Is Rohnert Park, CA tap water safe?
Data: U.S. EPA · How we read the data · How we check it
Summary
No federal limits exceeded in EPA data for Marin Municipal Water District.
3 public water systems serve parts of Rohnert Park. The largest, Marin Municipal Water District, serves 188,116 people. Your water bill names your system.
Largest system
Marin Municipal Water District
188,116 people · Surface water · EPA ID CA2110002
Buys treated water from Sonoma County Water Agency.
| PFAS | Highest average | Limit |
|---|---|---|
| PFOA Not detected | – | 4 ppt |
| PFOS Not detected | – | 4 ppt |
| PFHxS Not detected | – | 10 ppt |
| PFNA Not detected | – | 10 ppt |
| HFPO-DA (GenX) Not detected | – | 10 ppt |
ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.
Lead: 0 ppb at the 90th percentile (Dec 2021, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0
Across California, 129 of 691 water systems EPA tested had PFAS above a 2024 federal limit, and 26 systems were above the lead action level in results from the last five years. California results.
Rohnert Park homes and lead pipes
Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.
Housing: Census American Community Survey 2020–2024 5-year estimates for Rohnert Park city (tables B25034, B25003). Estimates for small places have a margin of error.
Other water systems serving Rohnert Park
- City of Rohnert Park43,821 people · Groundwater · California · lists this cityPFOS detectedAlso: PFHxS detected · Lithium above screening level
- Sonoma State University Water System1,500 people · Groundwater · California · reported ZIPs hereNo PFAS above limitsAlso: 1 health-based violation since 2016
How nearby cities compare
| City | PFAS | Lead (90th pct.) |
|---|---|---|
| Santa Rosa 7 mi City of Santa Rosa | None above limits | 1.32 ppb |
| Petaluma 8 mi City of Petaluma | None above limits | 0 ppb |
| Windsor 15 mi Town of Windsor | None above limits | 0 ppb |
| Novato 20 mi Marin Municipal Water District | None above limits | 0 ppb |
| Napa 22 mi City of Napa | None above limits | 0 ppb |
| San Rafael 27 mi Marin Municipal Water District | None above limits | 0 ppb |
Rohnert Park ZIP codes (1)
- 94928
Questions
Is Rohnert Park tap water safe to drink?
Marin Municipal Water District has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.
Who supplies water in Rohnert Park, CA?
3 public water systems serve parts of Rohnert Park. The largest is Marin Municipal Water District (188,116 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.
Does Rohnert Park tap water have PFAS?
None detected above EPA's reporting limits. Marin Municipal Water District had no PFAS detected in EPA's 2023–2025 testing. "Not detected" means below the reporting limit (about 2 to 20 ppt), not proven zero.
Do Rohnert Park homes have lead pipes?
Census estimates put 43% of Rohnert Park homes as built before 1980 (California: 56%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Marin Municipal Water District's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.