LONDON , England ( CNN ) -- What to do with 50,000 used , possibly smelly and dirty prison mattresses that need to be disposed of every year ? Discarded mattresses pile up alongside trash in London in January of this year . Britain 's Prison Service won praise Thursday for its innovative solution to the problem : recycle the mattresses for carpet underlay , or break them down for fencing or even roof tiles . Most of the mattresses are sent to landfills . There are enough of them each year to fill 30 double-decker buses , the National Audit Office said Thursday . The Prison Service wanted to find a better way to dispose of the mattresses -- a `` zero-waste '' solution that also cost less money , the NAO said . It worked with suppliers and launched a competition to find the best solution . They ended up coming up with several proposals to reuse the mattresses , and the Prison Service is now testing them out , the NAO said . Thursday 's report highlighted several other examples of ways that government departments have used innovation to their advantage . `` We have selected them as good examples of innovative approaches which have lessons for how innovation can be managed in government , '' the report said .
UK 's prison system wins praise for recycling mattresses . Prison mattresses sent to landfills could fill 30 double-decker buses . Score: 7