Deep well injection. Must be kept out of aquifers. May cause earthquakes or high pressure blowouts. Still must landfill sludges and ashes Expensive and the material must be dry to save energy and keep the temperature up. Temperatures must exceed 1000 o C to break the chemical bonds and destroy the activity of complex molecules.
Some municipalities use incineration to burn garbage and it can also generate heat and energy.
Where they are located is usually in industrial or near poor housing. The Vulcan is a ship incinerator that burns in the open ocean. Plasma arc torches heat materials to 90,000 o F at which electrons are separated from atomic nuclei. On the edge of a landfill. Problems and diseases differ with each site, but perhaps all of the causes are from drinking water.