Loudoun County, Virginia
35 ZIP codes · Avg score 77/100 · Grade B · Updated
ZipCheckup grade for Loudoun County: B.
This ZIP looks solid, with a few items worth a quick check.
In recent assessments, Loudoun County's 35 ZIP codes record strong, consistent water safety outcomes.
How Loudoun County Compares
How Loudoun County Compares
Loudoun County scores 2 points above the Virginia state average (75/100) and 4 points above 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: Loudoun County, Virginia
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 9.7 (asthma 8.9%, diabetes 9.5%)
Estimated additional annual cost per homeowner: $1,872, driven primarily by sea_level
Violation History (2024–2025)
→ Stable trendEPA violation counts by year across Loudoun County water systems. Health-based shown in red, total in blue.
Peak year: 2025 with 2 violations. Past 5 years: 3 total (3 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: $1,872
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 Loudoun County
Remediation costs are relatively manageable for most homeowners in Loudoun 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 Loudoun County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving Loudoun County
8 community water systems serving Loudoun County.
- B
- B
- B
- C
- C
- C
Show all 8 water systems
- B
- B
12 total water systems serve Loudoun County.
Systems with the most violations in Loudoun County
3 water systems with recorded EPA violations.
- B
- B
All ZIP Codes in Loudoun County
35 ZIP codes tracked in Loudoun County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 20147 | Ashburn | 83 | B | 1 | $680K |
| 2 | 20148 | Ashburn | 83 | B | 1 | $844K |
| 3 | 20152 | Chantilly | 83 | B | 1 | $708K |
| 4 | 20165 | Sterling | 83 | B | 1 | $661K |
| 5 | 20166 | Sterling | 83 | B | 1 | $576K |
| 6 | 20176 | Leesburg | 83 | B | 1 | $702K |
| 7 | 20175 | Leesburg | 82 | B | 3 | $718K |
| 8 | 20141 | Round Hill | 67 | C | 0 | $677K |
| 9 | 20132 | Purcellville | 66 | C | 2 | $704K |
| 10 | 20158 | Hamilton | 66 | C | 2 | $771K |
| 11 | 20164 | Sterling | 66 | C | 1 | $527K |
| 12 | 20101 | Dulles | — | — | — | |
| 13 | 20102 | Dulles | — | — | — | |
| 14 | 20103 | Dulles | — | — | — | |
| 15 | 20104 | Dulles | — | — | — | |
| 16 | 20105 | Aldie | — | — | 5 | $807K |
| 17 | 20117 | Middleburg | — | — | 4 | $948K |
| 18 | 20118 | Middleburg | — | — | — | |
| 19 | 20129 | Paeonian Springs | — | — | $1206K | |
| 20 | 20131 | Philomont | — | — | — | |
| 21 | 20134 | Purcellville | — | — | — | |
| 22 | 20142 | Round Hill | — | — | — | |
| 23 | 20146 | Ashburn | — | — | — | |
| 24 | 20149 | Ashburn | — | — | — | |
| 25 | 20159 | Hamilton | — | — | — | |
| 26 | 20160 | Lincoln | — | — | — | |
| 27 | 20163 | Sterling | — | — | — | |
| 28 | 20167 | Sterling | — | — | — | |
| 29 | 20177 | Leesburg | — | — | — | |
| 30 | 20178 | Leesburg | — | — | — | |
| 31 | 20180 | Lovettsville | — | — | 0 | $629K |
| 32 | 20189 | Dulles | — | — | — | |
| 33 | 20197 | Waterford | — | — | 0 | $989K |
| 34 | 20598 | Dhs | — | — | — | |
| 35 | 22093 | Ashburn | — | — | — |
Recommended Buyer Guides for Loudoun County
While many sites publish identical guide lists across every county they cover, the selection here changes by location - driven by the EPA, NSF, FEMA, and CDC datasets that describe the actual conditions documented for this jurisdiction in the federal record.
- Best Water Testing Kits — Baseline water quality check for your ZIP
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant peace of mind
Deep Dive Reports
Detailed analysis for Loudoun County, Virginia
Overview
Loudoun County in Virginia covers 35 tracked ZIP records with an average Home Safety Score of B (77/100) across 11 scored records.
12 of 15 ZIP codes with a reported violation count in the available EPA record have recorded EPA violations. The available record reports no health-based violations for this measured scope.
← Back to Virginia 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.