Share of sludge we can trace, through the company's published routes, to an advanced digester

90.9%2024-25sourcedmedium confidence

An independent check on the reported 98%, and a floor, not an estimate of the whole. It shows the 98% is an outcome of where the tonnes actually go, not a target. Our arithmetic from the company's published return.

Welsh Water, Bioresources market information 2024-25sheets WwTW, Small WwTW and STC: where each works sends its sludge, and where each treatment centre sends it on

Each of the 137 larger works names where its sludge goes (and what share). Each of the 23 thickening and dewatering centres, and the two conventional digesters, names where they send it on, and almost all of it goes to Afan, Cardiff Bay, Cog Moors or Five Fords. Following the tonnes through those links puts 68,591 of 75,426 tDS at an advanced plant. The other 9% cannot be traced in the return: the 450 small works give no route (1,493 tDS), some routes do not add up to 100%, and a few destinations are not listed.