Ontario Municipal Utilities Company

PFAS monitoring results for a public water system in California

CA3610034UCMR 5EPA monitoring data
30Highest PFOA result, ppt
5.2Highest PFOS result, ppt
0.42Highest Hazard Index
1,080Results
PWSID
CA3610034
State
California
System type
community water system (CWS)
Population served
185,010
City
Ontario
Counties
San Bernardino County
Primary source water
surface water (purchased)
UCMR 5 sampling
2023-02-01 to 2024-02-28 · 17 entry point(s) · water types: GW;SW
Service-area boundary
authoritative

PFOA ≥ 3 × its limit highest single result
PFOA ≥ 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

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)30154
PFOS (ppt)5.22.64
Hazard Index0.420.211.0†

“<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 California guidance levels

Highest single resultWorst entry-point average*California
PFHxS (ppt)4.22.13 (guidance)
PFOA (ppt)30154 (guidance)
PFOS (ppt)5.22.64 (guidance)
PFBS (ppt)00500 (guidance)
PFHxA (ppt)7.13.551,000 (guidance)

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 2023-02-01 to 2024-02-28 · 17 entry point(s) · water types: GW;SW · 42 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2023-02-01CA3610034_036_036 (GW)SE1<4<40none
2023-02-01CA3610034_806_806 (GW)SE1<4<40none
2023-02-01CA3610034_808_808 (GW)SE1<4<40none
2023-02-01CA3610034_810_810 (GW)SE1<4<40none
2023-02-01CA3610034_818_818 (GW)SE1<4<40none
2023-02-02CA3610034_053_053 (GW)SE1<4<40none
2023-02-07CA3610034_807_807 (GW)SE1<4<40none
2023-02-09CA3610034_035_035 (SW)SE1<4<40PFBA 6.2
2023-02-15CA3610034_811_811 (GW)SE1<45.20.42PFBA 6.4, PFHxA 7.1, PFPeA 6.7
2023-02-15CA3610034_814_814 (GW)SE1<4<40none
2023-02-15CA3610034_816_816 (GW)SE1<4<40none
2023-02-15CA3610034_820_820 (GW)SE1<4<40none
2023-02-22CA3610034_802_802 (GW)SE1<4<40none
2023-02-28CA3610034_037_037 (GW)SE1<4<40none
2023-02-28CA3610034_039_039 (GW)SE1n/an/an/anone
2023-02-28CA3610034_051_051 (GW)SE130<40none
2023-04-05CA3610034_039_039 (GW)SE1<4<40none
2023-04-07CA3610034_819_819 (GW)SE1<4<40none
2023-05-02CA3610034_037_037 (GW)SE1n/an/an/anone
2023-05-02CA3610034_039_039 (GW)SE1n/an/an/anone
2023-05-02CA3610034_051_051 (GW)SE1n/an/an/anone
2023-05-11CA3610034_035_035 (SW)SE2n/an/an/anone
2023-06-20CA3610034_035_035 (SW)SE2<4<40none
2023-08-02CA3610034_036_036 (GW)SE2<4<40none
2023-08-02CA3610034_810_810 (GW)SE2<4<40none
2023-08-02CA3610034_818_818 (GW)SE2<4<40none
2023-08-09CA3610034_811_811 (GW)SE2<4<40PFPeA 4.8
2023-08-09CA3610034_816_816 (GW)SE2<4<40none
2023-08-09CA3610034_820_820 (GW)SE2<4<40none
2023-08-10CA3610034_035_035 (SW)SE3<4<40none
2023-08-15CA3610034_039_039 (GW)SE2<4<40none
2023-08-15CA3610034_053_053 (GW)SE2<4<40none
2023-08-16CA3610034_037_037 (GW)SE2<4<40none
2023-08-16CA3610034_802_802 (GW)SE2<4<40none
2023-08-16CA3610034_806_806 (GW)SE2<4<40none
2023-08-16CA3610034_814_814 (GW)SE2<4<40none
2023-08-23CA3610034_807_807 (GW)SE2<4<40none
2023-08-24CA3610034_051_051 (GW)SE2<4<40none
2023-09-13CA3610034_819_819 (GW)SE2<4<40none
2023-11-01CA3610034_808_808 (GW)SE2<4<40none
2023-11-09CA3610034_035_035 (SW)SE4n/an/an/anone
2024-02-28CA3610034_035_035 (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

1080 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.

