To what minimum height must a water service pipe be above ground?

The correct answer is based on the guidelines established in the National Plumbing Code of Canada, which specifies the minimum height for a water service pipe above ground. A height of 300 mm is considered necessary to protect the pipe from potential damage or obstruction while ensuring that proper drainage can occur. This height helps to prevent freezing in colder climates, where a higher elevation may also protect the pipe from physical interference.

In terms of the other options, while heights such as 150 mm and 250 mm might seem reasonable, they fall short of providing adequate protection and may lead to issues related to frost or mechanical damage. A height of 400 mm, although it provides even more clearance, is not the minimum requirement outlined in the code. Thus, the standard has established 300 mm as the optimal minimum height for functionality and safety in various environmental conditions.