New Castle County, Delaware
52 ZIP codes · Avg score 76/100 · Grade B · Updated 2026-06-03
Within New Castle County's 52 tracked ZIP codes, safety indicators remain above the national average with few health-based violations on record.
How New Castle County Compares
How New Castle County Compares
New Castle County scores 5 points below the Delaware state average (81/100) and 8 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: New Castle County, Delaware
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.3 (asthma 10.4%, diabetes 12.2%)
Estimated additional annual cost per homeowner: $4,198, driven primarily by sea_level
Infrastructure: 0.365% avg pipe failure probability, 37% of ZIPs at high risk
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $4,198
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Water Safety Affordability
How much it costs to fix water issues relative to home values in New Castle County
Remediation costs are relatively manageable for most homeowners in New Castle County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for New Castle County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in New Castle County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Artesian Water Company | 231,114 | 61 |
| 2 | Newark Water Department | 40,000 | 55 |
| 3 | Artesian Southern Sussex Regional | 18,015 | 55 |
| 4 | Church Creek (awc) | 9,654 | 55 |
| 5 | Artesian Northern Kent Regional | 7,014 | 55 |
26 total water systems serve New Castle County.
All ZIP Codes in New Castle County
52 ZIP codes tracked in New Castle County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 19721 | New Castle | 83 | B | 0 | — |
| 2 | 19730 | Odessa | 83 | B | 0 | $299K |
| 3 | 19731 | Port Penn | 83 | B | 0 | $348K |
| 4 | 19734 | Townsend | 83 | B | 0 | $426K |
| 5 | 19850 | Wilmington | 83 | B | 1 | — |
| 6 | 19880 | Wilmington | 83 | B | 1 | — |
| 7 | 19884 | Wilmington | 83 | B | 1 | — |
| 8 | 19885 | Wilmington | 83 | B | 1 | — |
| 9 | 19886 | Wilmington | 83 | B | 1 | — |
| 10 | 19887 | Wilmington | 83 | B | 1 | — |
| 11 | 19890 | Wilmington | 83 | B | 1 | — |
| 12 | 19891 | Wilmington | 83 | B | 1 | — |
| 13 | 19892 | Wilmington | 83 | B | 1 | — |
| 14 | 19893 | Wilmington | 83 | B | 1 | — |
| 15 | 19894 | Wilmington | 83 | B | 1 | — |
| 16 | 19895 | Wilmington | 83 | B | 1 | — |
| 17 | 19896 | Wilmington | 83 | B | 1 | — |
| 18 | 19897 | Wilmington | 83 | B | 1 | — |
| 19 | 19898 | Wilmington | 83 | B | 1 | — |
| 20 | 19899 | Wilmington | 83 | B | 1 | — |
| 21 | 19712 | Newark | 81 | B | 5 | — |
| 22 | 19714 | Newark | 81 | B | 5 | — |
| 23 | 19715 | Newark | 81 | B | 5 | — |
| 24 | 19716 | Newark | 81 | B | 5 | — |
| 25 | 19717 | Newark | 81 | B | 5 | — |
| 26 | 19718 | Newark | 81 | B | 5 | — |
| 27 | 19725 | Newark | 81 | B | 5 | — |
| 28 | 19726 | Newark | 81 | B | 5 | — |
| 29 | 19706 | Delaware City | 78 | B | 0 | $245K |
| 30 | 19806 | Wilmington | 78 | B | 1 | $371K |
| 31 | 19809 | Wilmington | 78 | B | 1 | $309K |
| 32 | 19710 | Montchanin | 75 | B | 2 | — |
| 33 | 19709 | Middletown | 73 | B | 0 | $445K |
| 34 | 19720 | New Castle | 73 | B | 0 | $243K |
| 35 | 19801 | Wilmington | 73 | B | 1 | $196K |
| 36 | 19802 | Wilmington | 73 | B | 1 | $188K |
| 37 | 19803 | Wilmington | 73 | B | 1 | $436K |
| 38 | 19805 | Wilmington | 73 | B | 1 | $220K |
| 39 | 19808 | Wilmington | 73 | B | 1 | $310K |
| 40 | 19810 | Wilmington | 73 | B | 1 | $420K |
| 41 | 19707 | Hockessin | 72 | B | 2 | $534K |
| 42 | 19702 | Newark | 71 | B | 5 | $331K |
| 43 | 19711 | Newark | 71 | B | 5 | $376K |
| 44 | 19713 | Newark | 71 | B | 5 | $268K |
| 45 | 19701 | Bear | 70 | B | 0 | $338K |
| 46 | 19804 | Wilmington | 68 | C | 1 | $245K |
| 47 | 19735 | Winterthur | 60 | C | 0 | — |
| 48 | 19703 | Claymont | 55 | C | 0 | $267K |
| 49 | 19732 | Rockland | 55 | C | 0 | $705K |
| 50 | 19736 | Yorklyn | 55 | C | 0 | — |
| 51 | 19708 | Kirkwood | 53 | D | 0 | — |
| 52 | 19733 | Saint Georges | 53 | D | 0 | $221K |
Recommended Buyer Guides for New Castle County
Editorial-only picks, screened against the EPA detections on file.
- Best Water Testing Kits — Baseline water quality check for your ZIP
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant peace of mind
Deep Dive Reports
Detailed analysis for New Castle County, Delaware
Overview
New Castle County in Delaware covers 52 ZIP codes with an average Home Safety Score of B (76/100).
38 of 52 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← Back to Delaware water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.