States › Wisconsin › Columbia County

Columbia County, WI Water Quality

Water quality data for 22 public water systems serving Columbia County, Wisconsin — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 22 water systems · 33 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

Columbia County Earns a B

Columbia County: 33 communities across 22 water systems. 90.9% have no open violations.

  • Median lead where detected: 2.00 ppb
  • 31 communities with a lead detection, 2 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 6 with significant inspection deficiencies
  • 90.9% of communities have no open violations
2 ppb
Median Lead Level
County-wide, 90th percentile
22
Water Systems
Active CWS & NTNCWS
90%
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
  • Leeds
    4.80 ppb
    No federal limits exceeded on record
    B
  • Marcellon
    1.70 ppb
    No federal limits exceeded on record
    B
  • Pardeeville
    1.70 ppb
    No federal limits exceeded on record
    B
  • Lake Wisconsin
    3.20 ppb
    No federal limits exceeded on record
    B
  • Lodi
    3.20 ppb
    No federal limits exceeded on record
    B
⚠ Needs Attention
  • Otsego
    1.40 ppb
    1 violation currently open
    D
  • Lodi
    18.00 ppb
    Lead above the 15 ppb action level
    D
  • Rio
    1.40 ppb
    1 violation currently open
    D
  • Lowville
    1.40 ppb
    1 violation currently open
    D
  • Friesland
    Not detected
    Copper above the 1,300 ppb action level
    C
County Lead Level — Median 2 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2 ppb — 13.3% of the federal action level
Systems by Lead Level
Under 5 ppb
26
5 – 10 ppb
4
10 – 15 ppb
1
No Data
2

All Cities in Columbia County

Portage 6.20 ppb A
Columbus 8.88 ppb B
Lodi 18.00 ppb D
Wisconsin Dells 1.70 ppb B
Poynette 3.05 ppb B
Pardeeville 1.70 ppb B
Fall River 0.93 ppb B
Lake Wisconsin 3.20 ppb B
Lodi 3.20 ppb B
Rio 1.40 ppb D
Arlington 2.00 ppb B
Pacific 3.32 ppb B
Cambria 4.20 ppb B
Wyocena 2.70 ppb B
Lewiston 0.14 ppb B
Friesland Not detected C
West Point 1.60 ppb B
Wyocena 1.70 ppb B
Lowville 1.40 ppb D
Doylestown Not detected B
Caledonia 4.60 ppb B
Fountain Prairie 0.93 ppb B
Dekorra 1.05 ppb B
Courtland 1.30 ppb B
Randolph 1.30 ppb B
Fort Winnebago 5.40 ppb B
Newport 1.70 ppb B
Columbus 8.88 ppb B
Arlington 2.00 ppb B
Marcellon 1.70 ppb B
Otsego 1.40 ppb D
Springvale 4.20 ppb B
Leeds 4.80 ppb B
Showing 33 cities
No active violations Active violations

About Columbia County Drinking Water

Columbia County is served by 22 water systems covering 33 communities. 91% have no open violations.

Of the communities reporting lead results, 31 recorded a detection, with a median of 2.00 ppb — 13% of the federal action level. 2 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 6 of them.

Frequently Asked Questions

Is Columbia County tap water safe to drink?▼
91% of communities have no open violation. No community has PFAS above the federal limit on record.
What is the lead level in Columbia County?▼
Among communities with a detection the median is 2.00 ppb, 13% of the 15 ppb action level. 2 reported none detected and 0 reported no result.
How many water systems serve Columbia County?▼
22 community water systems serve 33 communities here.
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