Tap Water Results

Is St. Joseph, MO tap water safe?

Supplied by Missouri American Water – St Joseph · serves 89,171 people (32,207 connections) · Groundwater · EPA ID MO1010714

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 2 samples (2023–2025).
Lithium
Above screening levelHighest result 114 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 level3 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.
What you can do

PFAS (“forever chemicals”)

EPA UCMR 5: 1 entry point tested Apr 2024 to Oct 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.

ContaminantHighest averageHighest resultLimitStatus
PFOA
Not detected
Limit 4 ppt
––4 pptNot detected
PFOS
Not detected
Limit 4 ppt
––4 pptNot detected
PFHxS
Not detected
Limit 10 ppt
––10 pptNot detected
PFNA
Not detected
Limit 10 ppt
––10 pptNot detected
HFPO-DA (GenX)
Not detected
Limit 10 ppt
––10 pptNot detected
Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit)
Not detected
Limit 1
––1Not detected
PFBS
Not detected
Guideline 2,000 ppt
––2,000 ppt guidelineNot detected
PFBA
Not detected
Guideline 6,000 ppt
––6,000 ppt guidelineNot detected
PFHxA
Not detected
Guideline 3,000 ppt
––3,000 ppt guidelineNot detected

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 2 of 2 samples. Highest result 114 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: 3 ppb lead (Jan 2023 – Dec 2025). Below action level

Monitoring periodLead (90th pct.)
Jan 2023 – Dec 20253 ppb
Jul 2022 – Dec 20222 ppb
Jan 2022 – Jun 20222 ppb
Earlier results (9)
Jan 2017 – Dec 20193 ppb
Jan 2014 – Dec 20162 ppb
Jan 2011 – Dec 20133 ppb
Jan 2008 – Dec 20104 ppb
Jan 2005 – Dec 20074 ppb
Jan 2004 – Dec 20043 ppb
Jan 2001 – Dec 20015.6 ppb
Jan 2000 – Dec 20008 ppb
Jan 1999 – Dec 19995 ppb

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

0
Health-based since 2016
0
Monitoring/reporting since 2016
0
Health-based unresolved now
1
Total ever recorded, incl. paperwork

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)

ContaminantHighestGuidelineDetectedTested
Manganese9 ppb300 ppb2 of 2UCMR 4 (2020)
Molybdenum4.5 ppb40 ppb4 of 4UCMR 3 (2013)
Chromium-60.94 ppb–4 of 4UCMR 3 (2013)
Vanadium0.6 ppb21 ppb4 of 4UCMR 3 (2013)
Strontium0.37 ppm1.5 ppm4 of 4UCMR 3 (2013)

Where it serves

St. Joseph

ZIP codes the system reported serving: 64401, 64430, 64436, 64448, 64484, 64485, 64501, 64502, 64503, 64504, 64505, 64506, 66024, 66090

Nearby utilities

Questions

Is St. Joseph tap water safe to drink?

Most of St. Joseph gets its water from Missouri American Water – St Joseph. Missouri American Water – St Joseph 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. Joseph water have PFAS?

EPA tested Missouri American Water – St Joseph for 29 PFAS between Apr 2024 and Oct 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. Joseph water?

The most recent 90th-percentile lead result for Missouri American Water – St Joseph is 3 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:

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.