Golden Hills Csd

PFAS monitoring results for a public water system in California

CA1510045UCMR 5EPA monitoring data
18.6Highest PFOA result, ppt
7.8Highest PFOS result, ppt
0.553Highest Hazard Index
480Results
PWSID
CA1510045
State
California
System type
community water system (CWS)
Population served
9,857
City
Tehachapi
Counties
Kern County
Primary source water
groundwater
UCMR 5 sampling
2024-06-04 to 2024-12-03 · 8 entry point(s) · water types: GW
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)18.614.454
PFOS (ppt)7.86.754
Hazard Index0.5530.4321.0†

“<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)5.54.33 (guidance)
PFOA (ppt)18.614.454 (guidance)
PFOS (ppt)7.86.754 (guidance)
PFBS (ppt)5.54.4500 (guidance)
PFHxA (ppt)7.35.851,000 (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 2024-06-04 to 2024-12-03 · 8 entry point(s) · water types: GW · 20 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2024-06-04Fisher Well (GW)SE1<4<40none
2024-06-04Iriart Well (GW)SE1<4<40none
2024-06-04Morris Park Well (GW)SE1<4<40none
2024-06-04Red Apple Well (GW)SE18.2<40.362PFHxA 6.8, PFPeA 7.2
2024-06-04Steuber Well (GW)SE1<4<40none
2024-06-04V Well (GW)SE1<4<40none
2024-06-04Well A (GW)SE1<4<40none
2024-06-04Well D (GW)SE1n/an/an/anone
2024-08-13Well D (GW)SE110.35.70.312PFHxA 4.3, PFPeA 5.3
2024-08-20Fisher Well (GW)SE1n/an/an/anone
2024-08-20Iriart Well (GW)SE1n/an/an/anone
2024-08-20Red Apple Well (GW)SE1n/an/an/anone
2024-12-03Fisher Well (GW)SE27.1<40none
2024-12-03Iriart Well (GW)SE2<4<40none
2024-12-03Morris Park Well (GW)SE2<4<40none
2024-12-03Red Apple Well (GW)SE25.4<40PFHxA 4.9, PFPeA 5.4
2024-12-03Steuber Well (GW)SE2<4<40none
2024-12-03V Well (GW)SE2<4<40none
2024-12-03Well A (GW)SE2<4<40none
2024-12-03Well D (GW)SE218.67.80.553PFHpA 3.7, PFHxA 7.3, PFPeA 9.3

“<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

480 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.

Fisher Well facility 10007 · sample point CA1510045020020 · groundwater

CompoundMRL2024-06-04
SE1
2024-08-20
SE1
2024-12-03
SE2
PFOA4 ppt< 4–7.1
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

Iriart Well facility 10003 · sample point CA1510045019019 · groundwater

CompoundMRL2024-06-04
SE1
2024-08-20
SE1
2024-12-03
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

Morris Park Well facility 10002 · sample point CA1510045039039 · groundwater

CompoundMRL2024-06-04
SE1
2024-12-03
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

Red Apple Well facility 10004 · sample point CA1510045006006 · groundwater

CompoundMRL2024-06-04
SE1
2024-08-20
SE1
2024-12-03
SE2
PFBS3 ppt3.9–< 3
PFHxA3 ppt6.8–4.9
PFHxS3 ppt3.6–< 3
PFOA4 ppt8.2–5.4
PFPeA3 ppt7.2–5.4
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
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
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

Steuber Well facility 10001 · sample point CA1510045045045 · groundwater

CompoundMRL2024-06-04
SE1
2024-12-03
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

V Well facility 10008 · sample point CA1510045021021 · groundwater

CompoundMRL2024-06-04
SE1
2024-12-03
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 A facility 10005 · sample point CA1510045010010 · groundwater

CompoundMRL2024-06-04
SE1
2024-12-03
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 D facility 10006 · sample point CA1510045012012 · groundwater

CompoundMRL2024-06-04
SE1
2024-08-13
SE1
2024-12-03
SE2
PFBS3 ppt–3.35.5
PFHpA3 ppt–< 33.7
PFHxA3 ppt–4.37.3
PFHxS3 ppt–3.15.5
PFOA4 ppt–10.318.6
PFOS4 ppt–5.77.8
PFPeA3 ppt–5.39.3
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
PFDA3 ppt–< 3< 3
PFDoA3 ppt–< 3< 3
PFEESA3 ppt–< 3< 3
PFHpS3 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/L< 9–< 9

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
PFOA1631%18.6
2024-12-03
3.1–5.85<MRL5.410.318.6
PFHxA1625%7.3
2024-12-03
1.46–3.71<MRL<MRL6.87.3
PFPeA1625%9.3
2024-12-03
1.7–3.95<MRL<MRL7.29.3
PFBS1619%5.5
2024-12-03
0.79–3.23<MRL<MRL3.95.5
PFHxS1619%5.5
2024-12-03
0.76–3.2<MRL<MRL3.65.5
PFOS1612%7.8
2024-12-03
0.84–4.34<MRL<MRL5.77.8
PFHpA166%3.7
2024-12-03
0.23–3.04<MRL<MRL<MRL3.7

Never detected (23): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFBA, PFDA, PFDoA, PFEESA, 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.