Out of 576 ZIP codes with data in California, these are the highest-ranked areas for lead (ppb). See also: National Worst ZIP Codes for Lead in Water | All California Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 576 |
| Highest value | 100.0 ppb |
| Median value | 2.8 ppb |
| State | California |
Top 100 Worst ZIP Codes
| Rank | ZIP Code | City | State | Lead (ppb) | Safety Score |
|---|---|---|---|---|---|
| 1 | 94130 | San Francisco | CA | 100.0 ppb | — |
| 2 | 95223 | Arnold | CA | 15.0 ppb | 81/100 |
| 3 | 95224 | Avery | CA | 15.0 ppb | 83/100 |
| 4 | 96146 | Olympic Valley | CA | 14.4 ppb | 75/100 |
| 5 | 93267 | Strathmore | CA | 13.0 ppb | — |
| 6 | 95017 | Davenport | CA | 12.0 ppb | — |
| 7 | 95033 | Los Gatos | CA | 12.0 ppb | 53/100 |
| 8 | 95319 | Empire | CA | 12.0 ppb | — |
| 9 | 95346 | Mi Wuk Village | CA | 12.0 ppb | — |
| 10 | 95350 | Modesto | CA | 12.0 ppb | 75/100 |
| 11 | 95351 | Modesto | CA | 12.0 ppb | 67/100 |
| 12 | 95354 | Modesto | CA | 12.0 ppb | 75/100 |
| 13 | 95355 | Modesto | CA | 12.0 ppb | 75/100 |
| 14 | 95356 | Modesto | CA | 12.0 ppb | 74/100 |
| 15 | 95357 | Modesto | CA | 12.0 ppb | 74/100 |
| 16 | 95358 | Modesto | CA | 12.0 ppb | 75/100 |
| 17 | 95383 | Twain Harte | CA | 12.0 ppb | 70/100 |
| 18 | 96052 | Lewiston | CA | 11.7 ppb | — |
| 19 | 96091 | Trinity Center | CA | 11.7 ppb | — |
| 20 | 96093 | Weaverville | CA | 11.7 ppb | 83/100 |
| 21 | 92252 | Joshua Tree | CA | 11.0 ppb | 74/100 |
| 22 | 93222 | Pine Mountain Club | CA | 11.0 ppb | — |
| 23 | 93205 | Bodfish | CA | 10.0 ppb | — |
| 24 | 93240 | Lake Isabella | CA | 10.0 ppb | — |
| 25 | 92322 | Cedarpines Park | CA | 9.8 ppb | — |
| 26 | 93602 | Auberry | CA | 9.5 ppb | — |
| 27 | 93664 | Shaver Lake | CA | 9.5 ppb | — |
| 28 | 93212 | Corcoran | CA | 9.3 ppb | 75/100 |
| 29 | 91750 | La Verne | CA | 9.0 ppb | 58/100 |
| 30 | 92705 | Santa Ana | CA | 8.4 ppb | 75/100 |
| 31 | 93614 | Coarsegold | CA | 8.4 ppb | 52/100 |
| 32 | 92382 | Running Springs | CA | 8.1 ppb | 57/100 |
| 33 | 96145 | Tahoe City | CA | 7.9 ppb | 75/100 |
| 34 | 92223 | Beaumont | CA | 7.8 ppb | 65/100 |
| 35 | 92320 | Calimesa | CA | 7.8 ppb | 49/100 |
| 36 | 94550 | Livermore | CA | 7.5 ppb | — |
| 37 | 94551 | Livermore | CA | 7.5 ppb | — |
| 38 | 94508 | Angwin | CA | 7.0 ppb | — |
| 39 | 94567 | Pope Valley | CA | 7.0 ppb | — |
| 40 | 95912 | Arbuckle | CA | 6.8 ppb | — |
| 41 | 95932 | Colusa | CA | 6.8 ppb | 99/100 |
| 42 | 95950 | Grimes | CA | 6.8 ppb | — |
| 43 | 95955 | Maxwell | CA | 6.8 ppb | — |
| 44 | 95957 | Meridian | CA | 6.8 ppb | — |
| 45 | 94566 | Pleasanton | CA | 6.7 ppb | — |
| 46 | 94568 | Dublin | CA | 6.7 ppb | — |
| 47 | 94582 | San Ramon | CA | 6.7 ppb | — |
| 48 | 94586 | Sunol | CA | 6.7 ppb | — |
| 49 | 94588 | Pleasanton | CA | 6.7 ppb | — |
| 50 | 96025 | Dunsmuir | CA | 6.6 ppb | — |
| 51 | 94010 | Burlingame | CA | 6.3 ppb | — |
| 52 | 92036 | Julian | CA | 6.1 ppb | — |
| 53 | 92070 | Santa Ysabel | CA | 6.1 ppb | — |
| 54 | 92708 | Fountain Valley | CA | 6.0 ppb | 75/100 |
