Really? Woodlands and hedgerows awash with fly-tipped litter (or just chucked out of car windows). Pursued and persecuted as vigorously as smokers, who are an easy touch for £75 and are generally regarded as pariahs with no rights anyway? I don't think so!
That would be littering. Disposing of it down the drain seems to me a perfectly sensible and acceptable non-littering solution. £75 for just dropping it in the street, fine, but sensibly put down the drain - should be no problem.