Los Angeles , California ( CNN ) -- It 's as tall as some of L.A. 's highest skyscrapers , but the only residents here are rats and cockroaches . Welcome to the Puente Hills Landfill , the largest rubbish dump in America . Over 150 meters of garbage has risen from the ground since the area became a designated dumping site in 1957 . Now , six days a week , an army of 1,500 trucks delivers a heaving 12,000 tons of municipal solid waste from the homes and offices of L.A. County 's millions of inhabitants . `` This used to be a dairy farm ; a valley filled with cows producing milk . And now it 's a geological feature made out of trash , '' said Edward Humes , author of `` Garbology : Our Dirty Love Affair with Trash '' -- a book that charts the history of garbage in America . Humes says most of the waste arrives straight from the bins of local residents . `` If you 're like most of us -- most Americans -- you 're making seven pounds of trash a day . Across a lifetime that adds up to 102 tons of trash per person , '' he said . In 2010 alone , Americans accumulated 250 million tons of garbage , and although recycling in the U.S. has increased by 34 % since 1960 , Humes believes the country 's attitude to waste is still not sustainable . `` It 's very convenient to roll your trash to the curb every week and have it disappear , but it 's a magic trick -- and really there 's not very much magic , '' he said . `` We need to have less packaging ; use less disposable items ; ( use ) things that last longer ; make purchasing decisions that are more studied and less wasteful . '' The environmental impact of landfill sites varies depending on how well they 're managed and resourced . However , typical problems include the contamination of soil and groundwater from toxic residues ; the release of methane , a greenhouse gas produced during the decaying process that is more potent than carbon dioxide ; and disease-carrying pests . Tom Freyberg , chief editor of industry publication Waste Management World agrees with Humes that we should all be trying to reduce waste and increase the amount we recycle . However , he says it 's likely there will always be a need for landfill , and we should applaud those sites that are well managed . `` What 's happening now compared to years ago is that the technology and practices around waste management have vastly improved . It might be hard to see it from the outside , but they ( Puente Hills ) have a state of the art landfill site , '' he said . Indeed , the layers of waste at Puente Hills are meticulously separated by plastic membranes , designed to contain the brew of noxious chemicals that would otherwise leak out into the groundwater . The `` leachate '' is then collected and filtered to make it safe . The slums of Mumbai : A model of urban sustainability ? In addition , the methane produced by the natural decomposition of materials inside the tower of trash is collected through a network of pipes and burned to generate electricity . The emitted methane from Puente Hills alone produces about 50 megawatts of power -- enough energy for 70,000 homes , according to Los Angeles County authorities . At present , just over half of all U.S. garbage is buried in landfills , a third is recycled and the rest is incinerated to produce electricity , a process known as waste-to-energy . A recent study by the U.S. Environmental Protection Agency concluded that incinerating a ton of trash emits at least 35 % less greenhouse gas and yields 10 times more electricity than burying it and capturing the methane . So why does America still seem so in love with landfill ? `` Quite simply , it 's the most cost-effective option across most of the U.S. , '' said Peter Borkey , head of the OECD 's waste division . `` Incineration plants require a large critical mass of waste to be financially worthwhile . This is easy to accomplish in densely populated areas , but the costs associated with processing and transporting garbage rise very quickly as the population density lowers . '' Borkey believes that landfill reduction will prove difficult until producers of waste and the municipal authorities responsible for handling it are given the right incentives . He says that in Europe -- where an EU directive on waste management has decreed landfill a disposal method of last resort -- large rubbish dumps are dwindling . `` In places like Germany and Scandinavia , landfill now constitutes less than 5 % of total waste management , '' he said . But some landfill is unavoidable : `` At present residual waste that can neither be burned nor recycled -- hazardous waste and incineration ash -- can only be confined in well-managed landfill . '' In Freyberg 's view , the public attitude surrounding the very idea of `` waste '' should be reformed . `` The term does n't do the industry any favors . Most of what we call waste can be reused , turned into fuel or new products altogether . We should instead think of it as a great resource . ''
L.A. is home to America 's largest landfill site , almost as high as a city . Americans dumped 100 million tons of garbage in 2010 , most ends up as landfill . But there is complex science behind a garbage dump and it is safe and sustainable .