States › Illinois › Madison County

Madison County, IL Water Quality

Water quality data for 23 public water systems serving Madison County, Illinois — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 23 water systems · 31 cities
✅
Generally Safe — Most Systems Performing Well

The majority of water systems have no active violations and lead levels well below the federal action level.

B

Madison County Earns a B

Madison County: 31 communities across 23 water systems. 96.8% have no open violations.

  • Median lead where detected: 1.90 ppb
  • 16 communities with a lead detection, 15 reporting none detected
  • 2 communities with PFAS above the federal limit
  • 25 with significant inspection deficiencies
  • 96.8% of communities have no open violations
1.9 ppb
Median Lead Level
County-wide, 90th percentile
23
Water Systems
Active CWS & NTNCWS
96%
Violation-Free
No active violations on record
How we grade counties: MyWaterIQ uses EPA SDWIS enforcement data — actual MCL violations and lead test results — not the aspirational MCLG targets used by some sites. A grade reflects real compliance history, not theoretical risk. Learn more →

Cities by Water Quality

⭐ Best Performing
  • Moro
    1.00 ppb
    Copper above the 1,300 ppb action level
    A
  • Alton
    3.00 ppb
    1 significant inspection deficiency
    A
  • Edwardsville
    Not detected
    2 significant inspection deficiencies
    A
  • Glen Carbon
    Not detected
    2 significant inspection deficiencies
    A
  • Godfrey
    3.00 ppb
    1 significant inspection deficiency
    A
⚠ Needs Attention
  • East Alton
    Not detected
    PFAS above the limit at 1 of 1 sampling points
    D
  • St. Jacob
    Not detected
    1 violation currently open
    D
  • Collinsville
    Not detected
    PFAS above the limit at 1 of 1 sampling points
    D
  • New Douglas
    Not detected
    1 significant inspection deficiency
    C
  • Grantfork
    Not detected
    4 significant inspection deficiencies
    C
County Lead Level — Median 1.9 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 1.9 ppb — 12.7% of the federal action level
Systems by Lead Level
Under 5 ppb
13
5 – 10 ppb
3
No Data
15

All Cities in Madison County

Granite City 6.00 ppb B
Alton 3.00 ppb A
Edwardsville Not detected A
Collinsville Not detected D
Glen Carbon Not detected A
Godfrey 3.00 ppb A
Highland Not detected B
Bethalto 1.00 ppb A
Troy Not detected B
Wood River 1.00 ppb A
Maryville 1.80 ppb B
East Alton Not detected D
Rosewood Heights 1.00 ppb A
Madison 6.00 ppb B
Pontoon Beach 0.60 ppb B
Holiday Shores 3.70 ppb B
South Roxana Not detected B
Venice 6.00 ppb B
Roxana 1.00 ppb A
St. Jacob Not detected D
Mitchell Not detected A
Hartford Not detected B
Worden 2.00 ppb B
Hamel Not detected B
Marine 1.20 ppb B
Livingston Not detected B
Alhambra 2.70 ppb B
New Douglas Not detected C
Grantfork Not detected C
Williamson Not detected B
Moro 1.00 ppb A
Showing 31 cities
No active violations Active violations

About Madison County Drinking Water

Madison County is served by 23 water systems covering 31 communities. 97% have no open violations.

Of the communities reporting lead results, 16 recorded a detection, with a median of 1.90 ppb — 13% of the federal action level. 15 reported none detected, which means below the laboratory limit rather than an absence of lead.

2 of 31 communities have PFAS above the limits EPA set in 2024, measured as a running annual average at each sampling point. State inspectors recorded significant deficiencies at 25 of them.

Frequently Asked Questions

Is Madison County tap water safe to drink?▼
97% of communities have no open violation. 2 of 31 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Madison County?▼
Among communities with a detection the median is 1.90 ppb, 13% of the 15 ppb action level. 15 reported none detected and 0 reported no result.
How many water systems serve Madison County?▼
23 community water systems serve 31 communities here.
← Back to Illinois water quality overview