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Counties → Illinois

Madison County, Illinois

SDWIS compliance plate

Sheet IL119 · Madison County 68 sys · 1,940 viol · #260/3254

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

  • VIOL-SEVERE 69.1% flagged
  • HEALTH-LOW 17.0% health
  • RANK-TOP #260/3254
  • PHOTO-FINISH ±0.4 pp
  • PFAS-HIGH 84.2% detect
  • SRC-SW SW lead 53%
  • SYS-MID 68 systems
  • BOOK-FULL 7/7 fields

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

According to EPA SDWIS county population served used on /counties, Madison County ranks #260 of 3,254 counties by people served, and #7 of 102 counties in Illinois. See methodology · corpus placement.

Madison County standing, lower-flagged corpus third

Flagged-system rate 69.1% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 17.0% is health-based share in the middle third (≤ 24.5%) . UCMR5 detect rate 84.2% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #260 of 3,254 · #7 of 102 in Illinois.

Flagged-rate neighbourhood around Madison County

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

0% 20% 40% 60% 80% 100% Sangamon · lowest Ford · near Perry · near Pulaski · highest 58.8% 68.8% 68.8% 69.1% 70% 70.4% 100%

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

Water Systems

System Name Population Violations PFAS
IL American-Alton 46,127 17 Detected
Collinsville 29,500 55 Detected
IL American-Granite City 27,549 3 Detected
Edwardsville 26,808 33 Detected
Troy 16,962 24 Detected
Bethalto 15,210 25 Detected
Glen Carbon 12,618 42 Detected
Highland 10,649 66 Detected
Wood River 10,464 29 Detected
Maryville 10,150 22 Clean
Fosterburg Pwd 7,940 25 Detected
East Alton 5,786 21 Detected
Mitchell Pwd 5,253 29 Detected
North East Central Pwd 3,975 25 Detected
Three County Pwd 3,575 38 -
Tritownship Water District 3,470 77 Clean
Pontoon Beach Pwd 3,325 18 Detected
Olin Winchester LLC 3,250 151 -
Holiday Shores SD 2,840 136 Clean
Southern IL University-Edwardsville 2,817 12 Detected
South Roxana 1,891 39 -
St Jacob 1,835 73 -
Meadowbrook Pwd 1,778 8 -
Grantfork 1,766 84 -
Pierron 1,709 70 -
Roxana 1,509 6 -
Hartford 1,260 25 -
Worden 1,096 25 -
Hamel 1,087 52 -
Marine 1,037 18 -
IL American-Livingston 825 13 -
Alhambra 755 20 -
Moro Pwd 723 61 Detected
Enchanted Village 720 25 -
Forge at the Lake 387 397 -
Meridian Village 339 13 -
Village Green Mobile Home Park 220 39 -
East 30 MHP 218 10 -
University Flats MHP 203 56 -
Quail Run Mobile Home Park 168 28 -
Country Hills Wtr, Inc. 166 4 -
Oak Grove MHP - Madison County 138 7 -
Twice the Ice Hamel 50 0 -
I-55 RV Park 30 8 -
Wal-Mart Supercenter 0435 25 0 -
Schnucks/Homer Adams 25 0 -
Schnucks (142257) 25 0 -
Schnucks/Godfrey 25 0 -
Schnucks Market (142422) 25 0 -
Schnucks Market 25 0 -

Compare beyond Illinois

Lower-flagged peers for Madison County

Cross-state counties nearest Madison County on flagged-system share (69.1%) and cumulative violation count (1,940). 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.