CSLB C-36 Plumbing ContractorRough-in PlumbingMedium
A plumbing contractor is installing a new water supply system for a single-family dwelling. The water service pipe is run horizontally under the front yard. What is the minimum required distance the water service pipe must be from a parallel building sewer pipe?
- A24 inches
- B6 inches
- C12 inches
- D18 inches
Show answer & explanationAnswer & explanation
Correct answer: C. 12 inches
To prevent potential contamination, the California Plumbing Code (CPC) requires that a water service pipe be installed at least 12 inches horizontally from any parallel building sewer or drainage pipe. This separation helps safeguard potable water quality.
Why the other options are wrong
- A. 24 inches is more separation than the minimum code requirement.
- B. 6 inches is insufficient separation to prevent potential contamination.
- D. 18 inches provides good separation but is not the minimum required.
Water/Sewer Separation
The minimum required distance between potable water supply pipes and drainage/sewer pipes to prevent contamination in case of leakage.
- Crucial for public health and safety.
- Applies to both parallel and crossing installations.
- Specific distances are mandated by plumbing codes.
Memory trick: Water and sewer, keep them apart, 12 inches parallel, a fresh start.