How many wastewater permits expire in Illinois in 2027?

302 NPDES permits held by publicly owned wastewater treatment plants in Illinois expire in 2027, covering a combined average flow of 37 MGD. The busiest month is May 2027 with 240 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 Illinois in 2027?

Roodhouse Stp, City Of in Roodhouse, treating about 1.32 MGD under permit ILG582010, 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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Illinois wastewater permits expiring in 2027

Name: Illinois NPDES permits expiring in 2027
Creator: Klarifi
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302 NPDES permits · 37 MGD combined average flow

302 publicly owned wastewater treatment plants in Illinois hold NPDES permits that expire during 2027, issued by Illinois Environmental Protection Agency. 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 (19)2028 (70)All Illinois NPDES permits →

Publicly owned wastewater treatment plants in Illinois 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)
Woodhull - South Stp, Village Of	Woodhull	0.16	IL0021415	Jan 2027	0
Ashland Stp, Village Of	Ashland	0.06	IL0027529	Jan 2027	7
Mazon Stp, Village Of	Mazon	0.17	IL0040070	Feb 2027	3
Sullivan STP	Sullivan	—	IL0021806	Feb 2027	47
New Baden Stp, Village Of	New Baden	0.32	IL0032603	Mar 2027	0
New Windsor Stp, Village Of	New Windsor	0.02	IL0079162	Mar 2027	96
Ridge Farm Stp, Village Of	Ridge Farm	—	IL0020966	Mar 2027	14
Nashville Stp, City Of	Nashville	0.47	IL0027081	Apr 2027	11
Summerfield WWTF	Summerfield	0.04	IL0064220	Apr 2027	5
Roodhouse Stp, City Of	Roodhouse	1.32	ILG582010	May 2027	3
Okawville STP	Okawville	0.96	ILG580268	May 2027	1
Carthage Stp, City Of	Carthage	0.55	IL0021229	May 2027	43
Mounds Stp, City Of	Mounds	0.5	ILG582003	May 2027	54
Windsor Stp, City Of	Windsor	0.45	ILG580131	May 2027	1
El Paso Stp, City Of	El Paso	0.44	ILG582005	May 2027	76
Elmwood Stp, City Of	Elmwood	0.43	ILG582012	May 2027	166
Sparland Stp, Village Of	Sparland	0.4	ILG580226	May 2027	18
Virginia Stp, City Of	Virginia	0.4	ILG582004	May 2027	113
Roanoke Stp, Village Of	Roanoke	0.39	ILG580074	May 2027	28
Mount Sterling SE Stp, City Of	Mount Sterling	0.39	ILG580089	May 2027	19
Delavan Stp, City Of	Delavan	0.37	ILG582018	May 2027	54
Tremont Stp, Village Of	Tremont	0.35	ILG582021	May 2027	10
Lanark Stp, City Of	Lanark	0.35	ILG582023	May 2027	38
Rockton Stp, Village Of	Rockton	0.35	IL0030791	May 2027	3
Aledo North Wwtp, City Of	Aledo	0.32	ILG582006	May 2027	5
Teutopolis Stp, Village Of	Teutopolis	0.3	ILG582024	May 2027	8
Allendale - North - Stp, Village Of	Allendale	0.3	ILG580208	May 2027	0
Versailles Stp, Village Of	Versailles	0.3	ILG580227	May 2027	66
Atkinson Stp, Village Of	Atkinson	0.29	ILG580018	May 2027	40
