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Jo Daviess County, IL Water Quality

Water quality data for 10 public water systems serving Jo Daviess County, Illinois — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 10 water systems · 10 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

Jo Daviess County Earns a B

Jo Daviess County: 10 communities across 10 water systems. 100.0% have no open violations.

  • Median lead where detected: 3.90 ppb
  • 5 communities with a lead detection, 5 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 8 with significant inspection deficiencies
  • 100.0% of communities have no open violations
3.9 ppb
Median Lead Level
County-wide, 90th percentile
10
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
  • Hanover
    3.90 ppb
    No federal limits exceeded on record
    A
  • Elizabeth
    Not detected
    No federal limits exceeded on record
    B
  • Warren
    Not detected
    2 significant inspection deficiencies
    B
  • Galena
    3.21 ppb
    2 significant inspection deficiencies
    B
  • Stockton
    Not detected
    2 significant inspection deficiencies
    B
⚠ Needs Attention
County Lead Level — Median 3.9 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 3.9 ppb — 26% of the federal action level
Systems by Lead Level
Under 5 ppb
4
10 – 15 ppb
1
No Data
5

All Cities in Jo Daviess County

Galena 3.21 ppb B
Stockton Not detected B
East Dubuque Not detected B
Warren Not detected B
The Galena Territory 11.00 ppb C
Hanover 3.90 ppb A
Elizabeth Not detected B
Scales Mound 4.82 ppb B
Apple Canyon Lake 3.60 ppb B
Apple River Not detected B
Showing 10 cities
No active violations Active violations

About Jo Daviess County Drinking Water

Jo Daviess County is served by 10 water systems covering 10 communities. No community here has an open violation on record.

Of the communities reporting lead results, 5 recorded a detection, with a median of 3.90 ppb — 26% of the federal action level. 5 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 8 of them.

Frequently Asked Questions

Is Jo Daviess County tap water safe to drink?▼
No community in Jo Daviess County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Jo Daviess County?▼
Among communities with a detection the median is 3.90 ppb, 26% of the 15 ppb action level. 5 reported none detected and 0 reported no result.
How many water systems serve Jo Daviess County?▼
10 community water systems serve 10 communities here.
← Back to Illinois water quality overview