Orange County, California
143 ZIP codes · Avg score 87/100 · Grade A · Updated 2026-06-03
Unlike many counties its size, Orange County keeps violation rates low — all 143 ZIP codes score at or above the state average for tap water safety, with no systemic concerns flagged in the current data set.
How Orange County Compares
How Orange County Compares
Orange County scores 14 points above the California state average (73/100) and 19 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Orange 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 9%, diabetes 11.5%)
Estimated additional annual cost per homeowner: $2,188, driven primarily by wildfire
Infrastructure: 0.327% avg pipe failure probability, 15% of ZIPs at high risk
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Orange County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 49 violations. Past 5 years: 105 total (105 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: $2,188
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 Orange County
Remediation costs are relatively manageable for most homeowners in Orange 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 Orange 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 Orange County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Irvine Ranch Water District | 444,800 | 150 |
| 2 | Mesa Water District | 110,000 | 94 |
| 3 | Big Basin Water Company | 1,120 | 84 |
| 4 | Cabana Holiday Ws | 506 | 84 |
| 5 | Arbor Mobile Home Park Ws | 340 | 84 |
81 total water systems serve Orange County.
All ZIP Codes in Orange County
143 ZIP codes tracked in Orange County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 92654 | Laguna Hills | 99 | A | 0 | — |
| 2 | 92684 | Westminster | 99 | A | 0 | — |
| 3 | 92685 | Westminster | 99 | A | 0 | — |
| 4 | 92688 | Rancho Santa Margarita | 99 | A | 1 | $857K |
| 5 | 92693 | San Juan Capistrano | 99 | A | 1 | — |
| 6 | 92834 | Fullerton | 99 | A | 0 | — |
| 7 | 92837 | Fullerton | 99 | A | 0 | — |
| 8 | 92838 | Fullerton | 99 | A | 0 | — |
| 9 | 92846 | Garden Grove | 99 | A | 0 | — |
| 10 | 92856 | Orange | 99 | A | 0 | — |
| 11 | 92857 | Orange | 99 | A | 0 | — |
| 12 | 92859 | Orange | 99 | A | 0 | — |
| 13 | 92862 | Orange | 99 | A | 0 | — |
| 14 | 92863 | Orange | 99 | A | 0 | — |
| 15 | 92864 | Orange | 99 | A | 0 | — |
| 16 | 92865 | Orange | 99 | A | 0 | $843K |
| 17 | 92803 | Anaheim | 98 | A | 2 | — |
| 18 | 92809 | Anaheim | 98 | A | 2 | — |
| 19 | 92812 | Anaheim | 98 | A | 2 | — |
| 20 | 92814 | Anaheim | 98 | A | 2 | — |
| 21 | 92815 | Anaheim | 98 | A | 2 | — |
| 22 | 92816 | Anaheim | 98 | A | 2 | — |
| 23 | 92817 | Anaheim | 98 | A | 2 | — |
| 24 | 92825 | Anaheim | 98 | A | 2 | — |
| 25 | 92850 | Anaheim | 98 | A | 2 | — |
| 26 | 92899 | Anaheim | 98 | A | 2 | — |
| 27 | 92885 | Yorba Linda | 97 | A | 2 | — |
| 28 | 92602 | Irvine | 96 | A | 6 | $1323K |
| 29 | 92616 | Irvine | 96 | A | 6 | — |
| 30 | 92618 | Irvine | 96 | A | 6 | $1153K |
