You cannot afford to collect rubbish or garden waste, dispose of it on
site,
chuck it in their bin or let the them get rid of it, as well as being very
time consuming tipping charges cost a fortune, skips also are not cheap,
how
much do you think it would cost for a skip? tell them to set aside a small
area for a compost heap or to burn what is left.

If they still insist that you take it then tell them there is a hefty
charge
for disposing of waste, actually its better to get that out of the way
first
so there is no misunderstandings later.

By the way, you are a registered waste carrier I take it?
Steve