Riverlution apprentice Morton Brearley, 19, said helping to run volunteer days was part of his training programme.
He said he had been inspired to become a water-based environment worker because he lived next to a river in Mosborough, where he played with friends.
“I’ve always had a thing with water, but when I was younger, I never thought I’d be able to do something like this,” he said.
“It’s definitely a big step up from just paddling.
“I stick my waders on now and I’m in the river litter picking, getting really stuck in.
“It’s a really nice thing to do, it really makes a difference.”