California County Drinking Water Report Cards
Compare county Drinking Water Violation Exposure Scores in California. Scores combine health-based violations per 100,000 people served and the share of active systems with unresolved health-based violations. View methodology or download the CSV.
| Score | Grade | County | Systems | Population | Health Violations | Per 100K | Active Health Systems |
|---|---|---|---|---|---|---|---|
| 0 | F | Tulare County | 12 | 183,576 | 191 | 104.0 | 3 |
| 0 | F | Merced County | 13 | 199,637 | 58 | 29.1 | 3 |
| 0 | F | Siskiyou County | 10 | 19,783 | 33 | 166.8 | 6 |
| 4 | F | Stanislaus County | 22 | 465,098 | 118 | 25.4 | 4 |
| 15 | F | Fresno County | 24 | 842,904 | 95 | 11.3 | 3 |
| 25 | F | Yolo County | 13 | 190,455 | 30 | 15.8 | 1 |
| 28 | F | Kern County | 17 | 294,918 | 57 | 19.3 | 1 |
| 40 | F | Napa County | 14 | 117,934 | 85 | 72.1 | 0 |
| 61 | D | Solano County | 10 | 379,624 | 6 | 1.6 | 1 |
| 76 | C | Santa Clara County | 10 | 788,554 | 16 | 2.0 | 0 |
| 91 | A | Los Angeles County | 48 | 6,562,362 | 29 | 0.4 | 1 |
| 91 | A | Riverside County | 11 | 636,906 | 5 | 0.8 | 0 |
| 93 | A | Sonoma County | 16 | 328,478 | 2 | 0.6 | 0 |
| 98 | A | Orange County | 19 | 1,905,324 | 3 | 0.2 | 0 |
| 100 | A | San Luis Obispo County | 14 | 13,877 | 0 | 0.0 | 0 |
| 100 | A | San Bernardino County | 14 | 906,556 | 0 | 0.0 | 0 |