Community Water System · PWS WI1130247
Mt Horeb Waterworks
Mount Horeb, Wisconsin 53572-2138 - drinking water served from groundwater sources to 7,756 people, tracked in EPA SDWIS and UCMR5.
- 7,756
- People served
- 182
- EPA violations
- 1
- Health-based
- 2 PFAS
- UCMR5 result
The verdict
EPA records 182 drinking-water violations at Mt Horeb Waterworks, 1% of them health-based - above the Wisconsin per-system average, and UCMR5 testing detected 2 PFAS compounds.
- 182
- Total EPA violations on record
- 1%
- Health-based (MCL / treatment failure)
- 7,756
- People served by this system
- 2
- PFAS compounds detected (UCMR5)
Water Quality Snapshot: Mt Horeb Waterworks
Mt Horeb Waterworks is a local-owned community water system that delivers drinking water to 7,756 residents in Mount Horeb, Wisconsin (Dane County) through 2,872 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 182 total violations for this system , of which 1 (1%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 178 monitoring and reporting violations are on file. The most recent violation on record dates to 2011.
The most frequently cited contaminant at this system is Tetrachloroethylene, recorded in 8 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 2 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 4.4 ppt (parts per trillion). PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.
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%).
Mt Horeb Waterworks's 182 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.
2 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 2,872
- County
- Dane
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 178
- Treatment Tech Violations
- 1
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Tetrachloroethylene | MR | 8 | 1994 |
| Benzene | MR | 8 | 1994 |
| Toluene | MR | 8 | 1994 |
| 1,2,4-Trichlorobenzene | MR | 8 | 1994 |
| Xylenes, Total | MR | 8 | 1994 |
| DICHLOROMETHANE | MR | 8 | 1994 |
| o-Dichlorobenzene | MR | 8 | 1994 |
| Carbon tetrachloride | MR | 8 | 1994 |
| 1,1,2-Trichloroethane | MR | 8 | 1994 |
| 1,1-Dichloroethylene | MR | 8 | 1994 |
| Vinyl chloride | MR | 8 | 1994 |
| CHLOROBENZENE | MR | 8 | 1994 |
| p-Dichlorobenzene | MR | 8 | 1994 |
| 1,2-Dichloroethane | MR | 8 | 1994 |
| 1,2-Dichloropropane | MR | 8 | 1994 |
| Trichloroethylene | MR | 8 | 1994 |
| cis-1,2-Dichloroethylene | MR | 8 | 1994 |
| trans-1,2-Dichloroethylene | MR | 8 | 1994 |
| 1,1,1-Trichloroethane | MR | 8 | 1994 |
| Ethylbenzene | MR | 8 | 1994 |
| Styrene | MR | 8 | 1994 |
| Coliform (TCR) | MR | 5 | 2001 |
| Nitrate | MR | 5 | 2005 |
| Lead and Copper Rule | TT | 1 | 2011 |
| Public Notice | Other | 1 | 2011 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 4 of 232 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFUnA | 5/20/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFBA | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| HFPO-DA | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| ADONA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 9Cl-PF3ONS | 5/20/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHxA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 4:2 FTS | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 5/20/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHpS | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOS | 5/20/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 5/20/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxS | 5/20/2024 | 3.30 ppt | 3.00 ppt | Detected |
| NMeFOSAA | 5/20/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFMPA | 5/20/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 5/20/2024 | 4.30 ppt | 3.00 ppt | Detected |
| PFMBA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 5/20/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFPeS | 5/20/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 5/20/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFTrDA | 5/20/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| NEtFOSAA | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFEESA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 5/20/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NFDHA | 5/20/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFPeS | 5/20/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHpS | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTrDA | 5/20/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| HFPO-DA | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NMeFOSAA | 5/20/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| NEtFOSAA | 5/20/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 5/20/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFNA | 5/20/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| ADONA | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 4:2 FTS | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 5/20/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOS | 5/20/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
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 Mt Horeb Waterworks.
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 WI1130247 on SDWISSource: EPA SDWIS Federal Reports Search
Wisconsin Drinking Water Authority
Wisconsin DNR, Drinking Water and Groundwater is the primacy agency that licenses and inspects Mt Horeb Waterworks under EPA-delegated authority.
Open WI regulator portalViolation 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 |
|---|---|---|---|---|
| 2011 | Lead and Copper Rule | TT | 1 | SDWIS / WI1130247 / 5000 |
| 2011 | Public Notice | Other | 1 | SDWIS / WI1130247 / 7500 |
| 2005 | Nitrate | MR | 5 | SDWIS / WI1130247 / 1040 |
| 2001 | Coliform (TCR) | MR | 5 | SDWIS / WI1130247 / 3100 |
| 1994 | Tetrachloroethylene | MR | 8 | SDWIS / WI1130247 / 2987 |
| 1994 | Benzene | MR | 8 | SDWIS / WI1130247 / 2990 |
| 1994 | Toluene | MR | 8 | SDWIS / WI1130247 / 2991 |
| 1994 | 1,2,4-Trichlorobenzene | MR | 8 | SDWIS / WI1130247 / 2378 |
| 1994 | Xylenes, Total | MR | 8 | SDWIS / WI1130247 / 2955 |
| 1994 | DICHLOROMETHANE | MR | 8 | SDWIS / WI1130247 / 2964 |
| 1994 | o-Dichlorobenzene | MR | 8 | SDWIS / WI1130247 / 2968 |
| 1994 | Carbon tetrachloride | MR | 8 | SDWIS / WI1130247 / 2982 |
| 1994 | 1,1,2-Trichloroethane | MR | 8 | SDWIS / WI1130247 / 2985 |
| 1994 | 1,1-Dichloroethylene | MR | 8 | SDWIS / WI1130247 / 2977 |
| 1994 | Vinyl chloride | MR | 8 | SDWIS / WI1130247 / 2976 |
How Mt Horeb Waterworks Compares
Cross-reference this system's record against state averages and the federal MCL framework for context.
| Metric | Mt Horeb Waterworks | Wisconsin avg | Federal benchmark |
|---|---|---|---|
| Total violations | 182 | 26 | SDWA compliance, any non-zero count is a recorded breach |
| Health-based violations | 1 | 5.3 | Indicates a contaminant exceeded a federal MCL |
| PFAS detection | 2 compounds | 38.6% | EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt |
| Population served | 7,756 | 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 Mt Horeb Waterworks water safe to drink? ▼
How many people does Mt Horeb Waterworks serve? ▼
What type of violations does Mt Horeb Waterworks have? ▼
Has PFAS been detected in Mt Horeb Waterworks water? ▼
What water source does Mt Horeb Waterworks use? ▼
Where does this data come from? ▼
Read our methodology - how this data is sourced, computed, and verified.
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.