Illinois wastewater permits expiring in 2027
293 NPDES permits · 18 MGD combined average flow
293 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.
| Facility | City | Avg flow (MGD) | NPDES permit | Expires | Technology | Violations (3y) |
|---|---|---|---|---|---|---|
| Woodhull - South Stp, Village Of | Woodhull | 0.09 | IL0021415 | Jan 2027 | Covered lagoons, Uncovered lagoons | 0 |
| Ashland Stp, Village Of | Ashland | 0.02 | IL0027529 | Jan 2027 | Uncovered lagoons | 7 |
| Mazon Stp, Village Of | Mazon | 0.05 | IL0040070 | Feb 2027 | Aerated lagoons | 3 |
| Sullivan STP | Sullivan | — | IL0021806 | Feb 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons | 47 |
| New Baden Stp, Village Of | New Baden | 0.18 | IL0032603 | Mar 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| New Windsor Stp, Village Of | New Windsor | 0.009 | IL0079162 | Mar 2027 | Covered lagoons | 97 |
| Ridge Farm Stp, Village Of | Ridge Farm | — | IL0020966 | Mar 2027 | Clarifiers, Uncovered lagoons, Biogas balloons | 14 |
| Nashville Stp, City Of | Nashville | 0.28 | IL0027081 | Apr 2027 | — | 10 |
| Summerfield WWTF | Summerfield | 0.1 | IL0064220 | Apr 2027 | — | 7 |
| Cerro Gordo Stp, Village Of | Cerro Gordo | 0.6 | ILG580066 | May 2027 | Aerated lagoons, Uncovered lagoons | 10 |
| Sigel, Village Of | Sigel | 0.38 | ILG580024 | May 2027 | Aerated lagoons | 52 |
| Mount Sterling SE Stp, City Of | Mount Sterling | 0.35 | ILG580089 | May 2027 | Aerated lagoons | 19 |
| Rockton Stp, Village Of | Rockton | 0.33 | IL0030791 | May 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons | 3 |
| Elmwood Stp, City Of | Elmwood | 0.32 | ILG582012 | May 2027 | Aerated lagoons, Uncovered lagoons | 164 |
| Lanark Stp, City Of | Lanark | 0.31 | ILG582023 | May 2027 | Uncovered lagoons | 19 |
| Carthage Stp, City Of | Carthage | 0.3 | IL0021229 | May 2027 | Aerated lagoons, Uncovered lagoons | 40 |
| Greenup, Village Of | Greenup | 0.29 | ILG580065 | May 2027 | Uncovered lagoons | 0 |
| Equality Stp, Village Of | Equality | 0.25 | ILG580234 | May 2027 | Uncovered lagoons | 2 |
| Roanoke Stp, Village Of | Roanoke | 0.24 | ILG580074 | May 2027 | Uncovered lagoons | 27 |
| Shannon WWTP | Shannon | 0.18 | ILG580021 | May 2027 | Aerated lagoons | 2 |
| Roodhouse Stp, City Of | Roodhouse | 0.18 | ILG582010 | May 2027 | Uncovered lagoons | 3 |
| Holiday Shores Sanitary District STP | Edwardsville | 0.18 | ILG580193 | May 2027 | — | 92 |
| Danvers Stp, Village Of | Danvers | 0.17 | ILG580059 | May 2027 | Aerated lagoons, Uncovered lagoons | 22 |
| Victoria Stp, Village Of | Victoria | 0.15 | ILG580036 | May 2027 | Uncovered lagoons | 134 |
| El Paso Stp, City Of | El Paso | 0.14 | ILG582005 | May 2027 | Uncovered lagoons | 96 |
| Sheffield Stp, Village Of | Sheffield | 0.13 | ILG580255 | May 2027 | Aerated lagoons, Uncovered lagoons | 2 |
| Mcleansboro Stp, Village Of | Mcleansboro | 0.13 | ILG582007 | May 2027 | Aerated lagoons, Uncovered lagoons | 4 |
| Williamsville East Stp, Village Of | Williamsville | 0.12 | ILG582011 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Stewardson Stp, Village Of | Stewardson | 0.12 | ILG580163 | May 2027 | Uncovered lagoons | 9 |
| Carrier Mills Stp, Village Of | Carrier Mills | 0.11 | ILG582014 | May 2027 | Aerated lagoons, Uncovered lagoons | 14 |
| Crainville Stp, Village Of | Carterville | 0.11 | ILG582002 | May 2027 | — | 1 |
| Atkinson Stp, Village Of | Atkinson | 0.11 | ILG580018 | May 2027 | Aerated lagoons, Uncovered lagoons | 41 |
| Odin STP | Odin | 0.11 | ILG580187 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Keithsburg Stp, Village Of | Keithsburg | 0.11 | ILG580246 | May 2027 | Uncovered lagoons | 0 |
