City of Santa Rosa
EPA ID: CA4910009 · 175,396 people served · 12 ZIP codes
ZipCheckup's reading of EPA records for City of Santa Rosa (CA4910009): no drinking-water violations recorded since 2021. Across the monitored periods in available EPA data, City of Santa Rosa has no violations listed for its service population of 175,396.
Data: EPA SDWIS
Service Area Map
Coverage area for City of Santa Rosa Source: EPA SDWIS service area boundaries.
Service area boundary - average Home Safety grade of mapped ZIPs: A
Demographics of ZIP Codes Served
The ZIP codes associated with City of Santa Rosa have a median household income of $113,853 and about 279,406 residents live in those ZIP codes (Census; not the number of people this system supplies). Approximately 67% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
City of Santa Rosa's water is classified in EPA records as a groundwater source. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
Infrastructure Risk
PFAS in ZIP Codes This System Serves
PFAS ("forever chemicals") have been reported in samples from water systems associated with the ZIP codes in this system's area. These results can come from other water systems serving the same ZIP codes; check the UCMR5 section for any results reported for this system. 6 detections recorded. 2 detections are above the level of a federal PFAS MCL (4 ppt for PFOA and PFOS), with compliance required from 2029.
Comparable Water Systems
Similar-sized systems in California
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
City of Santa Rosa, (EPA ID: CA4910009) is a community water system in California that serves approximately 175,396 people from groundwater sources.
This system provides water to 12 ZIP codes across 7 communities.
ZIP-Area Home Safety Context: A (96/100)
This is the average Home Safety Score for 6 of 12 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.
Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.0013 mg/L | No | 2025-12-31 |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
12 of 12 ZIP records with known zones are in EPA Radon Zone 3.
The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by CA or modeled from parcel and building-footprint data.
- 94574 - Saint Helena
- 95401 - Santa Rosa
- 95403 - Santa Rosa
- 95404 - Santa Rosa
- 95405 - Santa Rosa
- 95407 - Santa Rosa
- 95409 - Santa Rosa
- 95439 - Fulton
- 95442 - Glen Ellen
- 95452 - Kenwood
- 95472 - Sebastopol
- 95492 - Windsor
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View available EPA compliance records for City of Santa Rosa (CA4910009) on EPA.gov.
Frequently Asked Questions
Is City of Santa Rosa water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for City of Santa Rosa in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
How many people does City of Santa Rosa serve?
City of Santa Rosa serves approximately 175,396 people across 12 ZIP codes in California.
Where does City of Santa Rosa get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: No PFAS Reported Above Reporting Levels
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were reported above UCMR5 minimum reporting levels.
EPA's April 2024 PFAS rule sets MCLs of 4 ppt for PFOA and PFOS and 10 ppt for PFHxS, PFNA and HFPO-DA (GenX); water systems must comply from 2029. Other PFAS compounds have no individual federal MCL. A state standard is shown only where this system's state has its own enforceable PFAS limit. Detection results are EPA UCMR5 samples, not a measurement at your tap.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). City of Santa Rosa, CA: Serves 175K People. https://zipcheckup.com/water-system/ca4910009/
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