Mcleansboro Stp, Village Of	Mcleansboro	0.27	ILG582007	May 2027	4
Bunker Hill Stp, City Of	Bunker Hill	0.27	ILG580154	May 2027	0
Farmersville Stp, Village Of	Farmersville	0.25	ILG580126	May 2027	6
Bushnell East Lagoon Treatment Plant	Bushnell	0.24	ILG580039	May 2027	13
Laharpe Stp, City Of	Laharpe	0.24	ILG580093	May 2027	11
Marine Stp, Village Of	Marine	0.24	ILG580228	May 2027	127
New Berlin Stp, Village Of	New Berlin	0.22	ILG580171	May 2027	10
Williamsville East Stp, Village Of	Williamsville	0.22	ILG582011	May 2027	0
Morrisonville Stp, Village Of	Morrisonville	0.22	ILG582013	May 2027	12
Brimfield Sanitary District STP	Brimfield	0.22	ILG580050	May 2027	21
Toledo Stp, Village Of	Toledo	0.21	ILG580158	May 2027	62
Pawnee Stp, Village Of	Pawnee	0.21	ILG582020	May 2027	8
Buffalo, Dawson, Mechanicsburg Sewer Commission STP	Buffalo	0.21	ILG580167	May 2027	65
Alpha - Stp, Village Of	Alpha	0.21	ILG580019	May 2027	26
Crainville Stp, Village Of	Carterville	0.2	ILG582002	May 2027	1
Strasburg Stp, Village Of	Strasburg	0.2	ILG580240	May 2027	64
Shabbona Stp, Village Of	Shabbona	0.2	ILG580139	May 2027	15
Bridgeport Stp, City Of	Bridgeport	0.2	ILG582001	May 2027	114
Livingston Wwtp, Village Of	Livingston	0.2	ILG580115	May 2027	5
Carrier Mills Stp, Village Of	Carrier Mills	0.19	ILG582014	May 2027	15
Holiday Shores Sanitary District STP	Edwardsville	0.19	ILG580193	May 2027	94
Chenoa Stp, City Of	Chenoa	0.19	ILG582009	May 2027	9
Oak Highlands-Ingalls Park Sd STP	Joliet	0.18	IL0024422	May 2027	0
Crossville Stp, Village Of	Crossville	0.18	ILG580211	May 2027	0
Illiopolis Stp, Village Of	Illiopolis	0.18	ILG580200	May 2027	10
Kirkwood Stp, Village Of	Kirkwood	0.18	ILG580077	May 2027	1
Olmsted Stp, Village Of	Olmsted	0.18	ILG580052	May 2027	12
Martinsville Stp, City Of	Martinsville	0.18	ILG580269	May 2027	3
Hull, Village Of	Hull	0.18	ILG580114	May 2027	0
Ashton Stp, Village Of	Ashton	0.18	ILG582015	May 2027	7
Rossville Stp, Village Of	Rossville	0.18	ILG580064	May 2027	14
Cerro Gordo Stp, Village Of	Cerro Gordo	0.17	ILG580066	May 2027	9
Potomac STP	Potomac	0.17	ILG580247	May 2027	15
Odell Stp, Village Of	Odell	0.17	ILG580043	May 2027	96
Ramsey Stp, Village Of	Ramsey	0.17	ILG580222	May 2027	8
Danvers Stp, Village Of	Danvers	0.15	ILG580059	May 2027	24
Wyanet Stp, Village Of	Wyanet	0.15	ILG580245	May 2027	48
Sherrard Stp, Village Of	Sherrard	0.15	ILG580037	May 2027	2
Colfax Stp, Village Of	Colfax	0.14	ILG580078	May 2027	25
Deer Creek Stp, Village Of	Deer Creek	0.14	ILG580097	May 2027	64
Dunlap, Village Of	Dunlap	0.14	ILG580099	May 2027	67
Easton STP	Easton	0.14	ILG580176	May 2027	8
Wamac Stp, City Of	Wamac	0.14	ILG580144	May 2027	2
Reynolds Stp, Village Of	Reynolds	0.14	ILG580225	May 2027	93
Sheffield Stp, Village Of	Sheffield	0.13	ILG580255	May 2027	0
