)
The final and often least desirable option is the output approach. It looks on solid waste as something to be discarded as cheaply and as safely as possible.

Dumps and landfills
The open garbage dumps have been recently replaced by the sanitary landfills. A sanitary landfill is a natural or manmade depression into which solid wastes are dumped, compressed, and daily covered with a layer of dirt. Since trash is covered, odors, flies, insects, rodents, and potential health problems are eliminated or sharply reduced.
The most important problem about landfills is that they require land, which is in short supply around many cities. Second, landfills, like dumps, require a lot of energy for excavation, filling, and hauling trash. Third, they can pollute groundwater, as toxic household wastes (paint thinner, pesticides and other pests) and feces are discarded in municipal landfills where they can leak into groundwater. Fourth, they produce methane gas from the decomposition of organic materials. Methane can seep through the ground into buildings built above and around reclaimed sites, and it is explosive at relatively low concentrations. Fifth, they sink or subside as the organic trash decays, requiring additional regrading and filling. Buildings constructed on top of reclaimed landfills may suffer serious structural damage. Sixth, they have low social acceptability - most people don’t want the noise, traffic, and blowing debris.

Composting
Composting is the most useful output strategy devised. Composting is a process in which organic wastes are allowed to undergo aerobic bacterial decay. The resulting product, compost, is used to build soil fertility.
Where there is abundance of organic matter, such as slaughterhouses and vegetable- and fruit- packing plants, composting is a good strategy (also for manure produced by animals in zoo). Large-scale composting has a few drawbacks: (1) it requires large tracts of land and may produce odor and provide breeding sites for pests, (2) sorting out the noncompostable materials such as metals and glass is costly, (3) the demand for the organic compost is often low, and (4) sites are aesthetically unappealing.
Citizens could be required to sort out recyclable metals, plastics, and glass, thus eliminating the cost of separating the wastes later.

Incineration
Incineration reduces waste volume by two-thirds, saving landfill space. It also produces heat and electricity, turning waste into energy.