bruneep, this is a thread complaining about travellers making a mess, you're right out of place complaining about them being too tidy 😉
Edinburgh did a thing a few years back, very simple, they started accepting "trade waste" from travellers. Unfair on proper traders of course, but as soon as they did it, the amount of dumping fell to bugger all. But after complaints, they stopped doing it and lo and behold, the dumping started again. It doesn't take a genius to figure out that if someone can't get rid of stuff legally they'll do it illegally. The question is basically, what do you prefer, dumping and messy traveller sites, or unfairly allowing them to use local dumping facilities. To the OP- after they clear it up, where will they take it? It's got to go somewhere.