| 31 | 92619 | Irvine | 96 | A | 6 | — |
| 32 | 92623 | Irvine | 96 | A | 6 | — |
| 33 | 92697 | Irvine | 96 | A | 6 | — |
| 34 | 92710 | Irvine | 96 | A | 6 | — |
| 35 | 92728 | Fountain Valley | 96 | A | 0 | — |
| 36 | 92781 | Tustin | 96 | A | 1 | — |
| 37 | 92782 | Tustin | 96 | A | 1 | $1029K |
| 38 | 90623 | La Palma | 95 | A | 0 | $920K |
| 39 | 92655 | Midway City | 95 | A | 1 | $724K |
| 40 | 92673 | San Clemente | 95 | A | 0 | $1208K |
| 41 | 92674 | San Clemente | 95 | A | 0 | — |
| 42 | 92678 | Trabuco Canyon | 95 | A | 0 | $989K |
| 43 | 92832 | Fullerton | 95 | A | 0 | $773K |
| 44 | 92833 | Fullerton | 95 | A | 0 | $844K |
| 45 | 92836 | Fullerton | 95 | A | 0 | — |
| 46 | 92842 | Garden Grove | 95 | A | 0 | — |
| 47 | 92844 | Garden Grove | 95 | A | 0 | $707K |
| 48 | 92845 | Garden Grove | 95 | A | 0 | $883K |
| 49 | 92866 | Orange | 95 | A | 0 | $892K |
| 50 | 92867 | Orange | 95 | A | 0 | $951K |
| 51 | 92868 | Orange | 95 | A | 0 | $714K |
| 52 | 92801 | Anaheim | 94 | A | 2 | $633K |
| 53 | 92802 | Anaheim | 94 | A | 2 | $722K |
| 54 | 92805 | Anaheim | 94 | A | 2 | $667K |
| 55 | 92806 | Anaheim | 94 | A | 2 | $791K |
| 56 | 92808 | Anaheim | 94 | A | 2 | $1037K |
| 57 | 91109 | Pasadena | 93 | A | 5 | — |
| 58 | 92887 | Yorba Linda | 93 | A | 2 | $1131K |
| 59 | 92603 | Irvine | 92 | A | 6 | $1719K |
| 60 | 92605 | Huntington Beach | 92 | A | 7 (3 health) | — |
| 61 | 92606 | Irvine | 92 | A | 6 | $1047K |
| 62 | 92614 | Irvine | 92 | A | 6 | $983K |
| 63 | 92615 | Huntington Beach | 92 | A | 7 (3 health) | — |
| 64 | 92617 | Irvine | 92 | A | 6 | $667K |
| 65 | 92620 | Irvine | 92 | A | 6 | $1204K |
| 66 | 92780 | Tustin | 92 | A | 1 | $832K |
| 67 | 92652 | Laguna Beach | 90 | A | 0 | — |
| 68 | 92653 | Laguna Hills | 90 | A | 0 | $978K |
| 69 | 92675 | San Juan Capistrano | 90 | A | 1 | $930K |
| 70 | 92679 | Trabuco Canyon | 90 | A | 0 | $1243K |
| 71 | 92831 | Fullerton | 90 | A | 0 | $821K |
| 72 | 92835 | Fullerton | 90 | A | 0 | $982K |
| 73 | 92840 | Garden Grove | 90 | A | 0 | $747K |
| 74 | 92841 | Garden Grove | 90 | A | 0 | $766K |
| 75 | 92869 | Orange | 90 | A | 0 | $935K |
| 76 | 92804 | Anaheim | 89 | A | 2 | $730K |
| 77 | 92807 | Anaheim | 89 | A | 2 | $918K |
| 78 | 90622 | Buena Park | 88 | A | 0 | — |
| 79 | 90624 | Buena Park | 88 | A | 0 | — |
| 80 | 90632 | La Habra | 88 | A | 0 | — |
| 81 | 90633 | La Habra | 88 | A | 0 | — |
| 82 | 92702 | Santa Ana | 88 | A | 1 | — |
| 83 | 92711 | Santa Ana | 88 | A | 1 | — |
| 84 | 92712 | Santa Ana | 88 | A | 1 | — |
| 85 | 92725 | Santa Ana | 88 | A | 1 | — |
| 86 | 92735 | Santa Ana | 88 | A | 1 | — |
| 87 | 92799 | Santa Ana | 88 | A | 1 | — |
| 88 | 92822 | Brea | 88 | A | 0 | — |
| 89 | 92823 | Brea | 88 | A | 0 | $1061K |
| 90 | 92871 | Placentia | 88 | A | 0 | — |
| 91 | 92886 | Yorba Linda | 88 | A | 2 | $1062K |
| 92 | 90620 | Buena Park | 87 | A | 0 | $782K |
| 93 | 92604 | Irvine | 87 | A | 6 | $994K |
| 94 | 92612 | Irvine | 87 | A | 6 | $939K |
