ᐅ Is it allowed to install sewer pipes in gravel?

Hello everyone,

Normally, underground sewer pipes should be embedded in sand. What confuses me, however, is that drainage pipes are supposed to be embedded in gravel (e.g., 22/32), even though drainage pipes seem considerably less stable than sewer pipes (e.g., KG-2000).

Why is that?

Best regards

The gravel in a drainage system is intended to direct water into the pipes.

The sand around the concrete pipes is meant to protect them from damage caused by stones or other debris.

Thank you. So far, so clear. But, can gravel not damage the drainage pipe, while a KG pipe can?

Gravel will not damage a sewer pipe (also known as a KG pipe)...

No idea if it is allowed, but I think the pipes should be able to handle it.

Why take the risk of a break? Is it failing because of just a few shovels of sand? And what kind of load is expected on the topsoil? A walkway or a freight yard? I might still be able to accept the walkway, but the latter is definitely too risky.