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Community Water System · PWS WI6120246

Mount Sterling Waterworks

Mt Sterling, Wisconsin 54645-0067 - drinking water served from groundwater sources to 206 people, tracked in EPA SDWIS and UCMR5.

206
People served
100
EPA violations
44
Health-based
Untested
UCMR5 result

The verdict

EPA records 100 drinking-water violations at Mount Sterling Waterworks, 44% of them health-based - above the Wisconsin per-system average.

100
Total EPA violations on record
44%
Health-based (MCL / treatment failure)
206
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Mount Sterling Waterworks

Mount Sterling Waterworks is a local-owned community water system that delivers drinking water to 206 residents in Mt Sterling, Wisconsin (Crawford County) through 76 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 100 total violations for this system , of which 44 (44%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 47 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 33 violations (MCL, health-based). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Wisconsin, EPA tracks 10,988 public water systems serving 5,131,439 people, with 285,161 cumulative violations and 58,688 health-based violations on record. About 72% of systems in the state carry at least one violation, and state-wide the average per system is 26 violations. Statewide, 51 of 202 UCMR5-tested systems have reported PFAS detections (25.2%).

Mount Sterling Waterworks's 100 violations sit above the Wisconsin average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
206
Total Violations
100
Health-Based Violations
44
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
76
County
Crawford
School/Daycare
No
MCL Violations
33
Monitoring Violations
47
Treatment Tech Violations
11

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 33 2015
Lead and Copper Rule MR 15 2024
Coliform (TCR) MR 8 2009
TTHM MR 8 2017
Lead and Copper Rule TT 8 2024
Total Haloacetic Acids (HAA5) MR 8 2017
Public Notice Other 6 2024
Revised Total Coliform Rule MON 5 2025
Chlorine MR 3 2009
Consumer Confidence Rule Other 2 2014
Stage 1 Disinfectants and Disinfection Byproducts Rule TT 2 2024
LEAD AND COPPER RULE REVISIONS TT 1 2024
LEAD AND COPPER RULE REVISIONS RPT 1 2024

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Mount Sterling Waterworks.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID WI6120246 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Wisconsin Drinking Water Authority

Wisconsin DNR, Drinking Water and Groundwater is the primacy agency that licenses and inspects Mount Sterling Waterworks under EPA-delegated authority.

Open WI regulator portal

Source: Wisconsin DNR, Drinking Water and Groundwater

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2025 Revised Total Coliform Rule MON 5 SDWIS / WI6120246 / 8000
2024 Lead and Copper Rule MR 15 SDWIS / WI6120246 / 5000
2024 Lead and Copper Rule TT 8 SDWIS / WI6120246 / 5000
2024 Public Notice Other 6 SDWIS / WI6120246 / 7500
2024 Stage 1 Disinfectants and Disinfection Byproducts Rule TT 2 SDWIS / WI6120246 / 0400
2024 LEAD AND COPPER RULE REVISIONS TT 1 SDWIS / WI6120246 / 5200
2024 LEAD AND COPPER RULE REVISIONS RPT 1 SDWIS / WI6120246 / 5200
2017 TTHM MR 8 SDWIS / WI6120246 / 2950
2017 Total Haloacetic Acids (HAA5) MR 8 SDWIS / WI6120246 / 2456
2015 Coliform (TCR) MCL 33 SDWIS / WI6120246 / 3100
2014 Consumer Confidence Rule Other 2 SDWIS / WI6120246 / 7000
2009 Coliform (TCR) MR 8 SDWIS / WI6120246 / 3100
2009 Chlorine MR 3 SDWIS / WI6120246 / 0999

How Mount Sterling Waterworks Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Mount Sterling Waterworks Wisconsin avg Federal benchmark
Total violations 100 26 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 44 5.3 Indicates a contaminant exceeded a federal MCL
PFAS detection None 25.2% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 206 467 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 10,988 regulated public water systems in Wisconsin.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Mount Sterling Waterworks water safe to drink? ▼
Mount Sterling Waterworks (PWS ID: WI6120246) has 100 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 206 people using Groundwater sources.
How many people does Mount Sterling Waterworks serve? ▼
Mount Sterling Waterworks serves 206 people in Mt Sterling, Wisconsin. It is a Local-owned system using Groundwater water sources with 76 service connections.
What type of violations does Mount Sterling Waterworks have? ▼
Mount Sterling Waterworks has 100 total violations: 44 health-based violations (MCL exceedances or treatment failures), 47 monitoring/reporting violations, and 11 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Mount Sterling Waterworks water? ▼
No PFAS testing data is available for Mount Sterling Waterworks under the EPA's UCMR5 monitoring program.
What water source does Mount Sterling Waterworks use? ▼
Mount Sterling Waterworks uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.