Community Water System · PWS CA4910027
Sonoma State University
Operator location Rohnert Park, California - 55% of 22 violations are health-based (upper-third health share (> 23%)); groundwater source; 10,986 served per SDWIS.
- 10,986
- People served (this PWS)
- 22
- EPA violations (this PWS)
- 12
- Health-based (this PWS)
- No PFAS
- UCMR5 (this PWS)
Sonoma State University standing, mid SDWIS violation third
55% of 22 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 55% is upper-third health share (> 23%). UCMR5: UCMR5 tested, none detected. Population rank #4,384 of 29,740 among systems serving 500+.
The verdict
Sonoma State University lands in the middle third by violation volume (22), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is large (10,986; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 55% - most of this ledger is MCL or treatment-technique exceedance. UCMR5 tested this system and reported no PFAS above the minimum reporting level.
- #4,384 of 29,740
- Population · /systems
- #462 of 1,701
- Population · CA
- 22
- Total EPA violations on record
- 55%
- 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
- State
- Connections
- 93
- County
- Sonoma
- School/Daycare
- Yes
- MCL Violations
- 10
- Monitoring Violations
- 7
- Treatment Tech Violations
- 2
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 10 | 2004 |
| Coliform (TCR) | MR | 4 | 2011 |
| Lead and Copper Rule | MR | 3 | 2017 |
| Groundwater Rule | TT | 2 | 2017 |
Violation Count vs. the National Corpus
Sonoma State University has 22 recorded EPA violations, 34% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 65% carry more. 55% of this system's own violations are health-based (12 of 22), and it ranks #4,384 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)
22 Lower than most fewer violations than 65% 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 54 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFDA | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 6/4/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 6/4/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 6/4/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 6/4/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| HFPO-DA | 6/4/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| ADONA | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 9Cl-PF3ONS | 6/4/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 6/4/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFUnA | 6/4/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFDoA | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 6/4/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 6/4/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFNA | 6/4/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxS | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 6/4/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| NFDHA | 6/4/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFEESA | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 6/4/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 12/5/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 12/5/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 12/5/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 12/5/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 12/5/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 12/5/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 12/5/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 12/5/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| NEtFOSAA | 12/5/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTrDA | 12/5/2023 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFUnA | 12/5/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| NMeFOSAA | 12/5/2023 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFPeS | 12/5/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFTA | 12/5/2023 | <8.00 ppt | 8.00 ppt | Not Detected |
| NFDHA | 12/5/2023 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFMBA | 12/5/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 12/5/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 12/5/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 12/5/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 12/5/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFEESA | 12/5/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 12/5/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 12/5/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 12/5/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFOS | 12/5/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
Health-based violations on Sonoma State University
12 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for CA4910027.
Sources: EPA SDWIS · California State Water Resources Control Board, Division of Drinking Water
Nationwide peers
22 violations · 10,986 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 Sonoma State University
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in California compares on the same EPA violation measures. California 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.