Much like New Year’s, spring is a time many of us resolve to improve. After spending winter indoors, it feels natural to celebrate the season of renewal by overhauling our homes. We dust, organize, and clear out clutter, bagging piles in trash bags and setting them by the curb. With April 22nd being Earth Day, you might consider a different type of resolution to improve your surroundings.
Landfills turn sanitary
Whether we spring clean or not, it is inevitable that we will produce some waste. Landfills, however, are not what they used to be. They are not heaping piles of detritus in open dumps that pollute air, soil, and groundwater. Paradises for rats and mosquitos have mostly been replaced by sanitary landfills, where waste is kept separate from the surrounding environment.
The mechanics of landfill sites
These sites are essentially large holes, with depths of up to 500 ft, in which waste is stored. The first layer is typically made of compacted clay that prevents liquids from passing into the surrounding soil. The clay is covered by a high-density plastic liner. Perforated pipes that sit on top of the liner collect liquids and funnel them to treatment facilities. The bulk of the landfill is composed of the waste itself that is compacted and covered with a layer of dirt every day to contain odors and deter pests.
The issue with methane
One of the biggest environmental issues for landfills is the emission of greenhouse gases, particularly methane. Landfill gas is a byproduct of decomposing organic material and is comprised of about 50% CO2 and 50% CH4. Methane, which is produced by anaerobic decomposition, is a greater concern than carbon dioxide because it is 28–36 times more effective at trapping heat than carbon dioxide, according to the Intergovernmental Panel on Climate Change.
Modern landfills collect about 60–90% of these gases and use them to produce electricity or other forms of power. J.D. Lindeberg of the consulting firm Resource Recycle Systems says he “has reason to believe that the collection efficiency of CH4 derived from food waste is quite a bit worse than 60–90% … The decay of food waste occurs in the first two to four weeks of landfilling, a period of time long before the gas collection for most landfills can be implemented.” As a result, much of the methane from food decomposition escapes into the atmosphere.
Gas collection systems are critical, but diverting waste away from landfills is the next step in improving disposal. Researchers at the Univ. of Sheffield, for example, are recycling discarded polymer and steel fibers to produce reinforced concrete (see pp. 12–13 in the April 2019 issue of CEP). Organics, on the other hand, can be diverted to composting facilities or at-home composting systems, in which the waste is aerated, producing CO2 instead of CH4. The rich, dark, soil-like substance that results can be mixed into soil to provide nutrients, improve soil structure, reduce the need for fertilizers and pesticides, and prevent erosion.
What you can do
Some communities have municipal organics collections that operate similar to waste and recycling programs, with designated bins and curbside pickup. You might also find organics drop-off sites in your community. You can keep food scraps in a container in your refrigerator or freezer to minimize odors between pickups or drop-offs. If you don’t have access to such services, you can also make your own compost at home that will be ready for use in three to six months.
Composting, like recycling, is a simple step we can take to improve the planet. This year, treat Earth Day as a chance for renewal and resolve to change a behavior to better the Earth.
This article originally appeared in the Editorial column of the April 2019 issue of CEP. Members have access online to complete issues, including a vast, searchable archive of back-issues found at aiche.org/cep.