Stanislaus County, California
26 ZIP codes · Avg score 84/100 · Grade B · Updated 2026-06-03
Across Stanislaus County's 26 ZIP codes, EPA compliance data shows above-average performance — violation rates are minimal, none of the county's systems have triggered health-based MCL exceedances in recent cycles, and the county's scores have stayed above the national baseline across every recent reporting period.
How Stanislaus County Compares
How Stanislaus County Compares
Stanislaus County scores 11 points above the California state average (73/100) and 16 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Stanislaus County, California
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.3 (asthma 10%, diabetes 11.9%)
Estimated additional annual cost per homeowner: $2,209, driven primarily by sea_level
Infrastructure: 0.326% avg pipe failure probability, 9% of ZIPs at high risk
56% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Stanislaus County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 30 violations. Past 5 years: 62 total (62 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
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $2,209
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
180,458 housing units in Stanislaus County
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 Stanislaus County
Remediation costs are relatively manageable for most homeowners in Stanislaus 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 Stanislaus County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Stanislaus County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | City of Ceres, | 54,513 | 43 |
| 2 | City of Hughson, | 7,481 | 36 |
| 3 | Cobles Corner | 50 | 36 |
| 4 | City of Modesto, | 218,771 | 19 |
| 5 | City of Riverbank, | 24,834 | 19 |
37 total water systems serve Stanislaus County.
All ZIP Codes in Stanislaus County
26 ZIP codes tracked in Stanislaus County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 95352 | Modesto | 99 | A | 0 | — |
| 2 | 95356 | Modesto | 99 | A | 0 | $496K |
| 3 | 95397 | Modesto | 99 | A | 0 | — |
| 4 | 95350 | Modesto | 95 | A | 0 | $397K |
| 5 | 95353 | Modesto | 95 | A | 0 | — |
| 6 | 95355 | Modesto | 95 | A | 0 | $448K |
| 7 | 95357 | Modesto | 95 | A | 0 | $418K |
| 8 | 95386 | Waterford | 95 | A | 0 | $391K |
| 9 | 95351 | Modesto | 90 | A | 0 | $316K |
| 10 | 95354 | Modesto | 90 | A | 0 | $360K |
| 11 | 95358 | Modesto | 90 | A | 0 | $401K |
| 12 | 95363 | Patterson | 90 | A | 0 | $448K |
| 13 | 95323 | Hickman | 88 | A | 0 | $523K |
| 14 | 95328 | Keyes | 88 | A | 0 | $435K |
| 15 | 95316 | Denair | 87 | A | 0 | $454K |
| 16 | 95329 | La Grange | 83 | B | 5 (1 health) | $387K |
| 17 | 95361 | Oakdale | 83 | B | 2 (1 health) | $480K |
| 18 | 95360 | Newman | 76 | B | 2 (1 health) | $386K |
| 19 | 95313 | Crows Landing | 74 | B | 5 (2 health) | $596K |
| 20 | 95387 | Westley | 73 | B | 0 | $349K |
| 21 | 95307 | Ceres | 71 | B | 7 (6 health) | $402K |
| 22 | 95326 | Hughson | 70 | B | 36 (35 health) | $499K |
| 23 | 95382 | Turlock | 70 | B | 0 | $483K |
| 24 | 95381 | Turlock | 66 | C | 0 | — |
| 25 | 95380 | Turlock | 65 | C | 0 | $410K |
| 26 | 95367 | Riverbank | 62 | C | 17 (17 health) | $445K |
Recommended Buyer Guides for Stanislaus County
While many sites publish identical guide lists across every county they cover, the selection here changes by location — driven by the EPA, NSF, FEMA, and CDC datasets that describe the actual conditions documented for this jurisdiction in the federal record.
- Best Water Filters for Lead — Lead above EPA action level in 3 ZIP codes
- Best Lead Paint Test Kits — 56% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for Stanislaus County, California
Overview
Stanislaus County in California covers 26 ZIP codes with an average Home Safety Score of B (84/100).
7 of 26 ZIP codes have recorded EPA violations. 63 health-based violations have been documented.
← Back to California water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.