Tap Water Quality Report
Tap water quality in St. Louis, Missouri
Tap water in St. Louis, Missouri receives a grade of D (67/100) from TapWaterSafety.org. It's served by ST LOUIS CITY PWS. The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Arsenic significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
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.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 24.3 ppb, 405x above the EWG health guideline of 0.06 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 19.5 ppb, 195x above the EWG health guideline of 0.1 ppb.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 0.736 ppb, 184x above the EWG health guideline of 0.004 ppb.
EPA compliance record
Official U.S. EPA records for ST LOUIS CITY PWS (system ID MO6010715) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Lead and Copper Rule | Missed testing or reporting | 12/30/2025 | Open |
| Lead and Copper Rule Revisions | Missed reporting | 07/02/2025 | Open |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for St. Louis
Filters matched to the specific contaminants in St. Louis's water supply.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Reverse osmosis certified for arsenic (NSF/ANSI 58)
$429-$599Reverse osmosis certified under NSF/ANSI 58 for arsenic is the most reliable home option.
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 |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
24.3 ppb | 0.06 | — | — | — | — | — | 405× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
19.5 ppb | 0.1 | 60.0 | 60 | — | — | — | 195× over |
| Arsenic Heavy metal |
0.736 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 184× over |
| Bromochloroacetic acid Disinfection byproduct |
2.03 ppb | 0.02 | — | — | — | — | — | 102× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
11.9 ppb | 0.15 | 80.0 | 100 | — | — | — | 80× over |
| Dichloroacetic acid Disinfection byproduct |
15.6 ppb | 0.2 | — | — | — | — | — | 78× over |
| Chromium (hexavalent) Heavy metal |
1.16 ppb | 0.02 | — | — | — | — | — | 58× over |
| Chloroform Disinfection byproduct |
10.2 ppb | 0.4 | — | — | — | — | — | 26× over |
| Bromodichloromethane Disinfection byproduct |
1.47 ppb | 0.06 | — | — | — | — | — | 25× over |
| Trichloroacetic acid Disinfection byproduct |
2.33 ppb | 0.1 | — | — | — | — | — | 23× over |
| Nitrate and nitrite Inorganic |
1.05 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 7.5× over |
| Nitrate Inorganic |
1.02 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 7.3× over |
| Dibromochloromethane Disinfection byproduct |
0.218 ppb | 0.1 | — | — | — | — | — | 2.2× over |
| Atrazine Pesticide/Herbicide |
0.2 ppb | 0.1 | 3.0 | 0.1 | 100 | 0.15 | — | Fails EU |
| Dibromoacetic acid Disinfection byproduct |
0.0419 ppb | 0.03 | — | — | — | — | — | 1.4× over |
| Antimony Heavy metal |
0.315 ppb | 1.0 | 6.0 | 10 | 20 | 1 | — | Below guideline |
| Vanadium Other |
2.08 ppb | 21.0 | — | — | — | — | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.0288 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Molybdenum Other |
2.31 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Selenium Heavy metal |
1.64 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
2.41 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
15.1 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.157 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
2.15 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Manganese Heavy metal |
0.314 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Strontium Radiological |
0.168 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
1.38 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.609 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Lithium Other |
18.6 ppb | — | — | — | — | — | — | Below guideline |
| Nitrite Inorganic |
0.0263 ppm | — | 1.0 | — | — | — | — | Below guideline |
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 CITY PWS.
General Contact
Treatment Plant
ZIP codes served
St. Louis's public water systems serve the following ZIP codes: