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Community Water System · PWS WI1530061

Lone Rock Waterworks

Lone Rock, Wisconsin 53556-0338 - drinking water served from groundwater sources to 895 people, tracked in EPA SDWIS and UCMR5.

895
People served
52
EPA violations
12
Health-based
Untested
UCMR5 result

The verdict

EPA records 52 drinking-water violations at Lone Rock Waterworks, 23% of them health-based - above the Wisconsin per-system average.

52
Total EPA violations on record
23%
Health-based (MCL / treatment failure)
895
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Lone Rock Waterworks

Lone Rock Waterworks is a local-owned community water system that delivers drinking water to 895 residents in Lone Rock, Wisconsin (Richland County) through 267 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 52 total violations for this system , of which 12 (23%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 37 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 12 violations (MR). 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%).

Lone Rock Waterworks's 52 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
895
Total Violations
52
Health-Based Violations
12
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
267
County
Richland
School/Daycare
No
MCL Violations
8
Monitoring Violations
37
Treatment Tech Violations
4

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 12 2012
Coliform (TCR) MCL 8 2016
Radium-228 MR 6 2009
Lead and Copper Rule MR 6 2021
Gross Alpha, Excl. Radon and U MR 5 1995
Lead and Copper Rule TT 4 2020
Nitrate MR 4 2023
Combined Radium (-226 and -228) MR 2 1994
Radium-226 MR 2 1994
Consumer Confidence Rule Other 1 2012

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 Lone Rock 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 WI1530061 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 Lone Rock 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
2023 Nitrate MR 4 SDWIS / WI1530061 / 1040
2021 Lead and Copper Rule MR 6 SDWIS / WI1530061 / 5000
2020 Lead and Copper Rule TT 4 SDWIS / WI1530061 / 5000
2016 Coliform (TCR) MCL 8 SDWIS / WI1530061 / 3100
2012 Coliform (TCR) MR 12 SDWIS / WI1530061 / 3100
2012 Consumer Confidence Rule Other 1 SDWIS / WI1530061 / 7000
2009 Radium-228 MR 6 SDWIS / WI1530061 / 4030
1995 Gross Alpha, Excl. Radon and U MR 5 SDWIS / WI1530061 / 4000
1994 Combined Radium (-226 and -228) MR 2 SDWIS / WI1530061 / 4010
1994 Radium-226 MR 2 SDWIS / WI1530061 / 4020

How Lone Rock Waterworks Compares

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

Metric Lone Rock Waterworks Wisconsin avg Federal benchmark
Total violations 52 26 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 12 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 895 467 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 Lone Rock Waterworks water safe to drink? ▼
Lone Rock Waterworks (PWS ID: WI1530061) has 52 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 895 people using Groundwater sources.
How many people does Lone Rock Waterworks serve? ▼
Lone Rock Waterworks serves 895 people in Lone Rock, Wisconsin. It is a Local-owned system using Groundwater water sources with 267 service connections.
What type of violations does Lone Rock Waterworks have? ▼
Lone Rock Waterworks has 52 total violations: 12 health-based violations (MCL exceedances or treatment failures), 37 monitoring/reporting violations, and 4 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Lone Rock Waterworks water? ▼
No PFAS testing data is available for Lone Rock Waterworks under the EPA's UCMR5 monitoring program.
What water source does Lone Rock Waterworks use? ▼
Lone Rock 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.