Howard County, Maryland
24 ZIP codes · Avg score 63/100 · Grade C · Updated
ZipCheckup grade for Howard County: C.
A mixed picture - some signals here are worth your attention.
Within Howard County, safety data across 24 ZIP codes suggests a fair but uneven system - violations are present and worth checking at the ZIP level.
How Howard County Compares
How Howard County Compares
Howard County scores 6 points below the Maryland state average (69/100) and 10 points below the national average (73/100).
Data: ZipCheckup Home Safety Score model 4.0.0; EPA SDWIS, UCMR 5, EPA radon zones, EPA AirData Last verified:
ZIP Code Risk Map
Water Quality Map: Howard County, Maryland
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 10.6 (asthma 9.1%, diabetes 10.4%)
Estimated additional annual cost per homeowner: $1,352, driven primarily by flood
41.1% of homes built before 1978 (lead paint era)
Violation History (2022–2024)
→ Stable trendEPA violation counts by year across Howard County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 7 violations. Past 5 years: 11 total (11 health-based).
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Modeled area-level indicator, not a failure probability. Sources: Census ACS housing age, EPA DWINS infrastructure needs, EPA SDWIS violations, and EPA lead indicators.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,352
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
124,219 housing units in Howard County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Howard County
Remediation costs are relatively manageable for most homeowners in Howard 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 Howard County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving Howard County
8 community water systems serving Howard County.
- C
- C
- C
- C
- C
Show all 8 water systems
- C
- D
Systems with the most violations in Howard County
5 water systems with recorded EPA violations.
- C
- D
- C
- C
All ZIP Codes in Howard County
24 ZIP codes tracked in Howard County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 20723 | Laurel | 66 | C | 1 | $508K |
| 2 | 21045 | Columbia | 66 | C | 1 | $439K |
| 3 | 21046 | Columbia | 66 | C | 1 | $469K |
| 4 | 21104 | Marriottsville | 66 | C | 3 | $660K |
| 5 | 20794 | Jessup | 63 | C | 7 (1 health) | $394K |
| 6 | 21043 | Ellicott City | 63 | C | 10 (2 health) | $607K |
| 7 | 21163 | Woodstock | 63 | C | 10 (2 health) | $599K |
| 8 | 21042 | Ellicott City | 48 | D | 6 (1 health) | $675K |
| 9 | 20759 | Fulton | — | — | 1 | $888K |
| 10 | 20763 | Savage | — | — | 1 | $406K |
| 11 | 20777 | Highland | — | — | $809K | |
| 12 | 21029 | Clarksville | — | — | 1 | $905K |
| 13 | 21036 | Dayton | — | — | $843K | |
| 14 | 21041 | Ellicott City | — | — | — | |
| 15 | 21044 | Columbia | — | — | 1 | $541K |
| 16 | 21075 | Elkridge | — | — | 1 | $439K |
| 17 | 21150 | Simpsonville | — | — | — | |
| 18 | 21268 | Baltimore | — | — | — | |
| 19 | 21723 | Cooksville | — | — | $915K | |
| 20 | 21737 | Glenelg | — | — | $1033K | |
| 21 | 21738 | Glenwood | — | — | $889K | |
| 22 | 21765 | Lisbon | — | — | — | |
| 23 | 21794 | West Friendship | — | — | 1 | $977K |
| 24 | 21797 | Woodbine | — | — | 4 | $713K |
Recommended Buyer Guides for Howard County
Strictly editorial - no paid placements influence which guides appear; the selection draws on NSF certifications and EPA detection records for water systems serving this county.
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Howard County, Maryland
Overview
Howard County in Maryland covers 24 tracked ZIP records with an average Home Safety Score of C (63/100) across 8 scored records.
15 of 15 ZIP codes with a reported violation count in the available EPA record have recorded EPA violations. 4 health-based violations appear in the available health breakdown.
← Back to Maryland Home Safety Profile
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- PFAS screening: EPA UCMR 5
- Radon zones: EPA Map of Radon Zones
- Air quality: EPA AirData annual AQI
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Reporting periods vary by source. Missing data is shown as unavailable, not as zero.