County · Wisconsin
Jefferson County, Wisconsin: drinking water records
This overview covers 10 ZIP codes and 19 community water systems in Jefferson 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 |
|---|---|---|---|---|---|
| Jefferson Waterworks WI1280104 | 7,926 | 180 | 0 | 7 | 3.5 ppb |
| Lake Mills Waterworks WI1280108 | 6,211 | 180 | 0 | 3 | 4.6 ppb |
| Waterloo Waterworks WI1280115 | 3,520 | 180 | 0 | 3 | 1.3 ppb |
| Watertown Waterworks WI1280044 | 23,945 | 180 | 0 | 0 | 11 ppb |
| Fort Atkinson Waterworks WI1280103 | 12,390 | 240 | 0 | 0 | 13 ppb |
| Johnson Creek Waterworks WI1280107 | 3,318 | 0 | 0 | 1 | 2.8 ppb |
| Palmyra Waterworks WI1280112 | 1,756 | 120 | 2 | 0 | 3.8 ppb |
| Tremain Mobile Home Park WI1280127 | 475 | 0 | 0 | 5 | 0.2 ppb |
| River Valley Apts South WI1281100 | 48 | 0 | 0 | 1 | 6.8 ppb |
| Parkview Apartments WI1280055 | 45 | 0 | 0 | 4 | 0.7 ppb |
| Autumn Ridge Water System LLC WI1281138 | 575 | 0 | 0 | 0 | 0.8 ppb |
| Spacious Acres Mobile Home Community WI1280114 | 525 | 0 | 0 | 0 | 0.5 ppb |
| Lakewood Village WI1280109 | 160 | 0 | 0 | 0 | 3.5 ppb |
| Stanton Place I WI1281122 | 66 | 0 | 0 | 0 | 4.5 ppb |
| River Valley Apts North WI1281099 | 48 | 0 | 0 | 0 | 0.5 ppb |
| Wolfs Mobile Homes WI1280126 | 40 | 0 | 0 | 0 | 0 ppb |
| Stanton Place II WI1281162 | 32 | 0 | 0 | 0 | 0 ppb |
| Hickory Hill Park LLC WI1280116 | 31 | 0 | 0 | 0 | 1.9 ppb |
| Rock River Mobile Home Park WI1280106 | 30 | 0 | 0 | 0 | 0.8 ppb |
ZIP reports in Jefferson 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: 53137.
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.