Howard County, Maryland
9 ZIP codes · Avg score 62/100 · Grade C · Updated 2026-06-03
Within Howard County, safety data across 9 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 1 points above the Maryland state average (61/100) and 6 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
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: $1,662, driven primarily by flood
Infrastructure: 0.289% avg pipe failure probability
47.9% 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 6 violations. Past 5 years: 9 total (9 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
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,662
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
91,773 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 with Most Violations
Top 5 systems in Howard County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Howard County D.p.w. Distribution | 286,158 | 34 |
| 2 | Cedar Mobile Home Park | 300 | 18 |
| 3 | CITY OF BALTIMORE | 1,600,000 | 16 |
| 4 | Lutheran Village at Miller's Grant | 315 | 15 |
| 5 | Rockbrook Village Mobile Home Park | 150 | 15 |
18 total water systems serve Howard County.
All ZIP Codes in Howard County
9 ZIP codes tracked in Howard County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 21041 | Ellicott City | 69 | C | 5 (1 health) | — |
| 2 | 20723 | Laurel | 65 | C | 0 | $508K |
| 3 | 21268 | Baltimore | 64 | C | 11 (2 health) | — |
| 4 | 21044 | Columbia | 62 | C | 6 | $541K |
| 5 | 21045 | Columbia | 62 | C | 6 | $439K |
| 6 | 21046 | Columbia | 62 | C | 6 | $469K |
| 7 | 20794 | Jessup | 59 | C | 6 (1 health) | $394K |
| 8 | 21042 | Ellicott City | 59 | C | 5 (1 health) | $675K |
| 9 | 21043 | Ellicott City | 54 | D | 5 (1 health) | $607K |
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 9 ZIP codes with an average Home Safety Score of C (62/100).
8 of 9 ZIP codes have recorded EPA violations. 6 health-based violations have been documented.
← Back to Maryland 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.