Community Water System · PWS WI2650113
Delavan Waterworks
Operator location Delavan, Wisconsin - 0% of 88 violations are health-based (lower-third health share (≤ 1%)); groundwater source; 8,451 served per SDWIS.
- 8,451
- People served (this PWS)
- 88
- EPA violations (this PWS)
- 0
- Health-based (this PWS)
- No PFAS
- UCMR5 (this PWS)
Delavan Waterworks standing, high SDWIS violation third
0% of 88 recorded violations are health-based - lower-third health share (≤ 1%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 0% is lower-third health share (≤ 1%). UCMR5: UCMR5 tested, none detected. Population rank #5,387 of 29,740 among systems serving 500+.
The verdict
Delavan Waterworks sits in the upper third of the sitemap cohort by violation count (88), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (8,451; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is only 0% - almost all of this trail is monitoring or reporting. UCMR5 tested this system and reported no PFAS above the minimum reporting level.
- #5,387 of 29,740
- Population · /systems
- #105 of 744
- Population · WI
- 88
- Total EPA violations on record
- 0%
- 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
- 3,130
- County
- Walworth
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 78
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Mercury | MR | 8 | 2003 |
| Consumer Confidence Rule | Other | 4 | 2000 |
| TTHM | MR | 4 | 2017 |
| Trichloroethylene | MR | 3 | 1995 |
| p-Dichlorobenzene | MR | 3 | 1995 |
| Vinyl chloride | MR | 3 | 1995 |
| 1,1-Dichloroethylene | MR | 3 | 1995 |
| 1,2-Dichloroethane | MR | 3 | 1995 |
| 1,1,1-Trichloroethane | MR | 3 | 1995 |
| 1,2-Dichloropropane | MR | 3 | 1995 |
| Toluene | MR | 3 | 1995 |
| Styrene | MR | 3 | 1995 |
| DICHLOROMETHANE | MR | 3 | 1995 |
| Fluoride | MR | 3 | 1999 |
| 1,2,4-Trichlorobenzene | MR | 3 | 1995 |
| Xylenes, Total | MR | 3 | 1995 |
| Benzene | MR | 3 | 1995 |
| Carbon tetrachloride | MR | 3 | 1995 |
| cis-1,2-Dichloroethylene | MR | 3 | 1995 |
| 1,1,2-Trichloroethane | MR | 3 | 1995 |
| o-Dichlorobenzene | MR | 3 | 1995 |
| CHLOROBENZENE | MR | 3 | 1995 |
| trans-1,2-Dichloroethylene | MR | 3 | 1995 |
| Tetrachloroethylene | MR | 3 | 1995 |
| Ethylbenzene | MR | 3 | 1995 |
Violation Count vs. the National Corpus
Delavan Waterworks has 88 recorded EPA violations, 70% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 29% carry more. 0% of this system's own violations are health-based (0 of 88), and it ranks #5,387 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)
88 Around the middle fewer violations than 29% 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
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 174 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| ADONA | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 9Cl-PF3ONS | 7/14/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 7/14/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFUnA | 7/14/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFOA | 7/14/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDoA | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDA | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 7/14/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 7/14/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 7/14/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 7/14/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFPeA | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 7/14/2025 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFPeS | 7/14/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 7/14/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFMPA | 7/14/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBS | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTA | 7/14/2025 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFTrDA | 7/14/2025 | <7.00 ppt | 7.00 ppt | Not Detected |
| NEtFOSAA | 7/14/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| NMeFOSAA | 7/14/2025 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFHxS | 7/14/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 7/14/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 4/21/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 4/21/2025 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFTrDA | 4/21/2025 | <7.00 ppt | 7.00 ppt | Not Detected |
| NEtFOSAA | 4/21/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| NMeFOSAA | 4/21/2025 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFBS | 4/21/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 4/21/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 4/21/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 4/21/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 4/21/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDA | 4/21/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 4/21/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFUnA | 4/21/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFOA | 4/21/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| 9Cl-PF3ONS | 4/21/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 4/21/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 4/21/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 4/21/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 4/21/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 4/21/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 4/21/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
Health-based violations on Delavan Waterworks
0 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for WI2650113.
Sources: EPA SDWIS · Wisconsin DNR, Drinking Water and Groundwater
Nationwide peers
88 violations · 8,451 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 with similar served population
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Delavan 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.