STATE REPORT DE HEALTH VIOLATIONS: 4

Delaware Home Safety Profiles by ZIP

97 ZIP codes · 77 water systems · IPC plumbing code

Data: ZipCheckup Home Safety Score model 4.0.0; EPA SDWIS, UCMR 5, EPA radon zones, EPA AirData, NWS, State plumbing boards, Rewiring America

ZipCheckup tracks drinking-water and home-safety data for 97 ZIP codes across Delaware, covering 77 public water systems that serve about 779,393 people. 25 ZIP codes are mapped to at least one water system with an EPA violation on record.

97
ZIP Codes
77
Water Systems
25
ZIPs with Violations
IPC
Plumbing Code
2
Avg Rebate Programs
B · 81
Avg Safety Score
3
ZIPs Mapped to a System Above the Lead Action Level
#13
of 50 States
63%
ZIPs Rated A or B
42%
ZIPs with Violations
B
Delaware average: 81/100 - ranked #13 of 50 states. 8 points above the national average (73). 63% of ZIP codes scored A or B.

State averages can hide local differences, and the high average for Delaware is a summary, not a guarantee for any single ZIP code or water system; the reports for individual ZIP codes, cities and water systems show what the average leaves out.

Score Distribution

How Delaware's 97 ZIP codes are distributed across safety grades.

12
A
17
B
17
C
0
D
0
F
85-10070-8455-6940-540-39

Home Safety Scores by State

Loading map…
F (0-39) D (40-54) C (55-69) B (70-84) A (85+)

Model 4.0.0 inputs: EPA SDWIS, UCMR5 PFAS, EPA radon zones, annual county AQI •

Top 10 ZIP Codes by Home Safety Score in Delaware

Highest Home Safety Scores in the state.

#ZIP CodeCityCountyScoreGrade
1 19901 DoverKent 100 A
2 19902 Dover AfbKent 100 A
3 19904 DoverKent 100 A
4 19933 BridgevilleSussex 100 A
5 19934 Camden WyomingKent 100 A
6 19936 CheswoldKent 100 A
7 19943 FeltonKent 100 A
8 19946 FredericaKent 100 A
9 19962 MagnoliaKent 100 A
10 19963 MilfordSussex 100 A

10 Lowest-Scoring ZIP Codes in Delaware

#ZIP CodeCityCountyScoreGradeViolations
1 19810 WilmingtonNew Castle 66 C 1
2 19809 WilmingtonNew Castle 66 C 1
3 19806 WilmingtonNew Castle 66 C 1
4 19805 WilmingtonNew Castle 66 C 1
5 19804 WilmingtonNew Castle 66 C 1
6 19803 WilmingtonNew Castle 66 C 1
7 19802 WilmingtonNew Castle 66 C 1
8 19801 WilmingtonNew Castle 66 C 1
9 19732 RocklandNew Castle 66 C 1
10 19720 New CastleNew Castle 66 C 1

County Rankings

Water quality breakdown by county. 3 counties with data in Delaware.

Loading county map…
F (0-39) D (40-54) C (55-69) B (70-84) A (85+)

County-level aggregation of measured ZIP Home Safety Scores • EPA SDWIS, UCMR 5 PFAS, EPA radon zones, EPA AirData

CountyAvg ScoreGradeZIPsBest ZIPWorst ZIP
10001 98 A 21 19901 (100) 19977 (83)
10003 67 C 52 19709 (83) 19810 (66)
10005 86 A 24 19933 (100) 19947 (81)

Most Common Contaminants in Delaware

Contaminant / RuleCategoryZIPs AffectedViolationsHealth Risk
Consumer Confidence Report Rule Reporting 14 14 Yes
Surface Water Treatment Rule Treatment Technique 10 15 No
Stage 1 DBP Rule Treatment Technique 7 8 No
Lead Inorganic 3 9 Yes
Contaminant 0700 Other 2 2 No

Overview

We track multi-source home safety signals for 97 ZIP records across Delaware. Home Safety Score model 4.0.0 is published for 46 scored records; missing required evidence suppresses the score.

The EPA snapshots used for this build directly map water systems to 60 ZIP records, covering 77 community water systems that serve approximately 779,393 people.

25 of 60 ZIP codes with a reported violation count in the available EPA record (42%) have recorded EPA violations. 4 health-based violations appear in the available health breakdown.

Plumbing Regulations

Delaware follows the International Plumbing Code (2021 edition).

  • Plumbing code: IPC (2021)
  • Homeowner DIY: Licensed plumber required
  • Water heater permit: Required
  • Annual backflow test: Required

Full Delaware regulations →

Energy & Water Rebates

Across 96 tracked ZIP codes in Delaware, residents have access to an average of 2 water-related rebate programs - including incentives for heat pump water heaters, efficient fixtures, and plumbing upgrades.

