D31/100
Rohnert Park Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 54,807 residents · California
What's In Rohnert Park's Tap Water?
66
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
vanadium | 25.00 µg/L | — | Above Goal |
EPA Violation History
1
Violation (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Monitoring Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2021 – July 31, 2021Rule: Total Coliform RuleEnforcement: Formal — state order issued
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
ROHNERT PARK, CITY OF
Population Served
43,821
Water Source
Groundwater
System ID
CA4910014
SONOMA STATE UNIVERSITY
Population Served
10,986
Water Source
Groundwater
System ID
CA4910027
Frequently Asked Questions About Rohnert Park Water
Is Rohnert Park tap water safe to drink?
Rohnert Park, California tap water receives a grade of D (31/100), which is considered poor. 0 contaminant(s) exceed EPA maximum contaminant levels and 291 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Rohnert Park's water?
Of the 66 contaminants tested in Rohnert Park's water supply, the most notable include vanadium. No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Rohnert Park have any water quality violations?
Yes, Rohnert Park has 291 EPA violation(s) on record, with the most recent in 2021. Violation types include MON, MR, TT. 8 of these are health-based violations, which are the most serious category.
Do I need a water filter in Rohnert Park?
Rohnert Park water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does Rohnert Park's tap water come from?
Rohnert Park's drinking water is sourced from groundwater and supplied by ROHNERT PARK, CITY OF and 1 other water system(s). The system serves approximately 54,807 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Rohnert Park's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Rohnert Park's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Rohnert Park's water compare to other cities in California?
Rohnert Park's water quality score of 31/100 earns a grade of D, which is considered poor. This is a concerning score that suggests significant water quality issues. Visit our California state page to see how all cities in the state compare.
What should I do if I'm concerned about Rohnert Park's water quality?
If you have concerns about Rohnert Park's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (ROHNERT PARK, CITY OF) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.