| Oak Highlands-Ingalls Park Sd STP | Joliet | 0.11 | IL0024422 | May 2027 | — | 0 |
| Marine Stp, Village Of | Marine | 0.11 | ILG580228 | May 2027 | Aerated lagoons | 127 |
| New Haven Stp, Village Of | New Haven | 0.1 | ILG580159 | May 2027 | Uncovered lagoons | 9 |
| Durand Sd STP | Durand | 0.1 | ILG582019 | May 2027 | Aerated lagoons, Uncovered lagoons | 8 |
| Ashton Stp, Village Of | Ashton | 0.09 | ILG582015 | May 2027 | Aerated lagoons, Uncovered lagoons | 8 |
| Rossville Stp, Village Of | Rossville | 0.09 | ILG580064 | May 2027 | Uncovered lagoons | 14 |
| Bushnell East Lagoon Treatment Plant | Bushnell | 0.09 | ILG580039 | May 2027 | Aerated lagoons | 14 |
| Oakland Stp, City Of | Oakland | 0.09 | ILG580001 | May 2027 | Aerated lagoons, Uncovered lagoons | 13 |
| Germantown Stp, Village Of | Germantown | 0.09 | ILG580186 | May 2027 | Aerated lagoons, Uncovered lagoons | 1 |
| Virginia Stp, City Of | Virginia | 0.09 | ILG582004 | May 2027 | Aerated lagoons, Uncovered lagoons | 110 |
| Wayne City South STP | Wayne City | 0.09 | ILG580220 | May 2027 | Aerated lagoons, Uncovered lagoons | 7 |
| Wyanet Stp, Village Of | Wyanet | 0.09 | ILG580245 | May 2027 | Aerated lagoons | 48 |
| Hanover Stp, Village Of | Hanover | 0.09 | ILG580189 | May 2027 | Aerated lagoons | 11 |
| Albers Stp, Village Of | Albers | 0.09 | ILG580017 | May 2027 | Aerated lagoons | 40 |
| Pawnee Stp, Village Of | Pawnee | 0.09 | ILG582020 | May 2027 | Aerated lagoons, Uncovered lagoons | 9 |
| Bunker Hill Stp, City Of | Bunker Hill | 0.09 | ILG580154 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Worden - Stp, Village Of | Worden | 0.09 | ILG580015 | May 2027 | Aerated lagoons, Uncovered lagoons | 4 |
| Colfax Stp, Village Of | Colfax | 0.08 | ILG580078 | May 2027 | Aerated lagoons, Uncovered lagoons | 26 |
| Toledo Stp, Village Of | Toledo | 0.08 | ILG580158 | May 2027 | Uncovered lagoons | 60 |
| Aledo North Wwtp, City Of | Aledo | 0.08 | ILG582006 | May 2027 | Uncovered lagoons | 4 |
| Annawan - Stp, Village Of | Annawan | 0.08 | ILG580012 | May 2027 | Aerated lagoons, Uncovered lagoons | 4 |
| Dongola Stp, Village Of | Dongola | 0.08 | ILG580028 | May 2027 | — | 11 |
| Odell Stp, Village Of | Odell | 0.08 | ILG580043 | May 2027 | Aerated lagoons, Uncovered lagoons | 96 |
| Morrisonville Stp, Village Of | Morrisonville | 0.08 | ILG582013 | May 2027 | Aerated lagoons | 12 |
| Deer Creek Stp, Village Of | Deer Creek | 0.08 | ILG580097 | May 2027 | Uncovered lagoons | 64 |
| Hamel Stp, Village Of | Hamel | 0.08 | ILG580011 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Ipava Stp, Village Of | Ipava | 0.07 | ILG580209 | May 2027 | Uncovered lagoons | 45 |
| Laharpe Stp, City Of | Laharpe | 0.07 | ILG580093 | May 2027 | Aerated lagoons | 11 |
| Chenoa Stp, City Of | Chenoa | 0.07 | ILG582009 | May 2027 | Aerated lagoons, Uncovered lagoons | 10 |
| Flanagan Sewage Treatment Plant | Flanagan | 0.07 | ILG580057 | May 2027 | Uncovered lagoons | 125 |
| Tamms WWTP | Tamms | 0.07 | ILG580033 | May 2027 | Uncovered lagoons | 184 |
| Illiopolis Stp, Village Of | Illiopolis | 0.07 | ILG580200 | May 2027 | Aerated lagoons, Uncovered lagoons | 10 |
| Apple River Stp, Village Of | Apple River | 0.07 | ILG580135 | May 2027 | Aerated lagoons | 26 |
| Delavan Stp, City Of | Delavan | 0.07 | ILG582018 | May 2027 | Aerated lagoons, Uncovered lagoons | 50 |
| Okawville STP | Okawville | 0.07 | ILG580268 | May 2027 | Aerated lagoons, Uncovered lagoons | 1 |
