Calvert County, Maryland
26 ZIP codes · Avg score 47/100 · Grade D · Updated 2026-06-03
Of 26 ZIP codes in Calvert County, a meaningful portion have recorded health-based violations in recent monitoring periods — placing the county in the lower tier for water safety.
How Calvert County Compares
How Calvert County Compares
Calvert County scores 14 points below the Maryland state average (61/100) and 21 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Calvert County, Maryland
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.8 (asthma 10.6%, diabetes 12.2%)
Estimated additional annual cost per homeowner: $3,113, driven primarily by sea_level
Infrastructure: 0.332% avg pipe failure probability, 12% of ZIPs at high risk
52.7% of homes built before 1978 (lead paint era)
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: $3,113
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
43,315 housing units in Calvert 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 Calvert County
Remediation costs are relatively manageable for most homeowners in Calvert 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 Calvert 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 Calvert County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Chesapeake Heights (bayside Forest) | 1,190 | 9 |
| 2 | PRINCE FREDERICK | 4,371 | 8 |
| 3 | THE CALVERTON SCHOOL | 461 | 7 |
| 4 | B&l Mobile Home Park | 65 | 7 |
| 5 | Scientists Cliffs | 1,425 | 7 |
23 total water systems serve Calvert County.
All ZIP Codes in Calvert County
26 ZIP codes tracked in Calvert County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 20676 | Port Republic | 70 | B | 1 | $472K |
| 2 | 20689 | Sunderland | 65 | C | 2 (1 health) | $468K |
| 3 | 20678 | Prince Frederick | 63 | C | 1 | $428K |
| 4 | 20732 | Chesapeake Beach | 60 | C | 1 | $426K |
| 5 | 20754 | Dunkirk | 55 | C | 1 | $601K |
| 6 | 20608 | Aquasco | 53 | D | 0 | $357K |
| 7 | 20675 | Pomfret | 53 | D | 0 | $437K |
| 8 | 20657 | Lusby | 51 | D | 5 (1 health) | $318K |
| 9 | 20714 | North Beach | 51 | D | 3 (1 health) | $363K |
| 10 | 20639 | Huntingtown | 50 | D | 7 (2 health) | $528K |
| 11 | 20612 | Benedict | 45 | D | 0 | — |
| 12 | 20677 | Port Tobacco | 45 | D | 0 | $525K |
| 13 | 20688 | Solomons | 45 | D | 0 | — |
| 14 | 20695 | White Plains | 45 | D | 0 | $447K |
| 15 | 20610 | Barstow | 40 | D | 0 | — |
| 16 | 20611 | Bel Alton | 40 | D | 0 | $395K |
| 17 | 20617 | Bryantown | 40 | D | 0 | $490K |
| 18 | 20629 | Dowell | 40 | D | 0 | $460K |
| 19 | 20632 | Faulkner | 40 | D | 0 | $491K |
| 20 | 20685 | Saint Leonard | 40 | D | 0 | $431K |
| 21 | 20693 | Welcome | 40 | D | 0 | $429K |
| 22 | 20733 | Churchton | 40 | D | 0 | $397K |
| 23 | 20751 | Deale | 40 | D | 0 | $448K |
| 24 | 20758 | Friendship | 40 | D | 0 | $604K |
| 25 | 21634 | Fishing Creek | 40 | D | 0 | $275K |
| 26 | 21669 | Taylors Island | 40 | D | 0 | $410K |
Recommended Buyer Guides for Calvert County
Retailer arrangements don't shape what appears here — the selection logic is independent, filtered against EPA detections and the federal hazard data on file for this county.
- Best Lead Paint Test Kits — 52.7% of homes built before 1978
- 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
Deep Dive Reports
Detailed analysis for Calvert County, Maryland
Overview
Calvert County in Maryland covers 26 ZIP codes with an average Home Safety Score of D (47/100).
8 of 26 ZIP codes have recorded EPA violations. 5 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.
What You Can Do
Calvert County has a grade of D. Here are steps to protect your household.
Test your tap water
Order a certified lab test kit ($20-$50) to check for lead, bacteria, and other contaminants specific to your ZIP code.
Consider a certified water filter
NSF-certified filters can remove most common contaminants. Match the filter to your test results for best protection. Try our filter matcher
Contact your water utility
Request the latest Consumer Confidence Report (CCR) from your water provider. It details exactly what was found in your water supply.
Check for lead in your home
52.7% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.