Delaware — At-Large
119th Congress · 97 ZIP codes · Avg score 81/100 · Grade B · Updated 2026-07-17
Data: EPA SDWIS / Census 119th Congress Last verified: 2026-07-17
ZipCheckup tracks water safety for 97 ZIP codes in Delaware's At-Large: the district earns a grade B (81/100). 155 EPA violations on record, 14 health-based.
Top Contaminants
ZIP Codes in This District
97 ZIP codes tracked in Delaware's At-Large. Showing top 50 by safety score.
| # | ZIP Code | City | Safety Score | Grade | Violations |
|---|---|---|---|---|---|
| 1 | 19902 | Dover Afb | 99 | A | 0 |
| 2 | 19955 | Kenton | 98 | A | 2 |
| 3 | 19979 | Viola | 97 | A | 4 |
| 4 | 19933 | Bridgeville | 95 | A | 0 |
| 5 | 19940 | Delmar | 95 | A | 0 |
| 6 | 19953 | Hartly | 95 | A | 1 |
| 7 | 19964 | Marydel | 95 | A | 0 |
| 8 | 19936 | Cheswold | 94 | A | 2 |
| 9 | 19941 | Ellendale | 94 | A | 2 |
| 10 | 19961 | Little Creek | 94 | A | 2 (1 health) |
| 11 | 19962 | Magnolia | 94 | A | 2 |
| 12 | 19967 | Millville | 94 | A | 3 (1 health) |
| 13 | 19903 | Dover | 93 | A | 3 (2 health) |
| 14 | 19905 | Dover | 93 | A | 3 (2 health) |
| 15 | 19906 | Dover | 93 | A | 3 (2 health) |
| 16 | 19947 | Georgetown | 93 | A | 4 |
| 17 | 19952 | Harrington | 93 | A | 4 |
| 18 | 19943 | Felton | 91 | A | 1 |
| 19 | 19960 | Lincoln | 91 | A | 3 (1 health) |
| 20 | 19807 | Wilmington | 90 | A | 1 |
| 21 | 19945 | Frankford | 90 | A | 0 |
| 22 | 19950 | Greenwood | 89 | A | 3 (1 health) |
| 23 | 19956 | Laurel | 89 | A | 2 |
| 24 | 19969 | Nassau | 88 | A | 0 |
| 25 | 19938 | Clayton | 87 | A | 0 |
| 26 | 19951 | Harbeson | 87 | A | 0 |
| 27 | 19977 | Smyrna | 87 | A | 7 |
| 28 | 19904 | Dover | 85 | A | 3 (2 health) |
| 29 | 19946 | Frederica | 85 | A | 0 |
| 30 | 19963 | Milford | 85 | A | 0 |
| 31 | 19970 | Ocean View | 84 | B | 2 |
| 32 | 19973 | Seaford | 84 | B | 2 |
| 33 | 19721 | New Castle | 83 | B | 0 |
| 34 | 19730 | Odessa | 83 | B | 0 |
| 35 | 19731 | Port Penn | 83 | B | 0 |
| 36 | 19734 | Townsend | 83 | B | 0 |
| 37 | 19850 | Wilmington | 83 | B | 1 |
| 38 | 19880 | Wilmington | 83 | B | 1 |
| 39 | 19884 | Wilmington | 83 | B | 1 |
| 40 | 19885 | Wilmington | 83 | B | 1 |
| 41 | 19886 | Wilmington | 83 | B | 1 |
| 42 | 19887 | Wilmington | 83 | B | 1 |
| 43 | 19890 | Wilmington | 83 | B | 1 |
| 44 | 19891 | Wilmington | 83 | B | 1 |
| 45 | 19892 | Wilmington | 83 | B | 1 |
| 46 | 19893 | Wilmington | 83 | B | 1 |
| 47 | 19894 | Wilmington | 83 | B | 1 |
| 48 | 19895 | Wilmington | 83 | B | 1 |
| 49 | 19896 | Wilmington | 83 | B | 1 |
| 50 | 19897 | Wilmington | 83 | B | 1 |
Overview
Delaware's At-Large encompasses 97 ZIP codes tracked by ZipCheckup. The district's average Home Safety Score is B (81/100).
155 EPA violations have been recorded across this district's water systems. 14 are health-based violations. About 68% of tracked ZIP codes have at least one violation.
Top Contaminants
The most frequently cited water quality issues in this district:
- Surface Water Treatment Rule - 74 violations
- Consumer Confidence Report Rule - 42 violations
- Stage 1 DBP Rule - 29 violations
- Contaminant 1032 - 5 violations
- Lead and Copper Rule - 1 violation
Housing Context
Homes in this district were built on average around 1978 (~48 years old). Older homes may have lead pipes or solder - consider a water filter if your home predates 1986.
Lead Alert: 1 ZIP code in this district exceed the EPA action level for lead. Consider using a certified lead-removal filter.
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 97 ZIP codes in Delaware's At-Large.