Confused about soil improvemant

I believe it is possible for the composting process to inactivate weedkiller residues, but only if the facilities and processes used are the correct ones, and how do you know what sort of expertise went into making your council compost?

Having said that, I was in Sheffield's Botanic Gardens yesterday and there were several huge piles of what looked like green waste compost (i.e. lots of twiggy bits and heaven knows what else  ) which is obviously being used to add to the beds and borders, so presumably they are reasonably confident about using it.

The possibility of weedkiller-contaminated green waste compost being responsible for plant damage is described in THIS RHS article (they use the word 'occasionally', but again, there's no easy way of knowing in advance if any given batch will be safe.)

Thanks for the link JayG, think I may use it to level an area at the back that won't be used for anything special!