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Community Water System · PWS WI2681086

Oakton Beach

Hales Corners, Wisconsin 53130 - drinking water served from groundwater sources to 144 people, tracked in EPA SDWIS and UCMR5.

144
People served
311
EPA violations
43
Health-based
Untested
UCMR5 result

The verdict

EPA records 311 drinking-water violations at Oakton Beach, 14% of them health-based - above the Wisconsin per-system average.

311
Total EPA violations on record
14%
Health-based (MCL / treatment failure)
144
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Oakton Beach

Oakton Beach is a private-owned community water system that delivers drinking water to 144 residents in Hales Corners, Wisconsin (Waukesha County) through 9 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 311 total violations for this system , of which 43 (14%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 232 monitoring and reporting violations are on file. The most recent violation on record dates to 2013.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 46 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, 51 of 202 UCMR5-tested systems have reported PFAS detections (25.2%).

Oakton Beach's 311 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
144
Total Violations
311
Health-Based Violations
43
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
9
County
Waukesha
School/Daycare
No
MCL Violations
43
Monitoring Violations
232
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 46 2000
Coliform (TCR) MCL 31 2006
Nitrate MR 26 2000
Consumer Confidence Rule Other 21 2013
Combined Radium (-226 and -228) MR 13 1999
Gross Alpha, Excl. Radon and U MR 13 1999
Radium-228 MR 11 1999
Radium-226 MR 11 1999
Barium MR 8 1997
Fluoride MR 8 1997
Nitrite MR 8 1997
Lead and Copper Rule MR 8 1999
Arsenic MR 8 1997
Chromium MR 8 1997
Nickel MR 8 1997
Nitrate-Nitrite MR 8 1997
Thallium, Total MR 8 1997
Cadmium MR 8 1997
Antimony, Total MR 8 1997
Beryllium, Total MR 8 1997
Selenium MR 8 1997
Mercury MR 8 1997
Gross Alpha, Excl. Radon and U MCL 6 2001
Combined Radium (-226 and -228) MCL 6 2001

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 Oakton Beach.

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 WI2681086 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 Oakton Beach 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
2013 Consumer Confidence Rule Other 21 SDWIS / WI2681086 / 7000
2006 Coliform (TCR) MCL 31 SDWIS / WI2681086 / 3100
2001 Gross Alpha, Excl. Radon and U MCL 6 SDWIS / WI2681086 / 4000
2001 Combined Radium (-226 and -228) MCL 6 SDWIS / WI2681086 / 4010
2000 Coliform (TCR) MR 46 SDWIS / WI2681086 / 3100
2000 Nitrate MR 26 SDWIS / WI2681086 / 1040
1999 Combined Radium (-226 and -228) MR 13 SDWIS / WI2681086 / 4010
1999 Gross Alpha, Excl. Radon and U MR 13 SDWIS / WI2681086 / 4000
1999 Radium-228 MR 11 SDWIS / WI2681086 / 4030
1999 Radium-226 MR 11 SDWIS / WI2681086 / 4020
1999 Lead and Copper Rule MR 8 SDWIS / WI2681086 / 5000
1997 Barium MR 8 SDWIS / WI2681086 / 1010
1997 Fluoride MR 8 SDWIS / WI2681086 / 1025
1997 Nitrite MR 8 SDWIS / WI2681086 / 1041
1997 Arsenic MR 8 SDWIS / WI2681086 / 1005

How Oakton Beach Compares

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

Metric Oakton Beach Wisconsin avg Federal benchmark
Total violations 311 26 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 43 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 144 467 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 Oakton Beach water safe to drink? ▼
Oakton Beach (PWS ID: WI2681086) has 311 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 144 people using Groundwater sources.
How many people does Oakton Beach serve? ▼
Oakton Beach serves 144 people in Hales Corners, Wisconsin. It is a Private-owned system using Groundwater water sources with 9 service connections.
What type of violations does Oakton Beach have? ▼
Oakton Beach has 311 total violations: 43 health-based violations (MCL exceedances or treatment failures), 232 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Oakton Beach water? ▼
No PFAS testing data is available for Oakton Beach under the EPA's UCMR5 monitoring program.
What water source does Oakton Beach use? ▼
Oakton Beach 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.