Community Water System · PWS WI2650060
Williams Bay Waterworks
Operator location Williams Bay, Wisconsin - upper-third violation load (> 74 violations) with 135 EPA violations; groundwater source; 2,601 served (PWS-level, not municipal population).
- 2,601
- People served (this PWS)
- 135
- EPA violations (this PWS)
- 1
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Williams Bay Waterworks standing, high SDWIS violation third
135 EPA SDWIS violations on record - upper-third violation load (> 74 violations). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 1% is middle-third health share (≤ 23%). Population rank #11,580 of 29,740 among systems serving 500+.
The verdict
Williams Bay Waterworks sits in the upper third of the sitemap cohort by violation count (135), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 2,601 (mid served population (≤ 3,309)). Health-based share is 1% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- #11,580 of 29,740
- Population · /systems
- #227 of 744
- Population · WI
- 135
- Total EPA violations on record
- 1%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 963
- County
- Walworth
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 117
- Treatment Tech Violations
- 1
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Nitrite | MR | 17 | 2012 |
| Nitrate | MR | 17 | 2012 |
| Consumer Confidence Rule | Other | 10 | 2021 |
| Coliform (TCR) | MR | 10 | 2012 |
| Chlorine | MR | 6 | 2012 |
| Lead and Copper Rule | MR | 4 | 2025 |
| Vinyl chloride | MR | 3 | 1996 |
| 1,1-Dichloroethylene | MR | 3 | 1996 |
| Carbon tetrachloride | MR | 3 | 1996 |
| CHLOROBENZENE | MR | 3 | 1996 |
| Benzene | MR | 3 | 1996 |
| Ethylbenzene | MR | 3 | 1996 |
| Styrene | MR | 3 | 1996 |
| Xylenes, Total | MR | 3 | 1996 |
| DICHLOROMETHANE | MR | 3 | 1996 |
| trans-1,2-Dichloroethylene | MR | 3 | 1996 |
| 1,2-Dichloropropane | MR | 3 | 1996 |
| cis-1,2-Dichloroethylene | MR | 3 | 1996 |
| Trichloroethylene | MR | 3 | 1996 |
| Tetrachloroethylene | MR | 3 | 1996 |
| 1,2-Dichloroethane | MR | 3 | 1996 |
| 1,2,4-Trichlorobenzene | MR | 3 | 1996 |
| p-Dichlorobenzene | MR | 3 | 1996 |
| 1,1,1-Trichloroethane | MR | 3 | 1996 |
| 1,1,2-Trichloroethane | MR | 3 | 1996 |
| o-Dichlorobenzene | MR | 3 | 1996 |
| Toluene | MR | 3 | 1996 |
| Public Notice | Other | 2 | 2025 |
| Lead and Copper Rule | TT | 1 | 2025 |
Violation Count vs. the National Corpus
Williams Bay Waterworks has 135 recorded EPA violations, 79% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 21% carry more. 1% of this system's own violations are health-based (1 of 135), and it ranks #11,580 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
135 Higher than most more violations than 79% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
SDWIS compliance record for Williams Bay Waterworks
135 violations on record for WI2650060; use EPA SDWIS to confirm return-to-compliance dates and monitoring categories.
Sources: EPA SDWIS · Wisconsin DNR, Drinking Water and Groundwater
Nationwide peers
135 violations · 2,601 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Williams Bay Waterworks
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Wisconsin compares on the same EPA violation measures. Wisconsin systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.