Out of 1,899 ZIP codes with data in California, these are the highest-ranked areas for lead (mg/l). See also: National Worst ZIP Codes for Lead in Water | All California Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 1,899 |
| Highest value | 600.0 ppb |
| Median value | 2.7 ppb |
| State | California |
Top 100 Worst ZIP Codes
| Rank | ZIP Code | City | State | Lead (mg/L) | Safety Score |
|---|---|---|---|---|---|
| 1 | 95363 | Patterson | CA | 600.0 ppb | 90/100 |
| 2 | 95914 | Bangor | CA | 490.0 ppb | 66/100 |
| 3 | 95923 | Canyon Dam | CA | 490.0 ppb | 66/100 |
| 4 | 95965 | Oroville | CA | 490.0 ppb | 86/100 |
| 5 | 95966 | Oroville | CA | 490.0 ppb | 86/100 |
| 6 | 95968 | Palermo | CA | 490.0 ppb | 65/100 |
| 7 | 93263 | Shafter | CA | 360.0 ppb | 79/100 |
| 8 | 91754 | Monterey Park | CA | 250.0 ppb | 74/100 |
| 9 | 91755 | Monterey Park | CA | 250.0 ppb | 79/100 |
| 10 | 91756 | Monterey Park | CA | 250.0 ppb | 79/100 |
| 11 | 93402 | Los Osos | CA | 250.0 ppb | 78/100 |
| 12 | 93412 | Los Osos | CA | 250.0 ppb | 83/100 |
| 13 | 95970 | Princeton | CA | 250.0 ppb | 95/100 |
| 14 | 91701 | Rancho Cucamonga | CA | 200.0 ppb | 77/100 |
| 15 | 91729 | Rancho Cucamonga | CA | 200.0 ppb | 82/100 |
| 16 | 91730 | Rancho Cucamonga | CA | 200.0 ppb | 77/100 |
| 17 | 91737 | Rancho Cucamonga | CA | 200.0 ppb | 82/100 |
| 18 | 91739 | Rancho Cucamonga | CA | 200.0 ppb | 82/100 |
| 19 | 95676 | Robbins | CA | 200.0 ppb | 73/100 |
| 20 | 95991 | Yuba City | CA | 200.0 ppb | 83/100 |
| 21 | 95992 | Yuba City | CA | 200.0 ppb | 93/100 |
| 22 | 95993 | Yuba City | CA | 200.0 ppb | 88/100 |
| 23 | 95632 | Galt | CA | 170.0 ppb | 78/100 |
| 24 | 94577 | San Leandro | CA | 160.0 ppb | 58/100 |
| 25 | 94578 | San Leandro | CA | 160.0 ppb | 58/100 |
| 26 | 94579 | San Leandro | CA | 160.0 ppb | 53/100 |
| 27 | 94548 | Knightsen | CA | 153.0 ppb | 63/100 |
| 28 | 94561 | Oakley | CA | 153.0 ppb | 53/100 |
| 29 | 94558 | Napa | CA | 102.5 ppb | 53/100 |
| 30 | 94559 | Napa | CA | 102.5 ppb | 53/100 |
| 31 | 94581 | Napa | CA | 102.5 ppb | 64/100 |
| 32 | 91962 | Pine Valley | CA | 99.4 ppb | 45/100 |
| 33 | 95665 | Pine Grove | CA | 87.9 ppb | 45/100 |
| 34 | 95720 | Kyburz | CA | 79.9 ppb | 50/100 |
| 35 | 93504 | California City | CA | 74.0 ppb | 79/100 |
| 36 | 93505 | California City | CA | 74.0 ppb | 79/100 |
| 37 | 93523 | Edwards | CA | 74.0 ppb | 63/100 |
| 38 | 93524 | Edwards | CA | 74.0 ppb | 53/100 |
| 39 | 93558 | Red Mountain | CA | 74.0 ppb | 53/100 |
| 40 | 93560 | Rosamond | CA | 66.0 ppb | 28/100 |
| 41 | 95046 | San Martin | CA | 60.0 ppb | 46/100 |
| 42 | 95913 | Artois | CA | 60.0 ppb | 95/100 |
| 43 | 95943 | Glenn | CA | 60.0 ppb | 73/100 |
| 44 | 95988 | Willows | CA | 60.0 ppb | 60/100 |
| 45 | 95436 | Forestville | CA | 50.0 ppb | 64/100 |
| 46 | 93452 | San Simeon | CA | 45.0 ppb | 48/100 |
| 47 | 96041 | Hayfork | CA | 44.1 ppb | 66/100 |
