Caldwell County Water District

PFAS monitoring results for a public water system in Kentucky

KY0170528UCMR 5EPA monitoring data
<MRLHighest PFOA result, ppt
<MRLHighest PFOS result, ppt
0Highest Hazard Index
360Results
PWSID
KY0170528
State
Kentucky
System type
community water system (CWS)
Population served
6,000
City
Princeton
Counties
Caldwell County
Primary source water
surface water (purchased)
UCMR 5 sampling
2023-01-11 to 2023-12-19 · 3 entry point(s) · water types: SW
Service-area boundary
authoritative

Other PFAS detected highest single result
Other 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.

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)<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 Kentucky 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 2023-01-11 to 2023-12-19 · 3 entry point(s) · water types: SW · 21 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2023-01-11Connection to Crittenden (SW)SE1n/an/an/anone
2023-01-11Connection to Princeton (SW)SE1n/an/an/anone
2023-01-11Connection to South Hopkins (SW)SE1n/an/an/anone
2023-03-13Connection to Crittenden (SW)SE1<4<40PFBA 15.4
2023-03-13Connection to Princeton (SW)SE1<4<40none
2023-03-13Connection to South Hopkins (SW)SE1<4<40PFBA 16.3
2023-04-19Connection to Crittenden (SW)SE2<4<40PFBA 5.5
2023-04-19Connection to Princeton (SW)SE2<4<40PFBA 5.5
2023-04-19Connection to South Hopkins (SW)SE2<4<40PFBA 12
2023-06-21Connection to South Hopkins (SW)SE1n/an/an/anone
2023-08-01Connection to Crittenden (SW)SE3n/an/an/anone
2023-08-01Connection to Princeton (SW)SE3<4<40none
2023-08-01Connection to South Hopkins (SW)SE3<4<40none
2023-09-20Connection to South Hopkins (SW)SE3n/an/an/anone
2023-10-17Connection to Princeton (SW)SE4<4<40none
2023-10-17Connection to South Hopkins (SW)SE4<4<40none
2023-10-25Connection to Crittenden (SW)SE3<4<40PFBA 30.6
2023-10-25Connection to Crittenden (SW)SE4n/an/an/anone
2023-11-21Connection to Crittenden (SW)SE4<4<40PFPeA 3.8
2023-12-05Connection to Crittenden (SW)SE4n/an/an/anone
2023-12-19Connection to Crittenden (SW)SE1n/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

360 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.

Connection to Crittenden facility 10003 · sample point EP3 · surface water

CompoundMRL2023-01-11
SE1
2023-03-13
SE1
2023-04-19
SE2
2023-08-01
SE3
2023-10-25
SE3
2023-10-25
SE4
2023-11-21
SE4
2023-12-05
SE4
2023-12-19
SE1
PFBA5 ppt–15.45.5–30.6–< 5––
PFPeA3 ppt–< 3< 3–< 3–3.8––
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––
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–––

Connection to Princeton facility 10001 · sample point EP1 · surface water

CompoundMRL2023-01-11
SE1
2023-03-13
SE1
2023-04-19
SE2
2023-08-01
SE3
2023-10-17
SE4
PFBA5 ppt–< 55.5< 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

Connection to South Hopkins facility 10002 · sample point EP2 · surface water

CompoundMRL2023-01-11
SE1
2023-03-13
SE1
2023-04-19
SE2
2023-06-21
SE1
2023-08-01
SE3
2023-09-20
SE3
2023-10-17
SE4
PFBA5 ppt–16.312–< 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

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
PFBA1250%30.6
2023-10-25
7.11–9.61<MRL1216.330.6
PFPeA128%3.8
2023-11-21
0.32–3.07<MRL<MRL<MRL3.8

Never detected (28): 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, PFHxA, PFHxS, PFMBA, PFMPA, PFNA, PFOA, PFOS, 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 2026-06-02; 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 fd8ef771e81e · 2026-10-18T04:08Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.