- PWSID
- CA3010027
- State
- California
- System type
- community water system (CWS)
- Population served
- 120,770
- City
- Orange
- Counties
- Orange County
- Primary source water
- surface water (purchased)
- UCMR 5 sampling
- 2023-03-14 to 2026-04-27 · 11 entry point(s) · water types: GW;SW
- Service-area boundary
- authoritative
PFOS ≥ 3 × its limit highest single result
PFOS ≥ 3 × its limit worst entry-point average
Open on the California map · All California systems · All results
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
- East Orange County Wd - Wz (CA3010093)
Seller not monitored under UCMR 5. - Metropolitan Water Dist. Of So. Cal. (CA1910087)
Seller not monitored under UCMR 5. - Serrano Water District (CA3010082)
Seller's highest results: PFOA <MRL · PFOS <MRL · HI 0 · detected: PFBA;PFPeA - City Of Anaheim (CA3010001)
Seller's highest results: PFOA 10.1 ppt · PFOS 29 ppt · HI 1.09 · detected: PFBA;PFBS;PFHxA;PFHxS;PFOA;PFOS;PFPeA - Golden State Wc - Cowan Heights (CA3010047)
Seller's highest results: PFOA <MRL · PFOS <MRL · HI 0 · detected: PFBA;PFPeA - Irvine Ranch Water District (CA3010092)
Seller's highest results: PFOA <MRL · PFOS <MRL · HI 0 · detected: PFBA;PFPeA
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 result | Worst entry-point average* | Limit | |
|---|---|---|---|
| PFOA (ppt) | 9.3 | 9.05 | 4 |
| PFOS (ppt) | 17 | 16.85 | 4 |
| Hazard Index | 1.022 | 1.017 | 1.0† |
“<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 result | Worst entry-point average* | California | |
|---|---|---|---|
| PFHxS (ppt) | 10.2 | 10.15 | 3 (guidance) |
| PFOA (ppt) | 9.3 | 9.05 | 4 (guidance) |
| PFOS (ppt) | 17 | 16.85 | 4 (guidance) |
| PFBS (ppt) | 3.3 | 3.15 | 500 (guidance) |
| PFHxA (ppt) | 10.1 | 8.95 | 1,000 (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 2023-03-14 to 2026-04-27 · 11 entry point(s) · water types: GW;SW · 34 sampling visits. PFAS in ppt (ng/L).
| Date | Entry point | Event | PFOA | PFOS | HI | Other detections |
|---|---|---|---|---|---|---|
| 2023-03-14 | MWD AMP (SW) | SE1 | n/a | n/a | n/a | none |
| 2023-03-14 | MWD Intertie 1 (SW) | SE1 | n/a | n/a | n/a | none |
| 2023-03-15 | SWD SWTP (SW) | SE1 | n/a | n/a | n/a | lithium 16.75 µg/L |
| 2023-03-29 | MWD AMP (SW) | SE1 | <4 | <4 | 0 | none |
| 2023-03-29 | MWD Intertie 1 (SW) | SE1 | <4 | <4 | 0 | none |
| 2023-03-29 | SWD SWTP (SW) | SE1 | <4 | <4 | 0 | PFBA 7.5, PFPeA 9.3 |
| 2023-06-20 | SWD SWTP (SW) | SE2 | <4 | <4 | 0 | PFBA 8.9, PFPeA 11.4, lithium 17.34 µg/L |
| 2023-06-21 | MWD AMP (SW) | SE2 | <4 | <4 | 0 | lithium 19.06 µg/L |
| 2023-06-21 | MWD Intertie 1 (SW) | SE2 | <4 | <4 | 0 | lithium 19.47 µg/L |
| 2023-09-12 | SWD SWTP (SW) | SE3 | <4 | <4 | 0 | PFBA 12.6, PFPeA 17, lithium 16.58 µg/L |
| 2023-09-13 | MWD AMP (SW) | SE3 | <4 | <4 | 0 | lithium 35.28 µg/L |
| 2023-09-13 | MWD Intertie 1 (SW) | SE3 | <4 | <4 | 0 | lithium 34.79 µg/L |
| 2023-12-05 | SWD SWTP (SW) | SE4 | <4 | <4 | 0 | lithium 21.27 µg/L |
| 2023-12-06 | MWD AMP (SW) | SE4 | <4 | <4 | 0 | lithium 30.03 µg/L |
| 2023-12-06 | MWD Intertie 1 (SW) | SE4 | <4 | <4 | 0 | lithium 30.52 µg/L |
| 2024-09-10 | Well 19 PFAS Treatment (GW) | SE1 | <4 | <4 | 0 | PFBA 7.6, PFHxA 4.3, PFPeA 12.6 |
| 2024-09-10 | Well 23 PFAS Treatment (GW) | SE1 | <4 | <4 | 0 | PFBA 8.7, PFHxA 7.8, PFPeA 13.9, lithium 10.56 µg/L |
| 2024-09-10 | Well 24 PFAS Treatment (GW) | SE1 | <4 | <4 | 0 | PFBA 8.2, PFHxA 4.9, PFPeA 13.5, lithium 9.64 µg/L |
| 2024-09-10 | Well 25 (GW) | SE1 | 8.4 | 11.6 | 0.612 | PFHxA 4.1, PFPeA 4.6 |
| 2024-09-10 | Well 26 (GW) | SE1 | 9.3 | 17 | 1.012 | PFHxA 4, PFPeA 3 |
| 2024-09-10 | Well 27 (GW) | SE1 | <4 | 4 | 0 | none |
| 2024-09-10 | Well 9 PFAS Treatment (GW) | SE1 | <4 | <4 | 0 | PFBA 10.1, PFHxA 5.1, PFPeA 17.7 |
| 2025-03-10 | Well 19 PFAS Treatment (GW) | SE2 | <4 | <4 | 0 | PFBA 7.3, PFHxA 8.5, PFPeA 12.7 |
| 2025-03-10 | Well 23 PFAS Treatment (GW) | SE2 | <4 | <4 | 0 | PFBA 8.7, PFHxA 10.1, PFPeA 13.3, lithium 11.15 µg/L |
| 2025-03-10 | Well 24 PFAS Treatment (GW) | SE2 | <4 | <4 | 0 | PFBA 7.4, PFHxA 8.2, PFPeA 13.8, lithium 10.4 µg/L |
