County · Iowa
Lyon County, Iowa: drinking water records
This overview covers 8 ZIP codes and 12 community water systems in Lyon County. It also stands in for 0 ZIP codes whose utility has too little EPA data for a page of its own.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems with the most complete records
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Lyon-Sioux Rws-Big Sioux IA6000755 | 1,530 | 180 | 0 | 0 | 4 ppb |
| Rock Rapids Municipal Water Works IA6065092 | 2,611 | 0 | 0 | 0 | 1.5 ppb |
| Lyon-Sioux Rws-Doon IA6000733 | 1,765 | 0 | 0 | 0 | 4 ppb |
| Lyon-Sioux Rws-Rock Rapids IA6000800 | 1,187 | 0 | 0 | 0 | 2 ppb |
| George Water Supply IA6028081 | 1,082 | 0 | 0 | 0 | 2 ppb |
| Inwood Water Supply IA6040076 | 928 | 0 | 0 | 0 | 2.1 ppb |
| Larchwood Water Supply IA6050059 | 926 | 0 | 0 | 0 | 2.4 ppb |
| Doon Water Supply IA6015047 | 619 | 0 | 0 | 0 | 4 ppb |
| Lyon-Sioux Rws-Boyden IA6000744 | 605 | 0 | 0 | 0 | 3.1 ppb |
| Little Rock Water Supply IA6060006 | 441 | 0 | 0 | 0 | 9.1 ppb |
| Lester Water Supply IA6055077 | 296 | 0 | 0 | 0 | 2.2 ppb |
| Alvord Municipal Water Supply IA6003032 | 206 | 0 | 0 | 0 | 4 ppb |
ZIP reports in Lyon County
No ZIP report in this county is published yet.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Page generated 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.