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Iroquois County, IL Water Quality

Water quality data for 20 public water systems serving Iroquois County, Illinois — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 20 water systems · 20 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

Iroquois County Earns a B

Iroquois County: 20 communities across 20 water systems. 90.0% have no open violations.

  • Median lead where detected: 2.50 ppb
  • 10 communities with a lead detection, 10 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 11 with significant inspection deficiencies
  • 90.0% of communities have no open violations
2.5 ppb
Median Lead Level
County-wide, 90th percentile
20
Water Systems
Active CWS & NTNCWS
90%
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
  • Cissna Park
    2.88 ppb
    No federal limits exceeded on record
    B
  • Crescent City
    Not detected
    No federal limits exceeded on record
    B
  • Wellington
    4.50 ppb
    No federal limits exceeded on record
    B
  • Milford
    5.10 ppb
    Lead at 5.10 ppb, above a third of the action level
    B
  • Clifton
    2.20 ppb
    Copper above the 1,300 ppb action level
    B
⚠ Needs Attention
  • Danforth
    Not detected
    Copper above the 1,300 ppb action level
    F
  • Loda
    1.70 ppb
    Copper above the 1,300 ppb action level
    D
  • Donovan
    Not detected
    4 significant inspection deficiencies
    C
  • Watseka
    5.00 ppb
    3 significant inspection deficiencies
    C
  • Woodland
    Not detected
    Copper above the 1,300 ppb action level
    C
County Lead Level — Median 2.5 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2.5 ppb — 16.7% of the federal action level
Systems by Lead Level
Under 5 ppb
8
5 – 10 ppb
2
No Data
10

All Cities in Iroquois County

Watseka 5.00 ppb C
Gilman 2.80 ppb B
Clifton 2.20 ppb B
Onarga Not detected B
Milford 5.10 ppb B
Chebanse 1.60 ppb B
Sheldon Not detected B
Cissna Park 2.88 ppb B
Ashkum 1.58 ppb B
Danforth Not detected F
Crescent City Not detected B
Buckley 1.60 ppb B
Martinton Not detected B
Loda 1.70 ppb D
Beaverville Not detected B
Donovan Not detected C
Woodland Not detected C
Wellington 4.50 ppb B
Thawville Not detected B
Papineau Not detected B
Showing 20 cities
No active violations Active violations

About Iroquois County Drinking Water

Iroquois County is served by 20 water systems covering 20 communities. 90% have no open violations.

Of the communities reporting lead results, 10 recorded a detection, with a median of 2.50 ppb — 17% of the federal action level. 10 reported none detected, which means below the laboratory limit rather than an absence of lead.

No community here has PFAS above the federal limit on record. State inspectors recorded significant deficiencies at 11 of them.

Frequently Asked Questions

Is Iroquois County tap water safe to drink?▼
90% of communities have no open violation. No community has PFAS above the federal limit on record.
What is the lead level in Iroquois County?▼
Among communities with a detection the median is 2.50 ppb, 17% of the 15 ppb action level. 10 reported none detected and 0 reported no result.
How many water systems serve Iroquois County?▼
20 community water systems serve 20 communities here.
← Back to Illinois water quality overview