Purcellville, Town Of

PFAS monitoring results for a public water system in Virginia

VA6107600UCMR 5EPA monitoring data
10.8Highest PFOA result, ppt
<MRLHighest PFOS result, ppt
0.342Highest Hazard Index
480Results
PWSID
VA6107600
State
Virginia
System type
community water system (CWS)
Population served
8,929
City
Purcellville
Counties
Loudoun County
Primary source water
surface water
UCMR 5 sampling
2025-02-18 to 2025-11-17 · 7 entry point(s) · water types: GW;SW
Service-area boundary
authoritative

PFOA 1–3 × its limit highest single result
PFOA 1–3 × its limit worst entry-point average

These are monitoring results collected under EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) at entry points, where treated water enters the distribution system; they are not tap-water samples. They are not compliance determinations: compliance with EPA's 2024 PFAS limits is judged on running annual averages of compliance monitoring, required from 2029, so a single UCMR 5 result at or above a limit is not a violation. “< MRL” means the compound was not quantified at EPA's minimum reporting level; it does not mean zero.

Compared with EPA's 2024 values

Highest single resultWorst entry-point average*Limit
PFOA (ppt)10.810.44
PFOS (ppt)<MRL04
Hazard Index0.3420.3271.0†

“<MRL” = every result for the compound was below its reporting limit. * Mean of all samples at each entry point with non-detects = 0 (EPA compliance convention; the Hazard Index also uses non-detects = 0); a screening comparison, not a formal running annual average. † Rescission proposed May 2026. PFOA/PFOS MCL 4 ppt (2024 NPDWR, in effect). PFHxS, PFNA, HFPO-DA (10 ppt each) and the Hazard Index (1.0) are 2024 NPDWR values; EPA proposed rescinding them on 18 May 2026 (comment period closed 20 Jul 2026).

No Virginia PFAS drinking-water standard in effect or proposed as of 2026-10-17: No Virginia-specific PFAS drinking-water MCL; Va. Code 62.1-44.34:29 defines PFAS MCL by reference to EPA's NPDWR.

Sampling history

Sampled 2025-02-18 to 2025-11-17 · 7 entry point(s) · water types: GW;SW · 16 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2025-02-18Cornwell, Forbes, Kane 1 & 2 Combined POE (GW)SE15.1<40.0046:2 FTS 15.5, PFBA 13.5, PFHpA 12.7, PFHxA 22.7, PFPeA 41.3
2025-02-18Hirst Farm #2 POE (GW)SE1<4<40lithium 9.11 µg/L
2025-02-18Jeffries Well (GW)SE1<4<40none
2025-02-18Main St Well #1 and VC Well POE (GW)SE1<4<40lithium 14.3 µg/L
2025-02-18Marsh Farm Well B POE (GW)SE1<4<40none
2025-02-18Mountain View Well POE (GW)SE110<40.342PFBA 5.4, PFHpA 3.8, PFHxA 5.1, PFPeA 4.7
2025-02-18Water Treatment Plant Entry Point (SW)SE1<4<40none
2025-05-19Water Treatment Plant Entry Point (SW)SE2<4<40none
2025-08-19Cornwell, Forbes, Kane 1 & 2 Combined POE (GW)SE26.2<40.0056:2 FTS 17.9, PFBA 15.2, PFHpA 13.7, PFHxA 26.2, PFPeA 46.6
2025-08-19Hirst Farm #2 POE (GW)SE2<4<40none
2025-08-19Jeffries Well (GW)SE2<4<40none
2025-08-19Main St Well #1 and VC Well POE (GW)SE2<4<40PFBA 5.7, lithium 14.9 µg/L
2025-08-19Marsh Farm Well B POE (GW)SE2<4<40none
2025-08-19Mountain View Well POE (GW)SE210.8<40.311PFBA 5.7, PFHpA 4, PFHxA 5.4, PFPeA 4.8
2025-08-19Water Treatment Plant Entry Point (SW)SE3<4<40none
2025-11-17Water Treatment Plant Entry Point (SW)SE4<4<40none

“<4” = not detected at the reporting limit shown; “n/a” = not analyzed in that sample. Highlighted = at or above the 4 ppt MCL. HI computed per sample with non-detects as 0. Other detections lists every other quantified compound (lithium in µg/L).

