PlainWater
States → Wisconsin

Community Water System · PWS WI4240217

Green Lake Waterworks

Green Lake, Wisconsin 54941 - drinking water served from groundwater sources to 1,002 people, tracked in EPA SDWIS and UCMR5.

1,002
People served
53
EPA violations
14
Health-based
Untested
UCMR5 result

The verdict

EPA records 53 drinking-water violations at Green Lake Waterworks, 26% of them health-based - above the Wisconsin per-system average.

53
Total EPA violations on record
26%
Health-based (MCL / treatment failure)
1,002
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Green Lake Waterworks

Green Lake Waterworks is a local-owned community water system that delivers drinking water to 1,002 residents in Green Lake, Wisconsin (Green Lake County) through 371 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 53 total violations for this system , of which 14 (26%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 22 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.

The most frequently cited contaminant at this system is Lead and Copper Rule, recorded in 16 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%).

Green Lake Waterworks's 53 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
1,002
Total Violations
53
Health-Based Violations
14
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
371
County
Green Lake
School/Daycare
No
MCL Violations
11
Monitoring Violations
22
Treatment Tech Violations
3

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Lead and Copper Rule MR 16 2024
Consumer Confidence Rule Other 12 2022
Coliform (TCR) MCL 11 1998
Public Notice Other 4 2024
Nitrate MR 4 2020
Coliform (TCR) MR 2 2001
LEAD AND COPPER RULE REVISIONS TT 2 2024
Lead and Copper Rule TT 1 2006

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 Green Lake 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 WI4240217 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 Green Lake 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
2024 Lead and Copper Rule MR 16 SDWIS / WI4240217 / 5000
2024 Public Notice Other 4 SDWIS / WI4240217 / 7500
2024 LEAD AND COPPER RULE REVISIONS TT 2 SDWIS / WI4240217 / 5200
2022 Consumer Confidence Rule Other 12 SDWIS / WI4240217 / 7000
2020 Nitrate MR 4 SDWIS / WI4240217 / 1040
2006 Lead and Copper Rule TT 1 SDWIS / WI4240217 / 5000
2001 Coliform (TCR) MR 2 SDWIS / WI4240217 / 3100
1998 Coliform (TCR) MCL 11 SDWIS / WI4240217 / 3100

How Green Lake Waterworks Compares

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

Metric Green Lake Waterworks Wisconsin avg Federal benchmark
Total violations 53 26 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 14 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 1,002 467 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 Green Lake Waterworks water safe to drink? ▼
Green Lake Waterworks (PWS ID: WI4240217) has 53 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,002 people using Groundwater sources.
How many people does Green Lake Waterworks serve? ▼
Green Lake Waterworks serves 1,002 people in Green Lake, Wisconsin. It is a Local-owned system using Groundwater water sources with 371 service connections.
What type of violations does Green Lake Waterworks have? ▼
Green Lake Waterworks has 53 total violations: 14 health-based violations (MCL exceedances or treatment failures), 22 monitoring/reporting violations, and 3 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Green Lake Waterworks water? ▼
No PFAS testing data is available for Green Lake Waterworks under the EPA's UCMR5 monitoring program.
What water source does Green Lake Waterworks use? ▼
Green Lake 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.