| Martinsville Stp, City Of | Martinsville | 0.06 | ILG580269 | May 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons | 3 |
| Joy Stp, Village Of | Joy | 0.06 | ILG580111 | May 2027 | Uncovered lagoons | 10 |
| Williamsfield WWTP | Williamsfield | 0.06 | ILG580087 | May 2027 | Uncovered lagoons | 2 |
| Hoyleton Stp, Village Of | Hoyleton | 0.06 | ILG580016 | May 2027 | Uncovered lagoons | 0 |
| Irvington WWTP | Irvington | 0.06 | ILG580006 | May 2027 | Aerated lagoons, Uncovered lagoons | 2 |
| West City Stp, Village Of | Benton | 0.06 | ILG580215 | May 2027 | Aerated lagoons | 8 |
| Dunlap, Village Of | Dunlap | 0.06 | ILG580099 | May 2027 | Uncovered lagoons | 67 |
| Newark Sd STP | Newark | 0.06 | ILG580153 | May 2027 | Covered lagoons, Uncovered lagoons | 0 |
| Tremont Stp, Village Of | Tremont | 0.06 | ILG582021 | May 2027 | Uncovered lagoons | 8 |
| New Berlin Stp, Village Of | New Berlin | 0.06 | ILG580171 | May 2027 | Aerated lagoons, Uncovered lagoons | 11 |
| Energy Stp, Village Of | Energy | 0.06 | ILG580117 | May 2027 | Aerated lagoons | 9 |
| Lamoille Stp, Village Of | Lamoille | 0.05 | ILG580127 | May 2027 | Uncovered lagoons | 2 |
| Campbell Hill Stp, Village Of | Campbell Hill | 0.05 | ILG580044 | May 2027 | Uncovered lagoons | 1 |
| Sherrard Stp, Village Of | Sherrard | 0.05 | ILG580037 | May 2027 | Aerated lagoons, Uncovered lagoons | 2 |
| Wataga - Stp, Village Of | Wataga | 0.05 | ILG580023 | May 2027 | Aerated lagoons | 25 |
| Ramsey Stp, Village Of | Ramsey | 0.05 | ILG580222 | May 2027 | Aerated lagoons, Uncovered lagoons | 8 |
| South Pekin Stp, Village Of | South Pekin | 0.05 | ILG580252 | May 2027 | Aerated lagoons | 52 |
| Table Grove Stp, Village Of | Table Grove | 0.05 | ILG580040 | May 2027 | Uncovered lagoons | 51 |
| Oneida Sanitary District - North STP | Oneida | 0.05 | ILG580143 | May 2027 | Aerated lagoons | 5 |
| Oneida Sanitary District South - STP | Oneida | 0.05 | ILG580151 | May 2027 | Aerated lagoons, Uncovered lagoons | 6 |
| Kirkwood Stp, Village Of | Kirkwood | 0.04 | ILG580077 | May 2027 | — | 1 |
| Prairie Du Rocher, Village Of | Prairie Du Rocher | 0.04 | ILG580005 | May 2027 | Uncovered lagoons | 0 |
| Chadwick Stp, Village Of | Chadwick | 0.04 | ILG580063 | May 2027 | Uncovered lagoons | 9 |
| Dalzell STP | Dalzell | 0.04 | ILG580130 | May 2027 | Aerated lagoons | 37 |
| Goreville Stp, Village Of | Goreville | 0.04 | ILG580116 | May 2027 | Uncovered lagoons | 0 |
| Hoffman, Village Of | Hoffman | 0.04 | ILG580205 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Tower Hill Stp, Village Of | Tower Hill | 0.04 | ILG580244 | May 2027 | Aerated lagoons | 1 |
| Ogden Stp, Village Of | Ogden | 0.04 | ILG580132 | May 2027 | Uncovered lagoons | 39 |
| Paw Paw Stp, Village Of | Paw Paw | 0.04 | ILG580213 | May 2027 | Uncovered lagoons | 13 |
| Warsaw Stw | Warsaw | 0.04 | ILG580046 | May 2027 | Uncovered lagoons | 7 |
| Harristown Stp, Village Of | Harristown | 0.04 | ILG580055 | May 2027 | Aerated lagoons, Uncovered lagoons | 14 |
| Galatia Stp, Village Of | Galatia | 0.04 | ILG580183 | May 2027 | Aerated lagoons | 3 |
| Kinmundy Stp, City Of | Kinmundy | 0.04 | ILG580123 | May 2027 | Aerated lagoons, Uncovered lagoons | 43 |
| St Jacob Stp, Village Of | Saint Jacob | 0.03 | ILG580212 | May 2027 | Aerated lagoons | 23 |
| Niantic Stp, Village Of | Niantic | 0.03 | ILG580149 | May 2027 | Uncovered lagoons | 40 |
| Ohio Stp, Village Of | Ohio | 0.03 | ILG580190 | May 2027 | Aerated lagoons | 30 |
| San Jose Stp, Village Of | San Jose | 0.03 | ILG580071 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Stonington Stp, Village Of | Stonington | 0.03 | ILG580173 | May 2027 | Aerated lagoons, Uncovered lagoons | 8 |
