Thornton, CO Water Quality
Thornton, CO has 1 public water system serving 226,465 people. The average Water Safety Score is 70/100 (C). No health violations are on record.
Water Systems in Thornton
Contaminants Detected in Thornton Water
| Contaminant | Systems Detected | Exceeding MCL |
|---|---|---|
| Chlorine | 1 | 0 |
| Gross Beta | 1 | 0 |
| Uranium | 1 | 0 |
| Gross Alpha | 1 | 0 |
| Combined Filter Effluent | 1 | 0 |
Frequently Asked Questions
Thornton has 1 public water system serving 226,465 people. The average Water Safety Score is 70/100. No health violations are currently on record. Check individual systems below for details.
Thornton water systems have detected 5 contaminants, including Chlorine, Gross Beta, Uranium. No contaminant exceedances above EPA limits are currently recorded.
The Water Safety Score (0-100, grades A through F) weighs health-based violations (40%), contaminant exceedances (30%), enforcement history (20%), and monitoring violations (10%). Scores are based on EPA SDWIS data from the last 10 years.
Request your utility's Consumer Confidence Report (CCR), consider an independent water test from a certified lab, and look into NSF-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. City data aggregates all public water systems serving the municipality.
The this entity record above pulls directly from the EPA Safe Drinking Water Information System (SDWIS). What follows is the per-entity context — how this entity sits in the broader U.S. public drinking-water safety distribution and which underlying factors drive the headline numbers.
Every number on this page links back to the EPA Safe Drinking Water Information System (SDWIS); the methodology page describes the inputs, refresh cadence, and known limitations of the underlying data product.
Practical use of this page is in combination with the comparison and ranking pages elsewhere on the site, which surface the same data for this entity’s peers within U.S. public water systems. A single-entity reading without peer context can be misleading when an entity is an outlier on one axis but typical on another.
Source: EPA Ground Water and Drinking Water, 2026.