Altamont North Stp, City Of	Altamont	0.13	ILG580152	May 2027	2
Joy Stp, Village Of	Joy	0.13	ILG580111	May 2027	10
Mackinaw Stp, Village Of	Mackinaw	0.13	ILG580038	May 2027	32
Shannon WWTP	Shannon	0.12	ILG580021	May 2027	2
Table Grove Stp, Village Of	Table Grove	0.12	ILG580040	May 2027	52
Newark Sd STP	Newark	0.12	ILG580153	May 2027	0
Stonington Stp, Village Of	Stonington	0.11	ILG580173	May 2027	8
St Jacob Stp, Village Of	Saint Jacob	0.11	ILG580212	May 2027	23
Germantown Stp, Village Of	Germantown	0.11	ILG580186	May 2027	1
Stewardson Stp, Village Of	Stewardson	0.11	ILG580163	May 2027	9
Oblong Stp, Village Of	Oblong	0.1	ILG582017	May 2027	1
Farina Stp, Village Of	Farina	0.1	ILG580047	May 2027	4
Minier-Stp, Village Of	Minier	0.1	ILG580098	May 2027	14
Ava Stp, City Of	Ava	0.1	ILG580148	May 2027	9
Durand Sd STP	Durand	0.1	ILG582019	May 2027	8
Mount Clare Stp, Village Of	Mount Clare	0.1	ILG580120	May 2027	12
Tamaroa Stp, Village Of	Tamaroa	0.1	ILG580182	May 2027	2
Chatsworth STP	Chatsworth	0.1	ILG580091	May 2027	16
Oneida Sanitary District South - STP	Oneida	0.1	ILG580151	May 2027	5
Oneida Sanitary District - North STP	Oneida	0.09	ILG580143	May 2027	4
Cedarville - Stp, Village Of	Cedarville	0.09	ILG580136	May 2027	35
Taylor Springs Stp, Village Of	Taylor Springs	0.09	ILG580140	May 2027	4
Annawan - Stp, Village Of	Annawan	0.09	ILG580012	May 2027	4
Percy Stp, Village Of	Percy	0.09	ILG580109	May 2027	0
Viola Stp, Village Of	Viola	0.09	ILG580233	May 2027	1
Mason Stp, Town Of	Mason	0.09	ILG580276	May 2027	8
Wayne City South STP	Wayne City	0.09	ILG580220	May 2027	7
Divernon Stp, Village Of	Divernon	0.09	ILG580175	May 2027	0
Scales Mound Stp, Village Of	Scales Mound	0.09	ILG580124	May 2027	5
Oakland Stp, City Of	Oakland	0.09	ILG580001	May 2027	13
Energy Stp, Village Of	Energy	0.09	ILG580117	May 2027	10
Coffeen Stp, City Of	Coffeen	0.09	ILG580243	May 2027	20
Hanover Stp, Village Of	Hanover	0.08	ILG580189	May 2027	12
Watson Wtp, Village Of	Watson	0.08	ILG580056	May 2027	8
Harristown Stp, Village Of	Harristown	0.08	ILG580055	May 2027	12
Albers Stp, Village Of	Albers	0.08	ILG580017	May 2027	41
Flanagan Sewage Treatment Plant	Flanagan	0.08	ILG580057	May 2027	105
Hamel Stp, Village Of	Hamel	0.08	ILG580011	May 2027	0
Odin STP	Odin	0.08	ILG580187	May 2027	0
Lenzburg - Stp, Village Of	Lenzburg	0.08	ILG580013	May 2027	0
Davis Stp, Village Of	Davis	0.08	ILG580278	May 2027	0
Palestine Stp, Village Of	Palestine	0.08	ILG580034	May 2027	0
Ipava Stp, Village Of	Ipava	0.08	ILG580209	May 2027	44
Chadwick Stp, Village Of	Chadwick	0.08	ILG580063	May 2027	9
Williamsfield WWTP	Williamsfield	0.07	ILG580087	May 2027	2
Ogden Stp, Village Of	Ogden	0.07	ILG580132	May 2027	39
Louisville STP	Louisville	0.07	ILG580081	May 2027	28
Waverly Stp, Village Of	Waverly	0.07	ILG580232	May 2027	6
