California — 31st District
119th Congress · 30 ZIP codes · Avg score 72/100 · Grade B · Updated 2026-07-17
Data: EPA SDWIS / Census 119th Congress Last verified: 2026-07-17
ZipCheckup tracks water safety for 30 ZIP codes in California's 31st District: the district earns a grade B (72/100). 37 EPA violations on record, 4 health-based.
Top Contaminants
ZIP Codes in This District
30 ZIP codes tracked in California's 31st District.
| # | ZIP Code | City | Safety Score | Grade | Violations |
|---|---|---|---|---|---|
| 1 | 91740 | Glendora | 83 | B | 1 |
| 2 | 91744 | La Puente | 83 | B | 0 |
| 3 | 91746 | La Puente | 83 | B | 0 |
| 4 | 91747 | La Puente | 83 | B | 0 |
| 5 | 91749 | La Puente | 83 | B | 0 |
| 6 | 91773 | San Dimas | 83 | B | 0 |
| 7 | 91706 | Baldwin Park | 82 | B | 2 |
| 8 | 91702 | Azusa | 79 | B | 3 (1 health) |
| 9 | 91731 | El Monte | 79 | B | 5 |
| 10 | 91732 | El Monte | 79 | B | 5 |
| 11 | 91734 | El Monte | 79 | B | 5 |
| 12 | 91735 | El Monte | 79 | B | 5 |
| 13 | 91797 | Pomona | 77 | B | 4 (2 health) |
| 14 | 91722 | Covina | 75 | B | 1 |
| 15 | 91724 | Covina | 75 | B | 1 |
| 16 | 91791 | West Covina | 75 | B | 0 |
| 17 | 91723 | Covina | 72 | B | 1 |
| 18 | 91792 | West Covina | 72 | B | 0 |
| 19 | 91793 | West Covina | 72 | B | 0 |
| 20 | 91017 | Monrovia | 70 | B | 1 |
| 21 | 91790 | West Covina | 70 | B | 0 |
| 22 | 91750 | La Verne | 69 | C | 2 (1 health) |
| 23 | 91016 | Monrovia | 68 | C | 1 |
| 24 | 91008 | Duarte | 63 | C | 0 |
| 25 | 91010 | Duarte | 63 | C | 0 |
| 26 | 91733 | South El Monte | 63 | C | 0 |
| 27 | 91009 | Duarte | 53 | D | 0 |
| 28 | 91714 | City Of Industry | 53 | D | 0 |
| 29 | 91715 | City Of Industry | 53 | D | 0 |
| 30 | 91716 | City Of Industry | 53 | D | 0 |
Overview
California's 31st District encompasses 30 ZIP codes tracked by ZipCheckup. The district's average Home Safety Score is B (72/100).
37 EPA violations have been recorded across this district's water systems. 4 are health-based violations. About 47% of tracked ZIP codes have at least one violation.
Top Contaminants
The most frequently cited water quality issues in this district:
- Consumer Confidence Report Rule - 16 violations
- Stage 2 DBP Rule - 6 violations
- Contaminant 1012 - 4 violations
- Total Trihalomethanes (TTHM) - 4 violations
- Lead - 2 violations
Housing Context
Homes in this district were built on average around 1964 (~62 years old). Older homes may have lead pipes or solder - consider a water filter if your home predates 1986.
Data Sources
- Water quality violations: EPA Safe Drinking Water Information System (SDWIS)
- Congressional district boundaries: U.S. Census Bureau, 119th Congress
- Housing age: U.S. Census Bureau American Community Survey
Updated daily. Data covers 30 ZIP codes in California's 31st District.