Nitrate violations in Iowa
190 active public water systems in Iowa had a Nitrate violation in the past three years, 34 of them in the latest quarter of EPA's data. What Nitrate is and why it matters.
Health effects: Methemoglobinemia in infants under 6 months: gut bacteria convert nitrate to nitrite, which blocks oxygen transport in blood. Pregnant women should also take precautions. Chronic adult exposure at elevated levels may increase cancer risk.
Systems with a Nitrate violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Preston Muni Water Supply Preston · Jackson County |
949 | 1 | 0 | |
|
Princeton Water Supply Princeton · Scott County |
923 | 1 | 0 | |
|
Neola Light & Water Neola · Pottawattamie County |
906 | 3 | 2 | |
|
Elkhart Water Supply Elkhart · Polk County |
882 | 1 | 0 | |
|
Carson Water Supply Carson · Pottawattamie County |
766 | 1 | 0 | |
|
McGregor Water Dept Mcgregor · Clayton County |
747 | 1 | 0 | |
|
Oxford Water Supply Oxford · Johnson County |
722 | 3 | 0 | |
|
Coggon Water Department Coggon · Linn County |
701 | 3 | 0 | |
|
Lyon-Sioux Rws-Boyden Rock Rapids · Lyon County |
605 | 1 | 0 | |
|
Caseys Store (nichols) #2472 Nichols · Muscatine County |
603 | 3 | 1 | |
|
Early Municipal Water Supply Early · Sac County |
587 | 1 | 0 | |
|
Fox Creek Benefitted Wtr. District Booneville · Dallas County |
553 | 1 | 0 | |
|
Shops Above the Wapsi Anamosa · Jones County |
515 | 4 | 0 | |
|
Scranton Water System Scranton · Greene County |
511 | 1 | 0 | |
|
Desoto Natl Wildlife Refuge-Visitor Ctr Missouri Valley · Harrison County |
505 | 2 | 0 | |
|
Lost Nation Water Supply Lost Nation · Clinton County |
434 | 3 | 0 | |
|
Epic Event Center Marion · Linn County |
404 | 3 | 1 | |
|
Dubuque Sports Complex Dubuque · Dubuque County |
400 | 3 | 0 | |
|
Thornton Water Supply Thornton · Cerro Gordo County |
400 | 1 | 0 | |
|
Marshalltown Estates Marshalltown · Marshall County |
382 | 3 | 0 | |
|
Plymouth Water Supply Plymouth · Cerro Gordo County |
378 | 5 | 1 | |
|
Lewis Water Supply Lewis · Cass County |
357 | 1 | 0 | |
|
Danbury Water Supply Danbury · Woodbury County |
320 | 1 | 0 | |
|
Williams Water Supply Williams · Hamilton County |
315 | 1 | 0 | |
|
Lofted View Events Sioux City · Woodbury County |
314 | 2 | 0 | |
|
Fertile Municipal Water Fertile · Worth County |
306 | 3 | 0 | |
|
Lakota Water Supply Lakota · Kossuth County |
267 | 1 | 0 | |
|
Fenton Municipal Water Supply Fenton · Kossuth County |
254 | 1 | 0 | |
|
Corner Market Mccausland · Scott County |
252 | 3 | 1 | |
|
Westfair Council Bluffs · Pottawattamie County |
238 | 3 | 1 | |
|
Super 20 Mobile Home Court Dubuque · Dubuque County |
236 | 2 | 0 | |
|
Johnson County AG Association Iowa City · Johnson County |
218 | 4 | 0 | |
|
Apostolic Christian Church West Bend · Kossuth County |
200 | 1 | 0 | |
|
Meadow Lake Campgrounds Tipton · Cedar County |
200 | 3 | 1 | |
|
Oakville Water Supply Oakville · Louisa County |
200 | 3 | 0 | |
|
Randolph Water Works Randolph · Fremont County |
192 | 2 | 0 | |
|
Sunnyside Village MHP LLC Missouri Valley · Harrison County |
190 | 5 | 3 | |
|
Moorhead Water Supply Moorhead · Monona County |
189 | 2 | 0 | |
|
Little Brown Church Nashua · Chickasaw County |
183 | 1 | 0 | |
|
Green Valley Golf Course Sioux City · Woodbury County |
180 | 1 | 0 | |
|
Deerwood Estates Utilities Fort Dodge · Webster County |
175 | 3 | 0 | |
|
Coralville Lake Manor Solon · Johnson County |
170 | 2 | 0 | |
|
Iowa Contract Fabricators INC Riceville · Howard County |
160 | 1 | 0 | |
|
Town Clock Centralia · Dubuque County |
158 | 3 | 0 | |
|
West Grand Golf West Des Moines · Dallas County |
157 | 2 | 0 | |
|
Community Orchard Fort Dodge · Webster County |
154 | 1 | 0 | |
|
Wanatee Park Marion · Linn County |
154 | 2 | 0 | |
|
Hastings Water Supply Hastings · Mills County |
152 | 2 | 1 | |
|
Cedarcrest Golf & Country Club Columbus Junction · Louisa County |
146 | 1 | 0 | |
|
Timber Valley Estates (1st & 2nd Add) Blue Grass · Scott County |
132 | 2 | 1 |
About this data
A system is counted once if any of its violations in the past three years involved Nitrate, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Nitrate alone.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Iowa records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.