Pocahontas Stp, Village Of	Pocahontas	0.07	ILG580010	May 2027	16
Sumner STP	Sumner	0.07	ILG580118	May 2027	2
New Canton Stp, Town Of	New Canton	0.07	ILG580264	May 2027	0
West City Stp, Village Of	Benton	0.07	ILG580215	May 2027	7
St. Peter Stp, Village Of	St Peter	0.06	ILG580007	May 2027	5
Niantic Stp, Village Of	Niantic	0.06	ILG580149	May 2027	39
Keithsburg Stp, Village Of	Keithsburg	0.06	ILG580246	May 2027	0
Altona Stp, Village Of	Altona	0.06	ILG580025	May 2027	29
Ohio Stp, Village Of	Ohio	0.06	ILG580190	May 2027	9
Worden - Stp, Village Of	Worden	0.06	ILG580015	May 2027	4
Hoffman, Village Of	Hoffman	0.06	ILG580205	May 2027	0
Tamms WWTP	Tamms	0.06	ILG580033	May 2027	184
Arenzville Stp, Village Of	Arenzville	0.06	ILG580165	May 2027	10
Dix-Kell Water & Sewer Commission STP	Dix	0.06	ILG580062	May 2027	70
Stonefort Stp, Village Of	Stonefort	0.06	ILG580082	May 2027	41
Apple River Stp, Village Of	Apple River	0.06	ILG580135	May 2027	25
Lamoille Stp, Village Of	Lamoille	0.05	ILG580127	May 2027	2
St Marie STP	Sainte Marie	0.05	ILG580058	May 2027	10
New Douglas Stw, Village Of	New Douglas	0.05	ILG580273	May 2027	65
Sorento STP	Sorento	0.05	ILG580049	May 2027	29
Kinmundy Stp, City Of	Kinmundy	0.05	ILG580123	May 2027	43
Murrayville Stp, Village Of	Murrayville	0.05	ILG580113	May 2027	3
Irvington WWTP	Irvington	0.05	ILG580006	May 2027	2
Goreville Stp, Village Of	Goreville	0.05	ILG580116	May 2027	0
Tower Hill Stp, Village Of	Tower Hill	0.05	ILG580244	May 2027	1
Saint Libory Stp, Village Of	Saint Libory	0.05	ILG580014	May 2027	0
Keyesport Stp, Village Of	Keyesport	0.05	ILG580204	May 2027	0
Wataga - Stp, Village Of	Wataga	0.05	ILG580023	May 2027	22
Industry Stp, Village Of	Industry	0.05	ILG580048	May 2027	12
Paw Paw Stp, Village Of	Paw Paw	0.05	ILG580213	May 2027	13
Campbell Hill Stp, Village Of	Campbell Hill	0.05	ILG580044	May 2027	1
Sigel, Village Of	Sigel	0.05	ILG580024	May 2027	52
Matherville Stp, Village Of	Matherville	0.05	ILG580238	May 2027	15
Galatia Stp, Village Of	Galatia	0.05	ILG580183	May 2027	3
Spoon Valley Lake STP	Dahinda	0.05	ILG580202	May 2027	3
Wilsonville Stp, Village Of	Wilsonville	0.04	ILG580172	May 2027	33
Gridley Stp, Village Of	Gridley	0.04	ILG580102	May 2027	0
Brownstown Stp, Village Of	Brownstown	0.04	ILG580027	May 2027	10
Willisville Stp, Village Of	Willisville	0.04	ILG580168	May 2027	19
Greenup, Village Of	Greenup	0.04	ILG580065	May 2027	0
South Pekin Stp, Village Of	South Pekin	0.04	ILG580252	May 2027	52
Mclean, Village Of	Mclean	0.04	ILG580162	May 2027	69
Coulterville STP	Coulterville	0.04	ILG580035	May 2027	0
Dalzell STP	Dalzell	0.04	ILG580130	May 2027	37
Herrick Stp, Village Of	Herrick	0.04	ILG580147	May 2027	14
Tallula Stp, Village Of	Tallula	0.04	ILG580142	May 2027	3
Tilden STP	Tilden	0.04	ILG580107	May 2027	16
