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Stephenson County, IL Water Quality

Water quality data for 12 public water systems serving Stephenson County, Illinois — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 12 water systems · 12 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

Stephenson County Earns a B

Stephenson County: 12 communities across 12 water systems. 91.7% have no open violations.

  • Median lead where detected: 1.55 ppb
  • 4 communities with a lead detection, 8 reporting none detected
  • 1 communities with PFAS above the federal limit
  • 9 with significant inspection deficiencies
  • 91.7% of communities have no open violations
1.55 ppb
Median Lead Level
County-wide, 90th percentile
12
Water Systems
Active CWS & NTNCWS
91%
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
  • Lena
    Not detected
    Copper above the 1,300 ppb action level
    B
  • Lake Summerset
    Not detected
    2 significant inspection deficiencies
    B
  • Orangeville
    Not detected
    2 significant inspection deficiencies
    B
  • Davis
    Not detected
    2 significant inspection deficiencies
    B
  • Dakota
    Not detected
    1 significant inspection deficiency
    B
⚠ Needs Attention
  • Freeport
    12.00 ppb
    PFAS above the limit at 1 of 4 sampling points
    C
  • Winslow
    Not detected
    1 violation currently open
    C
  • Cedarville
    2.00 ppb
    Copper above the 1,300 ppb action level
    C
  • Pearl City
    0.45 ppb
    3 significant inspection deficiencies
    B
  • German Valley
    1.10 ppb
    2 significant inspection deficiencies
    B
County Lead Level — Median 1.55 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 1.55 ppb — 10.3% of the federal action level
Systems by Lead Level
Under 5 ppb
3
10 – 15 ppb
1
No Data
8

All Cities in Stephenson County

Freeport 12.00 ppb C
Lena Not detected B
Lake Summerset Not detected B
Orangeville Not detected B
Pearl City 0.45 ppb B
Cedarville 2.00 ppb C
Davis Not detected B
Dakota Not detected B
Willow Lake Not detected B
German Valley 1.10 ppb B
Rock City Not detected B
Winslow Not detected C
Showing 12 cities
No active violations Active violations

About Stephenson County Drinking Water

Stephenson County is served by 12 water systems covering 12 communities. 92% have no open violations.

Of the communities reporting lead results, 4 recorded a detection, with a median of 1.55 ppb — 10% of the federal action level. 8 reported none detected, which means below the laboratory limit rather than an absence of lead.

1 of 12 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 9 of them.

Frequently Asked Questions

Is Stephenson County tap water safe to drink?▼
92% of communities have no open violation. 1 of 12 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Stephenson County?▼
Among communities with a detection the median is 1.55 ppb, 10% of the 15 ppb action level. 8 reported none detected and 0 reported no result.
How many water systems serve Stephenson County?▼
12 community water systems serve 12 communities here.
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