Drinking water quality · 2024
· Verified
· PWSID MO6010715
What's in St Louis, MO tap water
Every one of the 14 core regulated contaminants reported for St Louis, MO came in below its federal limit.
- !1 open monitoring or reporting violation
- !1 contaminant within 20% of a limit
- !14 of 27 core regulated contaminants reported — 13 never appear in this report
- ✓Nothing over a federal limit
+How this score is calculated
Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.
- −0 contaminants at or above a federal limit
- −4 contaminants within 20% of a limit
- −0 open health-based violations
- −3 open monitoring / reporting violations
- −0 health-based violations resolved in the last 5 years
- −8 core regulated contaminants never reported (14/27)
A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.
Full grading methodology, constant for constant →What to worry about
- Chloramine92% of the federal limit3.66 mg/L · limit 4 mg/L
Holds disinfection further into the pipe network, but is regulated under the same residual-disinfectant cap as chlorine.
higher than 80% of U.S. systems
+18 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| HAA5 | 36 ug/L | 60 ug/L |
| TTHM | 18.2 ug/L | 80 ug/L |
| Nitrate Nitrite | 2.099 mg/L | 10 mg/L |
| Fluoride | 0.76 mg/L | 4 mg/L |
| Atrazine | 0.57 ug/L | 3 ug/L |
| Lead | 2.12 ug/L | 15 ug/L |
| Turbidity | 0.1 NTU | 1 NTU |
| Antimony | 0.31 ug/L | 6 ug/L |
| Arsenic | 0.39 ug/L | 10 ug/L |
| Selenium | 1.18 ug/L | 50 ug/L |
| Copper | 0.0176 mg/L | 1.3 mg/L |
| Barium | 0.027 mg/L | 2 mg/L |
| Chromium | 0.93 ug/L | 100 ug/L |
| Lithium | 27.5 ug/L | — |
| Nickel | 0.85 ug/L | — |
| TOC | 4.81 mg/L | — |
| Gross Alpha | Not detected pCi/L | 15 pCi/L |
| Uranium | Not detected ug/L | 30 ug/L |
What this report doesn't tell you
13 of the 27 contaminants a community water system normally reports do not appear anywhere in St Louis, MO's data. Absent is not the same as absent-from-the-water — it means nobody published a number.
+Full detail: PFAS testing, water source, historical monitoring, and the federal violation record
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
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Monitoring & reporting1 violation on record · most recent Dec 20251 open
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