Hi Hayley, I have lived close by for a few years now and personally i have not had any negative smells travel from the waste treatment centre. If you were to walk close by the centre or pass by in the car after heavy rain and hot days you will notice a slight smell but its not enough to be offensive.
Working in the area with the residents I haven't had anyone complain to me about the smell. It is only really noticeable around the immediate area of the treatment centre (near the Tavern) and when it is humid and there isn't any wind. Let me know if I can help with anything else :)