| 48 | 96025 | Dunsmuir | CA | 42.2 ppb | 57/100 |
| 49 | 95986 | Washington | CA | 41.4 ppb | 54/100 |
| 50 | 95757 | Elk Grove | CA | 38.5 ppb | 60/100 |
| 51 | 95758 | Elk Grove | CA | 38.5 ppb | 70/100 |
| 52 | 91931 | Guatay | CA | 35.0 ppb | 33/100 |
| 53 | 95380 | Turlock | CA | 32.0 ppb | 65/100 |
| 54 | 95381 | Turlock | CA | 32.0 ppb | 66/100 |
| 55 | 95382 | Turlock | CA | 32.0 ppb | 70/100 |
| 56 | 91750 | La Verne | CA | 28.0 ppb | 69/100 |
| 57 | 92341 | Green Valley Lake | CA | 24.9 ppb | 54/100 |
| 58 | 95454 | Laytonville | CA | 23.0 ppb | 66/100 |
| 59 | 92564 | Murrieta | CA | 22.0 ppb | 42/100 |
| 60 | 95415 | Boonville | CA | 22.0 ppb | 70/100 |
| 61 | 93243 | Lebec | CA | 21.0 ppb | 58/100 |
| 62 | 95490 | Willits | CA | 20.0 ppb | 59/100 |
| 63 | 91906 | Campo | CA | 19.0 ppb | 82/100 |
| 64 | 93237 | Kaweah | CA | 19.0 ppb | 53/100 |
| 65 | 93262 | Sequoia National Park | CA | 19.0 ppb | 53/100 |
| 66 | 93271 | Three Rivers | CA | 19.0 ppb | 70/100 |
| 67 | 94951 | Penngrove | CA | 18.5 ppb | 68/100 |
| 68 | 92327 | Daggett | CA | 17.0 ppb | 17/100 |
| 69 | 92339 | Forest Falls | CA | 16.0 ppb | 45/100 |
| 70 | 93247 | Lindsay | CA | 16.0 ppb | 28/100 |
| 71 | 95677 | Rocklin | CA | 16.0 ppb | 49/100 |
| 72 | 95765 | Rocklin | CA | 16.0 ppb | 45/100 |
| 73 | 91316 | Encino | CA | 15.0 ppb | 23/100 |
| 74 | 91416 | Encino | CA | 15.0 ppb | 17/100 |
| 75 | 91426 | Encino | CA | 15.0 ppb | 17/100 |
| 76 | 91436 | Encino | CA | 15.0 ppb | 18/100 |
| 77 | 92328 | Death Valley | CA | 15.0 ppb | 82/100 |
| 78 | 93208 | Camp Nelson | CA | 15.0 ppb | 53/100 |
| 79 | 93265 | Springville | CA | 15.0 ppb | 65/100 |
| 80 | 93637 | Madera | CA | 15.0 ppb | 74/100 |
| 81 | 93638 | Madera | CA | 15.0 ppb | 79/100 |
| 82 | 93639 | Madera | CA | 15.0 ppb | 78/100 |
| 83 | 94130 | San Francisco | CA | 15.0 ppb | 53/100 |
| 84 | 96019 | Shasta Lake | CA | 15.0 ppb | 90/100 |
| 85 | 96079 | Shasta Lake | CA | 15.0 ppb | 99/100 |
| 86 | 96089 | Shasta Lake | CA | 15.0 ppb | 99/100 |
| 87 | 93627 | Helm | CA | 14.0 ppb | 48/100 |
| 88 | 92322 | Cedarpines Park | CA | 13.0 ppb | 82/100 |
| 89 | 93267 | Strathmore | CA | 13.0 ppb | 39/100 |
| 90 | 93287 | Woody | CA | 13.0 ppb | 32/100 |
| 91 | 94945 | Novato | CA | 13.0 ppb | 61/100 |
| 92 | 94947 | Novato | CA | 13.0 ppb | 56/100 |
| 93 | 94948 | Novato | CA | 13.0 ppb | 68/100 |
| 94 | 94949 | Novato | CA | 13.0 ppb | 66/100 |
| 95 | 94998 | Novato | CA | 13.0 ppb | 68/100 |
| 96 | 95383 | Twain Harte | CA | 12.6 ppb | 60/100 |
| 97 | 91903 | Alpine | CA | 12.4 ppb | 69/100 |
| 98 | 95724 | Norden | CA | 12.2 ppb | 59/100 |
| 99 | 95364 | Pinecrest | CA | 12.1 ppb | 55/100 |
| 100 | 92333 | Fawnskin | CA | 12.0 ppb | 65/100 |
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: 2026-06-04.
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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