Prairie Du Rocher, Village Of	Prairie Du Rocher	0.04	ILG580005	May 2027	0
Good Hope STP	Good Hope	0.04	ILG580194	May 2027	14
Liberty WWTP	Liberty	0.04	ILG580160	May 2027	0
Junction City Stp, Village Of	Junction City	0.04	ILG580277	May 2027	0
Hoyleton Stp, Village Of	Hoyleton	0.04	ILG580016	May 2027	0
Xenia Stp, Village Of	Xenia	0.03	ILG580029	May 2027	0
Keensburg Stp, Village Of	Keensburg	0.03	ILG580112	May 2027	0
Kinderhook Stp, Village Of	Kinderhook	0.03	ILG580192	May 2027	3
Humbolt STP	Humboldt	0.03	ILG580051	May 2027	42
Warsaw Stw	Warsaw	0.03	ILG580046	May 2027	7
San Jose Stp, Village Of	San Jose	0.03	ILG580071	May 2027	0
Ashley Stp, City Of	Ashley	0.03	ILG580199	May 2027	0
Mendon, Village Of	Mendon	0.03	ILG580104	May 2027	0
Bonnie Stp, Village Of	Bonnie	0.03	ILG580119	May 2027	0
Pittsburg, Village Of	Pittsburg	0.03	ILG580128	May 2027	0
Orient Stw	Orient	0.03	ILG580272	May 2027	19
Valmeyer, Village Of	Valmeyer	0.03	ILG580042	May 2027	3
Marietta Stp, Village Of	Marietta	0.03	ILG580231	May 2027	15
Plainville Stp, Village Of	Plainville	0.03	ILG580169	May 2027	0
Flat Rock Stp, Village Of	Flat Rock	0.03	ILG580224	May 2027	5
Clayton Stp, Village Of	Clayton	0.02	ILG580178	May 2027	0
Valier Stp, Village Of	Valier	0.02	ILG580083	May 2027	14
Edgewood Stp, Village Of	Edgewood	0.02	ILG580070	May 2027	3
Seward Stp, Village Of	Seward	0.02	ILG580138	May 2027	0
Woodson Stp, Village Of	Woodson	0.02	ILG580179	May 2027	3
Rock City - Stp, Village Of	Rock City	0.02	ILG580267	May 2027	6
Golden Stp, Village Of	Golden	0.02	ILG580157	May 2027	0
Maquon Stw, Village Of	Maquon	0.02	ILG580094	May 2027	22
Fairview Stp, Village Of	Fairview	0.02	ILG580068	May 2027	6
New Haven Stp, Village Of	New Haven	0.02	ILG580159	May 2027	10
Hillsdale Stp, Village Of	Hillsdale	0.02	ILG580009	May 2027	23
Smithfield Stp, Village Of	Smithfield	0.02	ILG580249	May 2027	44
Mill Shoals STP	Mill Shoals	0.02	ILG580195	May 2027	97
Mulberry Grove Sd	Mulberry Grove	0.02	ILG580191	May 2027	7
Broughton Stp, Village Of	Broughton	0.02	ILG580259	May 2027	7
Nilwood, Village Of	Nilwood	0.02	ILG580090	May 2027	1
Elkville Stp, Village Of	Elkville	0.02	ILG580088	May 2027	2
Perry Stp, Village Of	Perry	0.02	ILG580106	May 2027	0
Willow Hill Stp, Village Of	Willow Hill	0.02	ILG580092	May 2027	4
Hanna City Stp, Village Of	Hanna City	0.02	ILG582022	May 2027	0
Central Alexander County Sd STP	Olive Branch	0.02	ILG580257	May 2027	1
Milton STP	Milton	0.02	ILG580086	May 2027	0
West Point Stp, Village Of	West Point	0.02	ILG580270	May 2027	4
Cedar Point - Stp, Village Of	Cedar Point	0.01	ILG580008	May 2027	0
Enfield East Stp, Village Of	Enfield	0.01	ILG580108	May 2027	3
Enfield West Stp, Village Of	Enfield	0.01	ILG580105	May 2027	19
Bardolph Stp, Village Of	Bardolph	0.01	ILG580020	May 2027	29