| 2025-03-10 | Well 25 (GW) | SE2 | 6.7 | 9.7 | 0.51 | PFHxA 3.4, PFPeA 4 |
| 2025-03-10 | Well 26 (GW) | SE2 | 8.8 | 16.7 | 1.022 | PFHxA 3.6, PFPeA 3.4 |
| 2025-03-10 | Well 9 PFAS Treatment (GW) | SE2 | <4 | <4 | 0 | PFBA 9.6, PFHxA 8.3, PFPeA 17.5 |
| 2025-05-13 | Well 27 (GW) | SE2 | <4 | <4 | 0 | none |
| 2025-07-28 | MWD Intertie 3 (SW) | SE1 | <4 | <4 | 0 | none |
| 2025-10-20 | MWD Intertie 3 (SW) | SE2 | n/a | n/a | n/a | lithium 27.87 µg/L |
| 2025-11-12 | MWD Intertie 3 (SW) | SE2 | <4 | <4 | 0 | none |
| 2026-01-27 | MWD Intertie 3 (SW) | SE3 | <4 | <4 | 0 | lithium 36.33 µg/L |
| 2026-04-27 | MWD Intertie 3 (SW) | SE4 | <4 | <4 | 0 | none |
“<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
895 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.
MWD AMP facility 91851 · sample point 3010027851 · surface water
| Compound | MRL | 2023-03-14 SE1 | 2023-03-29 SE1 | 2023-06-21 SE2 | 2023-09-13 SE3 | 2023-12-06 SE4 |
|---|---|---|---|---|---|---|
| 11Cl-PF3OUdS | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| 4:2 FTS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| 6:2 FTS | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| 8:2 FTS | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | – | < 2 | < 2 | < 2 | < 2 |
| ADONA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| HFPO-DA | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | – | < 5 | < 5 | < 5 |
| NFDHA | 20 ppt | – | < 20 | < 20 | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | – | < 6 | < 6 | < 6 |
| PFBA | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| PFBS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFDA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFDoA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFEESA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHpA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHpS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHxA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHxS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFMBA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFMPA | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFNA | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFOA | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFOS | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFPeA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFPeS | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | – | < 8 | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | – | < 7 | < 7 | < 7 |
| PFUnA | 2 ppt | – | < 2 | < 2 | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | – | 19.059 | 35.2774 | 30.0348 |
MWD Intertie 1 facility 91826 · sample point 3010027826 · surface water
| Compound | MRL | 2023-03-14 SE1 | 2023-03-29 SE1 | 2023-06-21 SE2 | 2023-09-13 SE3 | 2023-12-06 SE4 |
|---|---|---|---|---|---|---|
| 11Cl-PF3OUdS | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| 4:2 FTS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| 6:2 FTS | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| 8:2 FTS | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | – | < 2 | < 2 | < 2 | < 2 |
| ADONA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| HFPO-DA | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | – | < 5 | < 5 | < 5 |
| NFDHA | 20 ppt | – | < 20 | < 20 | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | – | < 6 | < 6 | < 6 |
| PFBA | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| PFBS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFDA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFDoA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFEESA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHpA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHpS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHxA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHxS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFMBA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFMPA | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFNA | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFOA | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFOS | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFPeA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFPeS | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | – | < 8 | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | – | < 7 | < 7 | < 7 |
