Montecito Water Dist

PFAS monitoring results for a public water system in California

CA4210007UCMR 5EPA monitoring data
<MRLHighest PFOA result, ppt
<MRLHighest PFOS result, ppt
0Highest Hazard Index
540Results
PWSID
CA4210007
State
California
System type
community water system (CWS)
Population served
12,010
City
Santa Barbara
Counties
Santa Barbara County
Primary source water
surface water
UCMR 5 sampling
2024-02-07 to 2025-06-17 · 7 entry point(s) · water types: GW;SW
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.

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).

Compared with California guidance levels

Highest single resultWorst entry-point average*California
PFHxS (ppt)003 (guidance)
PFOA (ppt)004 (guidance)
PFOS (ppt)004 (guidance)
PFBS (ppt)00500 (guidance)
PFHxA (ppt)001,000 (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 2024-02-07 to 2025-06-17 · 7 entry point(s) · water types: GW;SW · 22 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2024-02-07Amapola Well (GW)SE1<4<40lithium 29 µg/L
2024-02-07Bella Vista TP (SW)SE1<4<40lithium 29 µg/L
2024-02-07Doulton Tunnel TP (SW)SE1<4<40lithium 30 µg/L
2024-02-07Ennisbrook Well 2 (GW)SE1<4<40lithium 20 µg/L
2024-02-07Paden/Las Entradas (GW)SE1<4<40lithium 31 µg/L
2024-02-07T Mosby Well (GW)SE1n/an/an/alithium 42 µg/L
2024-04-16T Mosby Well (GW)SE1<4<40none
2024-05-08Bella Vista TP (SW)SE2<4<40lithium 38 µg/L
2024-05-08Doulton Tunnel TP (SW)SE2<4<40lithium 37 µg/L
2024-08-05Amapola Well (GW)SE2<4<40lithium 27 µg/L
2024-08-05Bella Vista TP (SW)SE3<4<40lithium 33 µg/L
2024-08-05Doulton Tunnel TP (SW)SE3<4<40lithium 35 µg/L
2024-08-05Ennisbrook Well 2 (GW)SE2<4<40lithium 29 µg/L
2024-08-05Paden/Las Entradas (GW)SE2<4<40lithium 29 µg/L
2024-08-05T Mosby Well (GW)SE2<4<40lithium 40 µg/L
2024-11-06Bella Vista TP (SW)SE4n/an/an/alithium 29 µg/L
2024-11-06Doulton Tunnel TP (SW)SE4n/an/an/alithium 30 µg/L
2024-11-06Ennisbrook Well 5 (GW)SE1<4<40lithium 54 µg/L
2025-01-20Bella Vista TP (SW)SE4<4<40none
2025-01-20Doulton Tunnel TP (SW)SE4<4<40none
2025-03-04Ennisbrook Well 5 (GW)SE2n/an/an/alithium 56 µg/L
2025-06-17Ennisbrook Well 5 (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

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.

Amapola Well facility 91805 · sample point 4210007805 · groundwater

CompoundMRL2024-02-07
SE1
2024-08-05
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/L2927

Bella Vista TP facility 91802 · sample point 4210007802 · surface water

CompoundMRL2024-02-07
SE1
2024-05-08
SE2
2024-08-05
SE3
2024-11-06
SE4
2025-01-20
SE4
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–
PFBA5 ppt< 5< 5< 5–< 5
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/L29383329–

Doulton Tunnel TP facility 91801 · sample point 4210007801 · surface water

CompoundMRL2024-02-07
SE1
2024-05-08
SE2
2024-08-05
SE3
2024-11-06
SE4
2025-01-20
SE4
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–
PFBA5 ppt< 5< 5< 5–< 5
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/L30373530–

Ennisbrook Well 2 facility 91803 · sample point 4210007803 · groundwater

CompoundMRL2024-02-07
SE1
2024-08-05
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/L2029

Ennisbrook Well 5 facility 91807 · sample point 4210007807 · groundwater

CompoundMRL2024-11-06
SE1
2025-03-04
SE2
2025-06-17
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/L5456–

Paden/Las Entradas facility 91804 · sample point 4210007804 · groundwater

CompoundMRL2024-02-07
SE1
2024-08-05
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/L3129

T Mosby Well facility 91806 · sample point 4210007806 · groundwater

CompoundMRL2024-02-07
SE1
2024-04-16
SE1
2024-08-05
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/L42–40

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
lithium18100%56
2025-03-04
34.33–34.3330385456

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 2026-06-17; 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.