This post is part of the Science Tuesday feature series on the U.S. Department of Agriculture (USDA) blog. Check back each week as we showcase the stories and news from the agency’s rich science and research portfolio.
Researchers with USDA’s Agricultural Research Service (ARS) have teamed up with the U.S. Environmental Protection Agency and private consultants to come up with a way to turn a landfill—nobody’s idea of a beauty spot—into a little touch of green heaven, with greenhouse-gas-reducing benefits to boot.
The secret? Instead of capping old trash dumps with a clay seal as is traditionally done, the scientists plant a mixture of trees, shrubbery and other native greenery in a mixture of topsoil and compost.
For five years, microbiologist Pat Millner and safety and health manager David Prevar, both with ARS, conducted a pilot study with EPA colleagues at an abandoned 30-acre municipal landfill at ARS’ Henry A. Wallace Beltsville Agricultural Research Center (BARC), a nearly 7,000-acre research farm in Beltsville, Md.
The project involved sealing the old landfill with a vegetative cap, a method that the scientists say is not only less expensive, but more environmentally sound. This technique has been gaining favor with municipal government agencies in the Mid-Atlantic region as a sustainable practice that enhances the land around old dumping sites.
In addition to turning an eyesore into a thing of beauty, the vegetative caps reduce methane emissions from the underground trash and keep rainfall from penetrating into the municipal waste and then leaching down into groundwater. Planting trees increases the forest canopy, which helps clean up the environment by sequestering carbon from the atmosphere and filtering runoff into nearby waterways, such as—in the case of the Beltsville project—the Chesapeake Bay.
The Maryland Department of the Environment is keeping a close watch on the Beltsville project, which officials see as an improvement over clay-capped landfills around the state. The EPA also is monitoring the project as a potential model for securing abandoned landfills.