Welsh Water released sewage into rivers, lakes and the sea around Wales for almost 600,000 hours last year, according to the latest data. The worst-hit rivers in 2022 were the Garw, Tawe, Teifi, Usk, Rhymney and Taff. To find out why, Fliss and James talk to Welsh Water's CEO Peter Perry and Gail Davies-Walsh from Afonydd Cymru.