Short answer: In the 2022–2024 records we hold for Duncan, no listed result is above a legal limit, but 9 health-based violations are on record (EPA SDWIS). Also worth knowing: lithium sits above a screening level. 5 substances were detected and 26 were tested and not detected. The water is from Duncan Public Utilities Authority, serving 23,000 residents.
DUNCAN PUBLIC UTILITIES AUTHORITY (EPA PWSID OK1010809) delivers surface water to 23,000 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
9health-based violations in the last 10 years
From EPA SDWIS. Counted once per contaminant per year, as in the Track record score. All 36 EPA filings are listed below.
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.
Health-based violations, last 10 years
Every filing is listed; the Track record score counts at most one per contaminant per year.
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 Duncan 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.
No product in our catalogue has verified certification for these concerns yet.
Is this right for my home?
Choose your situation
Your path: I live in an older buildingLead from plumbing is the main question
Older buildings may have lead service lines, solder or fixtures. Duncan’s utility reported 10,938 service lines of unknown material in EPA’s inventory, so only a tap test tells you. Test first-draw water, then filter if needed.
4 of 29 PFAS tested were detected in Duncan’s record (PFHxA 3.3 ng/L, PFBA 7.5 ng/L and PFHpA 3.4 ng/L, and more). If PFAS matters to you, a filter certification names each compound it covers.
Look forNSF/ANSI 53 or 58, with each compound you care about named on the listing
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 Duncan, PFAS were detected below their limits, and PFBA 7.5 ng/L, PFHpA 3.4 ng/L and PFPeA 3.8 ng/L with no federal or state limit. DUNCAN PUBLIC UTILITIES AUTHORITY (PWSID OK1010809) has a Purity Score of 88/100 (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 Duncan?+
DUNCAN PUBLIC UTILITIES AUTHORITY (PWS ID OK1010809) is the public water system on record for Duncan, Oklahoma, serving about 23,000 people. Confirm the utility on your water bill before acting on a specific finding. Water utility →
Where does Duncan get its drinking water?+
Surface water (primary source of record in EPA SDWIS). Water utility →
Are PFAS "forever chemicals" in Duncan's water?+
In EPA's UCMR 5 testing (2023-10-03 to 2024-07-10), PFHxA was detected at 3.3 ng/L, below the 400,000 ng/L state limit. PFBA (7.5 ng/L), PFHpA (3.4 ng/L) and PFPeA (3.8 ng/L) were also detected; they have no federal or state limit. What we found →
Is there lead in Duncan's tap water?+
Lead is not in Duncan'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 Duncan water report show?+
PurityMap's current record for Duncan holds 31 findings: 1 above a reference, 1 detected within the reference, 3 detected with no limit and 26 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. DUNCAN PUBLIC UTILITIES AUTHORITY · PWSID OK1010809 · Purity Score 88/100 (Good) · Confidence: moderate · Assessed at the water-system level
Lead at Duncan Public Utilities Authority: not detected (90th percentile, 2022–2024 monitoring period). Lead has no taste, so a taste neither shows nor rules it out.
ZIP codes in Duncan
A ZIP code is a postal area, not a water service area. Your water bill names your supplier.