Community Water System · PWS WI2460111
Grafton Waterworks
Operator location Grafton, Wisconsin - larger served population (> 3,309) at 12,269 people served; 237 SDWIS violations on record from groundwater sources.
- 12,269
- People served (this PWS)
- 237
- EPA violations (this PWS)
- 6
- Health-based (this PWS)
- No PFAS
- UCMR5 (this PWS)
Grafton Waterworks standing, high SDWIS violation third
12,269 people served (SDWIS) - larger served population (> 3,309). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 3% is middle-third health share (≤ 23%). UCMR5: UCMR5 tested, none detected. Population rank #4,049 of 29,740 among systems serving 500+.
The verdict
Grafton Waterworks sits in the upper third of the sitemap cohort by violation count (237), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (12,269; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 3% (middle-third health share (≤ 23%)). UCMR5 tested this system and reported no PFAS above the minimum reporting level.
- #4,049 of 29,740
- Population · /systems
- #71 of 744
- Population · WI
- 237
- Total EPA violations on record
- 3%
- 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
- 4,544
- County
- Ozaukee
- School/Daycare
- No
- MCL Violations
- 6
- Monitoring Violations
- 206
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Tetrachloroethylene | MR | 9 | 2004 |
| 1,1,2-Trichloroethane | MR | 9 | 2004 |
| 1,1,1-Trichloroethane | MR | 9 | 2004 |
| trans-1,2-Dichloroethylene | MR | 9 | 2004 |
| Toluene | MR | 9 | 2004 |
| o-Dichlorobenzene | MR | 9 | 2004 |
| p-Dichlorobenzene | MR | 9 | 2004 |
| Vinyl chloride | MR | 9 | 2004 |
| cis-1,2-Dichloroethylene | MR | 9 | 2004 |
| DICHLOROMETHANE | MR | 9 | 2004 |
| CHLOROBENZENE | MR | 9 | 2004 |
| 1,2,4-Trichlorobenzene | MR | 9 | 2004 |
| 1,2-Dichloroethane | MR | 9 | 2004 |
| 1,2-Dichloropropane | MR | 9 | 2004 |
| Styrene | MR | 9 | 2004 |
| Ethylbenzene | MR | 9 | 2004 |
| Benzene | MR | 9 | 2004 |
| Trichloroethylene | MR | 9 | 2004 |
| 1,1-Dichloroethylene | MR | 9 | 2004 |
| Xylenes, Total | MR | 9 | 2004 |
| Carbon tetrachloride | MR | 9 | 2004 |
| Coliform (TCR) | MCL | 6 | 2000 |
| Coliform (TCR) | MR | 5 | 2006 |
| Total Haloacetic Acids (HAA5) | MR | 5 | 2008 |
| TTHM | MR | 5 | 2008 |
| Public Notice | Other | 2 | 2004 |
| Consumer Confidence Rule | Other | 2 | 2002 |
| Lead and Copper Rule | MR | 1 | 1999 |
| CYANIDE | MR | 1 | 1996 |
Violation Count vs. the National Corpus
Grafton Waterworks has 237 recorded EPA violations, 88% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 12% carry more. 3% of this system's own violations are health-based (6 of 237), and it ranks #4,049 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)
237 Higher than most more violations than 88% 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 348 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFMPA | 9/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 9/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NFDHA | 9/18/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFPeA | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 9/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHpS | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTA | 9/18/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| NEtFOSAA | 9/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTrDA | 9/18/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFHpA | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 9/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBS | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 9/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHxS | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 9/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 9/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 9/18/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDA | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NMeFOSAA | 9/18/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFUnA | 9/18/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/18/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 9/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 9/18/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFDoA | 9/18/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NMeFOSAA | 4/10/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| NEtFOSAA | 4/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTrDA | 4/10/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFTA | 4/10/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFHpS | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 4/10/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFMBA | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 4/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 4/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 4/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 6:2 FTS | 4/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFOS | 4/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDA | 4/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 4/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
Population served record for Grafton Waterworks
EPA SDWIS lists 12,269 people served and 4,544 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS · Wisconsin DNR, Drinking Water and Groundwater
Nationwide peers
237 violations · 12,269 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 Grafton 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.