COUNTY REPORT CA

Imperial County, California

22 ZIP codes · Avg score 80/100 · Grade B · Updated 2026-06-03

Throughout Imperial County, the 22 monitored ZIP codes show low violation rates and healthy safety scores — a pattern that puts the county well above the state baseline for drinking water quality.

How Imperial County Compares

Imperial County80/100
California avg73/100
National avg68/100

How Imperial County Compares

B
County Grade
80/100
Avg Safety Score
22
ZIP Codes
36
Water Systems

Imperial County scores 7 points above the California state average (73/100) and 12 points above the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-03

B
County Grade
80
Avg Safety Score
22
ZIP Codes
Best ZIP: 92283 (93/100)
Lowest ZIP: 92257 (65/100)
$272K
Median Home Value
$1,174
Avg Remediation (43% of home value)

ZIP Code Risk Map

Water Quality Map: Imperial 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: 12 (asthma 9.2%, diabetes 14.3%)

Estimated additional annual cost per homeowner: $1,372, driven primarily by wildfire

Infrastructure: 0.318% avg pipe failure probability, 5% of ZIPs at high risk

52.2% of homes built before 1978 (lead paint era)

Violation History (2021–2024)

↑ Worsening trend

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

2021
6 (6 health)
2022
4 (4 health)
2023
4 (4 health)
2024
28 (28 health)

Peak year: 2024 with 28 violations. Past 5 years: 42 total (42 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 9.2% (national: 8.9%)
Diabetes 14.3% (national: 10.5%)
Obesity 33.1% (national: 32.4%)

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

Infrastructure Overview

1982
Median Build Year
52.2%
Pre-1978 Housing
32%
Pipe Failure Probability
5%
ZIPs at High Infra Risk
Low
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $1,372

Wildfire $532/yr
Energy Code Gap $307/yr
Flood $236/yr

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

Housing Age Distribution

113,953 housing units in Imperial County

Pre-1940 1%
1940–1959 8%
1960–1979 34%
1980–1999 36%
2000+ 20%

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 Imperial County

$272K
Median Home Value
$1,174
Est. Remediation Cost
0.4%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Imperial 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 Imperial County residents

Asthma 9.2% (US avg: 8.9%)
Diabetes 14.3% (US avg: 11%)
Obesity 33.1% (US avg: 32.4%)

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

Water Systems with Most Violations

Top 5 systems in Imperial County ranked by EPA violation count.

# Water System Population Violations
1 City of Calexico, 40,357 25
2 Naf El Centro 637 20
3 City of El Centro, 43,772 17
4 Valley Mobile Home Park 70 14
5 Gateway 1,800 14

36 total water systems serve Imperial County.

All ZIP Codes in Imperial County

22 ZIP codes tracked in Imperial County.

# ZIP Code City Safety Score Grade Violations Home Value
1 92283 Winterhaven 93 A 12 (2 health) $91K
2 92250 Holtville 91 A 3 (1 health) $279K
3 92251 Imperial 91 A 3 (1 health) $350K
4 92259 Ocotillo 91 A 4 (1 health) $159K
5 92231 Calexico 89 A 7 (2 health) $282K
6 92232 Calexico 89 A 7 (2 health)
7 92244 El Centro 89 A 7 (5 health)
8 92249 Heber 88 A 1 $284K
9 92227 Brawley 87 A 1 $272K
10 92243 El Centro 87 A 7 (5 health) $286K
11 92273 Seeley 83 B 3 (1 health) $191K
12 92266 Palo Verde 80 B 9 (4 health)
13 92281 Westmorland 78 B 4 (2 health) $222K
14 92233 Calipatria 73 B 0 $177K
15 92242 Earp 73 B 0 $134K
16 92656 Aliso Viejo 73 B 0 $850K
17 92691 Mission Viejo 73 B 0 $917K
18 92222 Bard 66 C 0
19 92274 Thermal 66 C 7 (4 health) $140K
20 92280 Vidal 66 C 0
21 92637 Laguna Woods 66 C 0 $365K
22 92257 Niland 65 C 0 $113K

Recommended Buyer Guides for Imperial County

Filtered against EPA monitoring data and CDC lead-exposure guidance, the guides below skip the generic catalog and connect directly to the contaminants and hazards on file here.

Overview

Imperial County in California covers 22 ZIP codes with an average Home Safety Score of B (80/100).

14 of 22 ZIP codes have recorded EPA violations. 30 health-based violations have been documented.

← Back to California water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in Imperial County?
Imperial County receives a grade of B, indicating generally safe tap water across its 22 ZIP codes.
How many water systems serve Imperial County?
Imperial County is served by 36 public water systems that supply drinking water to residents across 22 ZIP codes.
What is the biggest environmental risk in Imperial County?
The primary environmental risk factor in Imperial County is wildfire. This contributes to an estimated additional annual cost of $1,372 per homeowner.
How old are homes in Imperial County?
The median home build year in Imperial County is 1982. 52.2% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Imperial County compare to California?
Imperial County has an average water safety score of 80/100, which is above the California state average of 73/100.

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