| 55 | 95348 | Merced | CA | 6.0 ppb | 83/100 |
| 56 | 95369 | Snelling | CA | 6.0 ppb | — |
| 57 | 95439 | Fulton | CA | 6.0 ppb | — |
| 58 | 95824 | Sacramento | CA | 6.0 ppb | 75/100 |
| 59 | 96141 | Homewood | CA | 6.0 ppb | — |
| 60 | 94070 | San Carlos | CA | 5.8 ppb | — |
| 61 | 91711 | Claremont | CA | 5.7 ppb | — |
| 62 | 91759 | Mt Baldy | CA | 5.7 ppb | — |
| 63 | 93656 | Riverdale | CA | 5.7 ppb | — |
| 64 | 90230 | Culver City | CA | 5.6 ppb | 75/100 |
| 65 | 90232 | Culver City | CA | 5.6 ppb | 75/100 |
| 66 | 92225 | Blythe | CA | 5.5 ppb | 74/100 |
| 67 | 90266 | Manhattan Beach | CA | 5.4 ppb | 75/100 |
| 68 | 93636 | Madera | CA | 5.4 ppb | 83/100 |
| 69 | 93444 | Nipomo | CA | 5.2 ppb | 83/100 |
| 70 | 95451 | Kelseyville | CA | 5.2 ppb | 100/100 |
| 71 | 95914 | Bangor | CA | 5.2 ppb | — |
| 72 | 95966 | Oroville | CA | 5.2 ppb | 100/100 |
| 73 | 95968 | Palermo | CA | 5.2 ppb | — |
| 74 | 95684 | Somerset | CA | 5.1 ppb | 83/100 |
| 75 | 92341 | Green Valley Lake | CA | 5.0 ppb | — |
| 76 | 93604 | Bass Lake | CA | 5.0 ppb | 83/100 |
| 77 | 93644 | Oakhurst | CA | 5.0 ppb | 83/100 |
| 78 | 93645 | O Neals | CA | 5.0 ppb | — |
| 79 | 92655 | Midway City | CA | 4.7 ppb | 75/100 |
| 80 | 92683 | Westminster | CA | 4.7 ppb | 75/100 |
| 81 | 95310 | Columbia | CA | 4.7 ppb | 83/100 |
| 82 | 95370 | Sonora | CA | 4.7 ppb | 76/100 |
| 83 | 95422 | Clearlake | CA | 4.6 ppb | 97/100 |
| 84 | 94401 | San Mateo | CA | 4.4 ppb | — |
| 85 | 94402 | San Mateo | CA | 4.4 ppb | — |
| 86 | 94403 | San Mateo | CA | 4.4 ppb | — |
| 87 | 96142 | Tahoma | CA | 4.4 ppb | — |
| 88 | 94080 | South San Francisco | CA | 4.1 ppb | — |
| 89 | 95543 | Gasquet | CA | 4.0 ppb | — |
| 90 | 95567 | Smith River | CA | 4.0 ppb | — |
| 91 | 95255 | West Point | CA | 4.0 ppb | — |
| 92 | 92026 | Escondido | CA | 4.0 ppb | 90/100 |
| 93 | 92059 | Pala | CA | 4.0 ppb | 70/100 |
| 94 | 92061 | Pauma Valley | CA | 4.0 ppb | 87/100 |
| 95 | 92082 | Valley Center | CA | 4.0 ppb | 70/100 |
| 96 | 94020 | La Honda | CA | 4.0 ppb | — |
| 97 | 94021 | Loma Mar | CA | 4.0 ppb | — |
| 98 | 94025 | Menlo Park | CA | 4.0 ppb | — |
Methodology
Lead rankings are based on the 90th percentile lead testing value (PB90) reported by water systems under the Lead and Copper Rule. When CCR data is unavailable, EPA SDWIS lead sampling data is used. The EPA action level for lead is 15 ppb (0.015 mg/L). There is no safe level of lead exposure.
Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-10-14.
Frequently Asked Questions
What is a dangerous lead level in water?
The EPA action level is 15 parts per billion (ppb). The American Academy of Pediatrics recommends no more than 1 ppb for school drinking water. There is no safe level of lead exposure for children.
How is lead measured in water?
Water systems collect samples from homes with known lead service lines or lead solder. The 90th percentile value (PB90) means 90% of samples tested below that level. If PB90 exceeds 15 ppb, the system must take corrective action.
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