slightly annoyed as I have a completion certificate from 2015 (after the tank was installed) and I would thought any non compliance would have been picked up then
It may have met regs in 2015.
Retrospective regs don’t apply unless you change the system.
There are oil tanks all round the land in places where they “shouldn’t be” according to regs but which can’t go anywhere else on the availible plot.
We used to get this with ours for being too close to a boundary. When asked where the guy would put it he pointed to an area…. I said so you’d rather it was next to the water course the other side of that boundary than my neighbours boundary ?
The matter was dropped.
Lots of factors at play here. Wouldn’t get too worried unless he’s condemned it.