Hanaford Stp, Village Of	Logan	0.01	ILG580221	May 2027	11
Thebes STP	Thebes	0.01	ILG580253	May 2027	139
West Salem Stp, Village Of	West Salem	0.01	ILG580164	May 2027	9
Colp Stp, Village Of	Colp	0.01	ILG580155	May 2027	30
Victoria Stp, Village Of	Victoria	0.01	ILG580036	May 2027	118
Iuka Stp, Village Of	Iuka	0.01	ILG580146	May 2027	1
Pierron East Stp, Village Of	Pierron	0.01	ILG580237	May 2027	2
New Grand Chain Stp, Village Of	New Grand Chain	0.01	ILG580196	May 2027	19
Muddy Stp, Village Of	Muddy	0.0091	ILG580174	May 2027	10
Hopkins Park Wtp, Village Of	Hopkins Park	0.009	ILG580217	May 2027	26
Grand Tower Stp, City Of	Grand Tower	0.0088	ILG580079	May 2027	35
Cambria Stp, Village Of	Cambria	0.0083	ILG580045	May 2027	30
Jeffersonville Stp, Village Of	Geff	0.0075	ILG580076	May 2027	22
Cutler Stp, Village Of	Cutler	0.0069	ILG580210	May 2027	0
Gorham Sd Stp, Village Of	Gorham	0.0068	ILG580185	May 2027	40
Joppa Sanitary District Stp, Village Of	Joppa	0.006	ILG580156	May 2027	1
Claremont Stp, Village Of	Claremont	0.0057	ILG580271	May 2027	21
Hettick Stp, Village Of	Hettick	0.0056	ILG580219	May 2027	2
Hecker Stw, Village Of	Hecker	0.0051	ILG580235	May 2027	4
Wataga South Stp, Village Of	Wataga	0.005	ILG580054	May 2027	24
Saint Francisville SW STP	Saint Francisville	0.0049	ILG580188	May 2027	0
Dahlgren, Village Of	Dahlgren	0.0038	ILG580080	May 2027	0
Belle Rive Stp, Village Of	Belle Rive	0.0032	ILG580129	May 2027	2
Ellis Grove Stp, Village Of	Ellis Grove	0.0031	ILG580145	May 2027	24
Cypress Stp, Village Of	Cypress	0.0026	ILG580150	May 2027	1
Bellmont Stp, Village Of	Bellmont	0.001	ILG580206	May 2027	0
Dongola Stp, Village Of	Dongola	—	ILG580028	May 2027	13
Equality Stp, Village Of	Equality	—	ILG580234	May 2027	2
Loraine Stp, Village Of	Loraine	—	ILG580184	May 2027	131
Macon Stp, City Of	Macon	—	ILG580141	May 2027	51
Nebo Stp, Village Of	Nebo	—	ILG580241	May 2027	81
Pierron West Stp, Village Of	Pierron	—	ILG580137	May 2027	0
Ware Sanitary Corporation STP	Ware	—	ILG580242	May 2027	4
Dupo Stp, Village Of	Dupo	0.33	IL0026441	Jun 2027	0
New Memphis Sd STP	New Baden	0.05	IL0076732	Jun 2027	13
Bureau Junction Stp, Village Of	Bureau Junction	0.04	IL0033120	Jun 2027	1
Verona Stp, Village Of	Verona	0.04	IL0050296	Jun 2027	7
Biggsville Stp, Village Of	Biggsville	0.02	IL0073318	Jun 2027	0
Waynesville Stp, Village Of	Waynesville	0.0028	IL0065447	Jun 2027	5
Eureka WTP	Eureka	0.72	IL0025119	Jul 2027	42
Noble Stp, Village Of	Noble	0.0034	IL0025500	Jul 2027	6
Fairfield, City Of	Fairfield	0.7	IL0020605	Aug 2027	0
Breese Stp, City Of	Breese	0.65	IL0022772	Aug 2027	0
Lena Stp, Village Of	Lena	0.29	IL0024945	Aug 2027	0
Palmyra STP	Palmyra	0.2	IL0044831	Aug 2027	9
Dieterich Stp, Village Of	Dieterich	0.15	IL0044792	Aug 2027	7
Augusta Stp, Village Of	Augusta	0.04	IL0027570	Aug 2027	40
