COUNTY REPORT CA

Contra Costa County, California

51 ZIP codes · Home Safety Score unavailable · 0 of 51 tracked ZIP records scored · Updated

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

Unavailable
0 of 51 tracked ZIP records scored
51
ZIP Codes
$794K
Median Home Value
$1,734
Avg Remediation (22% of home value)

ZIP Code Risk Map

Water Quality Map: Contra Costa 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: 10.7 (asthma 9.4%, diabetes 11.3%)

Estimated additional annual cost per homeowner: $2,892, driven primarily by sea_level

67.3% of homes built before 1978 (lead paint era)

Violation History (2021–2025)

↑ Worsening trend

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

2021
3 (3 health)
2022
5 (5 health)
2023
16 (16 health)
2024
35 (35 health)
2025
23 (23 health)

Peak year: 2024 with 35 violations. Past 5 years: 82 total (82 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 9.4% (national: 8.9%)
Diabetes 11.3% (national: 10.5%)
Obesity 28% (national: 32.4%)

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

Infrastructure Overview

1976
Median Build Year
67.3%
Pre-1978 Housing
43/100
Infrastructure Stress Indicator
59%
ZIPs with High Infrastructure Stress
High
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: $2,892

Sea Level Rise $1,118/yr
Flood $954/yr
Energy Code Gap $452/yr

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

Housing Age Distribution

420,819 housing units in Contra Costa County

Pre-1940 5%
1940–1959 19%
1960–1979 30%
1980–1999 28%
2000+ 17%

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 Contra Costa County

$794K
Median Home Value
$1,734
Est. Remediation Cost
0.2%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Contra Costa 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 Contra Costa County residents

Asthma 9.4% (US avg: 8.9%)
Diabetes 11.3% (US avg: 11%)
Obesity 28% (US avg: 32.4%)

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

Water systems serving Contra Costa County

8 community water systems serving Contra Costa County.

Show all 8 water systems

13 total water systems serve Contra Costa County.

All ZIP Codes in Contra Costa County

51 ZIP codes tracked in Contra Costa County.

# ZIP Code City Safety Score Grade Violations Home Value
1 94505 Discovery Bay 0 $788K
2 94506 Danville 0 $1790K
3 94507 Alamo 0 $2000K
4 94509 Antioch 0 $565K
5 94511 Bethel Island 0 $550K
6 94513 Brentwood 0 $794K
7 94514 Byron 0 $853K
8 94516 Canyon 0 $787K
9 94517 Clayton 0 $996K
10 94518 Concord 0 $827K
11 94519 Concord 0 $728K
12 94520 Concord 0 $572K
13 94521 Concord 0 $823K
14 94523 Pleasant Hill 0 $1038K
15 94524 Concord
16 94525 Crockett 0 $709K
17 94526 Danville 0 $1588K
18 94527 Concord
19 94528 Diablo 0 $2000K
20 94529 Concord
21 94530 El Cerrito 0 $1097K
22 94531 Antioch 0 $660K
23 94547 Hercules 0 $741K
24 94548 Knightsen 0 $918K
25 94549 Lafayette 0 $1969K
26 94553 Martinez 0 $781K
27 94561 Oakley 0 $632K
28 94563 Orinda 0 $1810K
29 94564 Pinole 0 $697K
30 94565 Pittsburg 0 $563K
31 94569 Port Costa 0 $587K
32 94570 Moraga
33 94572 Rodeo 0 $654K
34 94575 Moraga 0
35 94582 San Ramon 0 $1544K
36 94583 San Ramon 0 $1234K
37 94595 Walnut Creek 0 $817K
38 94596 Walnut Creek 0 $1245K
39 94597 Walnut Creek 0 $987K
40 94598 Walnut Creek 0 $1307K
41 94708 Berkeley 0 $1517K
42 94801 Richmond 0 $594K
43 94802 Richmond
44 94803 El Sobrante 0 $729K
45 94804 Richmond 0 $618K
46 94805 Richmond 0 $739K
47 94806 San Pablo 0 $582K
48 94807 Richmond
49 94808 Richmond
50 94820 El Sobrante
51 94850 Richmond

Recommended Buyer Guides for Contra Costa County

Below: editorial picks, no sponsored placements.

Overview

Contra Costa County in California covers 51 tracked ZIP records. No Home Safety Score is published because the required model evidence is incomplete for every tracked record; missing evidence is not treated as zero.

The available EPA record reports 0 violations for 42 ZIP codes with a reported violation count.

← 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

How many water systems serve Contra Costa County?
Contra Costa County is served by 13 public water systems that supply drinking water to residents across 51 ZIP codes.
What is the biggest environmental risk in Contra Costa County?
The primary environmental risk factor in Contra Costa County is sea_level. This contributes to an estimated additional annual cost of $2,892 per homeowner.
How old are homes in Contra Costa County?
The median home build year in Contra Costa County is 1976. 67.3% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.

How to cite this page

APA ZipCheckup. (2026). Contra Costa County, California Home Safety Profile. https://zipcheckup.com/county/california/contra-costa/
BibTeX
@misc{zipcheckup-county-california-contra-costa,
  author = {{ZipCheckup}},
  title  = {{Contra Costa County, California Home Safety Profile}},
  year   = {2026},
  url    = {https://zipcheckup.com/county/california/contra-costa/}
}

Page version: August 2026.

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