All results by entry point

480 results. Each column is one sampling visit (date and UCMR 5 sample event). A number is a measured concentration; “< 4” = below the minimum reporting level shown; “–” = not analyzed in that visit. PFAS in ppt (ng/L); lithium in µg/L.

Cornwell, Forbes, Kane 1 & 2 Combined POE facility 40324 · sample point EP011 · groundwater

CompoundMRL2025-02-18
SE1
2025-08-19
SE2
6:2 FTS5 ppt15.517.9
PFBA5 ppt13.515.2
PFBS3 ppt8.710.4
PFHpA3 ppt12.713.7
PFHxA3 ppt22.726.2
PFOA4 ppt5.16.2
PFPeA3 ppt41.346.6
11Cl-PF3OUdS5 ppt< 5< 5
4:2 FTS3 ppt< 3< 3
8:2 FTS5 ppt< 5< 5
9Cl-PF3ONS2 ppt< 2< 2
ADONA3 ppt< 3< 3
HFPO-DA5 ppt< 5< 5
NEtFOSAA5 ppt< 5< 5
NFDHA20 ppt< 20< 20
NMeFOSAA6 ppt< 6< 6
PFDA3 ppt< 3< 3
PFDoA3 ppt< 3< 3
PFEESA3 ppt< 3< 3
PFHpS3 ppt< 3< 3
PFHxS3 ppt< 3< 3
PFMBA3 ppt< 3< 3
PFMPA4 ppt< 4< 4
PFNA4 ppt< 4< 4
PFOS4 ppt< 4< 4
PFPeS4 ppt< 4< 4
PFTA8 ppt< 8< 8
PFTrDA7 ppt< 7< 7
PFUnA2 ppt< 2< 2
lithium9 µg/L< 9< 9

Hirst Farm #2 POE facility EP007 · sample point EP007 · groundwater

CompoundMRL2025-02-18
SE1
2025-08-19
SE2
11Cl-PF3OUdS5 ppt< 5< 5
4:2 FTS3 ppt< 3< 3
6:2 FTS5 ppt< 5< 5
8:2 FTS5 ppt< 5< 5
9Cl-PF3ONS2 ppt< 2< 2
ADONA3 ppt< 3< 3
HFPO-DA5 ppt< 5< 5
NEtFOSAA5 ppt< 5< 5
NFDHA20 ppt< 20< 20
NMeFOSAA6 ppt< 6< 6
PFBA5 ppt< 5< 5
PFBS3 ppt< 3< 3
PFDA3 ppt< 3< 3
PFDoA3 ppt< 3< 3
PFEESA3 ppt< 3< 3
PFHpA3 ppt< 3< 3
PFHpS3 ppt< 3< 3
PFHxA3 ppt< 3< 3
PFHxS3 ppt< 3< 3
PFMBA3 ppt< 3< 3
PFMPA4 ppt< 4< 4
PFNA4 ppt< 4< 4
PFOA4 ppt< 4< 4
PFOS4 ppt< 4< 4
PFPeA3 ppt< 3< 3
PFPeS4 ppt< 4< 4
PFTA8 ppt< 8< 8
PFTrDA7 ppt< 7< 7
PFUnA2 ppt< 2< 2
lithium9 µg/L9.11< 9

Jeffries Well facility EP012 · sample point EP012 · groundwater

CompoundMRL2025-02-18
SE1
2025-08-19
SE2
11Cl-PF3OUdS5 ppt< 5< 5
4:2 FTS3 ppt< 3< 3
6:2 FTS5 ppt< 5< 5
8:2 FTS5 ppt< 5< 5
9Cl-PF3ONS2 ppt< 2< 2
ADONA3 ppt< 3< 3
HFPO-DA5 ppt< 5< 5
NEtFOSAA5 ppt< 5< 5
NFDHA20 ppt< 20< 20
NMeFOSAA6 ppt< 6< 6
PFBA5 ppt< 5< 5
PFBS3 ppt< 3< 3
PFDA3 ppt< 3< 3
PFDoA3 ppt< 3< 3
PFEESA3 ppt< 3< 3
PFHpA3 ppt< 3< 3
PFHpS3 ppt< 3< 3
PFHxA3 ppt< 3< 3
PFHxS3 ppt< 3< 3
PFMBA3 ppt< 3< 3
PFMPA4 ppt< 4< 4
PFNA4 ppt< 4< 4
PFOA4 ppt< 4< 4
PFOS4 ppt< 4< 4
PFPeA3 ppt< 3< 3
PFPeS4 ppt< 4< 4
PFTA8 ppt< 8< 8
PFTrDA7 ppt< 7< 7
PFUnA2 ppt< 2< 2
lithium9 µg/L< 9< 9

