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Walworth County, WI Water Quality

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

📅 2026 Report 🔄 Data updated 2026 Q2 📍 20 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

Walworth County Earns a A

Walworth County: 26 communities across 20 water systems. 100.0% have no open violations.

  • Median lead where detected: 3.10 ppb
  • 25 communities with a lead detection, 1 reporting none detected
  • 3 communities with PFAS above the federal limit
  • 0 with significant inspection deficiencies
  • 100.0% of communities have no open violations
3.1 ppb
Median Lead Level
County-wide, 90th percentile
20
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
  • East Troy
    4.40 ppb
    No federal limits exceeded on record
    A
  • Darien
    0.89 ppb
    No federal limits exceeded on record
    B
  • Geneva
    1.20 ppb
    No federal limits exceeded on record
    B
  • Darien
    1.16 ppb
    No federal limits exceeded on record
    B
  • Delavan
    0.80 ppb
    No federal limits exceeded on record
    B
⚠ Needs Attention
  • Elkhorn
    14.00 ppb
    Copper above the 1,300 ppb action level
    C
  • Williams Bay
    16.00 ppb
    Lead above the 15 ppb action level
    C
  • Lake Geneva
    8.00 ppb
    PFAS above the limit at 1 of 2 sampling points
    C
  • Bloomfield
    8.00 ppb
    PFAS above the limit at 1 of 2 sampling points
    C
  • Linn
    8.00 ppb
    PFAS above the limit at 1 of 2 sampling points
    C
County Lead Level — Median 3.1 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 3.1 ppb — 20.7% of the federal action level
Systems by Lead Level
Under 5 ppb
16
5 – 10 ppb
4
10 – 15 ppb
5
No Data
1

All Cities in Walworth County

Whitewater 10.00 ppb A
Elkhorn 14.00 ppb C
Delavan 10.00 ppb A
Lake Geneva 8.00 ppb C
East Troy 4.40 ppb A
Fontana-on-Geneva Lake 3.10 ppb B
Genoa City 4.56 ppb C
Bloomfield 1.94 ppb B
Walworth 6.30 ppb B
Williams Bay 16.00 ppb C
Darien 0.89 ppb B
Sharon 1.40 ppb B
Geneva 1.20 ppb B
Darien 1.16 ppb B
Delavan 0.80 ppb B
Bloomfield 8.00 ppb C
Lyons 1.35 ppb B
Walworth 3.10 ppb B
Richmond 0.30 ppb B
Troy 0.86 ppb B
Whitewater 10.00 ppb A
Linn 8.00 ppb C
Sugar Creek 0.45 ppb B
Spring Prairie Not detected B
Sharon 1.40 ppb B
East Troy 4.40 ppb A
Showing 26 cities
No active violations Active violations

About Walworth County Drinking Water

Walworth County is served by 20 water systems covering 26 communities. No community here has an open violation on record.

Of the communities reporting lead results, 25 recorded a detection, with a median of 3.10 ppb — 21% of the federal action level. 1 reported none detected, which means below the laboratory limit rather than an absence of lead.

3 of 26 communities have PFAS above the limits EPA set in 2024, measured as a running annual average at each sampling point. State inspectors recorded no significant deficiencies.

Frequently Asked Questions

Is Walworth County tap water safe to drink?▼
No community in Walworth County has an open violation on record. 3 of 26 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Walworth County?▼
Among communities with a detection the median is 3.10 ppb, 21% of the 15 ppb action level. 1 reported none detected and 0 reported no result.
How many water systems serve Walworth County?▼
20 community water systems serve 26 communities here.
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