Great Basin Water Co Spring Creek

PFAS monitoring results for a public water system in Nevada

NV0000036UCMR 5EPA monitoring data
<MRLHighest PFOA result, ppt
<MRLHighest PFOS result, ppt
0Highest Hazard Index
540Results
PWSID
NV0000036
State
Nevada
System type
community water system (CWS)
Population served
9,340
City
Spring Creek
Counties
Elko County
Primary source water
groundwater
UCMR 5 sampling
2023-02-07 to 2023-10-18 · 9 entry point(s) · water types: GW
Service-area boundary
EPA-modeled (Random Forest) — approximate: estimated by EPA with a statistical model, not a surveyed service area

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 Nevada PFAS drinking-water standard in effect or proposed as of 2026-10-17: No Nevada-specific PFAS drinking-water standard; NDEP implementing federal NPDWR.

Sampling history

Sampled 2023-02-07 to 2023-10-18 · 9 entry point(s) · water types: GW · 20 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2023-02-07GREAT BASIN WATER CO SPRING CREEK (GW)SE1<4<40none
2023-02-07GREAT BASIN WATER CO SPRING CREEK (GW)SE1<4<40lithium 30.8 µg/L
2023-02-07GREAT BASIN WATER CO SPRING CREEK (GW)SE1<4<40lithium 30.3 µg/L
2023-02-07GREAT BASIN WATER CO SPRING CREEK (GW)SE1<4<40lithium 24.6 µg/L
2023-02-07GREAT BASIN WATER CO SPRING CREEK (GW)SE1<4<40none
2023-02-08GREAT BASIN WATER CO SPRING CREEK (GW)SE1<4<40lithium 30.1 µg/L
2023-02-08GREAT BASIN WATER CO SPRING CREEK (GW)SE1<4<40lithium 31.1 µg/L
2023-02-08GREAT BASIN WATER CO SPRING CREEK (GW)SE1<4<40none
2023-02-08GREAT BASIN WATER CO SPRING CREEK (GW)SE1<4<40lithium 31.1 µg/L
2023-08-14GREAT BASIN WATER CO SPRING CREEK (GW)SE2<4<40lithium 26.5 µg/L
2023-08-14GREAT BASIN WATER CO SPRING CREEK (GW)SE2<4<40none
2023-08-15GREAT BASIN WATER CO SPRING CREEK (GW)SE2<4<40lithium 33.5 µg/L
2023-08-15GREAT BASIN WATER CO SPRING CREEK (GW)SE2<4<40lithium 31.7 µg/L
2023-08-15GREAT BASIN WATER CO SPRING CREEK (GW)SE2<4<40lithium 34.8 µg/L
2023-08-15GREAT BASIN WATER CO SPRING CREEK (GW)SE2<4<40lithium 33 µg/L
2023-08-16GREAT BASIN WATER CO SPRING CREEK (GW)SE2<4<40none
2023-08-16GREAT BASIN WATER CO SPRING CREEK (GW)SE2<4<40lithium 31.2 µg/L
2023-08-16GREAT BASIN WATER CO SPRING CREEK (GW)SE2n/an/an/anone
2023-10-18GREAT BASIN WATER CO SPRING CREEK (GW)SE2<4<40none
2023-10-18GREAT BASIN WATER CO SPRING CREEK (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

540 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.

GREAT BASIN WATER CO SPRING CREEK facility W01 · sample point 01 · groundwater

CompoundMRL2023-02-07
SE1
2023-08-16
SE2
2023-10-18
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–

GREAT BASIN WATER CO SPRING CREEK facility W02 · sample point 02 · groundwater

CompoundMRL2023-02-07
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/L30.833.5

GREAT BASIN WATER CO SPRING CREEK facility W03 · sample point 03 · groundwater

CompoundMRL2023-02-08
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/L30.131.7

GREAT BASIN WATER CO SPRING CREEK facility W04 · sample point 04 · groundwater

CompoundMRL2023-02-07
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/L30.334.8

GREAT BASIN WATER CO SPRING CREEK facility W05 · sample point 05 · groundwater

CompoundMRL2023-02-08
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/L31.133

GREAT BASIN WATER CO SPRING CREEK facility W06 · sample point 06 · groundwater

CompoundMRL2023-02-08
SE1
2023-08-16
SE2
2023-10-18
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–

GREAT BASIN WATER CO SPRING CREEK facility W07 · sample point 07 · groundwater

CompoundMRL2023-02-08
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/L31.131.2

GREAT BASIN WATER CO SPRING CREEK facility W08 · sample point 08 · groundwater

CompoundMRL2023-02-07
SE1
2023-08-14
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/L24.626.5

GREAT BASIN WATER CO SPRING CREEK facility W09 · sample point 09 · groundwater

CompoundMRL2023-02-07
SE1
2023-08-14
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
lithium1867%34.8
2023-08-15
20.48–23.4830.131.233.534.8

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 2026-06-16; 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 4c0ec2d78e0b · 2026-10-18T04:05Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.