Marshfield Water Department

PFAS monitoring results for a public water system in Massachusetts

MA4171000UCMR 5EPA monitoring data
7Highest PFOA result, ppt
4.6Highest PFOS result, ppt
0.002Highest Hazard Index
935Results
PWSID
MA4171000
State
Massachusetts
System type
community water system (CWS)
Population served
34,000
City
Marshfield
Counties
Plymouth County
Primary source water
groundwater
UCMR 5 sampling
2024-03-05 to 2025-03-19 · 16 entry point(s) · water types: GW
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

  • Duxbury Water Department (MA4082000)
    Seller's highest results: PFOA 7.5 ppt · PFOS 35 ppt · HI 3.102 · detected: 6:2 FTS;PFBA;PFBS;PFHpA;PFHpS;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)76.94
PFOS (ppt)4.62.34
Hazard Index0.0020.0021.0†

“<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 Massachusetts standards

Highest single resultWorst entry-point average*Massachusetts
PFAS6 (sum) (ppt)10.21020

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 2024-03-05 to 2025-03-19 · 16 entry point(s) · water types: GW · 46 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2024-03-05Fairgrounds Well (GW)SE1<4<40none
2024-03-05S. River Street Well (GW)SE1<4<40none
2024-03-06Furnace Brook Well 1A (GW)SE17<40.002PFBA 6, PFHpA 3.2, PFHxA 11.7, PFPeA 14.7
2024-03-06Furnace Brook Well 2 (GW)SE1n/an/an/anone
2024-03-06Furnace Brook Well 4 (GW)SE15.4<40PFHxA 3.1, PFPeA 3.2
2024-03-06Mt. Skirgo Wells (GW)SE1<4<40none
2024-03-06Spring Street Well (GW)SE1<4<40none
2024-03-06Union Station 1 (GW)SE1<4<40none
2024-03-06Union Station 2 (GW)SE1<4<40none
2024-03-13Church Street Well (GW)SE1<4<40none
2024-03-13Ferry Street 2 Wellfield (GW)SE1<4<40none
2024-03-13Ferry Street Well (GW)SE1<4<40none
2024-03-13School Street Well (GW)SE1<4<40none
2024-03-20Webster Well 1 (GW)SE1n/an/an/anone
2024-03-20Webster Well 2 (GW)SE1n/an/an/anone
2024-03-27Ferry Street 2 Wellfield (GW)SE1n/an/an/anone
2024-04-30Furnace Brook Well 3 (GW)SE1n/an/an/anone
2024-06-24Webster Well 1 (GW)SE15.3<40.002PFHxA 5.2, PFPeA 4.6
2024-06-24Webster Well 2 (GW)SE14.2<40none
2024-07-30Furnace Brook Well 3 (GW)SE1<4<40PFHxA 3.9, PFPeA 4.6
2024-09-05Furnace Brook Well 2 (GW)SE1<4<40PFHxA 5, PFPeA 4.3
2024-10-16Furnace Brook Well 2 (GW)SE2n/an/an/anone
2024-10-16Union Station 1 (GW)SE2<4<40none
2024-10-16Union Station 2 (GW)SE2<4<40none
2024-10-16Webster Well 2 (GW)SE24.1<40none
2024-10-17Church Street Well (GW)SE2<4<40none
2024-10-24Furnace Brook Well 4 (GW)SE2n/an/an/anone
2024-10-24Webster Well 1 (GW)SE24.8<40.002PFHxA 4.7, PFPeA 4
2024-10-31Furnace Brook Well 1A (GW)SE2n/an/an/anone
2024-11-13Furnace Brook Well 3 (GW)SE2<4<40PFHxA 3.9, PFPeA 4.1
2024-11-13Spring Street Well (GW)SE2<4<40none
2024-11-14Mt. Skirgo Wells (GW)SE2<4<40none
2024-11-14S. River Street Well (GW)SE2<4<40none
2024-12-04Fairgrounds Well (GW)SE2<4<40none
2024-12-17Ferry Street 2 Wellfield (GW)SE2<44.60lithium 19.3 µg/L
2024-12-17Ferry Street Well (GW)SE2n/an/an/anone
2025-01-22School Street Well (GW)SE2n/an/an/anone
2025-01-28Fairgrounds Well (GW)SE2n/an/an/anone
2025-01-28Furnace Brook Well 2 (GW)SE2<4<40PFHxA 3.2
2025-01-28Furnace Brook Well 4 (GW)SE24.4<40PFPeA 3
2025-01-28Mt. Skirgo Wells (GW)SE2n/an/an/anone
2025-01-28S. River Street Well (GW)SE2n/an/an/anone
2025-01-29Church Street Well (GW)SE2n/an/an/anone
2025-01-29Ferry Street Well (GW)SE2<4<40none
2025-01-29Furnace Brook Well 1A (GW)SE26.8<40.002PFBA 5.7, PFHpA 3, PFHxA 10.4, PFPeA 13.2
2025-03-19Spring Street Well (GW)SE2n/an/an/anone

“<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

935 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.

Church Street Well facility 90010 · sample point 10001 · groundwater

CompoundMRL2024-03-13
SE1
2024-10-17
SE2
2025-01-29
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–

Fairgrounds Well facility 90016 · sample point 10067 · groundwater

CompoundMRL2024-03-05
SE1
2024-12-04
SE2
2025-01-28
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–

Ferry Street 2 Wellfield facility 90015 · sample point 10064 · groundwater

CompoundMRL2024-03-13
SE1
2024-03-27
SE1
2024-12-17
SE2
PFOS4 ppt< 4–4.6
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
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
PFPeA3 ppt< 3–< 3
PFPeS4 ppt< 4–< 4
PFTA8 ppt–< 8< 8
PFTrDA7 ppt–< 7< 7
PFUnA2 ppt< 2–< 2
lithium9 µg/L< 9–19.3

Ferry Street Well facility 90008 · sample point 10002 · groundwater

CompoundMRL2024-03-13
SE1
2024-12-17
SE2
2025-01-29
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–

Furnace Brook Well 1A facility 90014 · sample point 10007 · groundwater

CompoundMRL2024-03-06
SE1
2024-10-31
SE2
2025-01-29
SE2
PFBA5 ppt6–5.7
PFBS3 ppt3.7–3.9
PFHpA3 ppt3.2–3
PFHxA3 ppt11.7–10.4
PFOA4 ppt7–6.8
PFPeA3 ppt14.7–13.2
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
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–

Furnace Brook Well 2 facility 90002 · sample point 10004 · groundwater

CompoundMRL2024-03-06
SE1
2024-09-05
SE1
2024-10-16
SE2
2025-01-28
SE2
PFHxA3 ppt–5–3.2
PFPeA3 ppt–4.3–< 3
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
PFHxS3 ppt–< 3–< 3
PFMBA3 ppt–< 3–< 3
PFMPA4 ppt–< 4–< 4
PFNA4 ppt–< 4–< 4
PFOA4 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–

Furnace Brook Well 3 facility 90003 · sample point 10005 · groundwater

CompoundMRL2024-04-30
SE1
2024-07-30
SE1
2024-11-13
SE2
PFHxA3 ppt–3.93.9
PFPeA3 ppt–4.64.1
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
PFHxS3 ppt–< 3< 3
PFMBA3 ppt–< 3< 3
PFMPA4 ppt–< 4< 4
PFNA4 ppt–< 4< 4
PFOA4 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

Furnace Brook Well 4 facility 90004 · sample point 10006 · groundwater

CompoundMRL2024-03-06
SE1
2024-10-24
SE2
2025-01-28
SE2
PFHxA3 ppt3.1–< 3
PFOA4 ppt5.4–4.4
PFPeA3 ppt3.2–3
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
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–

Mt. Skirgo Wells facility 90001 · sample point 10009 · groundwater

CompoundMRL2024-03-06
SE1
2024-11-14
SE2
2025-01-28
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–

S. River Street Well facility 90005 · sample point 10012 · groundwater

CompoundMRL2024-03-05
SE1
2024-11-14
SE2
2025-01-28
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–

School Street Well facility 90006 · sample point 10011 · groundwater

CompoundMRL2024-03-13
SE1
2025-01-22
SE2
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< 5
NFDHA20 ppt< 20–
NMeFOSAA6 ppt< 6< 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< 8
PFTrDA7 ppt< 7< 7
PFUnA2 ppt< 2–
lithium9 µg/L< 9< 9

Spring Street Well facility 90013 · sample point 10051 · groundwater

CompoundMRL2024-03-06
SE1
2024-11-13
SE2
2025-03-19
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–

Union Station 1 facility 90011 · sample point 10013 · groundwater

CompoundMRL2024-03-06
SE1
2024-10-16
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/L< 9< 9

Union Station 2 facility 90012 · sample point 10014 · groundwater

CompoundMRL2024-03-06
SE1
2024-10-16
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/L< 9< 9

Webster Well 1 facility 90007 · sample point 10015 · groundwater

CompoundMRL2024-03-20
SE1
2024-06-24
SE1
2024-10-24
SE2
PFBS3 ppt–3.53.1
PFHxA3 ppt–5.24.7
PFOA4 ppt–5.34.8
PFPeA3 ppt–4.64
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
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

Webster Well 2 facility 90009 · sample point 10016 · groundwater

CompoundMRL2024-03-20
SE1
2024-06-24
SE1
2024-10-16
SE2
PFOA4 ppt–4.24.1
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
PFNA4 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

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
PFHxA3129%11.7
2024-03-06
1.65–3.78<MRL3.2510.4
PFPeA3129%14.7
2024-03-06
1.8–3.93<MRL3.24.613.2
PFOA3126%7
2024-03-06
1.35–4.32<MRL4.15.36.8
PFBS3113%3.9
2025-01-29
0.46–3.07<MRL<MRL3.13.7
PFBA316%6
2024-03-06
0.38–5.05<MRL<MRL<MRL5.7
PFHpA316%3.2
2024-03-06
0.2–3.01<MRL<MRL<MRL3
PFOS313%4.6
2024-12-17
0.15–4.02<MRL<MRL<MRL<MRL
lithium323%19.3
2024-12-17
0.6–9.32<MRL<MRL<MRL<MRL

Never detected (22): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFDA, PFDoA, PFEESA, 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 2023-01-09 to 2026-05-28; 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 a6eeb89a233e · 2026-10-18T04:09Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.