PlainWater
Counties → Wisconsin

Rock County, Wisconsin

SDWIS compliance plate

Sheet WI105 · Rock County 156 sys · 3,788 viol · #425/3254

VIOL-SEVERE · HEALTH-MID · RANK-TOP · PHOTO-FINISH · PFAS-LOW · SRC-GW · SYS-LARGE · BOOK-FULL

  • VIOL-SEVERE 78.2% flagged
  • HEALTH-MID 38.8% health
  • RANK-TOP #425/3254
  • PHOTO-FINISH ±0.4 pp
  • PFAS-LOW 16.7% detect
  • SRC-GW GW lead 100%
  • SYS-LARGE 156 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Walworth County ( -0.4 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Rock County ranks #425 of 3,254 counties by people served, and #8 of 71 counties in Wisconsin. See methodology · corpus placement.

Rock County standing, lower-flagged corpus third

Flagged-system rate 78.2% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 38.8% is health-based share above the upper third (> 24.5%) . UCMR5 detect rate 16.7% is UCMR5 detect rate in the tested-pool middle third (≤ 33.3%) . Population served ranks #425 of 3,254 · #8 of 71 in Wisconsin.

Flagged-rate neighbourhood around Rock County

Lowest/highest poles plus in-state counties nearest Rock County on % of SDWIS systems with ≥1 violation. Full ladder: /counties.

0% 20% 40% 60% 80% 100% Bayfield · lowest Wood · near Dodge · near Milwaukee · highest 52.1% 77.5% 77.7% 77.8% 77.8% 78.2% 95.3%

Source: EPA SDWIS (county aggregates) As of 2026-05-15

Water Systems

System Name Population Violations PFAS
Janesville Water Utility 64,415 14 Clean
Beloit City Of 36,677 37 Detected
Evansville Waterworks 5,703 83 Clean
Milton Waterworks 5,588 86 Clean
Edgerton Waterworks 5,512 51 Clean
WI DOT Rest Area 22 Turtle 3,005 34 -
WI DOT Rest Area 17 Milton 2,503 23 -
Clinton Waterworks 2,119 221 Clean
Orfordville Waterworks 1,475 44 -
Culvers of Newville 1,233 102 -
Rockvale MHP 1,200 23 -
McDonalds Newville 1,085 49 -
Footville Waterworks 816 37 -
Lakeland Camp & Trailer Park 755 2 -
Rock River Leisure Estates Coop 650 24 -
Carls Shell/Taco Johns 520 18 -
Milton KOA RV Resort 505 2 -
Jakes Mobil 465 9 -
Station 51 LLC 412 2 -
Luther Valley Church 401 2 -
Blackhawk RV LLC 1 Restaurant 356 2 -
Blackhawk RV Eagle Hill 356 22 -
Blackhawk RV LLC 3 Wigwam 350 2 -
Fairbanks Morse Engine Div 330 19 -
Rock River Thresheree Restrooms 302 7 -
Rock River Thresheree Shelter 302 15 -
Caravilla Education and Rehab Center 298 74 -
Newville Travel Centersubway 254 18 -
Ste Well 1 250 4 -
Wrights Mobile Home Park 240 35 -
Fulton Congregational Church 232 2 -
Butterfly Supper Club 222 22 -
Anchor Inn 220 6 -
Red Barn Tavern LLC 210 5 -
Heritage Hall 210 2 -
Rock River Heritage Park 5 210 0 -
Oak Ridge Golf Course 208 0 -
Beloit Youth Sports Complex 208 0 -
Rock Prairie United Pres Ch 206 20 -
Riverside Mobil 205 0 -
Westside Baptist Church 201 14 -
Fulton Utility District 200 26 -
Lakeland Campground Store 200 0 -
Bass Creek Golf Club 200 11 -
Alliant Energy & Wp&l Co Maintenance 180 14 -
Stagecoach Inn 175 17 -
Beloit Club 174 5 -
Evansville Golf Club Clubhouse 168 0 -
Midway Village Mobile Home Park 160 27 -
Shady Hill Mobile Home Park 140 280 -

Compare beyond Wisconsin

Lower-flagged peers for Rock County

Cross-state counties nearest Rock County on flagged-system share (78.2%) and cumulative violation count (3,788). In-state neighbours stay on the compliance plate above.

Similar flagged-system rate

Nearest cross-state counties by % of SDWIS systems with at least one violation on record.

4 peers

Similar violation load

Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).

4 peers

Read our methodology · Check your water system - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.