Check rebates for your ZIP code →

Areas with Most Violations

ZIP Code City Home Safety Grade Violations Health-Based System
19973 Seaford A 8 3 Seaford Water Department
19956 Laurel A 6 3 Laurel Water Department
19947 Georgetown B 4 3 Georgetown Water Department
19944 Fenwick Island B 3 0 Artesian Southern Sussex Regional
19807 Wilmington B 2 0 Wilmington Water Department
19930 Bethany Beach B 2 0 Bethany Beach Water Department
19939 Dagsboro B 2 0 Bethany Bay Pump District
19950 Greenwood — 2 1 Greenwood Water Department
19952 Harrington — 2 0 Harrington Water Department
19970 Ocean View B 2 0 Bethany Bay Pump District

Areas with No Violations

ZIP Code City Home Safety Grade System Population
19701 Bear C Artesian Water Company 231,114
19702 Newark C Artesian Water Company 231,114
19703 Claymont C Veolia Water Delaware, Inc. 100,495
19706 Delaware City — Delaware City Water Department (awc) 2,610
19707 Hockessin C Artesian Water Company 231,114
19709 Middletown B Artesian Water Company 231,114
19711 Newark C Newark Water Department 40,000
19713 Newark C Veolia Water Delaware, Inc. 100,495
19716 Newark — Newark Water Department 40,000
19717 Newark — Newark Water Department 40,000

Home Safety Score

Average Home Safety Score for Delaware: B (81/100) across 46 scored of 97 tracked ZIP records.

Model 4.0.0 uses the canonical components water-compliance, pfas-mcl-screen, radon-zone, annual-aqi across 3 required domains. The sections below provide additional context and do not change that score. Missing required evidence suppresses the score, and a favorable result is not a property-level safety certification.

Lead & Copper

  • Average of reported 90th-percentile lead results: 0.0034 mg/L (EPA action level: 0.015 mg/L)
  • 3 of 60 ZIP codes with known status exceed the EPA lead action level

Radon Risk

  • High risk (Zone 1): 0 ZIP codes (0%)
  • Moderate risk (Zone 2): 52 ZIP codes
  • Low risk (Zone 3): 45 ZIP codes

ZIP Code Reports for Delaware

Largest Communities

ZIP Code City Population Safety Grade Violations
19720 New Castle 447,744 C 1
19801 Wilmington 439,585 C 1
19804 Wilmington 439,585 C 1
19805 Wilmington 439,585 C 1
19702 Newark 371,609 C 0
19711 Newark 371,609 C 0
19713 Newark 371,609 C 0
19807 Wilmington 339,150 B 2
19701 Bear 331,609 C 0
19709 Middletown 261,768 B 0
19731 Port Penn 236,652 — 0
19730 Odessa 234,204 — 0
19734 Townsend 234,204 — 0
19707 Hockessin 231,114 C 0
19736 Yorklyn 231,114 — 0
19808 Wilmington 231,114 C 0
19802 Wilmington 208,471 C 1
19803 Wilmington 208,471 C 1
19809 Wilmington 208,471 C 1
19810 Wilmington 208,471 C 1

Lowest Published Home Safety Scores

ZIP Code City Score Grade Violations
19720 New Castle 66 C 1
19732 Rockland 66 C 1
19801 Wilmington 66 C 1
19802 Wilmington 66 C 1
19803 Wilmington 66 C 1

Highest Published Home Safety Scores

ZIP Code City Score Grade Violations
19901 Dover 100 A 0
19902 Dover Afb 100 A 0
19904 Dover 100 A 0
19933 Bridgeville 100 A 1
19934 Camden Wyoming 100 A 0

All 97 ZIP Codes in Delaware

Data Sources

Reporting periods vary by source. Missing data is shown as unavailable, not as zero.

Largest water systems in Delaware

The 12 largest community water systems in Delaware, out of 77 in our data.

Show all 12 water systems

Systems with the most violations in Delaware

12 systems in Delaware with the most recorded EPA violations.

Frequently Asked Questions

Is the water safe to drink in Delaware?

Delaware has 77 community water systems serving 779,393 people across 97 ZIP codes. There are 21 recorded violations among these water systems, including 4 health-based. 25 of 97 ZIP codes are mapped to at least one water system with a recorded violation.

What plumbing code does Delaware follow?

Delaware's listed plumbing code type is IPC as of our last review; local jurisdictions may adopt or amend codes. Plumbing work may require a licensed plumber; check state exemptions and local requirements.

Is lead a concern in Delaware's drinking water?

3 ZIP codes in Delaware are mapped to water systems whose reported 90th-percentile lead result exceeded the EPA action level of 0.015 mg/L.

How to cite this page

APA ZipCheckup. (2026). Delaware Home Safety Profiles by ZIP. https://zipcheckup.com/states/delaware/
BibTeX 
@misc{zipcheckup-states-delaware,
  author = {{ZipCheckup}},
  title  = {{Delaware Home Safety Profiles by ZIP}},
  year   = {2026},
  url    = {https://zipcheckup.com/states/delaware/}
}

Page version: October 2026.

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