If a bin is obviously contaminated , why is it getting emptied into the truck? Most places would put a label on the bin to state it could not be emptied and the reason why, then the bin would be left uncollected. This helps reduce contamination.
Some of the public hide their contamination at the bottom of the bin so we can't see it, it's only apparent once the bin has been emptied & it's too late by then to take it out !! 🙁
