Forty-five metal pipes and poles, 22 tyres, 15 shopping trolleys, 12 bicycles, nine carpets, five traffic cones, three suitcases, two mattresses, two vacuum cleaners, two safes, one car door, one washing machine… This is just a selection of the rubbish pulled from a 50-yard stretch of South London’s Wandle river in November by 65 hardy volunteers, all organised by the river’s self-appointed guardians, the Wandle Trust.