Landfill mining is worth a look, essentially digging through existing landfills and sorting things of economic value, recyclables, biodegradables, fuel sources, etc. while creating more space in the process. It is of course a costly undertaking, but there are MSW sites in the US that have profitably implemented landfill reclamation. Here's the EPA spiel on it with sources: https://www.epa.gov/sites/production/files/2016-03/documents/land-rcl.pdf
I work at a waste to energy facility, and would say the landfill model is sustainable. My plant reduces every 7 tons of incoming waste to 1 ton of ash that goes to the landfill as cover. Plus we have a system to recover metal out of the bottom ash and we sell that to scrappers for recycling. Then add in that our ash can be sold for use in concrete, and the "new" industry of landfill mining for precious metals reduces it even further. Just in my county/city our records show that incoming waste has been leveling off and as our ability to recycle increases, I don't see any reason to say that the landfill model couldn't be sustainable.
Heyoo, used to work I waste disposal politics. Here are the big 3:
Waste transfer (i.e. "the dump") - with new methods for sorting recyclables and biodegrables most states don't have a "room" problem when it comes to big ole trash pits. The problems are usually industrial scale and competition across state lines. For example, in Virginia and Maryland it's cheaper in some counties to ship their waste out of state. Other states have larger industrial areas, so if their waste transfer stations are near rail or harbor stations they are quite economical.
Waste to energy/incineration - basically, burn trash to generate power. They are somewhat controversial in the states due to byproducts like fly-ash and dioxins. Basically, not everything burns and what is left over can be quite toxic. The power output per cubic ton of trash is usually quite good.
Aerobic digestion - basically, using acids and bacteria to turn trash into goo, most also have a methane/gas capture component to produce energy, but not at the same output as conventional incineration. Quite popular in countries with large agriculture productions the technology is still generally considered emerging. There's also some controversy about the "slurry" byproduct, similar to the waste incineration (dioxins and other VOCs).
Waste disposal is a multi billion dollar industry and growing, so opinions of all 3 have strong supporters and opponents. The science is critical when comparing them as different regions of the country produce different varieties of trash when viewed at the macro level.
Can't speak for your hosers down in the US of A, but up here in Canada the latest and greatest is likely the Edmonton Waste Management Centre.
The biggest innovation is all non-recyclable materials such as organics, soiled paper and non-recyclable plastics are fed into a [big-ass gasifier](https://www.edmonton.ca/programs_services/documents/PDF/Enerkem_Alberta_Biofuels_430px.jpg
). The gasifier breaks down these materials and turns them into methanol. Eventually the methanol will be converted into ethanol (booze), which will then be blended with gasoline at a nearby refinery. Down in the States a lot of the ethanol is coming from corn, but we're making it from garbage. The banana peel or yoghurt container you threw away will be eventually burned in somebody's car. It's pretty much the Mr. Fusion-equipped DeLorean.
Other cool stuff is the facility has a composting program for organics, yard waste & sewage, and in addition to a separate recycling program, sorts all garbage to remove recyclable materials. In order to extract non-ferrous metals such as aluminum which aren't magnetic, the waste goes through a large electromagnetic field which induces a current in the metal, generating a tiny magnetic field allowing for extraction. This means if you throw a soda can into your garbage it will still be pulled out and recycled.
The facility is so successful the landfill has been closed and the old landfill has pipes drilled into it to extract methane which is being burned to generate electricity (currently enough to power nearly 5,000 homes). In 2018 they are adding an anaerobic digester which will take a bunch of the organics currently being composted and turn them directly into methane to further provide more fuel for these generators.
Essentially the facility is awesome for the environment and actually makes money by selling the compost, electricity and methanol/ethanol.
TLDR: Some areas in Canada don't have landfills anymore because everything is recycled or turned into biofuels, and they make money doing it.
It generally depends on the type of fill in the landfill and the configuration of said landfill. I will clarify:
If it has historically been a free for all dumping ground then it's gonna contain all types of things include heavy metals and methane generating bits and bobs.
If so then the methane can be 'tapped' for power generation and the metals collected in leachate form (via leachate lagoon).
BUT if the landfill has not been adequately lined or tanked beforehand then it becomes an environmental legacy and a big headache. It takes a lot of work beforehand to get the most benefit from the dumped material.
Now fast forward 100yrs and assuming we follow the same principle that 'where there's muck there's brass' (because landfills are concentrated deposits of man made materials ) then there's every chance that some landfills will be 'recycled' to remove metals and other materials before being stabilised again for future re-use.
Google coal wash refinery for a similar analogy.
Source : i used to work on a landfill site.
) for power is more pervasive in Europe than it is in the US. It may not necessarily be the latest in trash tech, but one can argue it is a more modern method with less environmental impact. Avoiding the anaerobic decomposition of organics means less methane released into the environment. But by virtue of burning it, you are still releasing CO2, a green house gas nonetheless.
All things being equal, our situation stands to improve significantly at the front end if we simply consume less such that we don't need to throw away as much. Per capita, Americans consume and generate far more waste than others, even by developed world standards. The stress of this consumption level is felt more by some of the denser metropolitan regions. [San Francisco](https://en.wikipedia.org/wiki/San_Francisco_Mandatory_Recycling_and_Composting_Ordinance
), for example, is making exceptional efforts to curb the residential solid waste stream.
Civil engineer here. As far as I've worked with, it's still traditional landfill capping. Nothing new. You can't do construction projects for buildings, but you can turn the area into a park, solar farm, concert venue, etc. Recreational areas that do not require excavating below the cap and liner.
I've worked on a few capping projects recently. A good amount of monitoring is required afterwards. If the landfill just closed and stopped accepting trash, you're gonna need to wait a decade or two for settlement before anything major is put there.
I wish there was an efficient system for municipalities to divert paper products and kitchen scraps from the waste stream into compost.
I recently started composting and vermicomposting again, and it's absurd how much it reduced what goes into the trash. (We don't have recycling here.) The trash that leaves our house is almost all metal, plastic, and other stuff that can't be composted.
I can apply the end product to my plants and feed them without chemical fertilizers. Plus the web of microorganisms in the compost make plants more resistant to stress and disease.
So many wins all around. Less do eet!