States › Wisconsin › Sauk County

Sauk County, WI Water Quality

Water quality data for 18 public water systems serving Sauk County, Wisconsin — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 18 water systems · 30 cities
✅
Excellent — All Systems Performing Well

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

A

Sauk County Earns a A

Sauk County: 30 communities across 18 water systems. 96.7% have no open violations.

  • Median lead where detected: 1.82 ppb
  • 21 communities with a lead detection, 9 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 1 with significant inspection deficiencies
  • 96.7% of communities have no open violations
1.82 ppb
Median Lead Level
County-wide, 90th percentile
18
Water Systems
Active CWS & NTNCWS
96%
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
  • Winfield
    Not detected
    No federal limits exceeded on record
    A
  • Reedsburg
    Not detected
    No federal limits exceeded on record
    A
  • Delton
    Not detected
    No federal limits exceeded on record
    B
  • Reedsburg
    Not detected
    No federal limits exceeded on record
    A
  • Excelsior
    Not detected
    No federal limits exceeded on record
    A
⚠ Needs Attention
  • Spring Green
    0.08 ppb
    1 violation currently open
    C
  • Baraboo
    8.10 ppb
    Copper above the 1,300 ppb action level
    B
  • Baraboo
    8.10 ppb
    Copper above the 1,300 ppb action level
    B
  • Greenfield
    8.10 ppb
    Copper above the 1,300 ppb action level
    B
  • Rock Springs
    0.82 ppb
    Copper above the 1,300 ppb action level
    B
County Lead Level — Median 1.82 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 1.82 ppb — 12.1% of the federal action level
Systems by Lead Level
Under 5 ppb
17
5 – 10 ppb
4
No Data
9

All Cities in Sauk County

Baraboo 8.10 ppb B
Reedsburg Not detected A
Prairie du Sac 1.40 ppb A
Sauk City 6.40 ppb A
Spring Green 3.70 ppb B
West Baraboo 0.66 ppb B
Plain 2.70 ppb B
North Freedom 2.40 ppb B
Sumpter 0.46 ppb B
Rock Springs 0.82 ppb B
La Valle 1.82 ppb B
Loganville 0.96 ppb B
Delton Not detected B
Merrimac 1.10 ppb B
Dellona Not detected B
Reedsburg Not detected A
Baraboo 8.10 ppb B
Spring Green 0.08 ppb C
Ironton Not detected B
Merrimac 1.10 ppb B
Excelsior Not detected A
Prairie du Sac 1.40 ppb A
Franklin 2.70 ppb B
Lake Delton Not detected B
Greenfield 8.10 ppb B
Winfield Not detected A
La Valle 1.82 ppb B
Ironton Not detected B
Freedom 2.40 ppb B
Westfield 0.96 ppb B
Showing 30 cities
No active violations Active violations

About Sauk County Drinking Water

Sauk County is served by 18 water systems covering 30 communities. 97% have no open violations.

Of the communities reporting lead results, 21 recorded a detection, with a median of 1.82 ppb — 12% of the federal action level. 9 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 1 of them.

Frequently Asked Questions

Is Sauk County tap water safe to drink?▼
97% of communities have no open violation. No community has PFAS above the federal limit on record.
What is the lead level in Sauk County?▼
Among communities with a detection the median is 1.82 ppb, 12% of the 15 ppb action level. 9 reported none detected and 0 reported no result.
How many water systems serve Sauk County?▼
18 community water systems serve 30 communities here.
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