Elizabeth Royte has written a fascinating book about garbage. The quantities of waste that we produce each day is staggering and technological approaches to managing the waste have evolved rapidly even since the eighties. Sanitary landfills, invented during the fifties in an attempt to control leachate, the intermixing of chemicals and organic materials, and prevent it from entering the groundwater supply, have become hugely expensive to build and maintain. They contain pipes to collect the leachate and return it to the top of the landfill, believing that it stimulates the breakdown of organic materials and speeds up the creation of methane, a valuable that gas that is used to produce electricity in many locations.
Other installations produce electricity by burning trash (WTE, or waste-to-energy, plants.) Metal and other obvious non-flammables are pulled from the huge daily loads by large magnets and recycled. The rest is burned and toxic chemicals (remember, people throw out all sorts of hazardous stuff in the trash) are scrubbed from the smoke (most of it anyway) and the resulting ash (at least that's the plan.) The problem is that evidence is mounting that people who live close to WTE plants and landfills (because methane that leaks out often contains a variety of really awful chemicals) show much higher incidence than normal of a variety of ailments.
The numbers are staggering and ironically the costs drive policy (so what else is new.) New York can no longer afford to recycle because the cost of shipping trash off to Pennsylvania (largest importer of trash in the country) is so high they can't afford the additional manpower and vehicles to process the recylables. That means more goes into the landfills or is burned, creating an even more bizarre mixture of chemicals to form who knows what in the landfill. And even 40 mm plastic sheathing at the bottom of these things is not 100% effective.