What is the minimum bury depth for underground service pipes?

• A. 450mm
• B. 750mm
• C. 900mm
• D. 1200mm

Answer: (B)

The main idea is that buried service pipes need a depth that protects them from freezing and from being damaged by surface activity. A standard minimum of 750 mm below finished ground level is used to keep the pipe out of the frost line and away from everyday digging or equipment. This depth helps ensure the water supply remains reliable in cold weather and reduces the chance of accidental damage from gardening, foot traffic, or vehicles.

Choosing a depth of 450 mm would be more vulnerable to freezing and damage, while 900 mm or 1200 mm adds extra cost and effort without necessity in normal conditions. That said, always follow local regulations, because frost depth, soil conditions, and specific installation circumstances (like under a road or driveway) can require deeper burial or protective measures. So, in typical cases, 750 mm is the required minimum.