fuel tank in the ground

[MKJ]

hello, I wonder if anyone can shed any light on this matter - we want to install central heating, fioul, and ideally would prefer to have the tank in the ground rather than in the garage.

My questions are
1) are there regulations (there must be) about how this has to be done ie does it need to be a concrete lined hole, does the tank itself need to be a certain material or grade (we were thinkign of one of those plastic ones) and any ideaas where we can find the regulations.
2) do we need planning permission or a declaration de travaux or any other permissions or can we jsut go ahead

thankyou in advance
Maria