| Spoon Valley Lake STP | Dahinda | 0.03 | ILG580202 | May 2027 | Aerated lagoons | 3 |
| Versailles Stp, Village Of | Versailles | 0.03 | ILG580227 | May 2027 | Uncovered lagoons | 67 |
| Chatsworth STP | Chatsworth | 0.03 | ILG580091 | May 2027 | Aerated lagoons, Uncovered lagoons | 17 |
| Mclean, Village Of | Mclean | 0.03 | ILG580162 | May 2027 | Uncovered lagoons | 71 |
| Mounds Stp, City Of | Mounds | 0.03 | ILG582003 | May 2027 | Uncovered lagoons | 54 |
| Saint Libory Stp, Village Of | Saint Libory | 0.03 | ILG580014 | May 2027 | Aerated lagoons | 0 |
| Shabbona Stp, Village Of | Shabbona | 0.03 | ILG580139 | May 2027 | Uncovered lagoons | 16 |
| Waverly Stp, Village Of | Waverly | 0.03 | ILG580232 | May 2027 | Aerated lagoons | 6 |
| Viola Stp, Village Of | Viola | 0.03 | ILG580233 | May 2027 | Covered lagoons, Uncovered lagoons | 2 |
| Cedarville - Stp, Village Of | Cedarville | 0.03 | ILG580136 | May 2027 | Uncovered lagoons | 35 |
| Valmeyer, Village Of | Valmeyer | 0.03 | ILG580042 | May 2027 | Uncovered lagoons | 3 |
| Keyesport Stp, Village Of | Keyesport | 0.03 | ILG580204 | May 2027 | Aerated lagoons | 0 |
| Humbolt STP | Humboldt | 0.03 | ILG580051 | May 2027 | Aerated lagoons, Uncovered lagoons | 42 |
| Davis Stp, Village Of | Davis | 0.03 | ILG580278 | May 2027 | Uncovered lagoons | 0 |
| Ashley Stp, City Of | Ashley | 0.03 | ILG580199 | May 2027 | Uncovered lagoons | 0 |
| Fairview Stp, Village Of | Fairview | 0.02 | ILG580068 | May 2027 | Aerated lagoons, Uncovered lagoons | 7 |
| Mendon, Village Of | Mendon | 0.02 | ILG580104 | May 2027 | Uncovered lagoons | 0 |
| Industry Stp, Village Of | Industry | 0.02 | ILG580048 | May 2027 | Aerated lagoons | 12 |
| Rock City - Stp, Village Of | Rock City | 0.02 | ILG580267 | May 2027 | Uncovered lagoons | 6 |
| Pierron West Stp, Village Of | Pierron | 0.02 | ILG580137 | May 2027 | Aerated lagoons, Uncovered lagoons, Biogas silos | 0 |
| Maquon Stw, Village Of | Maquon | 0.02 | ILG580094 | May 2027 | Uncovered lagoons | 22 |
| Pocahontas Stp, Village Of | Pocahontas | 0.02 | ILG580010 | May 2027 | Aerated lagoons | 16 |
| Lenzburg - Stp, Village Of | Lenzburg | 0.02 | ILG580013 | May 2027 | Uncovered lagoons | 0 |
| Thebes STP | Thebes | 0.02 | ILG580253 | May 2027 | Uncovered lagoons | 44 |
| Wilsonville Stp, Village Of | Wilsonville | 0.02 | ILG580172 | May 2027 | Uncovered lagoons | 33 |
| Valier Stp, Village Of | Valier | 0.02 | ILG580083 | May 2027 | Uncovered lagoons | 12 |
| Coulterville STP | Coulterville | 0.02 | ILG580035 | May 2027 | — | 0 |
| Gridley Stp, Village Of | Gridley | 0.02 | ILG580102 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Cedar Point - Stp, Village Of | Cedar Point | 0.02 | ILG580008 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Clayton Stp, Village Of | Clayton | 0.02 | ILG580178 | May 2027 | Uncovered lagoons | 0 |
| Elkville Stp, Village Of | Elkville | 0.02 | ILG580088 | May 2027 | Aerated lagoons, Uncovered lagoons | 2 |
| Golden Stp, Village Of | Golden | 0.02 | ILG580157 | May 2027 | Uncovered lagoons | 0 |
| Milton STP | Milton | 0.02 | ILG580086 | May 2027 | Uncovered lagoons | 0 |
| Altona Stp, Village Of | Altona | 0.01 | ILG580025 | May 2027 | Uncovered lagoons | 29 |
| Minier-Stp, Village Of | Minier | 0.01 | ILG580098 | May 2027 | Uncovered lagoons | 14 |
| West Salem Stp, Village Of | West Salem | 0.01 | ILG580164 | May 2027 | Uncovered lagoons | 7 |
| Watson Wtp, Village Of | Watson | 0.01 | ILG580056 | May 2027 | Aerated lagoons | 7 |
