San Diego County, California
187 ZIP codes · Avg score 72/100 · Grade B · Updated 2026-06-04
Throughout San Diego County, the 187 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 San Diego County Compares
How San Diego County Compares
San Diego County scores 1 points below the California state average (73/100) and 4 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: San Diego County, California
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 10.2 (asthma 8.9%, diabetes 10%)
Estimated additional annual cost per homeowner: $3,552, driven primarily by wildfire
Infrastructure: 0.347% avg pipe failure probability, 19% of ZIPs at high risk
Violation History (2021–2025)
↓ Improving trendEPA violation counts by year across San Diego County water systems. Health-based shown in red, total in blue.
Peak year: 2022 with 267 violations. Past 5 years: 629 total (629 health-based). Health-based violations are declining versus the prior 2-year window.
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: $3,552
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 San Diego County
Remediation costs are relatively manageable for most homeowners in San Diego 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 San Diego 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 San Diego County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | San Diego County Water Authority | — | 1061 |
| 2 | SAN DIEGO, CITY OF | 1,385,379 | 1056 |
| 3 | Nas North Island & Nab Coronado | 36,990 | 1040 |
| 4 | Butterfield Ranch | 353 | 1040 |
| 5 | Cottonwood Ridge Manufactured Housing Company | 205 | 1040 |
70 total water systems serve San Diego County.
All ZIP Codes in San Diego County
187 ZIP codes tracked in San Diego County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 91909 | Chula Vista | 99 | A | 0 | — |
| 2 | 91912 | Chula Vista | 99 | A | 0 | — |
| 3 | 91913 | Chula Vista | 99 | A | 0 | $750K |
| 4 | 91914 | Chula Vista | 99 | A | 0 | $960K |
| 5 | 91921 | Chula Vista | 99 | A | 0 | — |
| 6 | 91934 | Jacumba | 99 | A | 0 | $353K |
| 7 | 91943 | La Mesa | 99 | A | 0 | — |
| 8 | 91944 | La Mesa | 99 | A | 0 | — |
| 9 | 92013 | Carlsbad | 99 | A | 0 | — |
| 10 | 92018 | Carlsbad | 99 | A | 0 | — |
| 11 | 92023 | Encinitas | 99 | A | 1 | — |
| 12 | 92030 | Escondido | 99 | A | 0 | — |
| 13 | 92046 | Escondido | 99 | A | 0 | — |
| 14 | 92055 | Camp Pendleton | 99 | A | 1 | — |
| 15 | 92074 | Poway | 99 | A | 0 | — |
| 16 | 92085 | Vista | 99 | A | 0 | — |
| 17 | 92060 | Palomar Mountain | 98 | A | 2 | $625K |
| 18 | 91979 | Spring Valley | 97 | A | 1 | — |
| 19 | 91911 | Chula Vista | 95 | A | 0 | $602K |
| 20 | 91915 | Chula Vista | 95 | A | 0 | $720K |
| 21 | 92010 | Carlsbad | 95 | A | 0 | $1016K |
| 22 | 92011 | Carlsbad | 95 | A | 0 | $1188K |
| 23 | 92025 | Escondido | 95 | A | 0 | $767K |
| 24 | 92033 | Escondido | 95 | A | 0 | — |
| 25 | 92081 | Vista | 95 | A | 0 | $775K |
| 26 | 92082 | Valley Center | 95 | A | 0 | $780K |
| 27 | 92088 | Fallbrook | 95 | A | 0 | — |
| 28 | 92091 | Rancho Santa Fe | 95 | A | 0 | $1695K |