CA3610034_035_035 facility 00035 · sample point WFACONNECTION · surface water

CompoundMRL2023-02-09
SE1
2023-05-11
SE2
2023-06-20
SE2
2023-08-10
SE3
2023-11-09
SE4
2024-02-28
SE4
PFBA5 ppt6.2–< 5< 5–< 5
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–
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–

CA3610034_036_036 facility 00036 · sample point WELL38EP · groundwater

CompoundMRL2023-02-01
SE1
2023-08-02
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

CA3610034_037_037 facility 00037 · sample point JCSDPOC1 · groundwater

CompoundMRL2023-02-28
SE1
2023-05-02
SE1
2023-08-16
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

CA3610034_039_039 facility 00039 · sample point JCSDPOC3 · groundwater

CompoundMRL2023-02-28
SE1
2023-04-05
SE1
2023-05-02
SE1
2023-08-15
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

CA3610034_051_051 facility 00051 · sample point CDAIITURNOUT · groundwater

CompoundMRL2023-02-28
SE1
2023-05-02
SE1
2023-08-24
SE2
PFOA4 ppt30–< 4
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

CA3610034_053_053 facility 00053 · sample point WELL41IXTPEFFLUE · groundwater

CompoundMRL2023-02-02
SE1
2023-08-15
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

CA3610034_802_802 facility 00802 · sample point WELL24EP · groundwater

CompoundMRL2023-02-22
SE1
2023-08-16
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

CA3610034_806_806 facility 00806 · sample point WELL29EP · groundwater

CompoundMRL2023-02-01
SE1
2023-08-16
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

CA3610034_807_807 facility 00807 · sample point WELL30EP · groundwater

CompoundMRL2023-02-07
SE1
2023-08-23
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/L< 9< 9

CA3610034_808_808 facility 00808 · sample point WELL31EP · groundwater

CompoundMRL2023-02-01
SE1
2023-11-01
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

CA3610034_810_810 facility 00810 · sample point WELL35EP · groundwater

CompoundMRL2023-02-01
SE1
2023-08-02
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

CA3610034_811_811 facility 00811 · sample point WELL36EP · groundwater

CompoundMRL2023-02-15
SE1
2023-08-09
SE2
PFBA5 ppt6.4< 5
PFHxA3 ppt7.1< 3
PFHxS3 ppt4.2< 3
PFOS4 ppt5.2< 4
PFPeA3 ppt6.74.8
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
PFBS3 ppt< 3< 3
PFDA3 ppt< 3< 3
PFDoA3 ppt< 3< 3
PFEESA3 ppt< 3< 3
PFHpA3 ppt< 3< 3
PFHpS3 ppt< 3< 3
PFMBA3 ppt< 3< 3
PFMPA4 ppt< 4< 4
PFNA4 ppt< 4< 4
PFOA4 ppt< 4< 4
PFPeS4 ppt< 4< 4
PFTA8 ppt< 8< 8
PFTrDA7 ppt< 7< 7
PFUnA2 ppt< 2< 2
lithium9 µg/L< 9< 9

CA3610034_814_814 facility 00814 · sample point WELL40EP · groundwater

CompoundMRL2023-02-15
SE1
2023-08-16
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

CA3610034_816_816 facility 00816 · sample point WELL49EP · groundwater

CompoundMRL2023-02-15
SE1
2023-08-09
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

CA3610034_818_818 facility 00818 · sample point WELL45EP · groundwater

CompoundMRL2023-02-01
SE1
2023-08-02
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

CA3610034_819_819 facility 00819 · sample point WELL46EP · groundwater

CompoundMRL2023-04-07
SE1
2023-09-13
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

CA3610034_820_820 facility 00820 · sample point WELL47EP · groundwater

CompoundMRL2023-02-15
SE1
2023-08-09
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
PFBA366%6.4
2023-02-15
0.35–5.07<MRL<MRL<MRL6.2
PFPeA366%6.7
2023-02-15
0.32–3.15<MRL<MRL<MRL4.8
PFHxA363%7.1
2023-02-15
0.2–3.11<MRL<MRL<MRL<MRL
PFHxS363%4.2
2023-02-15
0.12–3.03<MRL<MRL<MRL<MRL
PFOA363%30
2023-02-28
0.83–4.72<MRL<MRL<MRL<MRL
PFOS363%5.2
2023-02-15
0.14–4.03<MRL<MRL<MRL<MRL

Never detected (24): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFBS, PFDA, PFDoA, PFEESA, PFHpA, PFHpS, PFMBA, PFMPA, PFNA, PFPeS, PFTA, PFTrDA, PFUnA, lithium.

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 2026-06-17; 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 90f0922cd84f · 2026-10-18T04:12Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.