Missoula Water

PFAS monitoring results for a public water system in Montana

MT0000294UCMR 5EPA monitoring data
<MRLHighest PFOA result, ppt
<MRLHighest PFOS result, ppt
0Highest Hazard Index
1,380Results
PWSID
MT0000294
State
Montana
System type
community water system (CWS)
Population served
68,200
City
Missoula
Counties
Missoula County
Primary source water
groundwater
UCMR 5 sampling
2023-04-26 to 2026-01-12 · 23 entry point(s) · water types: GW
Service-area boundary
authoritative

No PFAS detected highest single result
No PFAS detected 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 Index001.0†

“<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 Montana PFAS drinking-water standard in effect or proposed as of 2026-10-17: No state PFAS drinking-water standard; follows federal NPDWR (BCLP state survey, Jan 2026).

Sampling history

Sampled 2023-04-26 to 2026-01-12 · 23 entry point(s) · water types: GW · 57 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2023-04-26Well # 04 (Sommers) (GW)SE1<4<40none
2023-04-26Well # 43 (Canyon River) (GW)SE1<4<40none
2023-04-26Well #12 (Judi) (GW)SE1<4<40none
2023-04-26Well #20 (Catlin) (GW)SE1<4<40none
2023-04-26Well #30 (Bank) (GW)SE1<4<40none
2023-04-26Well #9 (Dixon) (GW)SE1<4<40lithium 9.3 µg/L
2023-04-26Wells #45A, #45B & #45C Common Header" (GW)SE1<4<40none
2023-10-25Well # 04 (Sommers) (GW)SE2<4<40none
2023-10-25Well # 43 (Canyon River) (GW)SE2<4<40none
2023-10-25Well #12 (Judi) (GW)SE2<4<40none
2023-10-25Well #20 (Catlin) (GW)SE2<4<40none
2023-10-25Well #30 (Bank) (GW)SE2<4<40none
2023-10-25Well #9 (Dixon) (GW)SE2<4<40lithium 9.7 µg/L
2023-10-25Wells #45A, #45B & #45C Common Header" (GW)SE2<4<40none
2023-11-28Wells #45A, #45B & #45C Common Header" (GW)SE2n/an/an/anone
2023-12-05Well #20 (Catlin) (GW)SE2n/an/an/anone
2023-12-05Well #9 (Dixon) (GW)SE2n/an/an/anone
2024-04-24Well #10 (Hilda) (GW)SE1<4<40none
2024-04-24Well #11 (Agnes) (GW)SE1<4<40none
2024-04-24Well #13 (Mountain View) (GW)SE1n/an/an/anone
2024-04-24Well #19 (N. Russell) (GW)SE1<4<40none
2024-04-24Well #2 (14th) (GW)SE1<4<40none
2024-04-24Well #26 (Benton) (GW)SE1<4<40none
2024-04-24Well #32 (Arthur) (GW)SE1<4<40none
2024-04-24Wells #40A, #40B & #40C Common Header" (GW)SE1<4<40lithium 15 µg/L
2024-06-17Well #13 (Mountain View) (GW)SE1<4<40none
2024-10-08Well #10 (Hilda) (GW)SE2n/an/an/anone
2024-10-08Well #13 (Mountain View) (GW)SE2n/an/an/anone
2024-10-08Well #19 (N. Russell) (GW)SE2n/an/an/anone
2024-10-08Well #2 (14th) (GW)SE2n/an/an/anone
2024-10-08Well #26 (Benton) (GW)SE2n/an/an/anone
2024-10-08Well #32 (Arthur) (GW)SE2n/an/an/anone
2024-10-08Wells #40A, #40B & #40C Common Header" (GW)SE2n/an/an/alithium 13 µg/L
2024-11-06Well #10 (Hilda) (GW)SE2<4<40none
2024-11-06Well #13 (Mountain View) (GW)SE2<4<40none
2024-11-06Well #19 (N. Russell) (GW)SE2<4<40none
2024-11-06Well #2 (14th) (GW)SE2<4<40none
2024-11-06Well #26 (Benton) (GW)SE2<4<40none
2024-11-06Well #32 (Arthur) (GW)SE2<4<40none
2024-11-06Wells #40A, #40B & #40C Common Header" (GW)SE2<4<40none
2025-04-22Well # 38 (23rd Street #01 East) (GW)SE1<4<40lithium 9 µg/L
2025-04-22Well # 8 (Schilling) (GW)SE1<4<40none
2025-04-22Well #17 (Momont) (GW)SE1<4<40none
2025-04-22Well #18 (Willow Wood) (GW)SE1<4<40lithium 9.3 µg/L
2025-04-22Well #21 (E. Central) (GW)SE1<4<40none
2025-04-22Well #22 (Intermountain) (GW)SE1<4<40none
2025-04-22Well #42 (Palmer) (GW)SE1<4<40none
2025-04-22Wells #3A & #3B Common Header (GW)SE1<4<40none
2025-10-21Well # 38 (23rd Street #01 East) (GW)SE2<4<40none
2025-10-21Well # 8 (Schilling) (GW)SE2<4<40none
2025-10-21Well #11 (Agnes) (GW)SE2<4<40none
2025-10-21Well #18 (Willow Wood) (GW)SE2<4<40none
2025-10-21Well #21 (E. Central) (GW)SE2<4<40none
2025-10-21Well #22 (Intermountain) (GW)SE2<4<40none
2025-10-21Well #42 (Palmer) (GW)SE2<4<40none
2025-10-21Wells #3A & #3B Common Header (GW)SE2<4<40none
2026-01-12Well #17 (Momont) (GW)SE2<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

