Santa Clara County, California
104 ZIP codes · Avg score 78/100 · Grade B · Updated 2026-06-04
In recent assessments, Santa Clara County's 104 ZIP codes record strong, consistent water safety outcomes.
How Santa Clara County Compares
How Santa Clara County Compares
Santa Clara County scores 5 points above the California state average (73/100) and 10 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Santa Clara County, California
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 9 (asthma 7.9%, diabetes 10.5%)
Estimated additional annual cost per homeowner: $3,980, driven primarily by sea_level
Infrastructure: 0.312% avg pipe failure probability, 12% of ZIPs at high risk
Violation History (2021–2024)
↑ Worsening trendEPA violation counts by year across Santa Clara County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 71 violations. Past 5 years: 100 total (100 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: $3,980
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Santa Clara County
Remediation costs are relatively manageable for most homeowners in Santa Clara 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 Santa Clara 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 Santa Clara County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | SAN JOSE WATER | 1,039,920 | 64 |
| 2 | Cws - Bakersfield | 267,881 | 57 |
| 3 | California Water Service - Stockton | 176,266 | 57 |
| 4 | City of Bakersfield, | 160,144 | 57 |
| 5 | California Water Service Company - Ela | 152,474 | 57 |
47 total water systems serve Santa Clara County.
All ZIP Codes in Santa Clara County
104 ZIP codes tracked in Santa Clara County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 94023 | Los Altos | 83 | B | 0 | — |
| 2 | 94302 | Palo Alto | 83 | B | 0 | — |
| 3 | 94304 | Palo Alto | 83 | B | 0 | $2000K |
| 4 | 94309 | Palo Alto | 83 | B | 0 | — |
| 5 | 95050 | Santa Clara | 83 | B | 0 | $1421K |
| 6 | 95052 | Santa Clara | 83 | B | 0 | — |
| 7 | 95053 | Santa Clara | 83 | B | 0 | — |
| 8 | 95054 | Santa Clara | 83 | B | 0 | $1475K |
| 9 | 95055 | Santa Clara | 83 | B | 0 | — |
| 10 | 95056 | Santa Clara | 83 | B | 0 | — |
| 11 | 95071 | Saratoga | 83 | B | 1 | — |
| 12 | 95140 | Mount Hamilton | 83 | B | 0 | $2000K |
| 13 | 95021 | Gilroy | 82 | B | 1 (1 health) | — |
| 14 | 95101 | San Jose | 82 | B | 1 (1 health) | — |
| 15 | 95103 | San Jose | 82 | B | 1 (1 health) | — |
| 16 | 95106 | San Jose | 82 | B | 1 (1 health) | — |
| 17 | 95108 | San Jose | 82 | B | 1 (1 health) | — |
| 18 | 95109 | San Jose | 82 | B | 1 (1 health) | — |
| 19 | 95111 | San Jose | 82 | B | 1 (1 health) | $826K |
| 20 | 95113 | San Jose | 82 | B | 1 (1 health) | $953K |
| 21 | 95115 | San Jose | 82 | B | 1 (1 health) | — |
| 22 | 95117 | San Jose | 82 | B | 1 (1 health) | $1425K |
| 23 | 95118 | San Jose | 82 | B | 1 (1 health) | $1377K |
| 24 | 95119 | San Jose | 82 | B | 1 (1 health) | $1176K |
| 25 | 95121 | San Jose | 82 | B | 1 (1 health) | $1025K |
| 26 | 95123 | San Jose | 82 | B | 1 (1 health) | $1108K |
| 27 | 95124 | San Jose | 82 | B | 1 (1 health) | $1597K |
| 28 | 95126 | San Jose | 82 | B | 1 (1 health) | $1196K |
| 29 | 95128 | San Jose | 82 | B | 1 (1 health) | $1215K |
| 30 | 95129 | San Jose | 82 | B | 1 (1 health) | $2000K |
| 31 | 95130 | San Jose | 82 | B | 1 (1 health) | $1775K |
| 32 | 95131 | San Jose | 82 | B | 1 (1 health) | $1134K |
| 33 | 95133 | San Jose | 82 | B | 1 (1 health) | $1074K |
| 34 | 95134 | San Jose | 82 | B | 1 (1 health) | $371K |
| 35 | 95135 | San Jose | 82 | B | 1 (1 health) | $1459K |
| 36 | 95136 | San Jose | 82 | B | 1 (1 health) | $1104K |
| 37 | 95138 | San Jose | 82 | B | 1 (1 health) | $1355K |
| 38 | 95139 | San Jose | 82 | B | 1 (1 health) | $1125K |
| 39 | 95141 | San Jose | 82 | B | 1 (1 health) | — |
