Cwsc Oak Hills
Published drinking-water records and contacts for Cwsc Oak Hills. System CA2710019. Review sources and dates; not a real-time water assessment.
- System ID
- CA2710019
- State or territory
- CA
- Published population served
- 3161
- System type (source code)
- CWS
Published records and dates
- PFAS / lithium (EPA UCMR 5): 120 — 2023-05-22 – 2024-01-22
- Lead and copper monitoring summaries: 27 — 1993-01-01 – 2025-12-31
- California DDW laboratory results: 193 — 2026-01-06 – 2026-06-29
Missing records here do not mean the provider did not test. Published records are not a real-time assessment of your tap water.
Published testing results
Selected recent records are shown below. Different sampling locations and dates are not interchangeable. These excerpts are not a complete testing history.
“<” means below the stated reporting limit, not zero. A reported measurement alone is not a safety verdict. Read an example
| Substance | Published result | Reporting limit | Sample date | Sampling location |
|---|---|---|---|---|
| 11Cl-PF3OUdS | < 0.005 µg/L | 0.005 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| 4:2 FTS | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| 6:2 FTS | < 0.005 µg/L | 0.005 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| 8:2 FTS | < 0.005 µg/L | 0.005 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| 9Cl-PF3ONS | < 0.002 µg/L | 0.002 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| ADONA | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| HFPO-DA | < 0.005 µg/L | 0.005 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| NEtFOSAA | < 0.005 µg/L | 0.005 µg/L | 2023-12-18 | Well 205-01 Chlorinated Water / SS002 |
| NFDHA | < 0.02 µg/L | 0.02 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| NMeFOSAA | < 0.006 µg/L | 0.006 µg/L | 2023-12-18 | OH 203-01 Chlorinated Effluent / SS001 |
| PFBA | < 0.005 µg/L | 0.005 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFBS | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFDA | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFDoA | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFEESA | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFHpA | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFHpS | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFHxA | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFHxS | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFMBA | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFMPA | < 0.004 µg/L | 0.004 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFNA | < 0.004 µg/L | 0.004 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFOA | < 0.004 µg/L | 0.004 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFOS | < 0.004 µg/L | 0.004 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFPeA | < 0.003 µg/L | 0.003 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFPeS | < 0.004 µg/L | 0.004 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| PFTA | < 0.008 µg/L | 0.008 µg/L | 2023-12-18 | Well 205-01 Chlorinated Water / SS002 |
| PFTrDA | < 0.007 µg/L | 0.007 µg/L | 2023-12-18 | OH 203-01 Chlorinated Effluent / SS001 |
| PFUnA | < 0.002 µg/L | 0.002 µg/L | 2024-01-22 | OH 203-01 Chlorinated Effluent / SS001 |
| lithium | 25.2 µg/L | 9 µg/L | 2023-12-18 | Well 205-01 Chlorinated Water / SS002 |
Download all EPA UCMR 5 records (CSV)
Lead and copper: 90th-percentile summaries
These describe a monitoring period across sampled locations, not the result at your home. How to read the 90th percentile
| Substance | Published 90th percentile | Monitoring period | Source quarter |
|---|---|---|---|
| Lead (PB90) | 0 mg/L | 2023-01-01 – 2025-12-31 | 2026Q3 |
| Lead (PB90) | 0.0015 mg/L | 2020-01-01 – 2022-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2017-01-01 – 2019-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2014-01-01 – 2016-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2011-01-01 – 2013-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2008-01-01 – 2010-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2007-01-01 – 2009-12-31 | 2026Q3 |
| Lead (PB90) | 0.005 mg/L | 2004-01-01 – 2004-12-31 | 2026Q3 |
| Substance | Published result | Sample date | Location / source |
|---|---|---|---|
| CHROMIUM, HEX | 7.6 UG/L | 2026-06-29 | STATION 205-01 IX WTP / California DDW laboratory results |
| CHROMIUM, HEX | 8.9 UG/L | 2026-06-23 | STATION 205-01 IX WTP / California DDW laboratory results |
| TTHM | < 4.000000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
| M-DICHLOROBENZENE | < 0.500000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
| TOLUENE | < 0.500000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
| DICHLOROMETHANE | < 0.500000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
| O-DICHLOROBENZENE | < 0.500000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
| STYRENE | < 0.500000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
| P-DICHLOROBENZENE | < 0.500000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
| 1,2-DICHLOROETHANE | < 0.500000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
| METHYL TERT-BUTYL ETHER | < 3.000000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
| 1,3-DICHLOROPROPENE | < 0.500000000 UG/L | 2026-06-16 | WELL 205-01 RAW / California DDW laboratory results |
State sampling points can include untreated water. Publisher qualifiers and units are retained; consult the full source notes before interpreting a record.
Download state records with source notes (CSV)
Published compliance history
0 imported records. Status is as recorded in the source; historical records are not current advisories. Missing records do not establish that no violations occurred.
Source dates and refresh checks
A refresh check is not a sample date. Publication periods, sample dates and checks are shown separately.
- EPA SDWIS lead/copper summaries and service areas — source period: — – —; last checked: 2026-10-17
- EPA SDWIS contacts and compliance records — source period: — – —; last checked: 2026-10-17
- EPA UCMR 5 sample results — source period: 2023-01-03 – 2026-06-17; last checked: 2026-10-17
- California DDW laboratory results — last successful check: 2026-10-17
Administrative contact (EPA filing)
James, Sophie: 408-367-8593
An administrative filing contact may not be a customer-service line. Confirm current contact details with the provider.