Work has begun on a new sewage treatment plant in Cumbria, which its operator says will benefit wildlife.
United Utilities is spending £13m on the project at Shap, to replace the existing facilities.
These were built in the 1960s and are not suitable for the standards which will soon be required as part of the European Habitats Directive.
Shap Beck runs into the River Leith, which in turn feeds into the River Eden Special Area of Conservation.
The new plant is being built on land adjacent to the existing facility In Pow Lane, which will then be demolished and returned to grassland.
Martin Williams, from United Utilities, said: "Once Shap's new treatment works is finished next September the quality of the treated wastewater we return to the River Leith will be better than ever before.
"Our new works will also have much more capacity than our current plant. And by adding a new storm detention tank we will be able to catch and store even more water during heavy rains, so less of it finds its way into the river."