| 29 | 91933 | Imperial Beach | 94 | A | 1 (1 health) | — |
| 30 | 91976 | Spring Valley | 93 | A | 1 | — |
| 31 | 91978 | Spring Valley | 93 | A | 1 | $597K |
| 32 | 92061 | Pauma Valley | 91 | A | 2 | $785K |
| 33 | 91910 | Chula Vista | 90 | A | 0 | $677K |
| 34 | 91941 | La Mesa | 90 | A | 0 | $885K |
| 35 | 91942 | La Mesa | 90 | A | 0 | $689K |
| 36 | 92008 | Carlsbad | 90 | A | 0 | $1142K |
| 37 | 92009 | Carlsbad | 90 | A | 0 | $1220K |
| 38 | 92024 | Encinitas | 90 | A | 1 | $1410K |
| 39 | 92026 | Escondido | 90 | A | 0 | $664K |
| 40 | 92027 | Escondido | 90 | A | 0 | $666K |
| 41 | 92028 | Fallbrook | 90 | A | 0 | $781K |
| 42 | 92029 | Escondido | 90 | A | 0 | $912K |
| 43 | 92067 | Rancho Santa Fe | 90 | A | 0 | $2000K |
| 44 | 92083 | Vista | 90 | A | 0 | $607K |
| 45 | 92084 | Vista | 90 | A | 0 | $746K |
| 46 | 91932 | Imperial Beach | 89 | A | 1 (1 health) | $811K |
| 47 | 92049 | Oceanside | 88 | A | 0 | — |
| 48 | 92051 | Oceanside | 88 | A | 0 | — |
| 49 | 92052 | Oceanside | 88 | A | 0 | — |
| 50 | 92070 | Santa Ysabel | 87 | A | 3 (1 health) | $483K |
| 51 | 92064 | Poway | 85 | A | 0 | $972K |
| 52 | 91977 | Spring Valley | 83 | B | 1 | $624K |
| 53 | 92014 | Del Mar | 83 | B | 1 | $2000K |
| 54 | 92040 | Lakeside | 83 | B | 2 | $649K |
| 55 | 91906 | Campo | 82 | B | 3 (1 health) | $328K |
| 56 | 92056 | Oceanside | 82 | B | 0 | $696K |
| 57 | 92057 | Oceanside | 82 | B | 0 | $692K |
| 58 | 92058 | Oceanside | 82 | B | 0 | $609K |
| 59 | 92072 | Santee | 79 | B | 5 (4 health) | — |
| 60 | 92054 | Oceanside | 77 | B | 0 | $851K |
| 61 | 92004 | Borrego Springs | 76 | B | 2 | $381K |
| 62 | 92086 | Warner Springs | 76 | B | 1 | $430K |
| 63 | 91908 | Bonita | 74 | B | 9 | — |
| 64 | 92071 | Santee | 74 | B | 5 (4 health) | $655K |
| 65 | 91917 | Dulzura | 73 | B | 0 | $757K |
| 66 | 91945 | Lemon Grove | 73 | B | 0 | $641K |
| 67 | 91946 | Lemon Grove | 73 | B | 0 | — |
| 68 | 92003 | Bonsall | 73 | B | 0 | $911K |
| 69 | 92038 | La Jolla | 73 | B | 0 | — |
| 70 | 92065 | Ramona | 73 | B | 18 (3 health) | $732K |
| 71 | 92178 | Coronado | 73 | B | 0 | — |
| 72 | 92078 | San Marcos | 71 | B | 28 (6 health) | $874K |
| 73 | 91902 | Bonita | 69 | C | 9 | $916K |
| 74 | 91903 | Alpine | 69 | C | 11 (6 health) | — |
| 75 | 91935 | Jamul | 69 | C | 10 (6 health) | $845K |
| 76 | 92079 | San Marcos | 69 | C | 28 (6 health) | — |
| 77 | 92096 | San Marcos | 69 | C | 28 (6 health) | — |
| 78 | 91901 | Alpine | 66 | C | 11 (6 health) | $804K |
| 79 | 91905 | Boulevard | 66 | C | 0 | $388K |
| 80 | 91916 | Descanso | 66 | C | 0 | $616K |
| 81 | 91948 | Mount Laguna | 66 | C | 0 | $273K |
| 82 | 91951 | National City | 66 | C | 0 | — |
| 83 | 91980 | Tecate | 66 | C | 0 | — |
| 84 | 91987 | Tecate | 66 | C | 0 | — |
| 85 | 92022 | El Cajon | 66 | C | 0 | — |
| 86 | 92039 | La Jolla | 66 | C | 0 | — |
| 87 | 92059 | Pala | 66 | C | 0 | $507K |
| 88 | 92066 | Ranchita | 66 | C | 0 | $364K |
| 89 | 92068 | San Luis Rey | 66 | C | 0 | — |
| 90 | 92069 | San Marcos | 66 | C | 28 (6 health) | $715K |