Main St Well #1 and VC Well POE facility 24273 · sample point EP005 · groundwater

CompoundMRL2025-02-18
SE1
2025-08-19
SE2
PFBA5 ppt< 55.7
11Cl-PF3OUdS5 ppt< 5< 5
4:2 FTS3 ppt< 3< 3
6:2 FTS5 ppt< 5< 5
8:2 FTS5 ppt< 5< 5
9Cl-PF3ONS2 ppt< 2< 2
ADONA3 ppt< 3< 3
HFPO-DA5 ppt< 5< 5
NEtFOSAA5 ppt< 5< 5
NFDHA20 ppt< 20< 20
NMeFOSAA6 ppt< 6< 6
PFBS3 ppt< 3< 3
PFDA3 ppt< 3< 3
PFDoA3 ppt< 3< 3
PFEESA3 ppt< 3< 3
PFHpA3 ppt< 3< 3
PFHpS3 ppt< 3< 3
PFHxA3 ppt< 3< 3
PFHxS3 ppt< 3< 3
PFMBA3 ppt< 3< 3
PFMPA4 ppt< 4< 4
PFNA4 ppt< 4< 4
PFOA4 ppt< 4< 4
PFOS4 ppt< 4< 4
PFPeA3 ppt< 3< 3
PFPeS4 ppt< 4< 4
PFTA8 ppt< 8< 8
PFTrDA7 ppt< 7< 7
PFUnA2 ppt< 2< 2
lithium9 µg/L14.314.9

Marsh Farm Well B POE facility 35529 · sample point EP006 · groundwater

CompoundMRL2025-02-18
SE1
2025-08-19
SE2
11Cl-PF3OUdS5 ppt< 5< 5
4:2 FTS3 ppt< 3< 3
6:2 FTS5 ppt< 5< 5
8:2 FTS5 ppt< 5< 5
9Cl-PF3ONS2 ppt< 2< 2
ADONA3 ppt< 3< 3
HFPO-DA5 ppt< 5< 5
NEtFOSAA5 ppt< 5< 5
NFDHA20 ppt< 20< 20
NMeFOSAA6 ppt< 6< 6
PFBA5 ppt< 5< 5
PFBS3 ppt< 3< 3
PFDA3 ppt< 3< 3
PFDoA3 ppt< 3< 3
PFEESA3 ppt< 3< 3
PFHpA3 ppt< 3< 3
PFHpS3 ppt< 3< 3
PFHxA3 ppt< 3< 3
PFHxS3 ppt< 3< 3
PFMBA3 ppt< 3< 3
PFMPA4 ppt< 4< 4
PFNA4 ppt< 4< 4
PFOA4 ppt< 4< 4
PFOS4 ppt< 4< 4
PFPeA3 ppt< 3< 3
PFPeS4 ppt< 4< 4
PFTA8 ppt< 8< 8
PFTrDA7 ppt< 7< 7
PFUnA2 ppt< 2< 2
lithium9 µg/L< 9< 9

Mountain View Well POE facility 35156 · sample point EP010 · groundwater

CompoundMRL2025-02-18
SE1
2025-08-19
SE2
PFBA5 ppt5.45.7
PFBS3 ppt33.1
PFHpA3 ppt3.84
PFHxA3 ppt5.15.4
PFHxS3 ppt3.43.1
PFOA4 ppt1010.8
PFPeA3 ppt4.74.8
11Cl-PF3OUdS5 ppt< 5< 5
4:2 FTS3 ppt< 3< 3
6:2 FTS5 ppt< 5< 5
8:2 FTS5 ppt< 5< 5
9Cl-PF3ONS2 ppt< 2< 2
ADONA3 ppt< 3< 3
HFPO-DA5 ppt< 5< 5
NEtFOSAA5 ppt< 5< 5
NFDHA20 ppt< 20< 20
NMeFOSAA6 ppt< 6< 6
PFDA3 ppt< 3< 3
PFDoA3 ppt< 3< 3
PFEESA3 ppt< 3< 3
PFHpS3 ppt< 3< 3
PFMBA3 ppt< 3< 3
PFMPA4 ppt< 4< 4
PFNA4 ppt< 4< 4
PFOS4 ppt< 4< 4
PFPeS4 ppt< 4< 4
PFTA8 ppt< 8< 8
PFTrDA7 ppt< 7< 7
PFUnA2 ppt< 2< 2
lithium9 µg/L< 9< 9

