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Counties → Illinois

Grundy County, Illinois

SDWIS compliance plate

Sheet IL063 · Grundy County 63 sys · 12,515 viol · #927/3254

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

  • VIOL-SEVERE 90.5% flagged
  • HEALTH-LOW 10.9% health
  • RANK-UPPER #927/3254
  • PHOTO-FINISH ±0.4 pp
  • PFAS-LOW 20.0% detect
  • SRC-GW GW lead 97%
  • SYS-MID 63 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Logan County (+ 0.4 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Grundy County ranks #927 of 3,254 counties by people served, and #26 of 102 counties in Illinois. See methodology · corpus placement.

Grundy County standing, lower-flagged corpus third

Flagged-system rate 90.5% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 10.9% is health-based share in the middle third (≤ 24.5%) . UCMR5 detect rate 20.0% is UCMR5 detect rate in the tested-pool middle third (≤ 33.3%) . Population served ranks #927 of 3,254 · #26 of 102 in Illinois.

Flagged-rate neighbourhood around Grundy County

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

0% 20% 40% 60% 80% 100% Sangamon · lowest Grundy · this county White · near Pulaski · highest 58.8% 90% 90.5% 90.9% 90.9% 91.1% 100%

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

Water Systems

System Name Population Violations PFAS
Morris 14,775 108 Clean
Minooka 12,800 266 Detected
Coal City 5,749 621 Clean
Diamond 2,508 346 -
Coal City Area Club 2,500 17 -
Gardner 1,361 322 -
Mazon 994 65 -
Shady Oaks MHP 912 262 Clean
Constellation Dresden Station 811 13 -
Braceville 800 210 -
First Christian Church (138818) 800 5 -
South Wilmington 700 198 -
Equistar Chemicals LP 600 62 -
Burt Estates Mhc 543 4 -
Bookwalter Woods MHP 504 33 Clean
South Wilmington Firemans #1 500 37 -
Express Lane Gas and Food Inc. 400 10 -
Indian Creek Office Well 390 10 -
Carbon Hill 370 1,635 -
Rainbow Council Scout Res Main 350 18 -
IL American-Nettle Creek 317 1 -
Grundy County Fairgrounds 300 14 -
Downers Grove Sportsman Club 300 14 -
Grundy County Fairgrl N Well 300 10 -
Indian Creek Pool Well 210 9 -
IL American-Ridgecrest 203 26 -
Honest Abes Tap and Grill 162 15 -
Ceco Recreation Association 125 20 -
Polynt Composites USA, Inc 120 482 -
Prairie Oaks Ests Homeowners Assn 107 151 -
Grundy County Rod & Gun Club 100 9 -
Loyal Order of Moose #967 100 4 -
Nouryon Surface Chemistry LLC 100 358 -
Twice the Ice Ice House Coal City 100 0 -
Kinsman 99 431 -
Heatherfield Subdivision 90 39 -
South Wilmington Firemans #2 75 27 -
Hatcher Recreation Area 75 15 -
First Christian Church Pre-Sch 75 5 -
E J Karzs 75 8 -
Northfield Block Company 2 75 1,750 -
Northfield Block Company 3 75 1,690 -
Ridgecrest North Subdivision 60 121 -
Nettle Creek School 50 199 -
Aux Sable Liquid Products Inc 50 119 -
Hawthorn Estates Subdivision 49 18 -
Indian Creek Lower Well 45 9 -
Recos Roadhouse 30 11 -
Lisbon North, Inc. 25 173 -
Goose Lake Club 25 19 -

Compare beyond Illinois

Lower-flagged peers for Grundy County

Cross-state counties nearest Grundy County on flagged-system share (90.5%) and cumulative violation count (12,515). 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.