| PFUnA | 2 ppt | – | < 2 | < 2 | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | – | 19.4726 | 34.7923 | 30.517 |
MWD Intertie 3 facility 91827 · sample point 3010027827 · surface water
| Compound | MRL | 2025-07-28 SE1 | 2025-10-20 SE2 | 2025-11-12 SE2 | 2026-01-27 SE3 | 2026-04-27 SE4 |
|---|---|---|---|---|---|---|
| 11Cl-PF3OUdS | 5 ppt | < 5 | – | < 5 | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | – | < 5 | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | – | < 5 | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | – | < 2 | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | – | < 5 | < 5 | < 5 |
| NEtFOSAA | 5 ppt | – | < 5 | – | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | – | < 20 | < 20 | < 20 |
| NMeFOSAA | 6 ppt | – | < 6 | – | < 6 | < 6 |
| PFBA | 5 ppt | < 5 | – | < 5 | < 5 | < 5 |
| PFBS | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFHxA | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | – | < 4 | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | – | < 4 | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | – | < 4 | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | – | < 4 | < 4 | < 4 |
| PFPeA | 3 ppt | < 3 | – | < 3 | < 3 | < 3 |
| PFPeS | 4 ppt | < 4 | – | < 4 | < 4 | < 4 |
| PFTA | 8 ppt | – | < 8 | – | < 8 | < 8 |
| PFTrDA | 7 ppt | – | < 7 | – | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | – | < 2 | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | 27.8737 | – | 36.33 | – |
SWD SWTP facility 91824 · sample point 3010027824 · surface water
| Compound | MRL | 2023-03-15 SE1 | 2023-03-29 SE1 | 2023-06-20 SE2 | 2023-09-12 SE3 | 2023-12-05 SE4 |
|---|---|---|---|---|---|---|
| PFBA | 5 ppt | – | 7.5 | 8.9 | 12.6 | < 5 |
| PFPeA | 3 ppt | – | 9.3 | 11.4 | 17 | < 3 |
| 11Cl-PF3OUdS | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| 4:2 FTS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| 6:2 FTS | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| 8:2 FTS | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | – | < 2 | < 2 | < 2 | < 2 |
| ADONA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| HFPO-DA | 5 ppt | – | < 5 | < 5 | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | – | < 5 | < 5 | < 5 |
| NFDHA | 20 ppt | – | < 20 | < 20 | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | – | < 6 | < 6 | < 6 |
| PFBS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFDA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFDoA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFEESA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHpA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHpS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHxA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFHxS | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFMBA | 3 ppt | – | < 3 | < 3 | < 3 | < 3 |
| PFMPA | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFNA | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFOA | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFOS | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFPeS | 4 ppt | – | < 4 | < 4 | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | – | < 8 | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | – | < 7 | < 7 | < 7 |
| PFUnA | 2 ppt | – | < 2 | < 2 | < 2 | < 2 |
| lithium | 9 µg/L | 16.7525 | – | 17.3392 | 16.5799 | 21.2679 |
Well 19 PFAS Treatment facility 91853 · sample point 3010027853 · groundwater
| Compound | MRL | 2024-09-10 SE1 | 2025-03-10 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | 7.6 | 7.3 |
| PFHxA | 3 ppt | 4.3 | 8.5 |
| PFPeA | 3 ppt | 12.6 | 12.7 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBS | 3 ppt | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 |
Well 23 PFAS Treatment facility 91854 · sample point 3010027854 · groundwater
