Water quality tests in the Rover Don have shown an improvement since multi-million pound equipment was installed at a waste water treatment works.
The equipment was installed as part of a £78 million project at the Blackburn Meadows waste water treatment works aimed at reducing the ammonia discharge levels being released into the River Don.
Just two weeks after the new equipment was installed water quality tests have shown a reduction in the ammonia levels.
Kevin Smith, Yorkshire Water project manager, said: “Yorkshire Water is committed to improving the quality of the water in the River Don and its tributaries. We’re really excited to see the effect these improvements will have on the local environment.”