Fallsburg Who-Ls-Sf

PFAS monitoring results for a public water system in New York

NY5203324UCMR 5EPA monitoring data
<MRLHighest PFOA result, ppt
<MRLHighest PFOS result, ppt
1.31Highest Hazard Index
450Results
PWSID
NY5203324
State
New York
System type
community water system (CWS)
Population served
7,850
City
South Fallsburg
Counties
Sullivan County
Primary source water
groundwater
UCMR 5 sampling
2025-04-14 to 2025-12-16 · 10 entry point(s) · water types: GW
Service-area boundary
authoritative

Hazard Index 1–3 × its limit highest single result
Hazard Index 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)<MRL04
PFOS (ppt)<MRL04
Hazard Index1.311.271.0†

“<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).

Compared with New York standards

Highest single resultWorst entry-point average*New York
PFOA (ppt)0010
PFOS (ppt)0010

Sum standards add the listed compounds within each sample (non-detects = 0). State compliance is normally judged on averages over time; these are screening comparisons.

Sampling history

Sampled 2025-04-14 to 2025-12-16 · 10 entry point(s) · water types: GW · 16 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2025-04-14FALLSBURG WHO-LS-SF (GW)SE1<4<40lithium 11.2 µg/L
2025-04-14FALLSBURG WHO-LS-SF (GW)SE1<4<40none
2025-04-15FALLSBURG WHO-LS-SF (GW)SE1<4<40lithium 60.9 µg/L
2025-04-15FALLSBURG WHO-LS-SF (GW)SE1<4<40lithium 11 µg/L
2025-04-22FALLSBURG WHO-LS-SF (GW)SE1<4<41.23lithium 19.1 µg/L
2025-04-22FALLSBURG WHO-LS-SF (GW)SE1<4<40lithium 13.2 µg/L
2025-07-08FALLSBURG WHO-LS-SF (GW)SE1<4<40none
2025-07-08FALLSBURG WHO-LS-SF (GW)SE1<4<40none
2025-08-05FALLSBURG WHO-LS-SF (GW)SE1<4<40none
2025-08-05FALLSBURG WHO-LS-SF (GW)SE1n/an/an/anone
2025-11-04FALLSBURG WHO-LS-SF (GW)SE2<4<40lithium 11.8 µg/L
2025-11-04FALLSBURG WHO-LS-SF (GW)SE2<4<40none
2025-11-05FALLSBURG WHO-LS-SF (GW)SE1<4<40none
2025-11-05FALLSBURG WHO-LS-SF (GW)SE2<4<40lithium 55.6 µg/L
2025-11-18FALLSBURG WHO-LS-SF (GW)SE2<4<41.31lithium 18.3 µg/L
2025-12-16FALLSBURG WHO-LS-SF (GW)SE2<4<40lithium 12.3 µg/L

“<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

450 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.

FALLSBURG WHO-LS-SF facility HTP02 · sample point EPH002 · groundwater

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

FALLSBURG WHO-LS-SF facility LSTP01 · sample point EPLS001 · groundwater

CompoundMRL2025-07-08
SE1
11Cl-PF3OUdS5 ppt< 5
4:2 FTS3 ppt< 3
6:2 FTS5 ppt< 5
8:2 FTS5 ppt< 5
9Cl-PF3ONS2 ppt< 2
ADONA3 ppt< 3
HFPO-DA5 ppt< 5
NEtFOSAA5 ppt< 5
NFDHA20 ppt< 20
NMeFOSAA6 ppt< 6
PFBA5 ppt< 5
PFBS3 ppt< 3
PFDA3 ppt< 3
PFDoA3 ppt< 3
PFEESA3 ppt< 3
PFHpA3 ppt< 3
PFHpS3 ppt< 3
PFHxA3 ppt< 3
PFHxS3 ppt< 3
PFMBA3 ppt< 3
PFMPA4 ppt< 4
PFNA4 ppt< 4
PFOA4 ppt< 4
PFOS4 ppt< 4
PFPeA3 ppt< 3
PFPeS4 ppt< 4
PFTA8 ppt< 8
PFTrDA7 ppt< 7
PFUnA2 ppt< 2
lithium9 µg/L< 9

