Baltimore County, Maryland
73 ZIP codes · Avg score 58/100 · Grade C · Updated 2026-06-03
Water safety in Baltimore County is uneven — some of its 73 ZIP codes meet standards cleanly while others carry documented violations.
How Baltimore County Compares
How Baltimore County Compares
Baltimore County scores 3 points below the Maryland state average (61/100) and 10 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Baltimore County, Maryland
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.7 (asthma 11.4%, diabetes 13.1%)
Estimated additional annual cost per homeowner: $1,699, driven primarily by sea_level
Infrastructure: 0.388% avg pipe failure probability, 36% of ZIPs at high risk
Violation History (2022–2024)
→ Stable trendEPA violation counts by year across Baltimore County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 100 violations. Past 5 years: 150 total (150 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: $1,699
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 Baltimore County
Remediation costs are relatively manageable for most homeowners in Baltimore 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 Baltimore 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 Baltimore County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | CITY OF BALTIMORE | 1,600,000 | 529 |
| 2 | Keswick Multi-care Center | 575 | 517 |
| 3 | Sunnybrook | 416 | 517 |
| 4 | Campus Hills Water Works | 250 | 517 |
| 5 | The Neighborhoods at St. Elizabeth | 162 | 517 |
12 total water systems serve Baltimore County.
All ZIP Codes in Baltimore County
73 ZIP codes tracked in Baltimore County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 21057 | Glen Arm | 68 | C | 8 (2 health) | $609K |
| 2 | 21201 | Baltimore | 68 | C | 11 (2 health) | $222K |
| 3 | 21205 | Baltimore | 68 | C | 11 (2 health) | $95K |
| 4 | 21217 | Baltimore | 68 | C | 11 (2 health) | $176K |
| 5 | 21298 | Baltimore | 68 | C | 11 (2 health) | — |
| 6 | 21233 | Baltimore | 64 | C | 11 (2 health) | — |
| 7 | 21235 | Baltimore | 64 | C | 11 (2 health) | — |
| 8 | 21241 | Baltimore | 64 | C | 11 (2 health) | — |
| 9 | 21250 | Baltimore | 64 | C | 11 (2 health) | — |
| 10 | 21251 | Baltimore | 64 | C | 11 (2 health) | — |
| 11 | 21260 | Baltimore | 64 | C | 11 (2 health) | — |
| 12 | 21263 | Baltimore | 64 | C | 11 (2 health) | — |
| 13 | 21264 | Baltimore | 64 | C | 11 (2 health) | — |
| 14 | 21265 | Baltimore | 64 | C | 11 (2 health) | — |
| 15 | 21270 | Baltimore | 64 | C | 11 (2 health) | — |
| 16 | 21273 | Baltimore | 64 | C | 11 (2 health) | — |
| 17 | 21274 | Baltimore | 64 | C | 11 (2 health) | — |
| 18 | 21275 | Baltimore | 64 | C | 11 (2 health) | — |
| 19 | 21278 | Baltimore | 64 | C | 11 (2 health) | — |
| 20 | 21279 | Baltimore | 64 | C | 11 (2 health) | — |
| 21 | 21280 | Baltimore | 64 | C | 11 (2 health) | — |
| 22 | 21281 | Baltimore | 64 | C | 11 (2 health) | — |
| 23 | 21282 | Baltimore | 64 | C | 11 (2 health) | — |
| 24 | 21283 | Baltimore | 64 | C | 11 (2 health) | — |