Water Treatment Plant Entry Point facility 23159 · sample point EP001 · surface water

CompoundMRL2025-02-18
SE1
2025-05-19
SE2
2025-08-19
SE3
2025-11-17
SE4
11Cl-PF3OUdS5 ppt< 5< 5< 5< 5
4:2 FTS3 ppt< 3< 3< 3< 3
6:2 FTS5 ppt< 5< 5< 5< 5
8:2 FTS5 ppt< 5< 5< 5< 5
9Cl-PF3ONS2 ppt< 2< 2< 2< 2
ADONA3 ppt< 3< 3< 3< 3
HFPO-DA5 ppt< 5< 5< 5< 5
NEtFOSAA5 ppt< 5< 5< 5< 5
NFDHA20 ppt< 20< 20< 20< 20
NMeFOSAA6 ppt< 6< 6< 6< 6
PFBA5 ppt< 5< 5< 5< 5
PFBS3 ppt< 3< 3< 3< 3
PFDA3 ppt< 3< 3< 3< 3
PFDoA3 ppt< 3< 3< 3< 3
PFEESA3 ppt< 3< 3< 3< 3
PFHpA3 ppt< 3< 3< 3< 3
PFHpS3 ppt< 3< 3< 3< 3
PFHxA3 ppt< 3< 3< 3< 3
PFHxS3 ppt< 3< 3< 3< 3
PFMBA3 ppt< 3< 3< 3< 3
PFMPA4 ppt< 4< 4< 4< 4
PFNA4 ppt< 4< 4< 4< 4
PFOA4 ppt< 4< 4< 4< 4
PFOS4 ppt< 4< 4< 4< 4
PFPeA3 ppt< 3< 3< 3< 3
PFPeS4 ppt< 4< 4< 4< 4
PFTA8 ppt< 8< 8< 8< 8
PFTrDA7 ppt< 7< 7< 7< 7
PFUnA2 ppt< 2< 2< 2< 2
lithium9 µg/L< 9< 9< 9< 9

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
PFBA1631%15.2
2025-08-19
2.84–6.28<MRL5.413.515.2
PFBS1625%10.4
2025-08-19
1.57–3.83<MRL<MRL8.710.4
PFHpA1625%13.7
2025-08-19
2.14–4.39<MRL<MRL12.713.7
PFHxA1625%26.2
2025-08-19
3.71–5.96<MRL<MRL22.726.2
PFOA1625%10.8
2025-08-19
2.01–5.01<MRL<MRL1010.8
PFPeA1625%46.6
2025-08-19
6.09–8.34<MRL<MRL41.346.6
lithium1619%14.9
2025-08-19
2.39–9.71<MRL<MRL14.314.9
6:2 FTS1612%17.9
2025-08-19
2.09–6.46<MRL<MRL15.517.9
PFHxS1612%3.4
2025-02-18
0.41–3.03<MRL<MRL3.13.4

Never detected (21): 11Cl-PF3OUdS, 4:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFDA, PFDoA, PFEESA, PFHpS, PFMBA, PFMPA, PFNA, PFOS, PFPeS, PFTA, PFTrDA, PFUnA.

Left-censored Kaplan–Meier statistics (Helsel 2005; Helsel & Lee 2006, NADA for R). Units: ppt; lithium µg/L. Each compound has one reporting limit, so the Kaplan–Meier mean equals the upper mean bound (non-detects at the MRL); the lower bound sets non-detects to 0. “<MRL” = the percentile falls below the reporting limit and cannot be estimated. These describe this system's UCMR 5 samples, not population estimates.

Sources

  • EPA UCMR 5 occurrence data text files (UCMR5_All.txt; samples 2023-01-10 to 2026-03-04; data summary dated Jul 2026)
  • EPA SDWIS via ECHO SDWA downloads, quarter 2026Q3
  • EPA Public Water System Service Areas v3 (Mar 2026)
  • US Census Bureau cartographic boundary counties 1:500k, 2024
  • EPA/USGS NHDPlus V2 (medium resolution) flowlines, Strahler order 2+

Data build c525414e2fcb · 2026-10-18T04:06Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.