Seven projects are due to start this month to improve water quality around the Eden Valley.
Water firm United Utilities is starting work at six wastewater treatment works in villages near Penrith.
The firm said it was part of £75m-worth of investment in the area that will see treated wastewater at 22 works improved and reduce the number of times that storm overflows at four sites operate.
The first batch of projects are at Great Asby, Orton, Dufton, Long Marton, Milburn and Morland.
The projects will help to reduce the amount of phosphorous in the treated wastewater that is returned to the environment and improve water quality in the receiving watercourses.
There is also second project starting at Morland wastewater treatment works to reduce the number of times that overflow operates.
This will see a storage tank capable of holding 35m3 – or 35,000 litres of stormwater – built at the site.
Andrew Kendall, wastewater county business lead for Cumbria at United Utilities, said: “We’re working at pace to deliver significant investment to our wastewater network right across Cumbria.
“These seven projects that are starting this month will directly improve water quality to the River Eden and its tributaries.”
It comes as United Utilities said it was embarking on the largest investment in water and wastewater infrastructure for a century.