| Mackinaw Stp, Village Of | Mackinaw | 0.01 | ILG580038 | May 2027 | Uncovered lagoons | 32 |
| Mulberry Grove Sd | Mulberry Grove | 0.01 | ILG580191 | May 2027 | Aerated lagoons, Uncovered lagoons | 7 |
| Bardolph Stp, Village Of | Bardolph | 0.01 | ILG580020 | May 2027 | Aerated lagoons | 29 |
| Allendale - North - Stp, Village Of | Allendale | 0.01 | ILG580208 | May 2027 | Uncovered lagoons | 0 |
| Edgewood Stp, Village Of | Edgewood | 0.01 | ILG580070 | May 2027 | Uncovered lagoons | 0 |
| Good Hope STP | Good Hope | 0.01 | ILG580194 | May 2027 | Uncovered lagoons | 13 |
| Liberty WWTP | Liberty | 0.01 | ILG580160 | May 2027 | Uncovered lagoons | 0 |
| Perry Stp, Village Of | Perry | 0.01 | ILG580106 | May 2027 | Uncovered lagoons | 0 |
| Taylor Springs Stp, Village Of | Taylor Springs | 0.01 | ILG580140 | May 2027 | Uncovered lagoons | 5 |
| Colp Stp, Village Of | Colp | 0.009 | ILG580155 | May 2027 | Uncovered lagoons | 31 |
| Marietta Stp, Village Of | Marietta | 0.009 | ILG580231 | May 2027 | Aerated lagoons | 14 |
| Tallula Stp, Village Of | Tallula | 0.009 | ILG580142 | May 2027 | Aerated lagoons | 3 |
| Tilden STP | Tilden | 0.009 | ILG580107 | May 2027 | Uncovered lagoons | 16 |
| Louisville STP | Louisville | 0.008 | ILG580081 | May 2027 | Uncovered lagoons | 27 |
| Orient Stw | Orient | 0.008 | ILG580272 | May 2027 | Aerated lagoons | 19 |
| Smithfield Stp, Village Of | Smithfield | 0.008 | ILG580249 | May 2027 | Aerated lagoons, Uncovered lagoons | 43 |
| Hillsdale Stp, Village Of | Hillsdale | 0.007 | ILG580009 | May 2027 | Clarifiers, Biogas silos, Biogas balloons | 23 |
| Seward Stp, Village Of | Seward | 0.007 | ILG580138 | May 2027 | Uncovered lagoons | 0 |
| St. Peter Stp, Village Of | St Peter | 0.007 | ILG580007 | May 2027 | Uncovered lagoons | 5 |
| Murrayville Stp, Village Of | Murrayville | 0.006 | ILG580113 | May 2027 | Uncovered lagoons | 3 |
| Alpha - Stp, Village Of | Alpha | 0.005 | ILG580019 | May 2027 | Aerated lagoons, Uncovered lagoons | 27 |
| Wataga South Stp, Village Of | Wataga | 0.005 | ILG580054 | May 2027 | Uncovered lagoons | 24 |
| Muddy Stp, Village Of | Muddy | 0.0048 | ILG580174 | May 2027 | Uncovered lagoons | 8 |
| Bonnie Stp, Village Of | Bonnie | 0.004 | ILG580119 | May 2027 | Uncovered lagoons | 0 |
| Hecker Stw, Village Of | Hecker | 0.004 | ILG580235 | May 2027 | — | 4 |
| Ellis Grove Stp, Village Of | Ellis Grove | 0.003 | ILG580145 | May 2027 | — | 43 |
| Hanaford Stp, Village Of | Logan | 0.0019 | ILG580221 | May 2027 | Uncovered lagoons | 11 |
| Belle Rive Stp, Village Of | Belle Rive | 0.001 | ILG580129 | May 2027 | Uncovered lagoons | 2 |
| Cambria Stp, Village Of | Cambria | 0.001 | ILG580045 | May 2027 | Aerated lagoons, Uncovered lagoons | 31 |
| Hanna City Stp, Village Of | Hanna City | 0.001 | ILG582022 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Jeffersonville Stp, Village Of | Geff | 0.001 | ILG580076 | May 2027 | Uncovered lagoons | 22 |
| Nilwood, Village Of | Nilwood | 0.001 | ILG580090 | May 2027 | Uncovered lagoons | 1 |
| Altamont North Stp, City Of | Altamont | — | ILG580152 | May 2027 | Aerated lagoons | 2 |
| Arenzville Stp, Village Of | Arenzville | — | ILG580165 | May 2027 | Uncovered lagoons | 10 |
| Ava Stp, City Of | Ava | — | ILG580148 | May 2027 | Uncovered lagoons | 9 |
| Bridgeport Stp, City Of | Bridgeport | — | ILG582001 | May 2027 | Aerated lagoons, Uncovered lagoons | 113 |
| Brimfield Sanitary District STP | Brimfield | — | ILG580050 | May 2027 | Uncovered lagoons | 23 |
| Broughton Stp, Village Of | Broughton | — | ILG580259 | May 2027 | Uncovered lagoons | 7 |
