Short answer: In the records we hold for O'Fallon, no listed result is above a legal limit. Also worth knowing: lithium sits above a screening level. 2 substances were detected and 29 were tested and not detected. The water is from O Fallon, serving 46,603 residents.
O FALLON (EPA PWSID IL1631100) delivers surface water to 46,603 residents. This report reflects 29 individual PFAS result(s) from the source UCMR5 observations and the latest Lead & Copper Rule 90th-percentile result. Water hardness and disinfectant type are pending the utility's own annual report.
Track record
0health-based violations in the last 10 years
From EPA SDWIS. A clean violation history means no enforcement action was recorded; it does not cover contaminants without a limit.
Not in this recordDisinfection by-products weren't monitored in this dataset
No result is not a pass. Your utility's annual water quality report may list them, and a certified lab test covers your own tap.
Your household
Your tap can differ from the city record
The record describes water leaving treatment and samples across the system. Pipes, solder and fixtures inside a building can add lead the record can’t see, especially in older buildings with lead service lines.
Each card names which O'Fallon findings its current certification covers, and which it doesn't.
As an Amazon Associate, PurityMap earns from qualifying purchases. A product appears here only when a current certification record covers at least one identified concern; every concern stays listed. The retail offer is looked up afterwards and never changes which products appear or their order. Affiliate disclosure.
O Fallon reported 33 galvanized service lines to replace in EPA’s inventory (2026Q2). Many utilities replace these lines for free or share the cost. Ask O Fallon whether your home’s line is on its list before you pay anyone.
Local help
Think your plumbing may be adding lead?
Call to be connected with a local plumbing provider about lead service lines, repiping or fixture replacement.
Your path: I live in an older buildingLead from plumbing is the main question
Older buildings may have lead service lines, solder or fixtures. O'Fallon’s utility reported 33 galvanized service lines in EPA’s inventory. Test first-draw water, then filter if needed.
Your path: My water tastes of chlorineThe disinfectant is not in this record
Most utilities keep chlorine or chloramine in the pipes. A carbon filter certified for taste and odor reduces either; your utility can tell you which it uses.
PurityMap does not give a safe/unsafe verdict; it shows what the public records measured. For O'Fallon, PFBA 13 ng/L was detected, with no federal or state limit. O FALLON (PWSID IL1631100) has a Purity Score of 100/100 (confidence: moderate), assessed at the water-system level and computed only from contaminants that were measured. Water can change in your own pipes, so a certified test is the only way to know what comes out of your tap. What we found →
Who provides tap water in O'Fallon?+
O FALLON (PWS ID IL1631100) is the public water system on record for O'Fallon, Illinois, serving about 46,603 people. Confirm the utility on your water bill before acting on a specific finding. Water utility →
Where does O'Fallon get its drinking water?+
Surface water (primary source of record in EPA SDWIS). Water utility →
Are PFAS "forever chemicals" in O'Fallon's water?+
Yes. In EPA's UCMR 5 testing (2024-02-07 to 2024-11-07), PFBA was detected at 13 ng/L. It has no federal or state limit, so PurityMap shows it without grading it. No PFAS with a limit was detected. What we found →
Is there lead in O'Fallon's tap water?+
Lead is not in O'Fallon's current published record. Lead usually enters from a building's own pipes and fixtures, so a certified home test is the way to know yours. Your household →
What does the latest O'Fallon water report show?+
PurityMap's current record for O'Fallon holds 31 findings: 1 above a reference, 1 detected with no limit and 29 not detected. Each finding links to its dated public record; a parameter that was never monitored is shown as pending, not as a pass. Records →
EPA SDWIS, EPA UCMR 5 and utility reports, each dated and linked.
02Normalize
Units converted to one basis; a non-detect kept distinct from zero.
03Classify
Each result tagged by reference type: MCL, action level, screening level or aesthetic.
04Compare to the named reference
Every value sits against its own reference, never a blended one.
05Score
Measured subjects summarised at the water-system level; an open health-based violation caps the score.
06Match treatment
Treatment is matched to what was found; a product is called certified only when its current certification names it.
What the Purity Score means: a summary of this water system’s published record, capped while a health-based violation is open. It is not a test of any tap. O FALLON · PWSID IL1631100 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
Lead at O Fallon: not detected (90th percentile, 2026–2028 monitoring period (still open)). Lead has no taste, so a taste neither shows nor rules it out.
ZIP codes in O'Fallon
A ZIP code is a postal area, not a water service area. Your water bill names your supplier.
