Police volunteers and an MP got their hands dirty when they delved into a river to clean it of rubbish.
Matthew Offord joined representatives from the force to clear up the Silk Stream, in Crossway, Colindale.
They pulled out soggy books and old rubbish bags which had been left dumped.
The following day, they cleared Watling Market car park, in Burnt Oak, where they found jewellery, beer cans and hundreds of nail polish bottles.
Around 30 to 40 volunteers from the Metropolitan Police joined in with the clear-up.