| 25 | 21284 | Baltimore | 64 | C | 11 (2 health) | — |
| 26 | 21285 | Baltimore | 64 | C | 11 (2 health) | — |
| 27 | 21287 | Baltimore | 64 | C | 11 (2 health) | — |
| 28 | 21288 | Baltimore | 64 | C | 11 (2 health) | — |
| 29 | 21289 | Baltimore | 64 | C | 11 (2 health) | — |
| 30 | 21290 | Baltimore | 64 | C | 11 (2 health) | — |
| 31 | 21297 | Baltimore | 64 | C | 11 (2 health) | — |
| 32 | 21202 | Baltimore | 63 | C | 11 (2 health) | $308K |
| 33 | 21206 | Baltimore | 63 | C | 11 (2 health) | $214K |
| 34 | 21210 | Baltimore | 63 | C | 11 (2 health) | $522K |
| 35 | 21212 | Baltimore | 63 | C | 11 (2 health) | $358K |
| 36 | 21213 | Baltimore | 63 | C | 11 (2 health) | $135K |
| 37 | 21214 | Baltimore | 63 | C | 11 (2 health) | $251K |
| 38 | 21216 | Baltimore | 63 | C | 11 (2 health) | $149K |
| 39 | 21218 | Baltimore | 63 | C | 11 (2 health) | $230K |
| 40 | 21223 | Baltimore | 63 | C | 11 (2 health) | $94K |
| 41 | 21224 | Baltimore | 63 | C | 11 (2 health) | $281K |
| 42 | 21239 | Baltimore | 63 | C | 11 (2 health) | $191K |
| 43 | 21153 | Stevenson | 62 | C | 4 (1 health) | $988K |
| 44 | 21209 | Baltimore | 58 | C | 11 (2 health) | $419K |
| 45 | 21211 | Baltimore | 58 | C | 11 (2 health) | $274K |
| 46 | 21215 | Baltimore | 58 | C | 11 (2 health) | $190K |
| 47 | 21229 | Baltimore | 58 | C | 11 (2 health) | $185K |
| 48 | 21230 | Baltimore | 58 | C | 11 (2 health) | $328K |
| 49 | 21231 | Baltimore | 58 | C | 11 (2 health) | $337K |
| 50 | 21053 | Freeland | 57 | C | 5 (2 health) | $445K |
| 51 | 20812 | Glen Echo | 53 | D | 0 | $1129K |
| 52 | 20855 | Derwood | 53 | D | 0 | $615K |
| 53 | 20876 | Germantown | 53 | D | 0 | $457K |
| 54 | 20877 | Gaithersburg | 53 | D | 0 | $463K |
| 55 | 20879 | Gaithersburg | 53 | D | 0 | $434K |
| 56 | 20882 | Gaithersburg | 53 | D | 0 | $706K |
| 57 | 20886 | Montgomery Village | 53 | D | 0 | $366K |
| 58 | 20896 | Garrett Park | 53 | D | 0 | $994K |
| 59 | 20815 | Chevy Chase | 45 | D | 0 | $1231K |
| 60 | 20818 | Cabin John | 45 | D | 0 | $1273K |
| 61 | 20852 | Rockville | 45 | D | 0 | $646K |
| 62 | 20874 | Germantown | 45 | D | 0 | $385K |
| 63 | 20878 | Gaithersburg | 45 | D | 0 | $675K |
| 64 | 21117 | Owings Mills | 45 | D | 0 | $371K |
| 65 | 20825 | Chevy Chase | 40 | D | 0 | — |
| 66 | 20848 | Rockville | 40 | D | 0 | — |
| 67 | 20875 | Germantown | 40 | D | 0 | — |
| 68 | 20880 | Washington Grove | 40 | D | 0 | $594K |
| 69 | 20884 | Gaithersburg | 40 | D | 0 | — |
| 70 | 20885 | Gaithersburg | 40 | D | 0 | — |
| 71 | 20897 | Suburb Maryland Fac | 40 | D | 0 | — |
| 72 | 20898 | Gaithersburg | 40 | D | 0 | — |
| 73 | 20899 | Gaithersburg | 40 | D | 0 | — |
Recommended Buyer Guides for Baltimore County
Four sources — EPA, NSF, FEMA, CDC — drive the match.
- 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 Baltimore County, Maryland
Overview
Baltimore County in Maryland covers 73 ZIP codes with an average Home Safety Score of C (58/100).
50 of 73 ZIP codes have recorded EPA violations. 99 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.