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Community Water System · PWS WI8660304

Shell Lake Waterworks

Shell Lake, Wisconsin 54871 - drinking water served from groundwater sources to 950 people, tracked in EPA SDWIS and UCMR5.

950
People served
88
EPA violations
70
Health-based
Untested
UCMR5 result

The verdict

EPA records 88 drinking-water violations at Shell Lake Waterworks, 80% of them health-based - above the Wisconsin per-system average.

88
Total EPA violations on record
80%
Health-based (MCL / treatment failure)
950
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Shell Lake Waterworks

Shell Lake Waterworks is a local-owned community water system that delivers drinking water to 950 residents in Shell Lake, Wisconsin (Washburn County) through 351 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 88 total violations for this system , of which 70 (80%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 9 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 69 violations (MCL, health-based). 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%).

Shell Lake Waterworks's 88 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
950
Total Violations
88
Health-Based Violations
70
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
351
County
Washburn
School/Daycare
No
MCL Violations
69
Monitoring Violations
9
Treatment Tech Violations
1

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 69 2014
Coliform (TCR) MR 7 2009
Consumer Confidence Rule Other 2 2002
Public Notice Other 2 2024
Lead and Copper Rule MR 2 2024
LEAD AND COPPER RULE REVISIONS RPT 1 2025
LEAD AND COPPER RULE REVISIONS TT 1 2024

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 Shell 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 WI8660304 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 Shell 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
2025 LEAD AND COPPER RULE REVISIONS RPT 1 SDWIS / WI8660304 / 5200
2024 Public Notice Other 2 SDWIS / WI8660304 / 7500
2024 Lead and Copper Rule MR 2 SDWIS / WI8660304 / 5000
2024 LEAD AND COPPER RULE REVISIONS TT 1 SDWIS / WI8660304 / 5200
2014 Coliform (TCR) MCL 69 SDWIS / WI8660304 / 3100
2009 Coliform (TCR) MR 7 SDWIS / WI8660304 / 3100
2002 Consumer Confidence Rule Other 2 SDWIS / WI8660304 / 7000

How Shell Lake Waterworks Compares

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

Metric Shell Lake Waterworks Wisconsin avg Federal benchmark
Total violations 88 26 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 70 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 950 467 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 Shell Lake Waterworks water safe to drink? ▼
Shell Lake Waterworks (PWS ID: WI8660304) has 88 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 950 people using Groundwater sources.
How many people does Shell Lake Waterworks serve? ▼
Shell Lake Waterworks serves 950 people in Shell Lake, Wisconsin. It is a Local-owned system using Groundwater water sources with 351 service connections.
What type of violations does Shell Lake Waterworks have? ▼
Shell Lake Waterworks has 88 total violations: 70 health-based violations (MCL exceedances or treatment failures), 9 monitoring/reporting violations, and 1 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Shell Lake Waterworks water? ▼
No PFAS testing data is available for Shell Lake Waterworks under the EPA's UCMR5 monitoring program.
What water source does Shell Lake Waterworks use? ▼
Shell 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.