COUNTY REPORT CA

Sonoma County, California

52 ZIP codes · Avg score 95/100 · Grade A · Updated

ZipCheckup grade for Sonoma County: A.

No federal data flags a major home-safety concern for this ZIP.

Sonoma County - 52 ZIP codes, above-average safety grade.

How Sonoma County Compares

Sonoma County95/100
California avg76/100
National avg73/100

How Sonoma County Compares

A
County Grade
95/100
Avg Safety Score
52
ZIP Codes
48
Water Systems

Sonoma County scores 19 points above the California state average (76/100) and 22 points above the national average (73/100).

Data: ZipCheckup Home Safety Score model 4.0.0; EPA SDWIS, UCMR 5, EPA radon zones, EPA AirData Last verified:

A
County Grade
95
Avg Safety Score
52
ZIP Codes
Best ZIP: 94556 (100/100)
Lowest ZIP: 95476 (69/100)
$798K
Median Home Value
$1,430
Avg Remediation (18% of home value)

ZIP Code Risk Map

Water Quality Map: Sonoma County, California

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 11.3 (asthma 9.8%, diabetes 10.7%)

Estimated additional annual cost per homeowner: $3,058, driven primarily by flood

64.8% of homes built before 1978 (lead paint era)

Violation History (2021–2025)

↑ Worsening trend

EPA violation counts by year across Sonoma County water systems. Health-based shown in red, total in blue.

2021
3 (3 health)
2022
4 (4 health)
2023
11 (11 health)
2024
15 (15 health)
2025
4 (4 health)

Peak year: 2024 with 15 violations. Past 5 years: 37 total (37 health-based). Health-based violations are rising versus the prior 2-year window - worth closer monitoring.

Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.

County Health Indicators vs National Average

Asthma 9.8% (national: 8.9%)
Diabetes 10.7% (national: 10.5%)
Obesity 26.1% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1976
Median Build Year
64.8%
Pre-1978 Housing
37/100
Infrastructure Stress Indicator
33%
ZIPs with High Infrastructure Stress
Low
Lead Pipe Risk

Modeled area-level indicator, not a failure probability. Sources: Census ACS housing age, EPA DWINS infrastructure needs, EPA SDWIS violations, and EPA lead indicators.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $3,058

Flood $1,130/yr
Wildfire $802/yr
Sea Level Rise $738/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

211,740 housing units in Sonoma County

Pre-1940 8%
1940–1959 13%
1960–1979 33%
1980–1999 31%
2000+ 16%

Source: U.S. Census Bureau ACS B25034 (Year Structure Built).

Water Safety Affordability

How much it costs to fix water issues relative to home values in Sonoma County

$798K
Median Home Value
$1,430
Est. Remediation Cost
0.2%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Sonoma County, representing a small fraction of property value.

Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.

Health Outcomes vs National Average

CDC PLACES data for Sonoma County residents

Asthma 9.8% (US avg: 8.9%)
Diabetes 10.7% (US avg: 11%)
Obesity 26.1% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water systems serving Sonoma County

8 community water systems serving Sonoma County.

Show all 8 water systems

48 total water systems serve Sonoma County.

Systems with the most violations in Sonoma County

5 water systems with recorded EPA violations.

All ZIP Codes in Sonoma County

52 ZIP codes tracked in Sonoma County.

# ZIP Code City Safety Score Grade Violations Home Value
1 94556 Moraga 100 A 0 $1594K
2 95401 Santa Rosa 100 A 0 $629K
3 95403 Santa Rosa 100 A 1 $652K
4 95436 Forestville 100 A 2 $704K
5 95446 Guerneville 100 A 2 $586K
6 95492 Windsor 100 A 1 $778K
7 94931 Cotati 99 A 2 $788K
8 94952 Petaluma 99 A 2 $1017K
9 94954 Petaluma 99 A 2 $790K
10 95407 Santa Rosa 99 A 2 $603K
11 95425 Cloverdale 99 A 1 $647K
12 95441 Geyserville 99 A 1 $1278K
13 95448 Healdsburg 99 A 5 $1030K
14 95472 Sebastopol 96 A 4 (1 health) $995K
15 95405 Santa Rosa 95 A 3 (2 health) $750K
16 95409 Santa Rosa 95 A 3 (1 health) $808K
17 95497 The Sea Ranch 95 A 4 (1 health) $1198K
18 95404 Santa Rosa 89 A 11 (3 health) $866K
19 95442 Glen Ellen 83 B 0 $1361K
20 94928 Rohnert Park 81 B 4 $635K
21 95476 Sonoma 69 C 9 (3 health) $882K
22 94922 Bodega
23 94923 Bodega Bay 0 $1178K
24 94926 Rohnert Park
25 94927 Rohnert Park
26 94951 Penngrove 2 $1213K
27 94953 Petaluma
28 94955 Petaluma
29 94972 Valley Ford 0
30 94975 Petaluma
31 94999 Petaluma
32 95402 Santa Rosa
33 95406 Santa Rosa
34 95412 Annapolis $746K
35 95416 Boyes Hot Springs
36 95419 Camp Meeker
37 95421 Cazadero 5 (1 health) $643K
38 95430 Duncans Mills 0
39 95431 Eldridge
40 95433 El Verano
41 95439 Fulton 0 $818K
42 95444 Graton $866K
43 95450 Jenner 5 (1 health) $798K
44 95452 Kenwood 1 $969K
45 95462 Monte Rio 0 $714K
46 95465 Occidental 0 $1123K
47 95466 Philo $699K
48 95471 Rio Nido 0 $618K
49 95473 Sebastopol
50 95480 Stewarts Point
51 95486 Villa Grande
52 95487 Vineburg

Recommended Buyer Guides for Sonoma County

Filtered against federal data, fitted to local risks.

Overview

Sonoma County in California covers 52 tracked ZIP records with an average Home Safety Score of A (95/100) across 21 scored records.

22 of 32 ZIP codes with a reported violation count in the available EPA record have recorded EPA violations. 8 health-based violations appear in the available health breakdown.

← Back to California Home Safety Profile

Data Sources

Reporting periods vary by source. Missing data is shown as unavailable, not as zero.

Frequently Asked Questions

Is water safe in Sonoma County?
Sonoma County receives a grade of A, indicating generally safe tap water across its 52 ZIP codes.
How many water systems serve Sonoma County?
Sonoma County is served by 48 public water systems that supply drinking water to residents across 52 ZIP codes.
What is the biggest environmental risk in Sonoma County?
The primary environmental risk factor in Sonoma County is flood. This contributes to an estimated additional annual cost of $3,058 per homeowner.
How old are homes in Sonoma County?
The median home build year in Sonoma County is 1976. 64.8% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Sonoma County compare to California?
Sonoma County has an average Home Safety Score of 95/100 under model 4.0.0, which is above the California state average of 76/100.

How to cite this page

APA ZipCheckup. (2026). Sonoma County, CA: HSS 95/100; 8 Health Violations. https://zipcheckup.com/county/california/sonoma/
BibTeX
@misc{zipcheckup-county-california-sonoma,
  author = {{ZipCheckup}},
  title  = {{Sonoma County, CA: HSS 95/100; 8 Health Violations}},
  year   = {2026},
  url    = {https://zipcheckup.com/county/california/sonoma/}
}

Page version: August 2026.

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