Tap Water Quality Report
Tap water quality in St. Louis, Missouri
Tap water in St. Louis, Missouri receives a grade of F (49/100) from TapWaterSafety.org. It's served by St. Louis Water Authority. The most significant water quality concerns are: PFAS contamination; Lead detected in source water; Chromium-6 detected. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database, and St. Louis's published Consumer Confidence Report.
What's in St. Louis's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving St. Louis.
PFAS contamination
Severe concernPFOA, PFOA detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Lead detected in source water
Severe concernLead detected at 5.2 ppb. EWG considers no level of lead safe; EPA's action level is 15 ppb.
Chromium-6 detected
Moderate concernChromium-6 detected at 0.11 ppb.
Recommended filters for St. Louis
Filters matched to the specific contaminants in St. Louis's water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
NSF/ANSI 53 certified for lead removal
$80-$750NSF 53 is the gold standard certification for lead removal. Required when lead is a documented concern.
Reverse Osmosis
$249-$750Chromium-6 requires reverse osmosis for reliable removal. Standard carbon filters do not address it.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in St. Louis's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| PFOA Organic |
7.0 ppt | 0.004 | 4 | 100 | 100 | 0.007 | 2022 | EPA violation |
| Haloacetic Acids (HAA5) Disinfection byproduct |
31.4 ppb | 0.1 | 60 | 60 | — | — | 2024 | 314× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
60.7 ppb | 0.6 | 80 | 100 | — | — | 2022 | 101× over |
| Nitrate Inorganic |
3.81 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2023 | 27× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.13 ppb | 0.02 | — | — | — | 0.02 | 2022 | 6.5× over |
| Lead Heavy metal |
6.29 ppb | 0 | 15 | 5 | 10 | 0.2 | 2023 | Fails EU |
| Contaminant | Detected (2024) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) Disinfection byproduct |
31.4 ppb | 0.1 | 60 | 60 | — | — | 314× over |
| Contaminant | Detected (2023) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Nitrate Inorganic |
3.81 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 27× over |
| Lead Heavy metal |
6.29 ppb | 0 | 15 | 5 | 10 | 0.2 | Fails EU |
| Contaminant | Detected (2022) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| PFOA Organic |
7.0 ppt | 0.004 | 4 | 100 | 100 | 0.007 | EPA violation |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
60.7 ppb | 0.6 | 80 | 100 | — | — | 101× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.13 ppb | 0.02 | — | — | — | 0.02 | 6.5× over |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from St. Louis Water Authority.
General Contact
Water Quality Contact
For questions about contaminants or test results.