Backflow testing & repair in Castro Valley, CA
BackflowCare tests backflow prevention assemblies in Castro Valley (Alameda County) and files the results with East Bay Municipal Utility District. The property owner hires a certified tester, and the test must be performed by a tester on EBMUD’s approved backflow testers list. If a device fails, we make minor repairs and file the passing retest with EBMUD.
- County
- Alameda County
- Water supplier
- East Bay Municipal Utility District
- Annual test
- EBMUD: owner hires a certified tester
- Our price
- $199 per device ($25 off for new customers), or from $180/year on a plan
- ZIP codes
- 94546, 94552
What EBMUD requires in Castro Valley
- Testers must be certified as a General Backflow Tester by AWWA, ABPA, NCBPA or ASSE and also pass an EBMUD exam.
- The completed test form is due by mail within 30 days of EBMUD’s notification.
- Since July 1, 2025, customers with a private well must test annually and submit the results (EBMUD Regulations, Section 26).
Source: EBMUD backflow program (official page), checked October 17, 2026.
Rules for new and replacement devices in Castro Valley
- The customer must install, test and maintain the required device and pays all of its costs.
Source: EBMUD backflow program (official page).
Installing or replacing a device takes a licensed plumbing contractor, usually with a permit. We can refer you to one we trust, test the new device once it’s in, and make minor repairs to existing ones.
Backflow questions from Castro Valley property owners
Which water supplier serves Castro Valley?
East Bay Municipal Utility District supplies water in Castro Valley (ZIP 94546, 94552) and runs its backflow program.
Who tests backflow devices for EBMUD customers in Castro Valley?
The property owner hires a certified tester, and the test must be performed by a tester on EBMUD’s approved backflow testers list.
When is the backflow test due in Castro Valley?
The completed test form is due by mail within 30 days of EBMUD’s notification.