Whenever a new recycling scheme or technology is announced one of its advantages is usually that it reduces the amount of waste going to landfill. In fact that’s one of the most important things new techniques can do – often it’s even more significant than recovering valuable metals or reducing the need for new raw materials. Landfill is a huge problem and the more it can be reduced the better.
A landfill site is one of the oldest methods of waste disposal, along with burning. It’s not much more than a huge version of the medieval village midden, but as the quantities of trash we produce increase the volume of waste going into huge pits in the ground, then being covered over and often landscaped, has skyrocketed. The problem is that a medieval village didn’t throw away much more than broken pottery, bones and old clothing; modern household garbage is filled with plastics, printed paper and old electronic devices.
Modern trash doesn’t simply biodegrade back into the food chain. Toxins in inks and old plastic are leached out by rain or groundwater and can contaminate aquifers. Electronic devices are particularly bad for this, as they contain many hazardous heavy metals. As organic waste rots it releases methane, a potent greenhouse gas – it’s up to a hundred times more damaging than carbon dioxide. Burning waste before burial doesn’t help either, as it simply releases more carbon and toxins into the atmosphere. Large accumulations of trash are a potential source of disease organisms that can then be spread by birds, insects and rodents. Even fire is a hazard – if a landfill catches fire it can burn underground for years, undermining the replaced soil above it and releasing pollutants.
There are multiple solutions to the problem of landfills. Some involve mitigating the issues caused by actual landfill sites, usually by managing drainage and improved capping of filled areas. These are only a partial solution, though. It’s far better to reduce the amount of waste that’s buried in the first place, which is where recycling comes in. Much of what gets landfilled can be reprocessed – paper, glass and many plastics. Organic wastes can be used to produce methane as a fuel. Electronics components can be dealt with by chemical or high-energy methods to recover their usable contents and reduce the rest to an inert, non-toxic residue that tales up far less space and is safe to bury.
Modern incinerator technology also allows much of the material that’s currently disposed of to be recovered. Metals and other minerals present in waste can be extracted from the smoke produced, while toxins and environmentally damaging chemicals are safely captured. Some of these methods are energy-intensive, which has to be balanced against the waste reduction, but others are capable of generating much of their own power from the incineration process.
Landfill is likely to be around for a while longer, although the Zero Waste movement’s ultimate goal is to see them phased out completely, but both consumer-led policies such as packaging reduction and improved waste handling and recycling can reduce the volume immensely. That’s good for the environment, good for natural resources and ultimately cheaper than burying so much potentially valuable material.