Water Quality Report · Updated May 12, 2026
ST LOUIS CITY PWS
ST LOUIS CITY PWS delivers tap water graded C (67/100) by TapWaterSafety.org. The utility serves approximately 304,709 residents in ST. LOUIS, Missouri using surface water. 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. For questions, the utility can be reached at 314-633-9012.
Is ST. LOUIS tap water safe to drink?
ST LOUIS CITY PWS delivers tap water that earns a grade of C (67/100) from TapWaterSafety.org — an average rating, with several contaminants above health guidelines but generally compliant with US legal limits.
The utility serves 304,709 residents in ST. LOUIS, drawing from surface water. Despite being legal under US EPA standards, this water would fail the European Union's Drinking Water Directive, primarily due to haloacetic acids (haa9) significantly above health guideline.
Public testing data identifies 15 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Haloacetic acids (HAA5), Arsenic, Bromochloroacetic acid, Total trihalomethanes (TTHMs), Dichloroacetic acid, Chromium (hexavalent), Chloroform, Bromodichloromethane, Trichloroacetic acid, Nitrate and nitrite, Nitrate, Dibromochloromethane, Atrazine, Dibromoacetic acid. 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.
Quick actions for ST. LOUIS residents
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 CITY PWS.
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.
Contact ST LOUIS CITY PWS
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for ST. LOUIS
Filters matched to the specific contaminants in this water supply.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
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 67/100 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 |
|---|---|---|---|---|---|---|---|---|
| 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
ST LOUIS CITY PWS service area
This water system serves 1 community in St. Louis city 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.