Community Water System · PWS OR4100218
Cornelius, City Of
Operator location Cornelius, Oregon - 0% of 42 violations are health-based (lower-third health share (≤ 1%)); surface water source; 14,490 served per SDWIS.
- 14,490
- People served (this PWS)
- 42
- EPA violations (this PWS)
- 0
- Health-based (this PWS)
- No PFAS
- UCMR5 (this PWS)
Cornelius, City Of standing, mid SDWIS violation third
0% of 42 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 #3,567 of 29,740 among systems serving 500+.
The verdict
Cornelius, City Of lands in the middle third by violation volume (42), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is large (14,490; 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.
- #3,567 of 29,740
- Population · /systems
- #46 of 373
- Population · OR
- 42
- 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
- 4,153
- County
- Washington
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 35
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 17 | 2013 |
| Consumer Confidence Rule | Other | 7 | 2023 |
| TTHM | MR | 5 | 2022 |
| Total Haloacetic Acids (HAA5) | MR | 5 | 2022 |
| Lead and Copper Rule | MR | 2 | 2005 |
| Combined Radium (-226 and -228) | MR | 1 | 2020 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 2020 |
| COLIPHAGE | MR | 1 | 2024 |
| DICHLOROMETHANE | MR | 1 | 2022 |
| Revised Total Coliform Rule | MON | 1 | 2018 |
| Combined Uranium | MR | 1 | 2020 |
Violation Count vs. the National Corpus
Cornelius, City Of has 42 recorded EPA violations, 52% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 48% carry more. 0% of this system's own violations are health-based (0 of 42), and it ranks #3,567 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)
42 Around the middle fewer violations than 48% 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 145 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFHpA | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 4:2 FTS | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 7/31/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFTA | 7/31/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFHpS | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 7/31/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| NFDHA | 7/31/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFEESA | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NMeFOSAA | 7/31/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFUnA | 7/31/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFTrDA | 7/31/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFOS | 7/31/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 7/31/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDA | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 7/31/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxA | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 7/31/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 7/31/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 7/31/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NEtFOSAA | 7/31/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 7/31/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 7/31/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 8:2 FTS | 7/31/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFDoA | 7/31/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBA | 5/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHpS | 5/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 5/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| NFDHA | 5/28/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFEESA | 5/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 5/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 5/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 5/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 5/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| HFPO-DA | 5/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 5/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| ADONA | 5/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 9Cl-PF3ONS | 5/28/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 4:2 FTS | 5/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 5/28/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFOS | 5/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxA | 5/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 5/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFNA | 5/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBS | 5/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 5/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
Health-based violations on Cornelius, City Of
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 OR4100218.
Sources: EPA SDWIS
Nationwide peers
42 violations · 14,490 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 Cornelius, 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.