County · Illinois
DeKalb County, Illinois: drinking water records
This overview covers 13 ZIP codes and 20 community water systems in DeKalb County. It also stands in for 1 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 |
|---|---|---|---|---|---|
| Dekalb IL0370100 | 40,290 | 300 | 0 | 0 | 13 ppb |
| Sycamore IL0370550 | 18,500 | 300 | 0 | 0 | 0 ppb |
| Sandwich IL0374850 | 7,156 | 120 | 0 | 0 | 0 ppb |
| Northern Illinois University-Dekalb IL0375500 | 6,500 | 180 | 0 | 0 | 0 ppb |
| Genoa IL0370150 | 5,298 | 180 | 2 | 0 | 8.7 ppb |
| Cortland IL0370051 | 4,398 | 240 | 0 | 0 | 0 ppb |
| Kingston IL0370250 | 1,160 | 0 | 0 | 2 | 5.0 ppb |
| Cortland Corners MHP IL0375125 | 205 | 0 | 0 | 2 | 0 ppb |
| Valley View Subdivision (Dekalb) IL0375200 | 120 | 0 | 0 | 1 | 0 ppb |
| Hinckley IL0370200 | 2,006 | 0 | 0 | 0 | 0 ppb |
| Kirkland IL0370300 | 2,000 | 0 | 0 | 0 | 0 ppb |
| Somonauk IL0374870 | 1,860 | 0 | 0 | 0 | 0 ppb |
| Waterman IL0370600 | 1,497 | 0 | 0 | 0 | 8.8 ppb |
| Malta IL0370350 | 1,143 | 0 | 0 | 0 | 0 ppb |
| Suburban Apartments (De Kalb Univ Dvl) IL0375148 | 1,050 | 0 | 0 | 0 | 3.2 ppb |
| Shabbona IL0370450 | 913 | 0 | 0 | 0 | 6.8 ppb |
| Buck Lake Estates Subdivision IL0375100 | 150 | 0 | 0 | 0 | 1.9 ppb |
| Triangle Manufactured Home Community IL0374865 | 124 | 0 | 0 | 0 | 0 ppb |
| Sandwich Estates MHP IL0374860 | 90 | 0 | 0 | 0 | 0 ppb |
| Donny Brook Estates Subdivision IL0375150 | 30 | 0 | 0 | 0 | 0 ppb |
ZIP reports in DeKalb 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: 60111.
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.