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Counties → Illinois

LaSalle County, Illinois

SDWIS compliance plate

Sheet IL099 · LaSalle County 174 sys · 13,172 viol · #530/3254

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

  • VIOL-SEVERE 91.4% flagged
  • HEALTH-MID 30.6% health
  • RANK-TOP #530/3254
  • PHOTO-FINISH ±0.3 pp
  • PFAS-MID 25.0% detect
  • SRC-GW GW lead 98%
  • SYS-LARGE 174 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Christian County (+ 0.3 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, LaSalle County ranks #530 of 3,254 counties by people served, and #16 of 102 counties in Illinois. See methodology · corpus placement.

LaSalle County standing, lower-flagged corpus third

Flagged-system rate 91.4% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 30.6% is health-based share above the upper third (> 24.5%) . UCMR5 detect rate 25.0% is UCMR5 detect rate in the tested-pool middle third (≤ 33.3%) . Population served ranks #530 of 3,254 · #16 of 102 in Illinois.

Flagged-rate neighbourhood around LaSalle County

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

0% 20% 40% 60% 80% 100% Sangamon · lowest Bureau · near Christian · near Pulaski · highest 58.8% 91.1% 91.1% 91.4% 91.7% 91.7% 100%

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

Water Systems

System Name Population Violations PFAS
IL American-Streator 19,000 71 Detected
Ottawa 18,097 365 Clean
Peru 10,300 37 Clean
La Salle 9,700 219 Detected
Mendota 6,926 171 Clean
Prairie Path Water Company-Lake Holiday 6,601 44 Clean
Marseilles 5,061 158 Clean
Oglesby 4,500 206 Clean
Woodsmoke Ranch 4,000 10 -
Seneca 2,353 151 -
Sheridan Correctional Center 1,670 124 -
Earlville 1,613 27 -
North Utica 1,400 254 -
Grand Bear Lodge Water Pk/Jacks Place 6N 1,005 3 -
Wildwood Estates 1,001 21 -
Constellation/Lasalle Cnty Gen Station 1,000 78 -
Leland 951 16 -
Streator Baptist Camp -Office Well 750 20 -
Tonica 705 129 -
Glenwood RV Resort 600 54 -
Serena Community School 555 98 -
Grand Ridge 515 355 -
Starved Rock State Park (94227) 500 25 -
Naplate 465 477 -
Lostant 463 318 -
Sabic Innovative Plastics 440 18 -
Fields Hill Improvement Association 312 210 -
Lakes Country Club 300 27 -
Illinois Waterway Visitor Ctr 300 6 -
Cedar Point Water Company 266 80 -
Rutland 259 181 -
Four Star Campground 250 410 -
Rolling Oaks Office Well 250 40 -
Harding Grade School 250 374 -
Wallace Consol Comm School 250 245 -
Rolling Oaks Campground (113555) 250 35 -
Jonesville Pwd 243 26 -
Getaway Starved Rock 230 19 -
Sheridan Grade School 227 199 -
Country Acres MHP (la Salle County) 222 500 -
American Nickeloid 200 17 -
Illini State Park 200 18 -
Grand Bear Vac Villas Town Home #1 200 3 -
Retz Addn Improvement Association 168 80 -
Countryside Estates MHP 158 42 -
Deer Park School 155 195 -
Pine Hills Golf Course 150 3 -
Miller Comm Consol Sch 210 150 324 -
Road Ranger LLC Ottawa 150 10 -
Hy-Vee Inc 135 4 -

Compare beyond Illinois

Lower-flagged peers for LaSalle County

Cross-state counties nearest LaSalle County on flagged-system share (91.4%) and cumulative violation count (13,172). 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.