Liz Twist is concerned about the number of sewage discharges into rivers through combined sewer overflows (CSOs), which are permitted but often used excessively. She cited data from Surfers Against Sewage that water companies discharged raw sewage into UK rivers 200,000 times in 2019 and 387 coastal discharges in Wales between October 2019 and September 2020. The World Wildlife Fund's research shows that 8% to 14% of overflows spill sewage weekly, with a third to half spilling monthly. In her constituency, Northumbrian Water recorded 1,383 spills from 109 storm overflows in 2018, the worst being at Hamsterley Mill pumping station's Riverview CSO.