County · Illinois
LaSalle County, Illinois: drinking water records
This overview covers 26 ZIP codes and 36 community water systems in LaSalle County. It also stands in for 2 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 |
|---|---|---|---|---|---|
| Ottawa IL0990800 | 18,097 | 120 | 0 | 1 | 5.0 ppb |
| Peru IL0990850 | 10,300 | 60 | 0 | 1 | 10.5 ppb |
| La Salle IL0990300 | 9,700 | 60 | 2 | 6 | 9.0 ppb |
| Mendota IL0990550 | 7,100 | 180 | 0 | 3 | 8.1 ppb |
| Marseilles IL0990500 | 5,061 | 120 | 0 | 1 | 19.1 ppb |
| Il American-Streator IL0995030 | 19,000 | 120 | 4 | 0 | 1 ppb |
| Prairie Path Water Company-Lake Holiday IL0995200 | 4,750 | 60 | 0 | 0 | 2 ppb |
| Oglesby IL0990700 | 4,500 | 60 | 0 | 0 | 0 ppb |
| North Utica IL0990650 | 1,323 | 0 | 0 | 1 | 5.3 ppb |
| Whispering Pines MHP FL4504396 | 760 | 0 | 0 | 1 | 1.1 ppb |
| Grand Ridge IL0990200 | 515 | 0 | 0 | 2 | 0 ppb |
| Lostant IL0990450 | 463 | 0 | 0 | 1 | 0.7 ppb |
| Fields Hill Improvement Association IL0995150 | 312 | 0 | 0 | 2 | 4.4 ppb |
| Retz Addn Improvement Association IL0995400 | 168 | 0 | 0 | 1 | 1.2 ppb |
| Countryside Estates MHP IL0995185 | 158 | 0 | 0 | 1 | 0 ppb |
| La Salle County Nursing Home IL0995329 | 100 | 0 | 0 | 1 | 0 ppb |
| Jons MHP IL0990020 | 92 | 0 | 0 | 1 | 0 ppb |
| Land and Wtr Assn IL0995050 | 83 | 0 | 0 | 15 | 7 ppb |
| Seneca Mobile Homes LLC IL0995425 | 10 | 0 | 0 | 6 | 0 ppb |
| Seneca IL0991050 | 2,353 | 0 | 0 | 0 | 0 ppb |
| Sheridan Correctional Center IL0995840 | 1,670 | 0 | 0 | 0 | 0 ppb |
| Earlville IL0990150 | 1,613 | 0 | 0 | 0 | 2.9 ppb |
| Leland IL0990350 | 951 | 0 | 0 | 0 | 0 ppb |
| Tonica IL0991150 | 705 | 0 | 0 | 0 | 0 ppb |
| Naplate IL0990600 | 465 | 0 | 0 | 0 | 0 ppb |
ZIP reports in LaSalle County
No ZIP report in this county is published yet.
These ZIP codes are covered by this overview because their utility has too little EPA data for a separate page: 60537, 60549.
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.