How many wastewater permits expire in Michigan in 2028?

29 NPDES permits held by publicly owned wastewater treatment plants in Michigan expire in 2028, covering a combined average flow of 30 MGD. The busiest month is Oct 2028 with 29 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 2028?

Holland WWTP in Holland, treating about 8.7 MGD under permit MI0023108, expiring Oct 2028.

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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Michigan wastewater permits expiring in 2028

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

29 NPDES permits · 30 MGD combined average flow

29 publicly owned wastewater treatment plants in Michigan hold NPDES permits that expire during 2028, 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 (25)2027 (43)All Michigan NPDES permits →

Publicly owned wastewater treatment plants in Michigan with NPDES permits expiring in 2028, from EPA ICIS-NPDES records. Refreshed on every release.
Facility	City	Avg flow (MGD)	NPDES permit	Expires	Technology	Violations (3y)
Holland WWTP	Holland	8.7	MI0023108	Oct 2028	Clarifiers, Carrousels / oxidation ditches, Biogas silos, Biogas balloons	0
Saginaw Twp WWTP	Saginaw	3.24	MI0023973	Oct 2028	Clarifiers, Aerated lagoons, Carrousels / oxidation ditches, Biogas silos, Biogas balloons	10
Adrian WWTP	Adrian	2.88	MI0022152	Oct 2028	Clarifiers, Biogas silos, Biogas balloons	0
Leoni Twp WWTP	Michigan Center	1.62	MI0045942	Oct 2028	Uncovered lagoons, Biogas balloons	1
Marysville WWTP	Marysville	1.5	MI0020656	Oct 2028	Clarifiers, Biogas silos	1
Tittabawassee Twp WWTP	Freeland	1.16	MI0027383	Oct 2028	Aerated lagoons, Uncovered lagoons	1
Ishpeming Area WWTP	Ishpeming	1.09	MI0044423	Oct 2028	Biogas balloons	64
Alma Wastewater Treatment Plant	Alma	1.01	MI0020265	Oct 2028	Clarifiers, Uncovered lagoons	0
South Lyon WWTP	South Lyon	0.97	MI0020273	Oct 2028	Clarifiers, Aerated lagoons	11
South Haven Area Water Sewer Authority WWTP	South Haven	0.96	MI0020320	Oct 2028	—	0
Marine City WWTP	Marine City	0.74	MI0020893	Oct 2028	Clarifiers, Carrousels / oxidation ditches, Biogas silos	9
Sandusky WWTP	Sandusky	0.68	MI0020222	Oct 2028	Clarifiers, Biogas silos	53
West Iron Co Sa WWTP	Caspian	0.62	MI0043281	Oct 2028	Biogas silos, Biogas balloons	6
Rollin-Woodstock WWTP	Addison	0.61	MI0027669	Oct 2028	Clarifiers, Aerated lagoons, Uncovered lagoons	1
Mackinac Island WWTP	Mackinac Island	0.54	MI0026751	Oct 2028	Clarifiers	129
Milford WWTP	Milford	0.49	MI0023604	Oct 2028	Clarifiers, Carrousels / oxidation ditches	6
Lakewood WW Auth WWTP	Lake Odessa	0.46	MI0042978	Oct 2028	Clarifiers, Aerated lagoons, Uncovered lagoons, Carrousels / oxidation ditches	1
Gladwin WWTP	Gladwin	0.43	MI0023001	Oct 2028	—	5
Clare WWTP	Clare	0.41	MI0020176	Oct 2028	Aerated lagoons, Uncovered lagoons	8
Gladstone WWTP	Gladstone	0.38	MI0057676	Oct 2028	—	10
St Clair River Sa WWTP	East China	0.35	MI0022845	Oct 2028	Clarifiers, Uncovered lagoons, Biogas silos	5
Imlay City WWTP	Imlay City	0.29	MI0023167	Oct 2028	Carrousels / oxidation ditches, Biogas balloons	3
Rockwood WWTP	Rockwood	0.25	MI0021181	Oct 2028	Clarifiers	24
Bronson WWTP	Bronson	0.17	MI0020729	Oct 2028	Clarifiers, Carrousels / oxidation ditches, Biogas balloons	10
Pinconning WWTP	Pinconning	0.12	MI0020711	Oct 2028	Clarifiers	0
Handy Twp WWTP	Fowlerville	0.07	MI0056839	Oct 2028	—	8
Onsted WWTP	Onsted	—	MI0028304	Oct 2028	Uncovered lagoons	2
Quincy WWTP	Quincy	—	MI0055751	Oct 2028	Aerated lagoons, Uncovered lagoons	4
Roscommon WWTP	Roscommon	—	MI0021482	Oct 2028	Aerated lagoons	0

Michigan 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 September 11, 2026.

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