| 91 | 92092 | La Jolla | 66 | C | 0 | — |
| 92 | 92093 | La Jolla | 66 | C | 0 | — |
| 93 | 92143 | San Ysidro | 66 | C | 0 | — |
| 94 | 92173 | San Ysidro | 66 | C | 0 | $522K |
| 95 | 92007 | Cardiff By The Sea | 65 | C | 0 | $1808K |
| 96 | 92019 | El Cajon | 65 | C | 0 | $727K |
| 97 | 92020 | El Cajon | 65 | C | 0 | $742K |
| 98 | 92021 | El Cajon | 65 | C | 0 | $572K |
| 99 | 92075 | Solana Beach | 65 | C | 0 | $1938K |
| 100 | 92104 | San Diego | 65 | C | 13 (4 health) | $862K |
| 101 | 92111 | San Diego | 65 | C | 13 (4 health) | $754K |
| 102 | 92118 | Coronado | 65 | C | 0 | $1999K |
| 103 | 92119 | San Diego | 65 | C | 13 (4 health) | $833K |
| 104 | 92122 | San Diego | 65 | C | 13 (4 health) | $1005K |
| 105 | 92123 | San Diego | 65 | C | 13 (4 health) | $800K |
| 106 | 92124 | San Diego | 65 | C | 13 (4 health) | $869K |
| 107 | 92126 | San Diego | 65 | C | 13 (4 health) | $802K |
| 108 | 92127 | San Diego | 65 | C | 13 (4 health) | $1165K |
| 109 | 92128 | San Diego | 65 | C | 13 (4 health) | $875K |
| 110 | 92129 | San Diego | 65 | C | 13 (4 health) | $1018K |
| 111 | 92130 | San Diego | 65 | C | 13 (4 health) | $1603K |
| 112 | 92131 | San Diego | 65 | C | 13 (4 health) | $1108K |
| 113 | 92139 | San Diego | 65 | C | 13 (4 health) | $599K |
| 114 | 92036 | Julian | 63 | C | 10 (4 health) | $545K |
| 115 | 91950 | National City | 60 | C | 0 | $581K |
| 116 | 92037 | La Jolla | 60 | C | 0 | $1858K |
| 117 | 92102 | San Diego | 60 | C | 13 (4 health) | $647K |
| 118 | 92103 | San Diego | 60 | C | 13 (4 health) | $987K |
| 119 | 92105 | San Diego | 60 | C | 13 (4 health) | $594K |
| 120 | 92106 | San Diego | 60 | C | 13 (4 health) | $1359K |
| 121 | 92107 | San Diego | 60 | C | 13 (4 health) | $1218K |
| 122 | 92110 | San Diego | 60 | C | 13 (4 health) | $885K |
| 123 | 92112 | San Diego | 60 | C | 13 (4 health) | — |
| 124 | 92114 | San Diego | 60 | C | 13 (4 health) | $604K |
| 125 | 92115 | San Diego | 60 | C | 13 (4 health) | $723K |
| 126 | 92116 | San Diego | 60 | C | 13 (4 health) | $899K |
| 127 | 92117 | San Diego | 60 | C | 13 (4 health) | $914K |
| 128 | 92132 | San Diego | 60 | C | 13 (4 health) | — |
| 129 | 92133 | San Diego | 60 | C | 13 (4 health) | — |
| 130 | 92134 | San Diego | 60 | C | 13 (4 health) | — |
| 131 | 92135 | San Diego | 60 | C | 13 (4 health) | — |
| 132 | 92136 | San Diego | 60 | C | 13 (4 health) | — |
| 133 | 92137 | San Diego | 60 | C | 13 (4 health) | — |
| 134 | 92138 | San Diego | 60 | C | 13 (4 health) | — |
| 135 | 92140 | San Diego | 60 | C | 13 (4 health) | — |
| 136 | 92142 | San Diego | 60 | C | 13 (4 health) | — |
| 137 | 92145 | San Diego | 60 | C | 13 (4 health) | — |
| 138 | 92147 | San Diego | 60 | C | 13 (4 health) | — |
| 139 | 92149 | San Diego | 60 | C | 13 (4 health) | — |
| 140 | 92150 | San Diego | 60 | C | 13 (4 health) | — |
| 141 | 92152 | San Diego | 60 | C | 13 (4 health) | — |
| 142 | 92153 | San Diego | 60 | C | 13 (4 health) | — |
| 143 | 92154 | San Diego | 60 | C | 13 (4 health) | $606K |
