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Non-Transient Non-Community Water System · PWS WI2681818

Squires I

Mequon, Wisconsin 53092 - drinking water served from groundwater sources to 172 people, tracked in EPA SDWIS and UCMR5.

172
People served
237
EPA violations
6
Health-based
Untested
UCMR5 result

The verdict

EPA records 237 drinking-water violations at Squires I, 3% of them health-based - above the Wisconsin per-system average.

237
Total EPA violations on record
3%
Health-based (MCL / treatment failure)
172
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Squires I

Squires I is a private-owned non-transient non-community water system that delivers drinking water to 172 residents in Mequon, Wisconsin (Waukesha County) through 1 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 237 total violations for this system , of which 6 (3%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 228 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 19 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%).

Squires I's 237 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
172
Total Violations
237
Health-Based Violations
6
Water Source
Groundwater

System Details

System Type
Non-Transient Non-Community
Owner Type
Private
Connections
1
County
Waukesha
School/Daycare
No
MCL Violations
6
Monitoring Violations
228
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 19 2003
Lead and Copper Rule MR 16 1996
Revised Total Coliform Rule MON 8 2025
Coliform (TCR) MCL 6 2006
Aldicarb sulfone MR 5 1995
Hexachlorocyclopentadiene MR 5 1995
Dinoseb MR 5 1995
Simazine MR 5 1995
Chlordane MR 5 1995
HEXACHLOROBENZENE MR 5 1995
Pentachlorophenol MR 5 1995
Total Polychlorinated Biphenyls (PCB) MR 5 1995
OXAMYL MR 5 1995
Dalapon MR 5 1995
Endrin MR 5 1995
Atrazine MR 5 1995
Carbofuran MR 5 1995
Nitrate MR 5 1995
Methoxychlor MR 5 1995
2,4,5-TP MR 5 1995
Aldicarb sulfoxide MR 5 1995
Picloram MR 5 1995
BHC-GAMMA MR 5 1995
Heptachlor epoxide MR 5 1995
Heptachlor MR 5 1995
Aldicarb MR 5 1995
Toxaphene MR 5 1995
2,4-D MR 5 1995
LASSO MR 5 1995
Vinyl chloride MR 2 1995

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 Squires I.

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 WI2681818 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 Squires I 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 8 SDWIS / WI2681818 / 8000
2006 Coliform (TCR) MCL 6 SDWIS / WI2681818 / 3100
2004 Public Notice Other 1 SDWIS / WI2681818 / 7500
2003 Coliform (TCR) MR 19 SDWIS / WI2681818 / 3100
1996 Lead and Copper Rule MR 16 SDWIS / WI2681818 / 5000
1995 Aldicarb sulfone MR 5 SDWIS / WI2681818 / 2044
1995 Hexachlorocyclopentadiene MR 5 SDWIS / WI2681818 / 2042
1995 Dinoseb MR 5 SDWIS / WI2681818 / 2041
1995 Simazine MR 5 SDWIS / WI2681818 / 2037
1995 Chlordane MR 5 SDWIS / WI2681818 / 2959
1995 HEXACHLOROBENZENE MR 5 SDWIS / WI2681818 / 2274
1995 Pentachlorophenol MR 5 SDWIS / WI2681818 / 2326
1995 Total Polychlorinated Biphenyls (PCB) MR 5 SDWIS / WI2681818 / 2383
1995 OXAMYL MR 5 SDWIS / WI2681818 / 2036
1995 Dalapon MR 5 SDWIS / WI2681818 / 2031

How Squires I Compares

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

Metric Squires I Wisconsin avg Federal benchmark
Total violations 237 26 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 6 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 172 467 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 Squires I water safe to drink? ▼
Squires I (PWS ID: WI2681818) has 237 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 172 people using Groundwater sources.
How many people does Squires I serve? ▼
Squires I serves 172 people in Mequon, Wisconsin. It is a Private-owned system using Groundwater water sources with 1 service connections.
What type of violations does Squires I have? ▼
Squires I has 237 total violations: 6 health-based violations (MCL exceedances or treatment failures), 228 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Squires I water? ▼
No PFAS testing data is available for Squires I under the EPA's UCMR5 monitoring program.
What water source does Squires I use? ▼
Squires I uses Groundwater as its primary water source. It is classified as a Non-Transient Non-Community Water System, serving the same people for at least 6 months per year.
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.