Public water system record
City of Sonoma
Serves Sonoma, Sonoma County, CA · 11,725 people served
Federal records show no health-based violations and 5 monitoring/reporting issues for City of Sonoma in the last ten years. At least one of these issues remains unresolved.
System profile
- Health-based violations, last 10 years
- 0
- Resolved
- 0
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 5
Key facts
- City of Sonoma draws water from 6 wells (1 of them for emergency, seasonal or other part-time use).
- Most recent formal enforcement: compliance order (no penalty) by California, September 2021.
- Record on file since 2006, with 1 health-based violation before October 19, 2016.
- Lead pipe inventory: 0 lead and 432 unknown out of 4,556 service lines.
Check whether City of Sonoma serves your address
Health-based violations
Since October 2016Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.
None since October 2016.
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
LEAD AND COPPER RULE REVISIONS
RPT
|
Jul 2, 2025 | Active |
|
Arsenic
Monitoring and reporting
|
Apr 1, 2021 | Resolved |
|
Total Trihalomethanes (TTHMs)
Monitoring and reporting
|
Jan 1, 2020 | Resolved |
|
Haloacetic Acids (HAA5)
Monitoring and reporting
|
Jan 1, 2020 | Resolved |
|
Revised Total Coliform Rule
Monitoring violation
|
Nov 1, 2017 | Resolved |
Full record since 2006
EPA's records for City of Sonoma go back to 2006. Before October 19, 2016 they list 1 health-based violation (1 resolved) and 3 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 2000s | 0 | 3 |
| 2010 to October 18, 2016 | 1 | 0 |
| October 19, 2016 to 2019 | 0 | 1 |
| 2020s | 0 | 4 |
Most recent health-based violation before October 19, 2016: Total Coliform, began January 2010, Resolved.
Show the health-based violation before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Total Coliform
Contaminant limit exceeded
|
Jan 1, 2010 | Resolved |
Enforcement actions
California regulators took 4 formal enforcement actions against City of Sonoma between 2007 and 2021. The most recent was a compliance order (no penalty) in September 2021.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Sep 8, 2021 | California | Compliance order (no penalty) | 1 violation: Arsenic |
| Mar 24, 2021 | California | Compliance order (no penalty) | 2 violations: Total Trihalomethanes (TTHMs), Haloacetic Acids (HAA5) |
| Apr 15, 2010 | California | Compliance order (no penalty) | 1 violation (1 health-based): Total Coliform |
| Jun 13, 2007 | California | Compliance order (no penalty) | 1 violation: Nitrate |
Where the water comes from
City of Sonoma draws water from 6 wells (1 of them for emergency, seasonal or other part-time use). It also buys water from Sonoma County Water Agency. It also has an emergency connection to Valley of the Moon Water District. 2 other public water systems have emergency connections to City of Sonoma.
Buys water from
- Sonoma County Water Agency Santa Rosa, CA
Emergency or part-time connections to
- Valley of the Moon Water District El Verano, CA
Annual water quality report
City of Sonoma must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.
Systems serving 10,000 or more people must mail or deliver the report to every customer, and from 2027 they must send it twice a year.
Find a posted report with EPA's Consumer Confidence Report search
Testing your own water
To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by California.
Certified drinking water labs by state EPA guidance for private wells