| 40 | 95150 | San Jose | 82 | B | 1 (1 health) | — |
| 41 | 95151 | San Jose | 82 | B | 1 (1 health) | — |
| 42 | 95152 | San Jose | 82 | B | 1 (1 health) | — |
| 43 | 95153 | San Jose | 82 | B | 1 (1 health) | — |
| 44 | 95154 | San Jose | 82 | B | 1 (1 health) | — |
| 45 | 95155 | San Jose | 82 | B | 1 (1 health) | — |
| 46 | 95156 | San Jose | 82 | B | 1 (1 health) | — |
| 47 | 95157 | San Jose | 82 | B | 1 (1 health) | — |
| 48 | 95158 | San Jose | 82 | B | 1 (1 health) | — |
| 49 | 95159 | San Jose | 82 | B | 1 (1 health) | — |
| 50 | 95160 | San Jose | 82 | B | 1 (1 health) | — |
| 51 | 95161 | San Jose | 82 | B | 1 (1 health) | — |
| 52 | 95164 | San Jose | 82 | B | 1 (1 health) | — |
| 53 | 95170 | San Jose | 82 | B | 1 (1 health) | — |
| 54 | 95172 | San Jose | 82 | B | 1 (1 health) | — |
| 55 | 95173 | San Jose | 82 | B | 1 (1 health) | — |
| 56 | 95190 | San Jose | 82 | B | 1 (1 health) | — |
| 57 | 95191 | San Jose | 82 | B | 1 (1 health) | — |
| 58 | 95192 | San Jose | 82 | B | 1 (1 health) | — |
| 59 | 95193 | San Jose | 82 | B | 1 (1 health) | — |
| 60 | 95194 | San Jose | 82 | B | 1 (1 health) | — |
| 61 | 95196 | San Jose | 82 | B | 1 (1 health) | — |
| 62 | 95036 | Milpitas | 81 | B | 2 | — |
| 63 | 95032 | Los Gatos | 79 | B | 2 (1 health) | $2000K |
| 64 | 94022 | Los Altos | 78 | B | 0 | $2000K |
| 65 | 94024 | Los Altos | 78 | B | 0 | $2000K |
| 66 | 94306 | Palo Alto | 78 | B | 0 | $2000K |
| 67 | 95031 | Los Gatos | 78 | B | 2 (1 health) | — |
| 68 | 95051 | Santa Clara | 78 | B | 0 | $1624K |
| 69 | 95070 | Saratoga | 78 | B | 1 | $2000K |
| 70 | 95020 | Gilroy | 77 | B | 1 (1 health) | $1006K |
| 71 | 95038 | Morgan Hill | 77 | B | 3 (1 health) | — |
| 72 | 95120 | San Jose | 77 | B | 1 (1 health) | $1925K |
| 73 | 95122 | San Jose | 77 | B | 1 (1 health) | $839K |
| 74 | 95127 | San Jose | 77 | B | 1 (1 health) | $995K |
| 75 | 95132 | San Jose | 77 | B | 1 (1 health) | $1264K |
| 76 | 95148 | San Jose | 77 | B | 1 (1 health) | $1211K |
| 77 | 94040 | Mountain View | 76 | B | 0 | $2000K |
| 78 | 94043 | Mountain View | 76 | B | 0 | $1648K |
| 79 | 94085 | Sunnyvale | 75 | B | 0 | $1535K |
| 80 | 94086 | Sunnyvale | 75 | B | 0 | $1784K |
| 81 | 94087 | Sunnyvale | 75 | B | 0 | $2000K |
| 82 | 94089 | Sunnyvale | 75 | B | 0 | $392K |
| 83 | 95013 | Coyote | 75 | B | 0 | — |
| 84 | 94035 | Mountain View | 74 | B | 0 | — |
| 85 | 94039 | Mountain View | 74 | B | 0 | — |
| 86 | 94041 | Mountain View | 74 | B | 0 | $2000K |
| 87 | 94042 | Mountain View | 74 | B | 0 | — |
| 88 | 95030 | Los Gatos | 74 | B | 2 (1 health) | $2000K |
| 89 | 94301 | Palo Alto | 73 | B | 0 | $2000K |
| 90 | 94088 | Sunnyvale | 72 | B | 0 | — |
| 91 | 94305 | Stanford | 72 | B | 0 | $2000K |
| 92 | 95015 | Cupertino | 72 | B | 0 | — |
| 93 | 95110 | San Jose | 72 | B | 1 (1 health) | $948K |
| 94 | 95112 | San Jose | 72 | B | 1 (1 health) | $956K |
| 95 | 95116 | San Jose | 72 | B | 1 (1 health) | $843K |
| 96 | 95125 | San Jose | 72 | B | 1 (1 health) | $1646K |
| 97 | 95035 | Milpitas | 71 | B | 2 | $1181K |
| 98 | 95014 | Cupertino | 70 | B | 0 | $2000K |
| 99 | 94303 | Palo Alto | 68 | C | 0 | $1825K |
| 100 | 95037 | Morgan Hill | 67 | C | 3 (1 health) | $1152K |
| 101 | 95026 | Holy City | 53 | D | 0 | — |
| 102 | 95044 | Redwood Estates | 53 | D | 0 | — |
| 103 | 95002 | Alviso | 50 | D | 0 | $1023K |
| 104 | 95046 | San Martin | 46 | D | 1 | $1397K |
Recommended Buyer Guides for Santa Clara 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 1 ZIP code
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for Santa Clara County, California
Overview
Santa Clara County in California covers 104 ZIP codes with an average Home Safety Score of B (78/100).
69 of 104 ZIP codes have recorded EPA violations. 64 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.