+1: landfills is the worst option and should be never used for non-inert materials (that is why EU mandates incineration before bringing waste to the landfill). It is very hard and expensive to do it properly, with a perfect first layer, in a stable place, putting a lot of heterogeneous compounds doing a lot of different (and even unexpected) chemical reactions, using pipes to exchange air and drain/burn methane, maintenance and monitoring the site even for hundreds of year after closing it. It is a nightmare to handle that kind of landfills. Please incinerate everything first, and maybe reuse the ashes for public roads, benches and so on.