Arapahoe County, Colorado
31 ZIP codes · Avg score 60/100 · Grade C · Updated 2026-06-03
Current EPA records place Arapahoe County in the middle tier for drinking water safety, with 31 ZIP codes showing a range of outcomes.
How Arapahoe County Compares
How Arapahoe County Compares
Arapahoe County scores 0 points above the Colorado state average (60/100) and 8 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Arapahoe County, Colorado
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 10.3 (asthma 10.5%, diabetes 8.6%)
Estimated additional annual cost per homeowner: $989, driven primarily by flood
Infrastructure: 0.343% avg pipe failure probability, 26% of ZIPs at high risk
54.1% 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: $989
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
270,140 housing units in Arapahoe 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 Arapahoe County
Remediation costs are relatively manageable for most homeowners in Arapahoe 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 Arapahoe 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 Arapahoe County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | City of Aurora | 533,407 | 144 |
| 2 | East Cherry Creek Valley Water Supply District | 66,130 | 132 |
| 3 | Poudre Valley Mhc | 985 | 132 |
| 4 | Collins Aire Mhc | 946 | 132 |
| 5 | Lago Vista Mobile Home Park | 842 | 132 |
27 total water systems serve Arapahoe County.
All ZIP Codes in Arapahoe County
31 ZIP codes tracked in Arapahoe County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 80121 | Littleton | 70 | B | 0 | $685K |
| 2 | 80110 | Englewood | 69 | C | 13 (1 health) | $456K |
| 3 | 80103 | Byers | 66 | C | 1 | $503K |
| 4 | 80105 | Deer Trail | 66 | C | 1 | $374K |
| 5 | 80160 | Littleton | 66 | C | 0 | — |
| 6 | 80161 | Littleton | 66 | C | 0 | — |
| 7 | 80165 | Littleton | 66 | C | 0 | — |
| 8 | 80166 | Littleton | 66 | C | 0 | — |
| 9 | 80120 | Littleton | 65 | C | 0 | $596K |
| 10 | 80122 | Littleton | 65 | C | 0 | $599K |
| 11 | 80123 | Littleton | 65 | C | 0 | $582K |
| 12 | 80150 | Englewood | 65 | C | 13 (1 health) | — |
| 13 | 80151 | Englewood | 65 | C | 13 (1 health) | — |
| 14 | 80155 | Englewood | 65 | C | 13 (1 health) | — |
| 15 | 80111 | Englewood | 64 | C | 13 (1 health) | $891K |
| 16 | 80112 | Englewood | 64 | C | 13 (1 health) | $628K |
| 17 | 80113 | Englewood | 64 | C | 13 (1 health) | $700K |
| 18 | 80137 | Watkins | 64 | C | 12 | $698K |
| 19 | 80222 | Denver | 64 | C | 3 | $596K |
| 20 | 80014 | Aurora | 56 | C | 12 | $387K |
| 21 | 80015 | Aurora | 56 | C | 12 | $559K |
| 22 | 80017 | Aurora | 56 | C | 12 | $384K |
| 23 | 80018 | Aurora | 56 | C | 12 | $559K |
| 24 | 80041 | Aurora | 56 | C | 12 | — |
| 25 | 80010 | Aurora | 51 | D | 12 | $386K |
| 26 | 80012 | Aurora | 51 | D | 12 | $398K |
| 27 | 80013 | Aurora | 51 | D | 12 | $454K |
| 28 | 80016 | Aurora | 51 | D | 12 | $708K |
| 29 | 80040 | Aurora | 51 | D | 12 | — |
| 30 | 80042 | Aurora | 51 | D | 12 | — |
| 31 | 80757 | Woodrow | 40 | D | 0 | $252K |
Recommended Buyer Guides for Arapahoe County
Independent picks. EPA-grounded. Matched here.
- Best Lead Paint Test Kits — 54.1% 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
- 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 Arapahoe County, Colorado
Overview
Arapahoe County in Colorado covers 31 ZIP codes with an average Home Safety Score of C (60/100).
22 of 31 ZIP codes have recorded EPA violations. 7 health-based violations have been documented.
← Back to Colorado 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.