| 144 | 92155 | San Diego | 60 | C | 13 (4 health) | — |
| 145 | 92158 | San Diego | 60 | C | 13 (4 health) | — |
| 146 | 92159 | San Diego | 60 | C | 13 (4 health) | — |
| 147 | 92160 | San Diego | 60 | C | 13 (4 health) | — |
| 148 | 92161 | San Diego | 60 | C | 13 (4 health) | — |
| 149 | 92162 | San Diego | 60 | C | 13 (4 health) | — |
| 150 | 92163 | San Diego | 60 | C | 13 (4 health) | — |
| 151 | 92164 | San Diego | 60 | C | 13 (4 health) | — |
| 152 | 92165 | San Diego | 60 | C | 13 (4 health) | — |
| 153 | 92166 | San Diego | 60 | C | 13 (4 health) | — |
| 154 | 92167 | San Diego | 60 | C | 13 (4 health) | — |
| 155 | 92168 | San Diego | 60 | C | 13 (4 health) | — |
| 156 | 92169 | San Diego | 60 | C | 13 (4 health) | — |
| 157 | 92170 | San Diego | 60 | C | 13 (4 health) | — |
| 158 | 92171 | San Diego | 60 | C | 13 (4 health) | — |
| 159 | 92172 | San Diego | 60 | C | 13 (4 health) | — |
| 160 | 92174 | San Diego | 60 | C | 13 (4 health) | — |
| 161 | 92175 | San Diego | 60 | C | 13 (4 health) | — |
| 162 | 92176 | San Diego | 60 | C | 13 (4 health) | — |
| 163 | 92177 | San Diego | 60 | C | 13 (4 health) | — |
| 164 | 92179 | San Diego | 60 | C | 13 (4 health) | — |
| 165 | 92182 | San Diego | 60 | C | 13 (4 health) | — |
| 166 | 92184 | San Diego | 60 | C | 13 (4 health) | — |
| 167 | 92186 | San Diego | 60 | C | 13 (4 health) | — |
| 168 | 92187 | San Diego | 60 | C | 13 (4 health) | — |
| 169 | 92190 | San Diego | 60 | C | 13 (4 health) | — |
| 170 | 92191 | San Diego | 60 | C | 13 (4 health) | — |
| 171 | 92192 | San Diego | 60 | C | 13 (4 health) | — |
| 172 | 92193 | San Diego | 60 | C | 13 (4 health) | — |
| 173 | 92194 | San Diego | 60 | C | 13 (4 health) | — |
| 174 | 92195 | San Diego | 60 | C | 13 (4 health) | — |
| 175 | 92196 | San Diego | 60 | C | 13 (4 health) | — |
| 176 | 92197 | San Diego | 60 | C | 13 (4 health) | — |
| 177 | 92198 | San Diego | 60 | C | 13 (4 health) | — |
| 178 | 92199 | San Diego | 60 | C | 13 (4 health) | — |
| 179 | 91963 | Potrero | 55 | C | 20 (16 health) | — |
| 180 | 91990 | Potrero | 55 | C | 20 (16 health) | — |
| 181 | 92108 | San Diego | 55 | C | 13 (4 health) | $607K |
| 182 | 92109 | San Diego | 55 | C | 13 (4 health) | $1136K |
| 183 | 92113 | San Diego | 55 | C | 13 (4 health) | $559K |
| 184 | 92120 | San Diego | 55 | C | 13 (4 health) | $870K |
| 185 | 92121 | San Diego | 55 | C | 13 (4 health) | $1092K |
| 186 | 91962 | Pine Valley | 45 | D | 12 (8 health) | $497K |
| 187 | 91931 | Guatay | 33 | F | 14 (12 health) | — |
Recommended Buyer Guides for San Diego 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 2 ZIP codes
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best HEPA Air Purifiers for Wildfire Smoke — Wildfire is the top compound risk factor
Deep Dive Reports
Detailed analysis for San Diego County, California
Overview
San Diego County in California covers 187 ZIP codes with an average Home Safety Score of B (72/100).
114 of 187 ZIP codes have recorded EPA violations. 433 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.