Winslow Stp, Village Of	Winslow	0.04	IL0048259	Aug 2027	23
Fillmore Stp, Village Of	Fillmore	0.03	IL0050156	Aug 2027	13
Blandinsville Stp, Village Of	Blandinsville	0.03	IL0072672	Aug 2027	1
Leroy Stp, City Of	Le Roy	0.74	IL0021563	Sep 2027	0
Carrollton Stp, City Of	Carrollton	0.46	IL0021679	Sep 2027	0
Orion Wastewater Treatment Plant	Orion	0.46	IL0024988	Sep 2027	0
Sheridan Sanitary District - STP	Sheridan	0.32	IL0031062	Sep 2027	0
Athens Stp, City Of	Athens	0.22	IL0041203	Sep 2027	3
Gillespie Stp, Village Of	Gillespie	0.16	IL0022497	Sep 2027	6
Buda Stp, Village Of	Buda	0.15	IL0072494	Sep 2027	7
Village Of Cordova - STP	Cordova	0.03	IL0025356	Sep 2027	10
Radom Stp, Village Of	Radom	0.0076	IL0066281	Sep 2027	50
Gilman North Stp, City Of	Gilman	0.46	IL0025062	Oct 2027	7
Earlville Stp, City Of	Earlville	0.34	IL0020877	Oct 2027	0
Pinckneyville STP 2 East, City Of	Pinckneyville	0.29	IL0071650	Oct 2027	6
Waltonville Stp, Village Of	Waltonville	0.08	IL0049123	Oct 2027	0
Paxton Stp, City Of	Paxton	0.68	IL0023205	Nov 2027	0
Poplar Grove - North Wwtp, Village Of	Poplar Grove	0.3	IL0023451	Nov 2027	15
Tonica Stp, Village Of	Tonica	0.12	IL0023639	Nov 2027	32
Germantown Hills Stp, Village Of	Metamora	0.11	IL0028916	Nov 2027	6
Sun River Terrace STP	Saint Anne	0.1	IL0045501	Nov 2027	1
Avon Stp, Village Of	Avon	0.1	IL0021334	Nov 2027	46
Richview Stp, Village Of	Richview	0.02	IL0038717	Nov 2027	0
Elizabethtown Stp, Village Of	Elizabethtown	0.0029	IL0074250	Nov 2027	21
Brighton Stp, Village Of	Brighton	0.54	IL0024457	Dec 2027	2
Forrest Stp, Village Of	Forrest	0.24	IL0028819	Dec 2027	7
Kincaid STP	Kincaid	0.22	IL0048607	Dec 2027	82
St. Anne - Stp, Village Of	Saint Anne	0.21	IL0025755	Dec 2027	4
Warren STP	Warren	0.15	IL0026301	Dec 2027	1
Stronghurst Stp, Village Of	Stronghurst	0.1	IL0064025	Dec 2027	10
Bowen - STP	Bowen	0.05	IL0021075	Dec 2027	0
Tiskilwa Stp, Village Of	Tiskilwa	0.04	IL0025160	Dec 2027	31
London Mills Wwtp, Village Of	London Mills	0.04	IL0047236	Dec 2027	6
Banner Stp, Village Of	Canton	0.01	IL0061140	Dec 2027	0
Ullin Stp, Village Of	Ullin	0.0089	IL0070114	Dec 2027	3
Cave In Rock STP	Cave In Rock	0.004	IL0055581	Dec 2027	3
Perks Stp, County Of Pulaski	Perks	0.0031	IL0076911	Dec 2027	23
Vergennes-Stp, Village Of	Vergennes	0.003	IL0063860	Dec 2027	21
Catlin Stp, Village Of	Catlin	—	IL0023108	Dec 2027	12

Illinois 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 · Biosolids · Filter press · 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: Illinois wastewater plants.” Updated October 26, 2026. https://klarifi.io/facilities/illinois/permits-expiring/2027

Need a custom cut of the data for a state, a county or a list of plants? Email info@klarifi.io.

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