Public water system record
Diablo Water District
Serves Oakley, Contra Costa County, CA · 43,357 people served
Federal records show no health-based violations and no monitoring or reporting issues for Diablo Water District in the last ten years.
System profile
- Health-based violations, last 10 years
- 0
- Resolved
- 0
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 0
Key facts
- Diablo Water District draws water from 3 wells (1 of them for emergency, seasonal or other part-time use).
- Lead pipe inventory: 0 lead and 0 unknown out of 13,792 service lines.
Check whether Diablo Water District 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, and no monitoring or reporting violations either.
Where the water comes from
Diablo Water District draws water from 3 wells (1 of them for emergency, seasonal or other part-time use). It also buys water from Randall-Bold Water Treatment Plant. 1 other public water system has an emergency connection to Diablo Water District.
Buys water from
- Randall-Bold Water Treatment Plant Concord, CA
Annual water quality report
Diablo Water District 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