Cwsc Los Altos Suburban
Published drinking-water records and contacts for Cwsc Los Altos Suburban. System CA4310001. Review sources and dates; not a real-time water assessment.
- System ID
- CA4310001
- State or territory
- CA
- Published population served
- 69973
- System type (source code)
- CWS
Published records and dates
- PFAS / lithium (EPA UCMR 5): 1080 — 2023-06-06 – 2025-03-25
- Lead and copper monitoring summaries: 26 — 1992-01-01 – 2025-12-31
- California DDW laboratory results: 2235 — 2026-01-12 – 2026-07-09
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 | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| 4:2 FTS | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| 6:2 FTS | < 0.005 µg/L | 0.005 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| 8:2 FTS | < 0.005 µg/L | 0.005 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| 9Cl-PF3ONS | < 0.002 µg/L | 0.002 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| ADONA | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| HFPO-DA | < 0.005 µg/L | 0.005 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| NEtFOSAA | < 0.005 µg/L | 0.005 µg/L | 2025-02-05 | Well 25-01 (GWRMP) / 4310001817 |
| NFDHA | < 0.02 µg/L | 0.02 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| NMeFOSAA | < 0.006 µg/L | 0.006 µg/L | 2025-02-05 | Well 25-01 (GWRMP) / 4310001817 |
| PFBA | < 0.005 µg/L | 0.005 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFBS | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFDA | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFDoA | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFEESA | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFHpA | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFHpS | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFHxA | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFHxS | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFMBA | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFMPA | < 0.004 µg/L | 0.004 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFNA | < 0.004 µg/L | 0.004 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFOA | < 0.004 µg/L | 0.004 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFOS | < 0.004 µg/L | 0.004 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFPeA | < 0.003 µg/L | 0.003 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFPeS | < 0.004 µg/L | 0.004 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| PFTA | < 0.008 µg/L | 0.008 µg/L | 2025-02-05 | Well 25-01 (GWRMP) / 4310001817 |
| PFTrDA | < 0.007 µg/L | 0.007 µg/L | 2025-02-05 | Well 25-01 (GWRMP) / 4310001817 |
| PFUnA | < 0.002 µg/L | 0.002 µg/L | 2025-03-25 | Well 25-01 (GWRMP) / 4310001817 |
| lithium | < 9 µg/L | 9 µg/L | 2025-02-05 | Well 25-01 (GWRMP) / 4310001817 |
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) | 0.0015 mg/L | 2023-01-01 – 2025-12-31 | 2026Q3 |
| Lead (PB90) | 0.0025 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 | 2016-01-01 – 2018-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2013-01-01 – 2015-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2010-01-01 – 2010-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2005-01-01 – 2007-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2002-01-01 – 2004-12-31 | 2026Q3 |
| Substance | Published result | Sample date | Location / source |
|---|---|---|---|
| 2,3,7,8-TCDD | < 0.005000000 NG/L | 2026-07-09 | WELL 015-01 / California DDW laboratory results |
| 2,3,7,8-TCDD | < 0.005000000 NG/L | 2026-07-09 | WELL 006-02 / California DDW laboratory results |
| 1,2-DIBROMO-3-CHLOROPROPANE | < 0.010000000 UG/L | 2026-06-11 | WELL 119-03 / California DDW laboratory results |
| NITRATE-NITRITE | 6.6 MG/L | 2026-06-11 | WELL 121-02 / California DDW laboratory results |
| MANGANESE | < 10.000000000 UG/L | 2026-06-11 | WELL 121-02 / California DDW laboratory results |
| PERCHLORATE | 1.9 UG/L | 2026-06-11 | WELL 121-02 / California DDW laboratory results |
| FLUORIDE | 0.1 MG/L | 2026-06-11 | WELL 121-02 / California DDW laboratory results |
| IRON | < 30.000000000 UG/L | 2026-06-11 | WELL 121-02 / California DDW laboratory results |
| NITRATE | 6.6 MG/L | 2026-06-11 | WELL 121-02 / California DDW laboratory results |
| ETHYLENE DIBROMIDE | < 0.020000000 UG/L | 2026-06-11 | WELL 119-03 / California DDW laboratory results |
| TEMPERATURE (CENTIGRADE) | 20.4 C | 2026-06-11 | WELL 121-02 / California DDW laboratory results |
| ALUMINUM | < 50.000000000 UG/L | 2026-06-11 | WELL 121-02 / 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.