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Federal water data

County water report

Columbia County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Columbia County, Wisconsin.

Water grade

F

Water score

22.3

State rank

#55

of 71

Health violations

41

EPA SDWIS, 5-year lookback

Watershed impaired

6.5%

355 water bodies assessed

Monitoring sites

68

164,009 recent measurements

Live streamflow

No gauge

Primary USGS station not mapped

Water at a glance

Key Water Indicators for Columbia County

EPA SDWIS

Safety Grade

F

Score: 22.3 / 100

EPA SDWIS

Active Violations

41

5-year health-based lookback

EPA ATTAINS

Watershed Health

7% impaired

355 bodies assessed

USGS NWIS

Streamflow Snapshot

No gauge

Primary USGS gauge not mapped

EPA WQP

Monitoring Sites

68

164,009 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

F

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

22.3/100

Health violations

41

Health-based violations

Violations per 100K served

107.5

Population-normalized SDWIS rate

Data center water stress

Columbia County has 1 facility in the DCWSI dataset.

ByCounty's DCWSI ranks this county #2384 nationally by combining its water score with mapped data center density.

DCWSIThe Data Center Water Stress Index: 60% the county's water-system stress plus 40% how concentrated data centers already are, scored 0-100. Higher means data-center density and water pressure overlap more here.

13.4

0-100 index

Facility count

1

0.0 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

-27.7

Compared with US county median

Mapped facilities

  • OpenStreetMap data center 1211362828

    Facility details limited

    OSM
See the Columbia County data-center reportReview methodology

Data Center Water Budget Calculator

Estimate daily water use for a hypothetical facility in Columbia County.

1 MW1,000 MW
40%100%
799K gallons/dayHigh Impact

Your facility would use 51.1% of this county's industrial water baseline. Verify water rights and long-term drought projections before committing.

51.1% of county industrial baseline0.76 Mgal/day remaining headroom

Based on USGS 2020 water-use data and EPA-standard cooling intensity constants. Not a substitute for site-specific water rights analysis.

Editorial analysis

Understanding Columbia County’s Water

Drinking Water Quality Overview

EPA SDWIS

Columbia County's water systems carry a failing grade, scoring 22.3 out of 100. Over the past five years, EPA SDWIS records 41 health-based violations — a pattern that public water utilities are required to disclose and correct.

Watershed Conditions

EPA ATTAINS

Under the Clean Water Act §303(d), EPA ATTAINS tracks whether waterways meet quality standards for drinking, recreation, and aquatic life (reporting cycle: 2022). A small share — 6.5% — of assessed waterways are impaired (23 of 355 water bodies) across Columbia County's watersheds. The leading impairment causes are phosphorus, total and polychlorinated biphenyls (pcbs). Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Columbia County has extensive coverage with 68 active monitoring sites with 164,009 recent measurements on record. Predominant monitoring categories include physical and organics, pesticide. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for Columbia County

Water Verdict

Columbia County receives a poor water quality assessment with a grade of F and a score of 22.3 out of 100. The water supply has documented quality issues. Residents are strongly encouraged to use filtered or bottled water for drinking and to stay informed about utility improvement plans.

Violation Context

Columbia County has recorded 41 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 107.5 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Columbia County has a Grade F compliance record with 41 health-based violations — among the highest levels in the country. Columbia County's drinking-water compliance score is 22.3 out of 100. Residents are strongly advised to use a certified NSF 58 reverse-osmosis filter or bottled water for all drinking and cooking until violations are corrected. Contacting the Wisconsin Department of Environmental Quality or Health can expedite utility compliance action. Phosphorus, Total is the leading impairment cause in Columbia County's watershed. With 68 active water-quality monitoring sites in Columbia County, data coverage is strong.

Regional Context

Columbia County has poorer water quality than the average county in Wisconsin. Its water score is 17.2 points lower than the state average, suggesting more challenges with contamination control or infrastructure than neighboring counties.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in Columbia County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Phosphorus (excess nutrients)

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 2

    Polychlorinated Biphenyls (Pcbs)

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 3

    Mercury

    Impairment cause per EPA Clean Water Act §303(d) assessment

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Columbia County

EPA How's My Waterway

Interactive watershed health data for Columbia County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Columbia County

Consumer Confidence Reports (WI)

Annual water quality reports from utilities in Wisconsin

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

6.5%

23 of 355 assessed

Mostly healthy

Top Impairment Causes

  • 1

    PHOSPHORUS, TOTAL

  • 2

    POLYCHLORINATED BIPHENYLS (PCBS)

  • 3

    MERCURY

Source: EPA ATTAINS · Reporting cycle 2022

Impairment is determined under the Clean Water Act §303(d): a water body is impaired when it fails to meet state-defined quality standards for designated uses (drinking, recreation, aquatic life). Assessment coverage varies by state; counties without assessed water bodies are not shown.

Past 5 years

Water Quality Monitoring

Monitoring Sites

68

Active in the past 5 years

Measurements Recorded

164K

164,009 total readings

Most Measured

  • Physical
  • Organics, Pesticide
  • Not Assigned

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Free tool

Estimate Your Water Costs

Water Cost Estimate

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Columbia County:C — Moderate

Some violations or watershed impairment detected.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

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Frequently Asked Questions

What is the water quality in Columbia County, Wisconsin?
Columbia County, Wisconsin has a drinking-water quality grade of F with a score of 22.3/100, based on EPA SDWIS compliance data. The county has 41 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.
Are there any water violations in Columbia County?
Columbia County has 41 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.
How healthy are the watersheds in Columbia County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 6.5% of Columbia County's 355 assessed water bodies are classified as impaired (23 impaired). The top reported causes are PHOSPHORUS, TOTAL, POLYCHLORINATED BIPHENYLS (PCBS), MERCURY. Impairment means the water body fails to meet state quality standards for at least one designated use — drinking water source, recreation, aquatic life, or fish consumption. Note: watershed impairment doesn't always translate to tap-water issues; treatment plants can remove most regulated contaminants.
How much water-quality monitoring happens in Columbia County?
EPA's Water Quality Portal records 164,009 measurements from 68 monitoring sites in Columbia County over the past five years. The most frequently measured characteristic groups are Physical, Organics, Pesticide, Not Assigned. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.
How does Columbia County water compare to the Wisconsin average?
Columbia County's SDWIS water quality score of 22.3/100 is lower than the Wisconsin state average of 39.5. The average water quality grade across Wisconsin is F, based on data from 71 counties with available SDWIS data.
Is tap water safe to drink in Columbia County?
Based on EPA SDWIS data, Columbia County has a water quality grade of F (22.3/100). This indicates below-average compliance with significant violations. Residents may want to consider home water filtration or independent testing. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).
Why does Columbia County have so many water violations?
Columbia County has 41 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.
How does Columbia County rank for water quality in Wisconsin?
Columbia County ranks #55 out of 71 counties in Wisconsin by SDWIS water quality score (1 = best). With a score of 22.3/100, it falls in the bottom third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Clark County

Wisconsin

F

22.0

Water score

Vernon County

Wisconsin

F

22.0

Water score

Lafayette County

Wisconsin

F

23.2

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Watershed health and impaired-waterway data from the EPA ATTAINS Clean Water Act §303(d) assessments, state-reported and EPA-finalized.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

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