Neighborhood Report
Grade C
Sioux City, IA Neighborhood Water Quality — Grade C
9 ZIP codes · 9 EPA violations
Data source: EPA SDWIS Last verified: 2026-06-04
Water quality varies significantly across Sioux City, IA. We analyzed 9 ZIP codes to help you compare neighborhoods by water safety, lead risk, and EPA compliance.
City Overview: Grade C (66/100)
| Grade | Neighborhoods | % |
|---|---|---|
| A | 0 | 0% |
| B | 4 | 44% |
| C | 5 | 56% |
| D | 0 | 0% |
| F | 0 | 0% |
Neighborhood Rankings
Every ZIP code in Sioux City ranked by Home Safety Score:
| Rank | ZIP Code | Score | Grade | Violations | Lead Risk |
|---|---|---|---|---|---|
| 1 | 51101 | 70 | B | 1 | 0.0020 mg/L |
| 2 | 51102 | 70 | B | 1 | 0.0020 mg/L |
| 3 | 51105 | 70 | B | 1 | 0.0020 mg/L |
| 4 | 51108 | 70 | B | 1 | 0.0020 mg/L |
| 5 | 51111 | 66 | C | 1 | 0.0020 mg/L |
| 6 | 51106 | 65 | C | 1 | 0.0020 mg/L |
| 7 | 51109 | 65 | C | 1 | 0.0020 mg/L |
| 8 | 51103 | 60 | C | 1 | 0.0020 mg/L |
| 9 | 51104 | 60 | C | 1 | 0.0020 mg/L |
How Neighborhoods Compare
Each ZIP code compared to county and state averages:
- 7 neighborhoods score better than county average
- 2 neighborhoods score worse than county average
EPA Violations
- 9 total violations across Sioux City
- 0 health-based violations
- 9 of 9 ZIP codes have violations
- 0 ZIP codes exceed EPA lead action level
Top Contaminants
| Contaminant | Violations | ZIPs |
|---|---|---|
| Haloacetic Acids (HAA5) | 9 | 9 |
Frequently Asked Questions
What is the safest neighborhood in Sioux City?
ZIP code 51101 has the highest safety score in Sioux City at 70/100 (grade B). Check the full report for details.
Is Sioux City water safe to drink?
Sioux City has an average water safety score of 66/100 (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.