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Community Water System · PWS WI2681104

Knollcrest

Middleton, Wisconsin 53562 - drinking water served from groundwater sources to 66 people, tracked in EPA SDWIS and UCMR5.

66
People served
335
EPA violations
40
Health-based
Untested
UCMR5 result

The verdict

EPA records 335 drinking-water violations at Knollcrest, 12% of them health-based - above the Wisconsin per-system average.

335
Total EPA violations on record
12%
Health-based (MCL / treatment failure)
66
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Knollcrest

Knollcrest is a private-owned community water system that delivers drinking water to 66 residents in Middleton, Wisconsin (Waukesha County) through 52 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 335 total violations for this system , of which 40 (12%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 285 monitoring and reporting violations are on file. The most recent violation on record dates to 2021.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 52 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%).

Knollcrest's 335 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
66
Total Violations
335
Health-Based Violations
40
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
52
County
Waukesha
School/Daycare
No
MCL Violations
40
Monitoring Violations
285
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 52 2003
Di(2-ethylhexyl) phthalate MCL 40 2021
Lead and Copper Rule MR 13 2021
Gross Alpha, Excl. Radon and U MR 11 2000
Radium-228 MR 11 2000
Combined Radium (-226 and -228) MR 11 2000
Radium-226 MR 11 2000
Nitrate MR 11 1999
1,2,4-Trichlorobenzene MR 6 2000
Tetrachloroethylene MR 6 2000
1,1,2-Trichloroethane MR 6 2000
Styrene MR 6 2000
Toluene MR 6 2000
trans-1,2-Dichloroethylene MR 6 2000
DICHLOROMETHANE MR 6 2000
o-Dichlorobenzene MR 6 2000
Xylenes, Total MR 6 2000
cis-1,2-Dichloroethylene MR 6 2000
p-Dichlorobenzene MR 6 2000
Trichloroethylene MR 6 2000
Carbon tetrachloride MR 6 2000
1,2-Dichloroethane MR 6 2000
1,2-Dichloropropane MR 6 2000
CHLOROBENZENE MR 6 2000
Ethylbenzene MR 6 2000
1,1-Dichloroethylene MR 6 2000
Benzene MR 6 2000
1,1,1-Trichloroethane MR 6 2000
Vinyl chloride MR 6 2000
Antimony, Total MR 3 2000

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 Knollcrest.

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 WI2681104 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 Knollcrest 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
2021 Di(2-ethylhexyl) phthalate MCL 40 SDWIS / WI2681104 / 2039
2021 Lead and Copper Rule MR 13 SDWIS / WI2681104 / 5000
2005 Public Notice Other 1 SDWIS / WI2681104 / 7500
2003 Coliform (TCR) MR 52 SDWIS / WI2681104 / 3100
2000 Gross Alpha, Excl. Radon and U MR 11 SDWIS / WI2681104 / 4000
2000 Radium-228 MR 11 SDWIS / WI2681104 / 4030
2000 Combined Radium (-226 and -228) MR 11 SDWIS / WI2681104 / 4010
2000 Radium-226 MR 11 SDWIS / WI2681104 / 4020
2000 1,2,4-Trichlorobenzene MR 6 SDWIS / WI2681104 / 2378
2000 Tetrachloroethylene MR 6 SDWIS / WI2681104 / 2987
2000 1,1,2-Trichloroethane MR 6 SDWIS / WI2681104 / 2985
2000 Styrene MR 6 SDWIS / WI2681104 / 2996
2000 Toluene MR 6 SDWIS / WI2681104 / 2991
2000 trans-1,2-Dichloroethylene MR 6 SDWIS / WI2681104 / 2979
2000 DICHLOROMETHANE MR 6 SDWIS / WI2681104 / 2964

How Knollcrest Compares

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

Metric Knollcrest Wisconsin avg Federal benchmark
Total violations 335 26 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 40 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 66 467 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 Knollcrest water safe to drink? ▼
Knollcrest (PWS ID: WI2681104) has 335 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 66 people using Groundwater sources.
How many people does Knollcrest serve? ▼
Knollcrest serves 66 people in Middleton, Wisconsin. It is a Private-owned system using Groundwater water sources with 52 service connections.
What type of violations does Knollcrest have? ▼
Knollcrest has 335 total violations: 40 health-based violations (MCL exceedances or treatment failures), 285 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Knollcrest water? ▼
No PFAS testing data is available for Knollcrest under the EPA's UCMR5 monitoring program.
What water source does Knollcrest use? ▼
Knollcrest 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.