Slurry store structural survey

[Cows 'n grass]

I have pp and a mid tier offer to cover my concrete below ground slurry store. It's a proper store made of L shape panels dug into the ground and backfilled by it is 30 years old.

The EA are saying I need to have a structural survey carried out. Has anyone, ideally in the SW, had this done and has a name they could recommend?

 

[Martyn]

I have pp and a mid tier offer to cover my concrete below ground slurry store. It's a proper store made of L shape panels dug into the ground and backfilled by it is 30 years old.

The EA are saying I need to have a structural survey carried out. Has anyone, ideally in the SW, had this done and has a name they could recommend?

Venture Dairy Services carried out structural surveys for DCC a few years if any help.
Maybe tricky as a lot of concrete work is given a 30 year life span.