Sonoma County Water Agency
Published drinking-water records and contacts for Sonoma County Water Agency. System CA4910020. Review sources and dates; not a real-time water assessment.
- System ID
- CA4910020
- State or territory
- CA
- Published population served
- 0
- System type (source code)
- CWS
Published records and dates
- California DDW laboratory results: 1936 — 2026-01-06 – 2026-06-24
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 | Sample date | Location / source |
|---|---|---|---|
| CHLOROBENZENE | < 0.500000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| STYRENE | < 0.500000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| MONOCHLOROACETIC ACID | < 2.000000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| 1,1-DICHLOROPROPENE | < 0.500000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| BROMOMETHANE | < 0.500000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| ETHYLBENZENE | < 0.500000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| TRANS-1,3-DICHLOROPROPENE | < 0.500000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| DICHLOROACETIC ACID | 3.87 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| 1,2,4-TRIMETHYLBENZENE | < 0.500000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| CHLOROMETHANE | < 0.500000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| 1,2,3-TRICHLOROPROPANE | < 0.005000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / California DDW laboratory results |
| 4-METHYL-2-PENTANONE | < 5.000000000 UG/L | 2026-06-24 | COTATI TANK #2 12MG - DIST SYS - TREATED / 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: 2026-10-18
Administrative contact (EPA filing)
Davis, Grant: 707-547-1911
An administrative filing contact may not be a customer-service line. Confirm current contact details with the provider.