| Brownstown Stp, Village Of | Brownstown | — | ILG580027 | May 2027 | Aerated lagoons, Uncovered lagoons | 10 |
| Buffalo, Dawson, Mechanicsburg Sewer Commission STP | Buffalo | — | ILG580167 | May 2027 | Clarifiers, Uncovered lagoons, Biogas silos | 65 |
| City Of Creal Springs STP | Creal Springs | — | ILG580125 | May 2027 | Uncovered lagoons | 14 |
| Coffeen Stp, City Of | Coffeen | — | ILG580243 | May 2027 | Aerated lagoons, Uncovered lagoons | 19 |
| Crossville Stp, Village Of | Crossville | — | ILG580211 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Cutler Stp, Village Of | Cutler | — | ILG580210 | May 2027 | Uncovered lagoons | 0 |
| Cypress Stp, Village Of | Cypress | — | ILG580150 | May 2027 | Uncovered lagoons | 1 |
| Divernon Stp, Village Of | Divernon | — | ILG580175 | May 2027 | Aerated lagoons | 0 |
| Dix-Kell Water & Sewer Commission STP | Dix | — | ILG580062 | May 2027 | Aerated lagoons, Uncovered lagoons | 65 |
| Easton STP | Easton | — | ILG580176 | May 2027 | Uncovered lagoons | 8 |
| Enfield East Stp, Village Of | Enfield | — | ILG580108 | May 2027 | Uncovered lagoons | 3 |
| Enfield West Stp, Village Of | Enfield | — | ILG580105 | May 2027 | Uncovered lagoons | 19 |
| Farina Stp, Village Of | Farina | — | ILG580047 | May 2027 | Aerated lagoons, Uncovered lagoons | 4 |
| Farmersville Stp, Village Of | Farmersville | — | ILG580126 | May 2027 | Uncovered lagoons | 6 |
| Flat Rock Stp, Village Of | Flat Rock | — | ILG580224 | May 2027 | Aerated lagoons, Uncovered lagoons | 5 |
| Gorham Sd Stp, Village Of | Gorham | — | ILG580185 | May 2027 | Uncovered lagoons | 39 |
| Herrick Stp, Village Of | Herrick | — | ILG580147 | May 2027 | Uncovered lagoons | 14 |
| Hettick Stp, Village Of | Hettick | — | ILG580219 | May 2027 | Uncovered lagoons | 6 |
| Hull, Village Of | Hull | — | ILG580114 | May 2027 | Uncovered lagoons | 0 |
| Iuka Stp, Village Of | Iuka | — | ILG580146 | May 2027 | Uncovered lagoons | 1 |
| Joppa Sanitary District Stp, Village Of | Joppa | — | ILG580156 | May 2027 | Uncovered lagoons | 1 |
| Junction City Stp, Village Of | Junction City | — | ILG580277 | May 2027 | Uncovered lagoons | 0 |
| Keensburg Stp, Village Of | Keensburg | — | ILG580112 | May 2027 | Uncovered lagoons | 0 |
| Kinderhook Stp, Village Of | Kinderhook | — | ILG580192 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Livingston Wwtp, Village Of | Livingston | — | ILG580115 | May 2027 | Uncovered lagoons | 5 |
| Loraine Stp, Village Of | Loraine | — | ILG580184 | May 2027 | Uncovered lagoons | 131 |
| Macon Stp, City Of | Macon | — | ILG580141 | May 2027 | — | 52 |
| Mason Stp, Town Of | Mason | — | ILG580276 | May 2027 | Uncovered lagoons | 8 |
| Matherville Stp, Village Of | Matherville | — | ILG580238 | May 2027 | Uncovered lagoons | 11 |
| Mill Shoals STP | Mill Shoals | — | ILG580195 | May 2027 | Uncovered lagoons | 97 |
| Mount Clare Stp, Village Of | Mount Clare | — | ILG580120 | May 2027 | Uncovered lagoons | 12 |
| Nebo Stp, Village Of | Nebo | — | ILG580241 | May 2027 | Uncovered lagoons | 62 |
| New Canton Stp, Town Of | New Canton | — | ILG580264 | May 2027 | Uncovered lagoons | 0 |
| New Douglas Stw, Village Of | New Douglas | — | ILG580273 | May 2027 | Uncovered lagoons | 65 |
| New Grand Chain Stp, Village Of | New Grand Chain | — | ILG580196 | May 2027 | Uncovered lagoons | 19 |
| Oblong Stp, Village Of | Oblong | — | ILG582017 | May 2027 | Uncovered lagoons | 2 |
| Olmsted Stp, Village Of | Olmsted | — | ILG580052 | May 2027 | Uncovered lagoons | 12 |
| Palestine Stp, Village Of | Palestine | — | ILG580034 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Percy Stp, Village Of | Percy | — | ILG580109 | May 2027 | Uncovered lagoons | 0 |
