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Federal water data

County water report

Monroe County Water Report

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

Water grade

F

Water score

37.3

State rank

#38

of 71

Health violations

13

EPA SDWIS, 5-year lookback

Watershed impaired

7.8%

464 water bodies assessed

Monitoring sites

58

3,806 recent measurements

Live streamflow

122%

LA CROSSE RIVER AT SPARTA, WI

Water at a glance

Key Water Indicators for Monroe County

EPA SDWIS

Safety Grade

F

Score: 37.3 / 100

EPA SDWIS

Active Violations

13

5-year health-based lookback

EPA ATTAINS

Watershed Health

8% impaired

464 bodies assessed

USGS NWIS

Streamflow Snapshot

122% of mean

LA CROSSE RIVER AT SPARTA, WI

EPA WQP

Monitoring Sites

58

3,806 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.

37.3/100

Health violations

13

Health-based violations

Violations per 100K served

39.2

Population-normalized SDWIS rate

Editorial analysis

Understanding Monroe County’s Water

Drinking Water Quality Overview

EPA SDWIS

Monroe County's water systems carry a failing grade, scoring 37.3 out of 100. Over the past five years, EPA SDWIS records 13 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 — 7.8% — of assessed waterways are impaired (36 of 464 water bodies) across Monroe County's watersheds. The leading impairment causes are phosphorus, total and mercury. Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T14:00:00.000-05:00) puts LA CROSSE RIVER at 214.0 cfs — flowing above its historical average at 122% of mean. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Monroe County has extensive coverage with 58 active monitoring sites with 3,806 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 Monroe County

Water Verdict

Monroe County receives a poor water quality assessment with a grade of F and a score of 37.3 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

Monroe County has recorded 13 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 39.2 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Drinking-water compliance in Monroe County is rated Grade F, reflecting significant health-based violations in the recent reporting period. Monroe County's drinking-water compliance score is 37.3 out of 100. The violation rate for Monroe County is 39.2 per 100,000 people served. An NSF 53 or NSF 58-certified filter is recommended for drinking and cooking water. Check the Consumer Confidence Report from your utility to identify the specific contaminants and required corrective actions — utilities are legally required to notify customers of violations. Phosphorus, Total is the leading impairment cause in Monroe County's watershed. With 58 active water-quality monitoring sites in Monroe County, data coverage is strong. A pipeline streamflow snapshot from the LA CROSSE RIVER gauge is also available on this page.

Regional Context

Monroe County has water quality close to the average county in Wisconsin. Its water score is within 2.2 points of the state average, meaning its overall water system performance is broadly representative of Wisconsin as a whole.

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 Monroe County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Phosphorus (excess nutrients)

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

  • 2

    Mercury

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

  • 3

    Total Suspended Solids (Tss)

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Monroe County

EPA How's My Waterway

Interactive watershed health data for Monroe County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Monroe County

Consumer Confidence Reports (WI)

Annual water quality reports from utilities in Wisconsin

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

7.8%

36 of 464 assessed

Mostly healthy

Top Impairment Causes

  • 1

    PHOSPHORUS, TOTAL

  • 2

    MERCURY

  • 3

    TOTAL SUSPENDED SOLIDS (TSS)

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

58

Active in the past 5 years

Measurements Recorded

3.8K

3,806 total readings

Most Measured

  • Physical
  • Organics, Pesticide
  • Nutrient

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).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

214cfs

May 14, 7:00 PM UTC

vs Long-Term Average

122%

Above typical

Primary Streamgage

LA CROSSE RIVER AT SPARTA, WI

USGS site
05382325
Drainage area
167 sq mi
Long-term mean
176 cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

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 Monroe 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 Monroe County, Wisconsin?
Monroe County, Wisconsin has a drinking-water quality grade of F with a score of 37.3/100, based on EPA SDWIS compliance data. The county has 13 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 Monroe County?
Monroe County has 13 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 Monroe County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 7.8% of Monroe County's 464 assessed water bodies are classified as impaired (36 impaired). The top reported causes are PHOSPHORUS, TOTAL, MERCURY, TOTAL SUSPENDED SOLIDS (TSS). 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 Monroe County?
EPA's Water Quality Portal records 3,806 measurements from 58 monitoring sites in Monroe County over the past five years. The most frequently measured characteristic groups are Physical, Organics, Pesticide, Nutrient. 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.
What's happening with rivers in Monroe County right now?
Monroe County's primary USGS streamgage on the LA CROSSE RIVER has a pipeline snapshot of 214 cubic feet per second — 122% of the long-term mean of 175.97 cfs. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.
How does Monroe County water compare to the Wisconsin average?
Monroe County's SDWIS water quality score of 37.3/100 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 Monroe County?
Based on EPA SDWIS data, Monroe County has a water quality grade of F (37.3/100). 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 Monroe County have so many water violations?
Monroe County has 13 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 Monroe County rank for water quality in Wisconsin?
Monroe County ranks #38 out of 71 counties in Wisconsin by SDWIS water quality score (1 = best). With a score of 37.3/100, it falls in the middle 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

Buffalo County

Wisconsin

F

36.7

Water score

Oneida County

Wisconsin

F

36.6

Water score

Green County

Wisconsin

F

39.1

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.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

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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