States › Wisconsin › Fond du Lac County

Fond du Lac County, WI Water Quality

Water quality data for 17 public water systems serving Fond du Lac County, Wisconsin — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 17 water systems · 26 cities
✅
Excellent — All Systems Performing Well

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

A

Fond du Lac County Earns a A

Fond du Lac County: 26 communities across 17 water systems. 100.0% have no open violations.

  • Median lead where detected: 1.90 ppb
  • 23 communities with a lead detection, 3 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 7 with significant inspection deficiencies
  • 100.0% of communities have no open violations
1.9 ppb
Median Lead Level
County-wide, 90th percentile
17
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
  • Oakfield
    Not detected
    No federal limits exceeded on record
    B
  • Eldorado
    1.60 ppb
    No federal limits exceeded on record
    B
  • Alto
    1.20 ppb
    No federal limits exceeded on record
    A
  • Eden
    1.85 ppb
    No federal limits exceeded on record
    B
  • Campbellsport
    1.12 ppb
    No federal limits exceeded on record
    B
⚠ Needs Attention
  • Fond du Lac
    6.10 ppb
    Copper above the 1,300 ppb action level
    C
  • North Fond du Lac
    9.10 ppb
    2 significant inspection deficiencies
    C
  • Fond du Lac
    9.10 ppb
    2 significant inspection deficiencies
    C
  • Taycheedah
    6.10 ppb
    Copper above the 1,300 ppb action level
    C
  • Empire
    6.10 ppb
    Copper above the 1,300 ppb action level
    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
15
5 – 10 ppb
8
No Data
3

All Cities in Fond du Lac County

Fond du Lac 6.10 ppb C
Ripon 3.50 ppb B
North Fond du Lac 9.10 ppb C
Campbellsport 1.12 ppb B
Fond du Lac 9.10 ppb C
Oakfield Not detected B
Brandon 6.86 ppb B
Friendship 1.60 ppb B
Taycheedah 6.10 ppb C
Mount Calvary 0.45 ppb B
Ripon 3.50 ppb B
St. Cloud 1.90 ppb B
Fairwater 1.75 ppb B
Empire 6.10 ppb C
Eden 1.85 ppb B
Marshfield 3.10 ppb B
Waupun 0.87 ppb C
Ashford Not detected B
Osceola 0.34 ppb B
Auburn 1.12 ppb B
Eden 1.85 ppb B
Byron 8.20 ppb B
Metomen 6.86 ppb B
Alto 1.20 ppb A
Oakfield Not detected B
Eldorado 1.60 ppb B
Showing 26 cities
No active violations Active violations

About Fond du Lac County Drinking Water

Fond du Lac County is served by 17 water systems covering 26 communities. No community here has an open violation on record.

Of the communities reporting lead results, 23 recorded a detection, with a median of 1.90 ppb — 13% of the federal action level. 3 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 7 of them.

Frequently Asked Questions

Is Fond du Lac County tap water safe to drink?▼
No community in Fond du Lac County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Fond du Lac County?▼
Among communities with a detection the median is 1.90 ppb, 13% of the 15 ppb action level. 3 reported none detected and 0 reported no result.
How many water systems serve Fond du Lac County?▼
17 community water systems serve 26 communities here.
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