1380 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.

Well # 04 (Sommers) facility 00041 · sample point EP541 · groundwater

CompoundMRL2023-04-26
SE1
2023-10-25
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

Well # 38 (23rd Street #01 East) facility 00039 · sample point EP539 · groundwater

CompoundMRL2025-04-22
SE1
2025-10-21
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< 9

Well # 43 (Canyon River) facility 00048 · sample point EP548 · groundwater

CompoundMRL2023-04-26
SE1
2023-10-25
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

Well # 8 (Schilling) facility 00008 · sample point EP508 · groundwater

CompoundMRL2025-04-22
SE1
2025-10-21
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

Well #10 (Hilda) facility 00010 · sample point EP510 · groundwater

CompoundMRL2024-04-24
SE1
2024-10-08
SE2
2024-11-06
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–

Well #11 (Agnes) facility 00011 · sample point EP511 · groundwater

CompoundMRL2024-04-24
SE1
2025-10-21
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

Well #12 (Judi) facility 00042 · sample point EP542 · groundwater

CompoundMRL2023-04-26
SE1
2023-10-25
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

Well #13 (Mountain View) facility 00013 · sample point EP513 · groundwater

CompoundMRL2024-04-24
SE1
2024-06-17
SE1
2024-10-08
SE2
2024-11-06
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–

Well #17 (Momont) facility 00017 · sample point EP517 · groundwater

CompoundMRL2025-04-22
SE1
2026-01-12
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

Well #18 (Willow Wood) facility 00018 · sample point EP518 · groundwater

CompoundMRL2025-04-22
SE1
2025-10-21
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/L9.3< 9

Well #19 (N. Russell) facility 00019 · sample point EP519 · groundwater

CompoundMRL2024-04-24
SE1
2024-10-08
SE2
2024-11-06
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–

Well #2 (14th) facility 00002 · sample point EP502 · groundwater

CompoundMRL2024-04-24
SE1
2024-10-08
SE2
2024-11-06
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–

Well #20 (Catlin) facility 00020 · sample point EP520 · groundwater

CompoundMRL2023-04-26
SE1
2023-10-25
SE2
2023-12-05
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/L< 9< 9–

Well #21 (E. Central) facility 00021 · sample point EP521 · groundwater

CompoundMRL2025-04-22
SE1
2025-10-21
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

Well #22 (Intermountain) facility 00022 · sample point EP522 · groundwater

CompoundMRL2025-04-22
SE1
2025-10-21
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

Well #26 (Benton) facility 00026 · sample point EP526 · groundwater

CompoundMRL2024-04-24
SE1
2024-10-08
SE2
2024-11-06
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–

Well #30 (Bank) facility 00030 · sample point EP530 · groundwater

CompoundMRL2023-04-26
SE1
2023-10-25
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

Well #32 (Arthur) facility 00032 · sample point EP532 · groundwater

CompoundMRL2024-04-24
SE1
2024-10-08
SE2
2024-11-06
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–

Well #42 (Palmer) facility 00047 · sample point EP547 · groundwater

CompoundMRL2025-04-22
SE1
2025-10-21
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

Well #9 (Dixon) facility 00009 · sample point EP509 · groundwater

CompoundMRL2023-04-26
SE1
2023-10-25
SE2
2023-12-05
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/L9.39.7–

Wells #3A & #3B Common Header facility 00001 · sample point EP503 · groundwater

CompoundMRL2025-04-22
SE1
2025-10-21
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

Wells #40A, #40B & #40C Common Header" facility 00003 · sample point EP543 · groundwater

CompoundMRL2024-04-24
SE1
2024-10-08
SE2
2024-11-06
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/L1513–

Wells #45A, #45B & #45C Common Header" facility 00005 · sample point EP549 · groundwater

CompoundMRL2023-04-26
SE1
2023-10-25
SE2
2023-11-28
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–

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
lithium4613%15
2024-04-24
1.42–9.25<MRL<MRL9.39.7

Never detected (29): 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, PFNA, 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 2023-01-09 to 2026-02-09; 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 4c7299147c58 · 2026-10-18T04:04Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.