wastewater permits expire in Michigan in 2027?

44 NPDES permits held by publicly owned wastewater treatment plants in Michigan expire in 2027, covering a combined average flow of 526 MGD. The busiest month is Oct 2027 with 43 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 Michigan in 2027?

GLWA Water Resource Recovery Facility in Detroit, treating about 416.18 MGD under permit MI0022802, expiring Oct 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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Michigan wastewater permits expiring in 2027

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

44 NPDES permits · 526 MGD combined average flow

44 publicly owned wastewater treatment plants in Michigan hold NPDES permits that expire during 2027, issued by Michigan Department of Environment, Great Lakes, and Energy. 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 (26)2028 (30)All Michigan NPDES permits →

Publicly owned wastewater treatment plants in Michigan 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)
Union Twp WWTP	Mt Pleasant	1.25	MI0055808	May 2027	0
GLWA Water Resource Recovery Facility	Detroit	416.18	MI0022802	Oct 2027	37
Lansing WWTP	Lansing	13.64	MI0023400	Oct 2027	6
Jackson WWTP	Jackson	11.39	MI0023256	Oct 2027	4
East Lansing Wastewater Treatment Plant	East Lansing	11.19	MI0022853	Oct 2027	1
Martin Rtb	Saint Clair Shores	10.63	MI0025453	Oct 2027	0
City Of Port Huron Wastewater Treatment Plant	Port Huron	7.93	MI0023833	Oct 2027	4
Mason WWTP	Mason	5.69	MI0020435	Oct 2027	31
Grand Ledge WWTP	Grand Ledge	5.17	MI0020800	Oct 2027	37
Delta Twp WWTP	Lansing	4.67	MI0022799	Oct 2027	4
Marquette WWTP	Marquette	2.86	MI0023531	Oct 2027	25
Southern Clinton Co WWTP	De Witt	2.5	MI0021008	Oct 2027	30
Delhi Twp WWTP	Holt	2.47	MI0022781	Oct 2027	0
Portage Lake Authority WWTP	Houghton	2.04	MI0020061	Oct 2027	9
Cadillac WWTP	Cadillac	1.99	MI0020257	Oct 2027	20
Bridgeport Twp WWTP	Bridgeport	1.79	MI0022446	Oct 2027	0
Howard City WWTP	Howard City	1.74	MI0053406	Oct 2027	10
Menominee WWTP	Menominee	1.66	MI0025631	Oct 2027	5
St Clair County-Algonac WWTP	Algonac	1.66	MI0020389	Oct 2027	0
Grosse Ile Twp WWTP	Grosse Ile	1.64	MI0026191	Oct 2027	12
Wixom WWTP	Wixom	1.61	MI0024384	Oct 2027	14
Dowagiac WWTP	Dowagiac	1.61	MI0022837	Oct 2027	5
Greenville WWTP	Greenville	1.57	MI0020397	Oct 2027	30
Howell WWTP	Howell	1.36	MI0021113	Oct 2027	42
Denton Township	Prudenville	1.05	MI0053317	Oct 2027	2
Flushing WWTP	Flushing	1.05	MI0020281	Oct 2027	27
St Louis WWTP	St. Louis	1.01	MI0021555	Oct 2027	9
Homer Wwsl	Homer	0.95	MI0060319	Oct 2027	0
Paw Paw Lake Area WWTP	Coloma	0.91	MI0023779	Oct 2027	0
Northfield Twp WWTP	Whitmore Lake	0.79	MI0023710	Oct 2027	1
Tecumseh WWTP	Tecumseh	0.65	MI0020583	Oct 2027	44
Lakeview WWTP	Lakeview	0.64	MI0023388	Oct 2027	8
Fowlerville WWTP	Fowlerville	0.54	MI0020664	Oct 2027	3
City Of Newaygo WWTP	Newaygo	0.53	MI0048577	Oct 2027	0
Reed City WWTP	Reed City	0.51	MI0020036	Oct 2027	11
Vassar WWTP	Vassar	0.48	MI0024252	Oct 2027	4
Columbiaville Wwsl	Columbiaville	0.47	MI0054810	Oct 2027	34
Williamston WWTP	Williamston	0.44	MI0021717	Oct 2027	6
Caro WWTP	Caro	0.41	MI0022551	Oct 2027	8
Leslie WWTP	Leslie	0.24	MI0020796	Oct 2027	41
Cass City WWTP	Cass City	0.24	MI0022594	Oct 2027	4
Dimondale/windsor WWTP	Dimondale	0.21	MI0053562	Oct 2027	3
Hartford WWTP	Hartford	0.19	MI0023094	Oct 2027	53
Otter Lake WWTP	Otter Lake	0.01	MI0056979	Oct 2027	14

Michigan 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 · Activated sludge · Oxidation ditch · 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: Michigan wastewater plants.” Updated October 26, 2026. https://klarifi.io/facilities/michigan/permits-expiring/2027

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