| Pierron East Stp, Village Of | Pierron | — | ILG580237 | May 2027 | Aerated lagoons, Biogas silos | 2 |
| Pittsburg, Village Of | Pittsburg | — | ILG580128 | May 2027 | Uncovered lagoons | 0 |
| Plainville Stp, Village Of | Plainville | — | ILG580169 | May 2027 | Uncovered lagoons | 0 |
| Potomac STP | Potomac | — | ILG580247 | May 2027 | Uncovered lagoons | 13 |
| Reynolds Stp, Village Of | Reynolds | — | ILG580225 | May 2027 | Uncovered lagoons | 109 |
| Saint Francisville SW STP | Saint Francisville | — | ILG580188 | May 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Scales Mound Stp, Village Of | Scales Mound | — | ILG580124 | May 2027 | Aerated lagoons, Uncovered lagoons | 5 |
| Sorento STP | Sorento | — | ILG580049 | May 2027 | Uncovered lagoons | 28 |
| Sparland Stp, Village Of | Sparland | — | ILG580226 | May 2027 | Uncovered lagoons | 19 |
| St Marie STP | Sainte Marie | — | ILG580058 | May 2027 | Uncovered lagoons | 9 |
| Stonefort Stp, Village Of | Stonefort | — | ILG580082 | May 2027 | Uncovered lagoons | 41 |
| Strasburg Stp, Village Of | Strasburg | — | ILG580240 | May 2027 | Uncovered lagoons | 61 |
| Sumner STP | Sumner | — | ILG580118 | May 2027 | Uncovered lagoons | 2 |
| Tamaroa Stp, Village Of | Tamaroa | — | ILG580182 | May 2027 | Uncovered lagoons | 2 |
| Teutopolis Stp, Village Of | Teutopolis | — | ILG582024 | May 2027 | Aerated lagoons, Uncovered lagoons | 8 |
| Wamac Stp, City Of | Wamac | — | ILG580144 | May 2027 | Aerated lagoons, Uncovered lagoons | 2 |
| Ware Sanitary Corporation STP | Ware | — | ILG580242 | May 2027 | Uncovered lagoons | 4 |
| West Point Stp, Village Of | West Point | — | ILG580270 | May 2027 | Uncovered lagoons | 3 |
| Willisville Stp, Village Of | Willisville | — | ILG580168 | May 2027 | Uncovered lagoons | 19 |
| Willow Hill Stp, Village Of | Willow Hill | — | ILG580092 | May 2027 | Uncovered lagoons | 4 |
| Windsor Stp, City Of | Windsor | — | ILG580131 | May 2027 | Uncovered lagoons | 1 |
| Woodson Stp, Village Of | Woodson | — | ILG580179 | May 2027 | Aerated lagoons | 3 |
| Xenia Stp, Village Of | Xenia | — | ILG580029 | May 2027 | Uncovered lagoons | 0 |
| Dupo Stp, Village Of | Dupo | 0.29 | IL0026441 | Jun 2027 | Clarifiers | 0 |
| New Memphis Sd STP | New Baden | 0.07 | IL0076732 | Jun 2027 | Covered lagoons | 13 |
| Verona Stp, Village Of | Verona | 0.03 | IL0050296 | Jun 2027 | — | 7 |
| Biggsville Stp, Village Of | Biggsville | 0.03 | IL0073318 | Jun 2027 | Aerated lagoons | 0 |
| Bureau Junction Stp, Village Of | Bureau Junction | 0.03 | IL0033120 | Jun 2027 | Aerated lagoons, Uncovered lagoons | 1 |
| Eureka WTP | Eureka | 0.39 | IL0025119 | Jul 2027 | Uncovered lagoons | 41 |
| Noble Stp, Village Of | Noble | 0.02 | IL0025500 | Jul 2027 | Aerated lagoons, Uncovered lagoons | 6 |
| Fairfield, City Of | Fairfield | 0.44 | IL0020605 | Aug 2027 | Uncovered lagoons, Carrousels / oxidation ditches | 0 |
| Breese Stp, City Of | Breese | 0.31 | IL0022772 | Aug 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Lena Stp, Village Of | Lena | 0.18 | IL0024945 | Aug 2027 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches, Biogas silos, Biogas balloons | 0 |
| Palmyra STP | Palmyra | 0.14 | IL0044831 | Aug 2027 | Aerated lagoons, Uncovered lagoons | 10 |
| Dieterich Stp, Village Of | Dieterich | 0.12 | IL0044792 | Aug 2027 | Aerated lagoons, Uncovered lagoons | 7 |
| Winslow Stp, Village Of | Winslow | 0.03 | IL0048259 | Aug 2027 | Uncovered lagoons | 23 |
