Boulder, CO Neighborhood Water Quality — Grade C
16 ZIP codes · 192 EPA violations
Data source: EPA SDWIS Last verified: 2026-06-03
Water quality varies significantly across Boulder, CO. We analyzed 16 ZIP codes to help you compare neighborhoods by water safety, lead risk, and EPA compliance.
City Overview: Grade C (62/100)
| Grade | Neighborhoods | % |
|---|---|---|
| A | 0 | 0% |
| B | 0 | 0% |
| C | 13 | 81% |
| D | 3 | 19% |
| F | 0 | 0% |
Neighborhood Rankings
Every ZIP code in Boulder ranked by Home Safety Score:
| Rank | ZIP Code | Score | Grade | Violations | Lead Risk |
|---|---|---|---|---|---|
| 1 | 80306 | 68 | C | 12 | 0.0020 mg/L |
| 2 | 80308 | 68 | C | 12 | 0.0020 mg/L |
| 3 | 80307 | 64 | C | 12 | 0.0020 mg/L |
| 4 | 80309 | 64 | C | 12 | 0.0020 mg/L |
| 5 | 80310 | 64 | C | 12 | 0.0020 mg/L |
| 6 | 80314 | 64 | C | 12 | 0.0020 mg/L |
| 7 | 80321 | 64 | C | 12 | 0.0020 mg/L |
| 8 | 80322 | 64 | C | 12 | 0.0020 mg/L |
| 9 | 80323 | 64 | C | 12 | 0.0020 mg/L |
| 10 | 80328 | 64 | C | 12 | 0.0020 mg/L |
| 11 | 80329 | 64 | C | 12 | 0.0020 mg/L |
| 12 | 80301 | 58 | C | 12 | 0.0020 mg/L |
| 13 | 80305 | 58 | C | 12 | 0.0020 mg/L |
| 14 | 80302 | 53 | D | 12 | 0.0020 mg/L |
| 15 | 80303 | 53 | D | 12 | 0.0020 mg/L |
| 16 | 80304 | 53 | D | 12 | 0.0020 mg/L |
How Neighborhoods Compare
Each ZIP code compared to county and state averages:
- 11 neighborhoods score better than county average
- 5 neighborhoods score worse than county average
EPA Violations
- 192 total violations across Boulder
- 32 health-based violations
- 16 of 16 ZIP codes have violations
- 0 ZIP codes exceed EPA lead action level
Top Contaminants
| Contaminant | Violations | ZIPs |
|---|---|---|
| Lead and Copper Rule | 96 | 16 |
| Surface Water Treatment Rule | 32 | 16 |
| Chlorine residual | 32 | 16 |
| E. coli | 16 | 16 |
| Fecal Coliform | 16 | 16 |
Frequently Asked Questions
What is the safest neighborhood in Boulder?
ZIP code 80306 has the highest safety score in Boulder at 68/100 (grade C). Check the full report for details.
Is Boulder water safe to drink?
Boulder has an average water safety score of 62/100 (C). Water quality varies by neighborhood — no ZIP codes currently exceed EPA lead limits. Always check your specific ZIP code.
Related Pages
Data Sources
- EPA SDWIS
- U.S. Census Bureau
Updated daily.