CSLB C-46 Solar ContractorElectrical and Plumbing CodesHard
A solar contractor is installing a solar thermal system on a residential building. The system includes piping for potable water. According to the Uniform Plumbing Code (UPC) and California Plumbing Code (CPC), what is the minimum required distance that a potable water pipe must be separated from a building drain or sewer pipe?
- A3 inches horizontally, 1 inch vertically
- B12 inches horizontally, 6 inches vertically
- C6 inches horizontally, 2 inches vertically
- D18 inches horizontally, 12 inches vertically
Show answer & explanationAnswer & explanation
Correct answer: C. 6 inches horizontally, 2 inches vertically
The UPC/CPC mandates specific separation distances to prevent contamination of potable water. For potable water pipes running parallel to building drains or sewers, a minimum horizontal separation of 6 inches is required. For potable water pipes crossing above building drains or sewers, a minimum vertical separation of 2 inches is required. This ensures that in the event of a leak in the drain/sewer, contamination of the potable water supply is minimized.
Why the other options are wrong
- A. These distances are too small and do not meet UPC/CPC requirements.
- B. These distances are greater than the minimum required but might be used in specific situations; they are not the minimum.
- D. These distances are significantly greater than the minimum required and would be impractical as a general minimum.
Potable Water & Drain Separation
Minimum separation distances required by UPC/CPC between potable water piping and building drains or sewers to prevent cross-contamination.
- 6 inches horizontal separation.
- 2 inches vertical separation (when crossing).
- Crucial for public health and safety.
Memory trick: Six horizontal, two vertical, keeps your water safe and ethical!