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Community Water System · PWS WI1140154

Theresa Waterworks

Theresa, Wisconsin 53091-0327 - drinking water served from groundwater sources to 1,262 people, tracked in EPA SDWIS and UCMR5.

1,262
People served
232
EPA violations
7
Health-based
Untested
UCMR5 result

The verdict

EPA records 232 drinking-water violations at Theresa Waterworks, 3% of them health-based - above the Wisconsin per-system average.

232
Total EPA violations on record
3%
Health-based (MCL / treatment failure)
1,262
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Theresa Waterworks

Theresa Waterworks is a local-owned community water system that delivers drinking water to 1,262 residents in Theresa, Wisconsin (Dodge County) through 569 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 232 total violations for this system , of which 7 (3%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 206 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 Consumer Confidence Rule, recorded in 10 violations (Other). 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%).

Theresa Waterworks's 232 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
1,262
Total Violations
232
Health-Based Violations
7
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
569
County
Dodge
School/Daycare
No
MCL Violations
4
Monitoring Violations
206
Treatment Tech Violations
3

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Consumer Confidence Rule Other 10 2019
cis-1,2-Dichloroethylene MR 6 2008
Xylenes, Total MR 6 2008
DICHLOROMETHANE MR 6 2008
o-Dichlorobenzene MR 6 2008
1,1-Dichloroethylene MR 6 2008
trans-1,2-Dichloroethylene MR 6 2008
1,2-Dichloroethane MR 6 2008
1,1,1-Trichloroethane MR 6 2008
1,2-Dichloropropane MR 6 2008
Trichloroethylene MR 6 2008
1,1,2-Trichloroethane MR 6 2008
Tetrachloroethylene MR 6 2008
1,2,4-Trichlorobenzene MR 6 2008
p-Dichlorobenzene MR 6 2008
Vinyl chloride MR 6 2008
Carbon tetrachloride MR 6 2008
Benzene MR 6 2008
Toluene MR 6 2008
Ethylbenzene MR 6 2008
Styrene MR 6 2008
CHLOROBENZENE MR 6 2008
Radium-228 MR 4 2009
Chlorine MR 4 2013
Coliform (TCR) MR 4 2013
TTHM MR 4 2018
Revised Total Coliform Rule MON 4 2017
Coliform (TCR) MCL 4 2014
Total Haloacetic Acids (HAA5) MR 4 2018
Public Notice Other 3 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 Theresa 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 WI1140154 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 Theresa 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 Stage 1 Disinfectants and Disinfection Byproducts Rule TT 2 SDWIS / WI1140154 / 0400
2024 Public Notice Other 3 SDWIS / WI1140154 / 7500
2024 LEAD AND COPPER RULE REVISIONS TT 1 SDWIS / WI1140154 / 5200
2019 Consumer Confidence Rule Other 10 SDWIS / WI1140154 / 7000
2018 TTHM MR 4 SDWIS / WI1140154 / 2950
2018 Total Haloacetic Acids (HAA5) MR 4 SDWIS / WI1140154 / 2456
2018 Lead and Copper Rule MR 2 SDWIS / WI1140154 / 5000
2017 Revised Total Coliform Rule MON 4 SDWIS / WI1140154 / 8000
2014 Coliform (TCR) MCL 4 SDWIS / WI1140154 / 3100
2013 Chlorine MR 4 SDWIS / WI1140154 / 0999
2013 Coliform (TCR) MR 4 SDWIS / WI1140154 / 3100
2009 Radium-228 MR 4 SDWIS / WI1140154 / 4030
2008 cis-1,2-Dichloroethylene MR 6 SDWIS / WI1140154 / 2380
2008 Xylenes, Total MR 6 SDWIS / WI1140154 / 2955
2008 DICHLOROMETHANE MR 6 SDWIS / WI1140154 / 2964

How Theresa Waterworks Compares

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

Metric Theresa Waterworks Wisconsin avg Federal benchmark
Total violations 232 26 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 7 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 1,262 467 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 Theresa Waterworks water safe to drink? ▼
Theresa Waterworks (PWS ID: WI1140154) has 232 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,262 people using Groundwater sources.
How many people does Theresa Waterworks serve? ▼
Theresa Waterworks serves 1,262 people in Theresa, Wisconsin. It is a Local-owned system using Groundwater water sources with 569 service connections.
What type of violations does Theresa Waterworks have? ▼
Theresa Waterworks has 232 total violations: 7 health-based violations (MCL exceedances or treatment failures), 206 monitoring/reporting violations, and 3 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Theresa Waterworks water? ▼
No PFAS testing data is available for Theresa Waterworks under the EPA's UCMR5 monitoring program.
What water source does Theresa Waterworks use? ▼
Theresa 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.