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Hancock County, IL Water Quality

Water quality data for 11 public water systems serving Hancock County, Illinois — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 11 water systems · 11 cities
✅
Excellent — All Systems Performing Well

Water quality across the county is outstanding with minimal violations and very low lead levels.

A

Hancock County Earns a A

Hancock County: 11 communities across 11 water systems. 100.0% have no open violations.

  • Median lead where detected: 3.05 ppb
  • 5 communities with a lead detection, 6 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 2 with significant inspection deficiencies
  • 100.0% of communities have no open violations
3.05 ppb
Median Lead Level
County-wide, 90th percentile
11
Water Systems
Active CWS & NTNCWS
100%
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
  • Hamilton
    2.20 ppb
    No federal limits exceeded on record
    B
  • Nauvoo
    Not detected
    No federal limits exceeded on record
    B
  • Dallas City
    3.05 ppb
    No federal limits exceeded on record
    B
  • Carthage
    Not detected
    1 health-based violation since 2015
    B
  • Plymouth
    8.00 ppb
    Lead at 8.00 ppb, above a third of the action level
    B
⚠ Needs Attention
  • Bowen
    Not detected
    Copper above the 1,300 ppb action level
    C
  • Warsaw
    2.90 ppb
    3 significant inspection deficiencies
    B
  • La Harpe
    Not detected
    7 health-based violations since 2015
    B
  • Augusta
    4.30 ppb
    Copper above the 1,300 ppb action level
    B
  • Elvaston
    Not detected
    2 significant inspection deficiencies
    B
County Lead Level — Median 3.05 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 3.05 ppb — 20.3% of the federal action level
Systems by Lead Level
Under 5 ppb
4
5 – 10 ppb
1
No Data
6

All Cities in Hancock County

Hamilton 2.20 ppb B
Carthage Not detected B
Warsaw 2.90 ppb B
La Harpe Not detected B
Nauvoo Not detected B
Augusta 4.30 ppb B
Dallas City 3.05 ppb B
Bowen Not detected C
Plymouth 8.00 ppb B
Elvaston Not detected B
West Point Not detected B
Showing 11 cities
No active violations Active violations

About Hancock County Drinking Water

Hancock County is served by 11 water systems covering 11 communities. No community here has an open violation on record.

Of the communities reporting lead results, 5 recorded a detection, with a median of 3.05 ppb — 20% of the federal action level. 6 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 2 of them.

Frequently Asked Questions

Is Hancock County tap water safe to drink?▼
No community in Hancock County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Hancock County?▼
Among communities with a detection the median is 3.05 ppb, 20% of the 15 ppb action level. 6 reported none detected and 0 reported no result.
How many water systems serve Hancock County?▼
11 community water systems serve 11 communities here.
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