Resin dust after wet sanding

Is that what everyone does? I thought there would be a simpler solution. I have no idea if there is a place in my town to take it or if they would even accept it. I see a lot of info about uncured resin disposal and disposal of the resin and hardener containers but there is nothing about the dust after wet sanding, did I just do it completely wrong? Where was all the dust supposed to go if not in the water? I thought that was the safest option. 😓 I’ll have to call the council and ask I guess?

That was my first thought but the water started to mould before it had evaporated. I used quite a large tub because I wasn’t sure how much would be enough and didn’t realise the problem I’d have until after. I drained it with a towel in a rush just now after I realised it had gone bad but now I don’t know what to do with the resin-dust-towel or how better to go about it next time. I’m assuming I’ll just have to throw it out and use bare minimum water next time?
Thanks for the advice