PWSID MS0360011 · Lafayette County · Large system (serves >10,000) · Groundwater · 5 entry points · sampled Mar 3, Sep 9 & Sep 22, 2025 under EPA UCMR 5 · generated June 8, 2026
The finding
Oxford's water is over the federal limit for two separate “forever chemicals,” at two different points where water enters the system.
PFOS
52.95 ppt
running annual average at Entry Point A — 13.2× the 4 ppt federal limit. Highest single sample: 72.2 ppt.
PFOA
4.35 ppt
at Entry Point C — 1.1× the 4 ppt federal limit (just over). A separate exceedance from the PFOS one.
The contamination is not system-wide — it is point-specific. Of Oxford's five entry points, two (D and E) are clean. PFOS is concentrated at one point; a group of shorter-chain PFAS at another; the PFOA exceedance at a third. That matters for cost: treatment can be placed on the affected entry points rather than the entire system.
Where it is
Marker = the Oxford water system; dashed box = approximate service area. EPA UCMR 5 does not publish exact coordinates for each sampling point, so the per-point results below are shown as data rather than placed on the map.
Each entry point's PFAS fingerprint
What was found at each of the five points where treated water enters Oxford's distribution system (running annual average, ppt).
Entry Point A
PFOS53.0 ppt
PFHxS10.3 ppt
PFBS4.3 ppt
PFPeA1.9 ppt
PFHxA1.9 ppt
Entry Point B
PFPeA24.1 ppt
6:2 FTS20.7 ppt
PFHxA14.6 ppt
PFBA5.6 ppt
PFBS4.5 ppt
PFHxS3.4 ppt
PFHpA3.2 ppt
Entry Point C
PFBS10.7 ppt
PFOA4.3 ppt
PFHxA3.4 ppt
PFPeA3.0 ppt
Entry Point D
No PFAS detected — clean
Entry Point E
No PFAS detected — clean
Every PFAS detected
All nine PFAS detected anywhere in Oxford's system, ranked by the worst entry point's average. Only PFOA and PFOS carry an enforceable federal limit today.
Federal limit (4 ppt)Hazard Index (proposed for removal)Monitored, no limit
PFOS
53.0 pptpeak 72.2
PFPeA
24.1 pptpeak 24.5
6:2 FTS
20.7 pptpeak 22.9
PFHxA
14.6 pptpeak 15.0
PFBS
10.7 pptpeak 10.9
PFHxS
10.3 pptpeak 13.6
PFBA
5.6 pptpeak 5.6
PFOA
4.3 pptpeak 4.4
PFHpA
3.2 pptpeak 3.4
What this means
PFOA and PFOS are the two PFAS the U.S. EPA limits in drinking water, at 4 parts per trillion (ppt) each. A part per trillion is tiny, but these chemicals are harmful at very low levels. The limit is measured as a running annual average at each entry point, so Oxford's PFOS average of 52.95 ppt — over thirteen times the limit at one point — is a clear exceedance, and its PFOA at a second point is just over.
The other seven (PFPeA, 6:2 FTS, PFHxA, PFBS, PFHxS, PFBA, PFHpA) have no enforceable single-compound limit today. PFHxS and PFBS were part of a combined “Hazard Index” limit in the 2024 federal rule, which EPA proposed to remove in May 2026. The rest are monitored but unregulated. They are present in the water regardless of their regulatory status.
Treatment. Oxford is a groundwater system, and the PFAS are concentrated at specific entry points. EPA recognizes granular activated carbon and ion exchange as effective for removing PFOA and PFOS. Because the problem is point-specific, treatment can be targeted to the affected entry points rather than the whole system.