| 95 | 92701 | Santa Ana | 87 | A | 1 | $608K |
| 96 | 92821 | Brea | 87 | A | 0 | $852K |
| 97 | 92861 | Villa Park | 87 | A | 0 | $1686K |
| 98 | 92658 | Newport Beach | 86 | A | 1 | — |
| 99 | 92659 | Newport Beach | 86 | A | 1 | — |
| 100 | 90740 | Seal Beach | 85 | A | 0 | $488K |
| 101 | 92672 | San Clemente | 85 | A | 0 | $1240K |
| 102 | 92683 | Westminster | 85 | A | 0 | $820K |
| 103 | 92843 | Garden Grove | 85 | A | 0 | $666K |
| 104 | 92648 | Huntington Beach | 84 | B | 7 (3 health) | $1176K |
| 105 | 90621 | Buena Park | 82 | B | 0 | $734K |
| 106 | 90631 | La Habra | 82 | B | 0 | $758K |
| 107 | 92705 | Santa Ana | 82 | B | 1 | $1136K |
| 108 | 92706 | Santa Ana | 82 | B | 1 | $839K |
| 109 | 92707 | Santa Ana | 82 | B | 1 | $636K |
| 110 | 92870 | Placentia | 82 | B | 0 | $871K |
| 111 | 92630 | Lake Forest | 80 | B | 5 (4 health) | $859K |
| 112 | 92651 | Laguna Beach | 80 | B | 0 | $2000K |
| 113 | 92661 | Newport Beach | 80 | B | 1 | $2000K |
| 114 | 92662 | Newport Beach | 80 | B | 1 | $2000K |
| 115 | 92375 | Redlands | 79 | B | 5 (4 health) | — |
| 116 | 92647 | Huntington Beach | 79 | B | 7 (3 health) | $964K |
| 117 | 92649 | Huntington Beach | 79 | B | 7 (3 health) | $1071K |
| 118 | 92629 | Dana Point | 78 | B | 9 | $1212K |
| 119 | 92708 | Fountain Valley | 78 | B | 0 | $1019K |
| 120 | 92703 | Santa Ana | 77 | B | 1 | $586K |
| 121 | 92660 | Newport Beach | 75 | B | 1 | $2000K |
| 122 | 92663 | Newport Beach | 75 | B | 1 | $2000K |
| 123 | 92646 | Huntington Beach | 74 | B | 7 (3 health) | $1032K |
| 124 | 90630 | Cypress | 73 | B | 0 | $866K |
| 125 | 90680 | Stanton | 73 | B | 0 | $571K |
| 126 | 92610 | Foothill Ranch | 73 | B | 0 | $939K |
| 127 | 92692 | Mission Viejo | 73 | B | 0 | $984K |
| 128 | 92704 | Santa Ana | 72 | B | 1 | $642K |
| 129 | 90721 | Los Alamitos | 66 | C | 0 | — |
| 130 | 92607 | Laguna Niguel | 66 | C | 0 | — |
| 131 | 92609 | El Toro | 66 | C | 0 | — |
| 132 | 92690 | Mission Viejo | 66 | C | 0 | — |
| 133 | 92694 | Ladera Ranch | 66 | C | 0 | $1043K |
| 134 | 92811 | Atwood | 66 | C | 0 | — |
| 135 | 90720 | Los Alamitos | 65 | C | 0 | $1166K |
| 136 | 90742 | Sunset Beach | 65 | C | 0 | $1625K |
| 137 | 90743 | Surfside | 65 | C | 0 | $2000K |
| 138 | 92625 | Corona Del Mar | 65 | C | 0 | $2000K |
| 139 | 92677 | Laguna Niguel | 65 | C | 0 | $1123K |
| 140 | 92676 | Silverado | 60 | C | 0 | $797K |
| 141 | 92627 | Costa Mesa | 57 | C | 28 (16 health) | $1075K |
| 142 | 92628 | Costa Mesa | 55 | C | 28 (16 health) | — |
| 143 | 92626 | Costa Mesa | 52 | D | 28 (16 health) | $1038K |
Recommended Buyer Guides for Orange County
Independent picks. EPA-grounded. Matched here.
- 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 Orange County, California
Overview
Orange County in California covers 143 ZIP codes with an average Home Safety Score of A (87/100).
72 of 143 ZIP codes have recorded EPA violations. 74 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.