| Blandinsville Stp, Village Of | Blandinsville | 0.02 | IL0072672 | Aug 2027 | Aerated lagoons | 1 |
| Augusta Stp, Village Of | Augusta | — | IL0027570 | Aug 2027 | Uncovered lagoons | 39 |
| Fillmore Stp, Village Of | Fillmore | — | IL0050156 | Aug 2027 | Uncovered lagoons | 13 |
| Leroy Stp, City Of | Le Roy | 0.41 | IL0021563 | Sep 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons | 0 |
| Orion Wastewater Treatment Plant | Orion | 0.3 | IL0024988 | Sep 2027 | Clarifiers | 0 |
| Carrollton Stp, City Of | Carrollton | 0.3 | IL0021679 | Sep 2027 | Uncovered lagoons | 0 |
| Sheridan Sanitary District - STP | Sheridan | 0.3 | IL0031062 | Sep 2027 | Clarifiers, Carrousels / oxidation ditches | 0 |
| Athens Stp, City Of | Athens | 0.11 | IL0041203 | Sep 2027 | Clarifiers, Uncovered lagoons | 3 |
| Buda Stp, Village Of | Buda | 0.07 | IL0072494 | Sep 2027 | Aerated lagoons | 7 |
| Gillespie Stp, Village Of | Gillespie | 0.06 | IL0022497 | Sep 2027 | Aerated lagoons, Uncovered lagoons | 6 |
| Village Of Cordova - STP | Cordova | 0.02 | IL0025356 | Sep 2027 | Aerated lagoons | 11 |
| Radom Stp, Village Of | Radom | 0.006 | IL0066281 | Sep 2027 | — | 27 |
| Pinckneyville STP 2 East, City Of | Pinckneyville | 0.35 | IL0071650 | Oct 2027 | — | 6 |
| Gilman North Stp, City Of | Gilman | 0.22 | IL0025062 | Oct 2027 | Uncovered lagoons, Carrousels / oxidation ditches | 6 |
| Earlville Stp, City Of | Earlville | 0.11 | IL0020877 | Oct 2027 | — | 0 |
| Waltonville Stp, Village Of | Waltonville | 0.08 | IL0049123 | Oct 2027 | Uncovered lagoons | 0 |
| Paxton Stp, City Of | Paxton | 0.37 | IL0023205 | Nov 2027 | Clarifiers, Uncovered lagoons | 0 |
| Poplar Grove - North Wwtp, Village Of | Poplar Grove | 0.22 | IL0023451 | Nov 2027 | — | 15 |
| Germantown Hills Stp, Village Of | Metamora | 0.07 | IL0028916 | Nov 2027 | Uncovered lagoons | 6 |
| Avon Stp, Village Of | Avon | 0.07 | IL0021334 | Nov 2027 | — | 46 |
| Tonica Stp, Village Of | Tonica | 0.05 | IL0023639 | Nov 2027 | Clarifiers, Carrousels / oxidation ditches | 31 |
| Richview Stp, Village Of | Richview | 0.04 | IL0038717 | Nov 2027 | Aerated lagoons, Uncovered lagoons | 0 |
| Sun River Terrace STP | Saint Anne | 0.03 | IL0045501 | Nov 2027 | Aerated lagoons | 1 |
| Elizabethtown Stp, Village Of | Elizabethtown | — | IL0074250 | Nov 2027 | Aerated lagoons, Uncovered lagoons | 21 |
| Brighton Stp, Village Of | Brighton | 0.26 | IL0024457 | Dec 2027 | Clarifiers | 2 |
| Kincaid STP | Kincaid | 0.11 | IL0048607 | Dec 2027 | Uncovered lagoons | 82 |
| Warren STP | Warren | 0.11 | IL0026301 | Dec 2027 | Clarifiers, Aerated lagoons, Uncovered lagoons, Carrousels / oxidation ditches | 1 |
| Forrest Stp, Village Of | Forrest | 0.08 | IL0028819 | Dec 2027 | Clarifiers, Aerated lagoons | 7 |
| St. Anne - Stp, Village Of | Saint Anne | 0.08 | IL0025755 | Dec 2027 | Uncovered lagoons | 4 |
| Stronghurst Stp, Village Of | Stronghurst | 0.05 | IL0064025 | Dec 2027 | — | 14 |
| Tiskilwa Stp, Village Of | Tiskilwa | 0.04 | IL0025160 | Dec 2027 | Aerated lagoons, Uncovered lagoons | 34 |
| London Mills Wwtp, Village Of | London Mills | 0.04 | IL0047236 | Dec 2027 | Clarifiers, Carrousels / oxidation ditches | 6 |
| Bowen - STP | Bowen | 0.02 | IL0021075 | Dec 2027 | Uncovered lagoons | 0 |
| Banner Stp, Village Of | Canton | 0.01 | IL0061140 | Dec 2027 | Uncovered lagoons, Carrousels / oxidation ditches | 0 |
| Catlin Stp, Village Of | Catlin | — | IL0023108 | Dec 2027 | Clarifiers, Uncovered lagoons | 12 |
| Ullin Stp, Village Of | Ullin | — | IL0070114 | Dec 2027 | Uncovered lagoons | 3 |
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 September 11, 2026.