St. Louis Tap Water
Water provider: City of St. Louis Water Division (St. Louis, MO)
Our recommendation
Premium filter strongly recommended
Your water has contaminants that require stronger filtration (heavy metals, PFAS, or limits exceeded). Reverse osmosis is the recommended tier.
See recommended water filters →What is in the water
Chromium-6 (hexavalent chromium)
DetectedIndustrial contaminant. Known human carcinogen. Unregulated at the federal level in the US.
EWG lists chromium-6 in many large Midwestern surface-water systems, including St. Louis.
Radium
DetectedNaturally occurring radioactive element. Long-term exposure increases cancer risk.
Regional source water and treatment monitoring include radiological contaminants.
Trihalomethanes (THMs)
DetectedDisinfection byproducts formed when chlorine reacts with organic matter. Long-term exposure linked to cancer risk.
Large river-fed chlorinated systems routinely report THMs.
PFAS (forever chemicals)
Not reportedPer- and polyfluoroalkyl substances. Bioaccumulate in the body. Linked to cancer, immune effects, and hormone disruption.
Verify the current EWG PFAS indicator on the utility page. Automation could not retrieve the live indicator behind Cloudflare.
Source
Data from the EWG Tap Water Database, City of St. Louis Water Division (2024). Last reviewed 2026-05-25.
Note: Contaminant levels vary by address (older plumbing can leach lead even when the source water does not), sampling location, and time of year. The figures above reflect utility-wide averages from the most recent public report. If you have specific health concerns, request a full report from your utility or test your own tap water.