Sonoma Springs
Published drinking-water records and contacts for Sonoma Springs. System CA4900533. Review sources and dates; not a real-time water assessment.
- System ID
- CA4900533
- State or territory
- CA
- Published population served
- 59
- System type (source code)
- CWS
Published records and dates
- Lead and copper monitoring summaries: 17 — 2000-01-01 – 2025-12-31
- California DDW laboratory results: 102 — 2026-03-25 – 2026-06-22
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
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 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) | 0.0057 mg/L | 2010-01-01 – 2012-12-31 | 2026Q3 |
| Lead (PB90) | 0.0057 mg/L | 2008-01-01 – 2010-12-31 | 2026Q3 |
| Lead (PB90) | 0 mg/L | 2007-01-01 – 2007-12-31 | 2026Q3 |
| Substance | Published result | Sample date | Location / source |
|---|---|---|---|
| TOXAPHENE | < 0.240000000 UG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| 1,2-DIBROMO-3-CHLOROPROPANE | < 0.010000000 UG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| MAGNESIUM | 6.7 MG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| IRON | 120 UG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| PARA-PARA DDT | < 0.004800000 UG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| ALKALINITY, CARBONATE | < 1.000000000 MG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| ATRAZINE | < 0.500000000 UG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| BERYLLIUM, TOTAL | < 1.000000000 UG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| DI(2-ETHYLHEXYL) ADIPATE | < 5.000000000 UG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| BARIUM | < 100.000000000 UG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| NITRATE | < 0.400000000 MG/L | 2026-06-22 | WELL 01 / California DDW laboratory results |
| ENDRIN ALDEHYDE | < 0.004800000 UG/L | 2026-06-22 | WELL 01 / 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
8 imported records. Status is as recorded in the source; historical records are not current advisories. Missing records do not establish that no violations occurred.
| Rule / record | Period | Recorded status | Health-based (EPA classification) | Source quarter |
|---|---|---|---|---|
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2019-01-01 – 2021-12-31 | Archived | No | 2026Q3 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP) | 2019-01-01 – 2021-12-31 | Archived | No | 2026Q3 |
| Miscellaneous Other Rules / Notification, Public | 1984-09-01 – 1984-09-30 | Archived | No | 2026Q3 |
| Miscellaneous Other Rules / Notification, Public | 1984-08-01 – 1984-08-31 | Archived | No | 2026Q3 |
| Miscellaneous Other Rules / Notification, Public | 1984-07-01 – 1984-07-31 | Archived | No | 2026Q3 |
| Miscellaneous Other Rules / Notification, Public | 1982-10-01 – 1982-10-31 | Archived | No | 2026Q3 |
| Radionuclides and Revised Rad Rule / Monitoring, Regular | 1981-10-01 – 1982-09-30 | Archived | No | 2026Q3 |
| Radionuclides and Revised Rad Rule / Monitoring, Regular | 1980-10-30 – 1981-10-29 | Archived | No | 2026Q3 |
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)
Wadsworth, Sean: 805-459-9121
An administrative filing contact may not be a customer-service line. Confirm current contact details with the provider.