| Compound | MRL | 2024-09-10 SE1 | 2025-03-10 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | 8.7 | 8.7 |
| PFHxA | 3 ppt | 7.8 | 10.1 |
| PFPeA | 3 ppt | 13.9 | 13.3 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBS | 3 ppt | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | 10.559 | 11.1463 |
Well 24 PFAS Treatment facility 91855 · sample point 3010027855 · groundwater
| Compound | MRL | 2024-09-10 SE1 | 2025-03-10 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | 8.2 | 7.4 |
| PFHxA | 3 ppt | 4.9 | 8.2 |
| PFPeA | 3 ppt | 13.5 | 13.8 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBS | 3 ppt | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | 9.6364 | 10.405 |
Well 25 facility 91817 · sample point 3010027817 · groundwater
| Compound | MRL | 2024-09-10 SE1 | 2025-03-10 SE2 |
|---|---|---|---|
| PFBS | 3 ppt | 3.2 | < 3 |
| PFHxA | 3 ppt | 4.1 | 3.4 |
| PFHxS | 3 ppt | 6.1 | 5.1 |
| PFOA | 4 ppt | 8.4 | 6.7 |
| PFOS | 4 ppt | 11.6 | 9.7 |
| PFPeA | 3 ppt | 4.6 | 4 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBA | 5 ppt | < 5 | < 5 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 |
Well 26 facility 91825 · sample point 3010027825 · groundwater
| Compound | MRL | 2024-09-10 SE1 | 2025-03-10 SE2 |
|---|---|---|---|
| PFBS | 3 ppt | 3.3 | 3 |
| PFHxA | 3 ppt | 4 | 3.6 |
| PFHxS | 3 ppt | 10.1 | 10.2 |
| PFOA | 4 ppt | 9.3 | 8.8 |
| PFOS | 4 ppt | 17 | 16.7 |
| PFPeA | 3 ppt | 3 | 3.4 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBA | 5 ppt | < 5 | < 5 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 |
Well 27 facility 91829 · sample point 3010027829 · groundwater
| Compound | MRL | 2024-09-10 SE1 | 2025-05-13 SE2 |
|---|---|---|---|
| PFOS | 4 ppt | 4 | < 4 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBA | 5 ppt | < 5 | < 5 |
| PFBS | 3 ppt | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFHxA | 3 ppt | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | < 4 |
| PFPeA | 3 ppt | < 3 | < 3 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 |
Well 9 PFAS Treatment facility 91852 · sample point 3010027852 · groundwater
| Compound | MRL | 2024-09-10 SE1 | 2025-03-10 SE2 |
|---|---|---|---|
| PFBA | 5 ppt | 10.1 | 9.6 |
| PFHxA | 3 ppt | 5.1 | 8.3 |
| PFPeA | 3 ppt | 17.7 | 17.5 |
| 11Cl-PF3OUdS | 5 ppt | < 5 | < 5 |
| 4:2 FTS | 3 ppt | < 3 | < 3 |
| 6:2 FTS | 5 ppt | < 5 | < 5 |
| 8:2 FTS | 5 ppt | < 5 | < 5 |
| 9Cl-PF3ONS | 2 ppt | < 2 | < 2 |
| ADONA | 3 ppt | < 3 | < 3 |
| HFPO-DA | 5 ppt | < 5 | < 5 |
| NEtFOSAA | 5 ppt | < 5 | < 5 |
| NFDHA | 20 ppt | < 20 | < 20 |
| NMeFOSAA | 6 ppt | < 6 | < 6 |
| PFBS | 3 ppt | < 3 | < 3 |
| PFDA | 3 ppt | < 3 | < 3 |
| PFDoA | 3 ppt | < 3 | < 3 |
| PFEESA | 3 ppt | < 3 | < 3 |
| PFHpA | 3 ppt | < 3 | < 3 |
| PFHpS | 3 ppt | < 3 | < 3 |
| PFHxS | 3 ppt | < 3 | < 3 |
| PFMBA | 3 ppt | < 3 | < 3 |
| PFMPA | 4 ppt | < 4 | < 4 |
| PFNA | 4 ppt | < 4 | < 4 |
| PFOA | 4 ppt | < 4 | < 4 |
| PFOS | 4 ppt | < 4 | < 4 |
| PFPeS | 4 ppt | < 4 | < 4 |
| PFTA | 8 ppt | < 8 | < 8 |
| PFTrDA | 7 ppt | < 7 | < 7 |
| PFUnA | 2 ppt | < 2 | < 2 |
| lithium | 9 µg/L | < 9 | < 9 |
Statistics by compound
| Compound | Results | Detected | Highest (date) | Mean bounds | KM median | P75 | P90 | P95 |
|---|---|---|---|---|---|---|---|---|
| lithium | 29 | 55% | 36.33 2026-01-27 | 11.97–16 | 10.4 | 19.47 | 34.79 | 35.28 |
| PFPeA | 30 | 50% | 17.7 2024-09-10 | 5.59–7.09 | <MRL | 12.7 | 13.9 | 17.5 |
| PFHxA | 30 | 40% | 10.1 2025-03-10 | 2.41–4.21 | <MRL | 4.3 | 8.2 | 8.5 |
| PFBA | 30 | 37% | 12.6 2023-09-12 | 3.22–6.39 | <MRL | 7.6 | 8.9 | 10.1 |
| PFOS | 30 | 17% | 17 2024-09-10 | 1.97–5.3 | <MRL | <MRL | 9.7 | 16.7 |
| PFHxS | 30 | 13% | 10.2 2025-03-10 | 1.05–3.65 | <MRL | <MRL | 5.1 | 10.1 |
| PFOA | 30 | 13% | 9.3 2024-09-10 | 1.11–4.57 | <MRL | <MRL | 6.7 | 8.8 |
| PFBS | 30 | 10% | 3.3 2024-09-10 | 0.32–3.02 | <MRL | <MRL | <MRL | 3.2 |
Never detected (22): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFDA, PFDoA, PFEESA, PFHpA, PFHpS, PFMBA, PFMPA, PFNA, 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.