Is St. Louis, MO tap water safe?
Supplied by St Louis City Public Water System · serves 304,709 people (96,080 connections) · Surface water · EPA ID MO6010715
Data: U.S. EPA · How we read the data · How we check it
Summary
No federal limits exceeded in EPA data.
- PFAS
- Not detectedNone of 29 PFAS found above EPA's reporting limits in 8 samples (2023–2025).
- Lithium
- Above screening levelHighest result 45.3 ppb. EPA uses 10 ppb to decide what to study further. It is not a health limit, and there is no federal limit for lithium. About 1 in 4 systems tested were above it.
- Lead
- Below action level1.8 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period ending Dec 2025. Your home's pipes can make yours higher.
- Violations
- None health-basedNo health-based violations since 2016.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read St Louis City Public Water System's 2026 water quality report (Consumer Confidence Report, from the utility). It lists every regulated contaminant tested, including ones not on this page. Questions: (314) 633-9012.
PFAS (“forever chemicals”)
EPA UCMR 5: 2 entry points tested Mar 2024 to Dec 2024. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA Not detected Limit 4 ppt | – |
| PFOS Not detected Limit 4 ppt | – |
| PFHxS Not detected Limit 10 ppt | – |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Not detected Limit 1 | – |
| PFBS Not detected Guideline 2,000 ppt | – |
| PFBA Not detected Guideline 6,000 ppt | – |
| PFHxA Not detected Guideline 3,000 ppt | – |
29 PFAS tested, 0 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Detected in 8 of 8 samples. Highest result 45.3 ppb. EPA's non-enforceable screening level is 10 ppb. Above screening level The screening level is how EPA decides what to study further, not a health limit. There is no federal limit for lithium and no filter is certified to remove it. About lithium.
Lead and copper
Latest 90th percentile: 1.8 ppb lead (Jan 2023 – Dec 2025). Below action level
Highest since 2016: 2.12 ppb (Dec 2022).
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2023 – Dec 2025 | 1.8 ppb |
| Jul 2022 – Dec 2022 | 2.12 ppb |
| Jan 2020 – Dec 2022 | 1.03 ppb |
Earlier results (9)
| Jan 2022 – Jun 2022 | 0.89 ppb |
| Jan 2018 – Dec 2020 | 1.03 ppb |
| Jan 2017 – Dec 2019 | 0.99 ppb |
| Jan 2015 – Dec 2017 | 0.99 ppb |
| Jan 2014 – Dec 2016 | 1.53 ppb |
| Jan 2012 – Dec 2014 | 1.53 ppb |
| Jan 2011 – Dec 2013 | 0 ppb |
| Jan 2008 – Dec 2010 | 1.26 ppb |
| Jan 2005 – Dec 2005 | 2.05 ppb |
Lead service lines: St Louis City Public Water System's inventory lists 9,000 lead, 58,000 of unknown material out of 113,000 service lines (as of 2024-10-10). Figures are approximate, as the utility published them.
Look up your address · Source (the utility, collected by us on Nov 14, 2026, not EPA data) · Checking your own line
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| Manganese | 0.71 ppb | 300 ppb |
| Chromium-6 | 1.5 ppb | – |
| Molybdenum | 4.5 ppb | 40 ppb |
| Vanadium | 4.19 ppb | 21 ppb |
| 1,4-Dioxane | 0.13 ppb | 0.35 ppb |
| Strontium | 0.28 ppm | 1.5 ppm |
Where it serves
St. Louis
34 ZIP codes the system reported serving
63017, 63101, 63102, 63103, 63104, 63105, 63106, 63107, 63108, 63109, 63110, 63111, 63112, 63113, 63115, 63116, 63117, 63118, 63119, 63120, 63121, 63123, 63125, 63130, 63132, 63133, 63136, 63137, 63138, 63139, 63143, 63145, 63147, 63155
Nearby utilities
- Missouri American Water – St Louis St Charles Counties St. Charles · 18 mi
- St Charles Public Water System St. Charles · 18 mi
- St Peters Public Water System St. Peters · 22 mi · PFAS above limit
- St Charles County Public Water Supply District 2 O'Fallon · 27 mi
- St James Public Water System St. James · 86 mi · PFAS above limit
- City of Columbia Utilities Columbia · 114 mi
Questions
Is St. Louis tap water safe to drink?
Most of St. Louis gets its water from St Louis City Public Water System. St Louis City Public Water System has no health-based violations since 2016. EPA testing found no PFAS above the federal limits. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does St. Louis water have PFAS?
EPA tested St Louis City Public Water System for 29 PFAS between Mar 2024 and Dec 2024 and none were detected above the reporting limits (about 2 to 20 ppt depending on the chemical).
What is the lead level in St. Louis water?
The most recent 90th-percentile lead result for St Louis City Public Water System is 1.8 ppb, for the period ending Dec 2025. The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for MO6010715: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID MO6010715).
- EPA SDWIS download: the lead results, population and violation records we use.
- St Louis City Public Water System's 2026 water quality report: the utility's own annual report, including contaminants EPA's national database doesn't carry (link checked Nov 14, 2026). Phone: (314) 633-9012.
- St Louis City Public Water System website
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.