Community Water System · PWS OR4100954
Wilsonville, City Of
Operator location Wilsonville, Oregon - 39% of 44 violations are health-based (upper-third health share (> 23%)); surface water source; 25,915 served per SDWIS.
- 25,915
- People served (this PWS)
- 44
- EPA violations (this PWS)
- 17
- Health-based (this PWS)
- No PFAS
- UCMR5 (this PWS)
Wilsonville, City Of standing, mid SDWIS violation third
39% of 44 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 39% is upper-third health share (> 23%). UCMR5: UCMR5 tested, none detected. Population rank #2,146 of 29,740 among systems serving 500+.
The verdict
Wilsonville, City Of lands in the middle third by violation volume (44), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is large (25,915; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 39% - most of this ledger is MCL or treatment-technique exceedance. UCMR5 tested this system and reported no PFAS above the minimum reporting level.
- #2,146 of 29,740
- Population · /systems
- #32 of 373
- Population · OR
- 44
- Total EPA violations on record
- 39%
- 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
- 7,187
- County
- Clackamas
- School/Daycare
- No
- MCL Violations
- 17
- Monitoring Violations
- 24
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 17 | 1995 |
| Coliform (TCR) | MR | 10 | 2013 |
| Surface Water Treatment Rule | MR | 4 | 2018 |
| Nitrate | MR | 2 | 2000 |
| Interim Enhanced Surface Water Treatment Rule | MR | 2 | 2018 |
| Revised Total Coliform Rule | MON | 2 | 2018 |
| Public Notice | Other | 1 | 2013 |
| TTHM | MR | 1 | 2016 |
| Total Haloacetic Acids (HAA5) | MR | 1 | 2016 |
| Combined Radium (-226 and -228) | MR | 1 | 1976 |
| Consumer Confidence Rule | Other | 1 | 2025 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 1976 |
Violation Count vs. the National Corpus
Wilsonville, City Of has 44 recorded EPA violations, 53% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 46% carry more. 39% of this system's own violations are health-based (17 of 44), and it ranks #2,146 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)
44 Around the middle fewer violations than 46% 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 116 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| 6:2 FTS | 9/3/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 9/3/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 9/3/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 9/3/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| NFDHA | 9/3/2025 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFHpA | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBA | 9/3/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFDA | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOS | 9/3/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| NMeFOSAA | 9/3/2025 | <6.00 ppt | 6.00 ppt | Not Detected |
| NEtFOSAA | 9/3/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 9/3/2025 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFTrDA | 9/3/2025 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFHxA | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 9/3/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| HFPO-DA | 9/3/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFOA | 9/3/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDoA | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 9/3/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 9/3/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/3/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 9/3/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 6/2/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFMPA | 6/2/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHpA | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 6/2/2025 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFPeS | 6/2/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxS | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 6/2/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 6/2/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 6/2/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 6/2/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFDoA | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| NEtFOSAA | 6/2/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| HFPO-DA | 6/2/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 6/2/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTA | 6/2/2025 | <8.00 ppt | 8.00 ppt | Not Detected |
Health-based violations on Wilsonville, City Of
17 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for OR4100954.
Sources: EPA SDWIS
Nationwide peers
44 violations · 25,915 served: nearest cross-state SDWIS matches.
Cross-state systems near this violation count
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 Wilsonville, City Of
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Oregon compares on the same EPA violation measures. Oregon 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.