Drinking water quality · 2024
· Verified
What's in St Louis, MO tap water
19 contaminants were measured in the St Louis, MO water system's 2024 annual report. Each is shown below against its federal limit.
- Reporting year
- 2024
- Contaminants measured
- 19
- Over federal limit
- 0
- Approaching the limit
- 1
- Service area
- MO
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound detected in St Louis, MO
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
Lithium
● Detected (no federal limit)near national p90 (76.59999999999991 mg/L across detecting U.S. systems)
Where your water comes from · EPA SDWIS
St Louis, MO's drinking water comes from surface water, drawn from 4 sources.
Source
- MISSISSIPPI RIVER · 2
- MISSOURI RIVER · 2
Treatment
- CHAIN OF ROCKS
- HOWARD BEND
Distribution
Historical readings · EPA Six-Year Review (2012–2019)
23 historically-detected contaminants in St Louis, MO
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
HAA5 worst: 2019 | 0.0427 mg/L within | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
ATRAZINE worst: 2012 | 0.00156 mg/L within above national p90 | 0.003 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE NITRITE worst: 2016 | 4.16 mg/L within | 10 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE worst: 2016 | 4.12 mg/L within | 10 mg/L | '12'13'14'15'16'17'18'19 |
TTHM worst: 2013 | 0.0309 mg/L within | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
SIMAZINE worst: 2018 | 0.00108 mg/L within | 0.004 mg/L | '13'15'16'18'19 |
FLUORIDE worst: 2013 | 0.65 mg/L within | 4 mg/L | '12'13'14'15'16'17'19 |
ARSENIC worst: 2012 | 0.00112 mg/L within below national p90 | 0.01 mg/L | '12'16'17'18'19 |
ANTIMONY worst: 2017 | 0.00039 mg/L within below national p90 | 0.006 mg/L | '17'18'19 |
SELENIUM worst: 2018 | 0.00259 mg/L within | 0.05 mg/L | '16'17'18'19 |
NITRITE worst: 2016 | 0.0395 mg/L within | 1 mg/L | '13'16'17'19 |
CHROMIUM worst: 2012 | 0.00182 mg/L within below national p90 | 0.1 mg/L | '12'13'14'15'16'17'18'19 |
BARIUM worst: 2016 | 0.0278 mg/L within below national p90 | 2 mg/L | '12'13'14'15'16'17'18'19 |
COPPER worst: 2012 | 0.00171 mg/L below national p90 | — | '12'14'15'16'17'18'19 |
LEAD worst: 2014 | 0.00668 mg/L | — | '14'17 |
DBAA worst: 2019 | 0.00297 mg/L | — | '19 |
DCAA worst: 2012 | 0.0151 mg/L | — | '12'13'14'15'16'19 |
MBAA worst: 2014 | 0.00563 mg/L | — | '14'19 |
MCAA worst: 2019 | 0.00701 mg/L | — | '19 |
TCAA worst: 2012 | 0.00178 mg/L | — | '12'13'14'15'16'19 |
BROMODICHLOROMETHANE worst: 2012 | 0.00539 mg/L | — | '12'13'14'15'16'18'19 |
CHLOROFORM worst: 2012 | 0.0183 mg/L | — | '12'13'14'15'16'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.00164 mg/L | — | '12'13'15'16'19 |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChloramineA longer-lasting disinfectant made by combining chlorine with ammonia. | 3.66 mg/LMaximumSystem-wide | 4 mg/LMRDL | Approaching the limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0.05 %Reported levelSystem-wide | 5 %MCL | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium, TotalTotal chromium — the sum of all chromium forms, from natural deposits and industrial discharge. | 0.93 ug/LMaximumSystem-wide | 100 ug/LMCL | Within the limit |
| NickelA metal from natural deposits and industrial discharge. | 0.8–0.85 ug/LRangeRange Detected | 100 ug/LMCL | Within the limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | Not detected pCi/LMaximumSystem-wide | 15 pCi/LMCL | None detected |
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | Not detected ug/LMaximumSystem-wide | 30 ug/LMCL | None detected |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 4.81 mg/LMaximumSystem-wide | None set | Detected — no federal limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.1 NTUHighest single sampleSystem-wide | None set | Detected — no federal limit |
People also ask about St Louis, MO's water
+Is St Louis, MO tap water safe to drink in 2024?
Every one of the 19 contaminants measured in St Louis, MO's 2024 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in St Louis, MO tap water?
19 contaminants were measured in St Louis, MO's 2024 Consumer Confidence Report, spanning metals, disinfection byproducts, and physical & aggregate. 16 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Are any contaminants in St Louis, MO tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: Chloramine. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from St Louis, MO's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is St Louis, MO's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2024 report; a new report will replace it once the utility publishes its next annual update.