Boulder County, Colorado
31 ZIP codes · Avg score 59/100 · Grade C · Updated
ZipCheckup grade for Boulder County: C.
A mixed picture - some signals here are worth your attention.
Across Boulder County's 31 ZIP codes, water safety results are uneven - a portion of systems carry active or recent violations, while others meet standards without issues.
How Boulder County Compares
How Boulder County Compares
Boulder County scores 0 points above the Colorado state average (59/100) and 14 points below 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: Boulder County, Colorado
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 8.7 (asthma 10.3%, diabetes 7.1%)
Estimated additional annual cost per homeowner: $1,458, driven primarily by flood
Violation History (2021–2025)
↓ Improving trendEPA violation counts by year across Boulder County water systems. Health-based shown in red, total in blue.
Peak year: 2021 with 14 violations. Past 5 years: 38 total (38 health-based). Health-based violations are declining versus the prior 2-year window.
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: $1,458
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 Boulder County
Remediation costs are relatively manageable for most homeowners in Boulder 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 Boulder County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving Boulder County
8 community water systems serving Boulder County.
- D
- D
- D
- C
- D
- C
Show all 8 water systems
- D
- C
22 total water systems serve Boulder County.
Systems with the most violations in Boulder County
5 water systems with recorded EPA violations.
- D
- C
- D
- D
All ZIP Codes in Boulder County
31 ZIP codes tracked in Boulder County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 80302 | Boulder | 66 | C | 3 | $1124K |
| 2 | 80304 | Boulder | 66 | C | 3 | $1166K |
| 3 | 80466 | Nederland | 66 | C | 1 | $660K |
| 4 | 80501 | Longmont | 66 | C | 2 | $461K |
| 5 | 80027 | Louisville | 60 | C | 16 (4 health) | $823K |
| 6 | 80303 | Boulder | 60 | C | 17 (3 health) | $942K |
| 7 | 80305 | Boulder | 57 | C | 19 (11 health) | $986K |
| 8 | 80026 | Lafayette | 51 | D | 24 (3 health) | $664K |
| 9 | 80301 | Boulder | 50 | D | 82 (4 health) | $762K |
| 10 | 80503 | Longmont | 49 | D | 4 | $705K |
| 11 | 80025 | Eldorado Springs | — | — | 2 | $644K |
| 12 | 80028 | Louisville | — | — | — | |
| 13 | 80306 | Boulder | — | — | — | |
| 14 | 80307 | Boulder | — | — | — | |
| 15 | 80308 | Boulder | — | — | — | |
| 16 | 80309 | Boulder | — | — | — | |
| 17 | 80310 | Boulder | — | — | 2 | — |
| 18 | 80314 | Boulder | — | — | — | |
| 19 | 80321 | Boulder | — | — | — | |
| 20 | 80322 | Boulder | — | — | — | |
| 21 | 80323 | Boulder | — | — | — | |
| 22 | 80328 | Boulder | — | — | — | |
| 23 | 80329 | Boulder | — | — | — | |
| 24 | 80455 | Jamestown | — | — | $536K | |
| 25 | 80471 | Pinecliffe | — | — | — | |
| 26 | 80481 | Ward | — | — | $552K | |
| 27 | 80502 | Longmont | — | — | — | |
| 28 | 80510 | Allenspark | — | — | $772K | |
| 29 | 80533 | Hygiene | — | — | — | |
| 30 | 80540 | Lyons | — | — | 43 (26 health) | $788K |
| 31 | 80544 | Niwot | — | — | — |
Recommended Buyer Guides for Boulder County
Editorial methodology pairs each documented risk in this county with the buyer category that addresses it, drawing on water-quality detections, housing-stock lead exposure, EPA Radon Zone designation, and FEMA flood and wildfire ratings. NSF-certified options surface where applicable, and products that match the specific contaminant take priority.
- Best Water Filters for PFAS — PFAS detected in 1 ZIP code
- 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 Boulder County, Colorado
Overview
Boulder County in Colorado covers 31 tracked ZIP records with an average Home Safety Score of C (59/100) across 10 scored records.
13 of 13 ZIP codes with a reported violation count in the available EPA record have recorded EPA violations. 45 health-based violations appear in the available health breakdown.
← Back to Colorado 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.