FALLSBURG WHO-LS-SF facility LSTP03 · sample point EPLS003 · groundwater

CompoundMRL2025-04-15
SE1
2025-11-05
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/L60.955.6

FALLSBURG WHO-LS-SF facility SFTP01 · sample point EPSF001 · groundwater

CompoundMRL2025-04-22
SE1
2025-11-18
SE2
PFNA4 ppt12.313.1
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
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/L19.118.3

FALLSBURG WHO-LS-SF facility SFTP02 · sample point EPSF002 · groundwater

CompoundMRL2025-04-22
SE1
11Cl-PF3OUdS5 ppt< 5
4:2 FTS3 ppt< 3
6:2 FTS5 ppt< 5
8:2 FTS5 ppt< 5
9Cl-PF3ONS2 ppt< 2
ADONA3 ppt< 3
HFPO-DA5 ppt< 5
NEtFOSAA5 ppt< 5
NFDHA20 ppt< 20
NMeFOSAA6 ppt< 6
PFBA5 ppt< 5
PFBS3 ppt< 3
PFDA3 ppt< 3
PFDoA3 ppt< 3
PFEESA3 ppt< 3
PFHpA3 ppt< 3
PFHpS3 ppt< 3
PFHxA3 ppt< 3
PFHxS3 ppt< 3
PFMBA3 ppt< 3
PFMPA4 ppt< 4
PFNA4 ppt< 4
PFOA4 ppt< 4
PFOS4 ppt< 4
PFPeA3 ppt< 3
PFPeS4 ppt< 4
PFTA8 ppt< 8
PFTrDA7 ppt< 7
PFUnA2 ppt< 2
lithium9 µg/L13.2

FALLSBURG WHO-LS-SF facility SFTP03 · sample point EPSF003 · groundwater

CompoundMRL2025-04-14
SE1
2025-12-16
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/L11.212.3

FALLSBURG WHO-LS-SF facility SFTP07 · sample point EPSF007 · groundwater

CompoundMRL2025-07-08
SE1
11Cl-PF3OUdS5 ppt< 5
4:2 FTS3 ppt< 3
6:2 FTS5 ppt< 5
8:2 FTS5 ppt< 5
9Cl-PF3ONS2 ppt< 2
ADONA3 ppt< 3
HFPO-DA5 ppt< 5
NEtFOSAA5 ppt< 5
NFDHA20 ppt< 20
NMeFOSAA6 ppt< 6
PFBA5 ppt< 5
PFBS3 ppt< 3
PFDA3 ppt< 3
PFDoA3 ppt< 3
PFEESA3 ppt< 3
PFHpA3 ppt< 3
PFHpS3 ppt< 3
PFHxA3 ppt< 3
PFHxS3 ppt< 3
PFMBA3 ppt< 3
PFMPA4 ppt< 4
PFNA4 ppt< 4
PFOA4 ppt< 4
PFOS4 ppt< 4
PFPeA3 ppt< 3
PFPeS4 ppt< 4
PFTA8 ppt< 8
PFTrDA7 ppt< 7
PFUnA2 ppt< 2
lithium9 µg/L< 9

FALLSBURG WHO-LS-SF facility WTP01 · sample point EPW001 · groundwater

CompoundMRL2025-04-15
SE1
2025-11-04
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/L1111.8

FALLSBURG WHO-LS-SF facility WTP02 · sample point EPW002 · groundwater

CompoundMRL2025-04-14
SE1
2025-11-04
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

FALLSBURG WHO-LS-SF facility WTP03 · sample point EPW003 · groundwater

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

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
lithium1560%60.9
2025-04-15
14.23–17.8311.218.355.660.9
PFNA1513%13.1
2025-11-18
1.69–5.16<MRL<MRL12.313.1

Never detected (28): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFBA, PFBS, PFDA, PFDoA, PFEESA, PFHpA, PFHpS, PFHxA, PFHxS, PFMBA, PFMPA, PFOA, PFOS, PFPeA, 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 2023-01-03 to 2026-06-17; 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 171ad949e257 · 2026-10-18T04:10Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.