Columbus Public Water System
Columbus, Ohio · PWSID: OH2504412
Columbus Water Quality Summary
Columbus Public Water System supplies drinking water to about 1,305,946 people in Columbus, Ohio, and draws from surface water (rivers, lakes, or reservoirs), which requires fuller treatment for runoff, sediment, and microbial risk. On the IsWaterSafe scale it earns a failing Water Safety Score of 40 out of 100 (Grade F), a composite of its EPA SDWIS violation and contaminant record.
EPA records show 3 health-based violations for this system. A health-based violation means a contaminant exceeded its legal EPA limit, the most serious category in the Safe Drinking Water Act. The system has 4 enforcement actions on file in response.
Among the single substance sampled, Nitrate is the clearest concern: a reading of 10.5 mg/l against an EPA limit (MCL) of 10 ppm, about 105% of the legal ceiling, sampled June 2016. In total, 3 contaminant exceedances are recorded for this system.
The most recent documented episode is a health-based violation involving Nitrate, beginning June 2016 and marked resolved November 2016.
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Detected Contaminants
| Contaminant | Detected Level | MCL (Limit) | Status | Sample Date |
|---|---|---|---|---|
| Nitrate | 10.5 mg/l | 10 mg/l | Exceeds Limit | Jun 1, 2016 |
Violation History
Frequently Asked Questions
Columbus Public Water System has a Water Safety Score of F (40/100). The system serves 1,305,946 people and has 3 health violations on record. Check the contaminant table above for specific detected substances.
Columbus Public Water System has 3 contaminant exceedances above EPA health guidelines. See the full contaminant detection table above for all tested substances and their levels relative to legal limits and health guidelines.
The Water Safety Score (0-100, grades A through F) is based on contaminant levels relative to legal limits, health guideline exceedances, violation history, and enforcement actions. Higher scores indicate fewer concerns.
If your water system has violations, request the Consumer Confidence Report from your utility, consider getting an independent water test from a certified lab, and look into certified water filters for specific contaminants of concern. For lead, run cold water for 30 seconds before drinking.
Water quality data sourced from EPA's Safe Drinking Water Information System (SDWIS). Safety scores are calculated based on contaminant levels, violations, and enforcement history. This is not a substitute for your utility's official Consumer Confidence Report.
Source: EPA Ground Water and Drinking Water, 2026.