Water Quality Report · Updated May 12, 2026
St. Louis Water Authority
St. Louis Water Authority delivers tap water graded F (49/100) by TapWaterSafety.org. The utility serves approximately 301,000 residents in St. Louis, Missouri using surface water from the Mississippi/Missouri Rivers. The most significant water quality concerns are: PFAS contamination; Lead detected in source water; Chromium-6 detected. For questions, the utility can be reached at (314) 593-7039.
Is St. Louis tap water safe to drink?
St. Louis Water Authority delivers tap water that earns a grade of F (49/100) from TapWaterSafety.org — a poor rating, with significant contamination concerns and/or recent violations.
The utility serves 301,000 residents in St. Louis, drawing from surface water (Mississippi/Missouri Rivers) and disinfecting with free chlorine. Despite being legal under US EPA standards, this water would fail the European Union's Drinking Water Directive, primarily due to pfas contamination.
Public testing data identifies 18 contaminants in this water above EWG's health-based guidelines, including: PFOA, PFOA, PFOA, Haloacetic Acids (HAA5), Haloacetic Acids (HAA5), Haloacetic Acids (HAA5), Total Trihalomethanes (TTHMs), Total Trihalomethanes (TTHMs), Total Trihalomethanes (TTHMs), Nitrate, Nitrate, Nitrate, Chromium-6 (Hexavalent), Chromium-6 (Hexavalent), Chromium-6 (Hexavalent), Lead, Lead, Lead. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for St. Louis Water Authority.
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.
Contact St. Louis Water Authority
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Water Quality Contact
For questions about contaminants, test results, or your Consumer Confidence Report.
Treatment Plant
Recommended water filters for St. Louis
Filters matched to the specific contaminants in this 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.
Score breakdown
This utility's overall score of 49/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). 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 |
| PFOA Organic |
5.7 ppt | 0.004 | 4 | 100 | 100 | 0.007 | 2024 | EPA violation |
| PFOA Organic |
5.15 ppt | 0.004 | 4 | 100 | 100 | 0.007 | 2023 | EPA violation |
| Haloacetic Acids (HAA5) Disinfection byproduct |
31.4 ppb | 0.1 | 60 | 60 | — | — | 2024 | 314× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
29.1 ppb | 0.1 | 60 | 60 | — | — | 2023 | 291× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
22.5 ppb | 0.1 | 60 | 60 | — | — | 2022 | 225× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
60.7 ppb | 0.6 | 80 | 100 | — | — | 2022 | 101× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
56.9 ppb | 0.6 | 80 | 100 | — | — | 2024 | 95× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
55.7 ppb | 0.6 | 80 | 100 | — | — | 2023 | 93× over |
| Nitrate Inorganic |
3.81 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2023 | 27× over |
| Nitrate Inorganic |
3.4 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2024 | 24× over |
| Nitrate Inorganic |
2.94 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2022 | 21× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.13 ppb | 0.02 | — | — | — | 0.02 | 2022 | 6.5× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.11 ppb | 0.02 | — | — | — | 0.02 | 2024 | 5.5× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.091 ppb | 0.02 | — | — | — | 0.02 | 2023 | 4.5× over |
| Lead Heavy metal |
5.2 ppb | 0 | 15 | 5 | 10 | 0.2 | 2024 | Fails EU |
| Lead Heavy metal |
6.29 ppb | 0 | 15 | 5 | 10 | 0.2 | 2023 | Fails EU |
| Lead Heavy metal |
4.21 ppb | 0 | 15 | 5 | 10 | 0.2 | 2022 | — |
| Contaminant | Detected (2024) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
56.9 ppb | 0.6 | 80 | 100 | — | — | 95× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
31.4 ppb | 0.1 | 60 | 60 | — | — | 314× over |
| Lead Heavy metal |
5.2 ppb | 0 | 15 | 5 | 10 | 0.2 | Fails EU |
| Chromium-6 (Hexavalent) Heavy metal |
0.11 ppb | 0.02 | — | — | — | 0.02 | 5.5× over |
| PFOA Organic |
5.7 ppt | 0.004 | 4 | 100 | 100 | 0.007 | EPA violation |
| Nitrate Inorganic |
3.4 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 24× over |
| Contaminant | Detected (2023) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
55.7 ppb | 0.6 | 80 | 100 | — | — | 93× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
29.1 ppb | 0.1 | 60 | 60 | — | — | 291× over |
| Lead Heavy metal |
6.29 ppb | 0 | 15 | 5 | 10 | 0.2 | Fails EU |
| Chromium-6 (Hexavalent) Heavy metal |
0.091 ppb | 0.02 | — | — | — | 0.02 | 4.5× over |
| PFOA Organic |
5.15 ppt | 0.004 | 4 | 100 | 100 | 0.007 | EPA violation |
| Nitrate Inorganic |
3.81 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 27× over |
| Contaminant | Detected (2022) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
60.7 ppb | 0.6 | 80 | 100 | — | — | 101× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
22.5 ppb | 0.1 | 60 | 60 | — | — | 225× over |
| Lead Heavy metal |
4.21 ppb | 0 | 15 | 5 | 10 | 0.2 | — |
| Chromium-6 (Hexavalent) Heavy metal |
0.13 ppb | 0.02 | — | — | — | 0.02 | 6.5× over |
| PFOA Organic |
7.0 ppt | 0.004 | 4 | 100 | 100 | 0.007 | EPA violation |
| Nitrate Inorganic |
2.94 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 21× 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database, and St. Louis Water Authority's Consumer Confidence Report.
St. Louis Water Authority service area
This water system serves 1 community in St. Louis County, Missouri. Click any city for its dedicated tap water quality page.
Find the right filter for St. Louis water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.