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Community Water System · PWS WI7371256

Hatley Waterworks

Hatley, Wisconsin 54440-0099 - drinking water served from groundwater sources to 550 people, tracked in EPA SDWIS and UCMR5.

550
People served
259
EPA violations
22
Health-based
Untested
UCMR5 result

The verdict

EPA records 259 drinking-water violations at Hatley Waterworks, 8% of them health-based - above the Wisconsin per-system average.

259
Total EPA violations on record
8%
Health-based (MCL / treatment failure)
550
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Hatley Waterworks

Hatley Waterworks is a local-owned community water system that delivers drinking water to 550 residents in Hatley, Wisconsin (Marathon County) through 191 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 259 total violations for this system , of which 22 (8%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 233 monitoring and reporting violations are on file. The most recent violation on record dates to 2022.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 22 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, 78 of 202 UCMR5-tested systems have reported PFAS detections (38.6%).

Hatley Waterworks's 259 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
550
Total Violations
259
Health-Based Violations
22
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
191
County
Marathon
School/Daycare
No
MCL Violations
22
Monitoring Violations
233
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 22 1995
Coliform (TCR) MR 16 2002
DICHLOROMETHANE MR 10 1995
Vinyl chloride MR 10 1995
1,1,2-Trichloroethane MR 10 1995
Carbon tetrachloride MR 10 1995
1,2-Dichloroethane MR 10 1995
Benzene MR 10 1995
CHLOROBENZENE MR 10 1995
cis-1,2-Dichloroethylene MR 10 1995
1,1,1-Trichloroethane MR 10 1995
trans-1,2-Dichloroethylene MR 10 1995
1,1-Dichloroethylene MR 10 1995
o-Dichlorobenzene MR 10 1995
Xylenes, Total MR 10 1995
1,2,4-Trichlorobenzene MR 10 1995
Styrene MR 10 1995
Toluene MR 10 1995
1,2-Dichloropropane MR 10 1995
Trichloroethylene MR 10 1995
p-Dichlorobenzene MR 10 1995
Tetrachloroethylene MR 10 1995
Ethylbenzene MR 10 1995
Lead and Copper Rule MR 7 2012
Consumer Confidence Rule Other 4 2022

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 Hatley 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 WI7371256 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 Hatley 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
2022 Consumer Confidence Rule Other 4 SDWIS / WI7371256 / 7000
2012 Lead and Copper Rule MR 7 SDWIS / WI7371256 / 5000
2002 Coliform (TCR) MR 16 SDWIS / WI7371256 / 3100
1995 Coliform (TCR) MCL 22 SDWIS / WI7371256 / 3100
1995 DICHLOROMETHANE MR 10 SDWIS / WI7371256 / 2964
1995 Vinyl chloride MR 10 SDWIS / WI7371256 / 2976
1995 1,1,2-Trichloroethane MR 10 SDWIS / WI7371256 / 2985
1995 Carbon tetrachloride MR 10 SDWIS / WI7371256 / 2982
1995 1,2-Dichloroethane MR 10 SDWIS / WI7371256 / 2980
1995 Benzene MR 10 SDWIS / WI7371256 / 2990
1995 CHLOROBENZENE MR 10 SDWIS / WI7371256 / 2989
1995 cis-1,2-Dichloroethylene MR 10 SDWIS / WI7371256 / 2380
1995 1,1,1-Trichloroethane MR 10 SDWIS / WI7371256 / 2981
1995 trans-1,2-Dichloroethylene MR 10 SDWIS / WI7371256 / 2979
1995 1,1-Dichloroethylene MR 10 SDWIS / WI7371256 / 2977

How Hatley Waterworks Compares

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

Metric Hatley Waterworks Wisconsin avg Federal benchmark
Total violations 259 26 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 22 5.3 Indicates a contaminant exceeded a federal MCL
PFAS detection None 38.6% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 550 467 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 Hatley Waterworks water safe to drink? ▼
Hatley Waterworks (PWS ID: WI7371256) has 259 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 550 people using Groundwater sources.
How many people does Hatley Waterworks serve? ▼
Hatley Waterworks serves 550 people in Hatley, Wisconsin. It is a Local-owned system using Groundwater water sources with 191 service connections.
What type of violations does Hatley Waterworks have? ▼
Hatley Waterworks has 259 total violations: 22 health-based violations (MCL exceedances or treatment failures), 233 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Hatley Waterworks water? ▼
No PFAS testing data is available for Hatley Waterworks under the EPA's UCMR5 monitoring program.
What water source does Hatley Waterworks use? ▼
Hatley 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.