Hilltown Twp Water&Sewer Auth

PFAS monitoring results for a public water system in Pennsylvania

PA1090117UCMR 5EPA monitoring data
8Highest PFOA result, ppt
6.8Highest PFOS result, ppt
0.003Highest Hazard Index
300Results
PWSID
PA1090117
State
Pennsylvania
System type
community water system (CWS)
Population served
5,770
City
Sellersville
Counties
Bucks County
Primary source water
surface water (purchased)
UCMR 5 sampling
2025-04-01 to 2025-12-09 · 4 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.

Water purchased from

  • North Penn Water Authority (PA1460034)
    Seller's highest results: PFOA 5.1 ppt · PFOS <MRL · HI 0.002 · detected: PFBS;PFOA;PFPeA
  • Telford Borough Authority (PA1460050)
    Seller's highest results: PFOA 14.9 ppt · PFOS 15.2 ppt · HI 0.553 · detected: 6:2 FTS;PFBA;PFBS;PFHpA;PFHxA;PFHxS;PFOA;PFOS;PFPeA

Seller results are the seller's own entry-point samples, not measurements of this system's water. This system's own samples (below) may reflect purchased water, its own sources, or both.

Compared with EPA's 2024 values

Highest single resultWorst entry-point average*Limit
PFOA (ppt)87.654
PFOS (ppt)6.86.74
Hazard Index0.0030.0031.0†

“<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 Pennsylvania standards

Highest single resultWorst entry-point average*Pennsylvania
PFOA (ppt)87.6514
PFOS (ppt)6.86.718

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 2025-04-01 to 2025-12-09 · 4 entry point(s) · water types: GW;SW · 10 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2025-04-01NPWA INTECONNECTION (SW)SE1<4<40none
2025-04-01WELL 1 (GW)SE17.36.60.003PFHxA 4.5, PFPeA 5.9, lithium 21.3 µg/L
2025-04-01WELL 2 (GW)SE1<4<40lithium 13.8 µg/L
2025-04-01WELL 5 (GW)SE1<4<40lithium 20.9 µg/L
2025-06-16NPWA INTECONNECTION (SW)SE2<4<40none
2025-09-23WELL 1 (GW)SE286.80.003PFHxA 5.5, PFPeA 6.6, lithium 22.7 µg/L
2025-09-23WELL 2 (GW)SE2<4<40lithium 14.9 µg/L
2025-09-24NPWA INTECONNECTION (SW)SE3<4<40none
2025-09-24WELL 5 (GW)SE2<4<40lithium 21.7 µg/L
2025-12-09NPWA INTECONNECTION (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

300 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.

NPWA INTECONNECTION facility 104 · sample point EP0001 · surface water

CompoundMRL2025-04-01
SE1
2025-06-16
SE2
2025-09-24
SE3
2025-12-09
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

WELL 1 facility 101 · sample point EP101 · groundwater

CompoundMRL2025-04-01
SE1
2025-09-23
SE2
PFBS3 ppt5.45.7
PFHxA3 ppt4.55.5
PFOA4 ppt7.38
PFOS4 ppt6.66.8
PFPeA3 ppt5.96.6
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
PFDA3 ppt< 3< 3
PFDoA3 ppt< 3< 3
PFEESA3 ppt< 3< 3
PFHpA3 ppt< 3< 3
PFHpS3 ppt< 3< 3
PFHxS3 ppt< 3< 3
PFMBA3 ppt< 3< 3
PFMPA4 ppt< 4< 4
PFNA4 ppt< 4< 4
PFPeS4 ppt< 4< 4
PFTA8 ppt< 8< 8
PFTrDA7 ppt< 7< 7
PFUnA2 ppt< 2< 2
lithium9 µg/L21.322.7

WELL 2 facility 102 · sample point EP102 · groundwater

CompoundMRL2025-04-01
SE1
2025-09-23
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/L13.814.9

WELL 5 facility 103 · sample point EP103 · groundwater

CompoundMRL2025-04-01
SE1
2025-09-24
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/L20.921.7

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
lithium1060%22.7
2025-09-23
11.53–15.1313.821.321.722.7
PFBS1020%5.7
2025-09-23
1.11–3.51<MRL<MRL5.45.7
PFHxA1020%5.5
2025-09-23
1–3.4<MRL<MRL4.55.5
PFOA1020%8
2025-09-23
1.53–4.73<MRL<MRL7.38
PFOS1020%6.8
2025-09-23
1.34–4.54<MRL<MRL6.66.8
PFPeA1020%6.6
2025-09-23
1.25–3.65<MRL<MRL5.96.6

Never detected (24): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFBA, PFDA, PFDoA, PFEESA, PFHpA, PFHpS, PFHxS, PFMBA, PFMPA, PFNA, 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 2026-04-09; 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 52bd2907cbc3 · 2026-10-18T04:10Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.