None of those can be left out in the open.
BCF - is a health hazard
Fertilzer would wash into the sea water and so would be illegal.
Salt would dissolve and its possibly illegal to allow that to run into the sea water as well.
It looks like different types of hardcore, they may just be holding it there temporarily for nearby projects, or other thing I can think of is they are load-testing the dock-side prior to building???
Perhaps they are going to part infill the docks for wirral waters project???
Birkenhead Asda site is one big hole in the ground when I looked a couple of days ago, it maybe the hardcore for that???
In a time of universal deceit - telling the truth is a revolutionary act. George Orwell
When the debate is lost, slander becomes the tool of the loser. Socrates