'Green' caps for old landfills tested

BELTSVILLE, Md., Feb. 9 (UPI) -- U.S. researchers say they're working on a "green" way to cap old landfills that could reduce emissions and protect water quality.

U.S. Department of Agriculture scientist Pat Millner says capping or sealing old landfills with trees and shrubs, planted in a mix of topsoil and compost, instead of the traditional clay caps, will reduce methane emissions while preventing rainfall from penetrating into the municipal waste and then leaching into groundwater, a USDA release said Wednesday.

A pilot project has been started on part of a long-abandoned, 30-acre municipal landfill in Beltsville, Md., where a newly planted forest canopy will contribute to improving the health of the Chesapeake Bay by sequestering carbon and filtering runoff in waterways in the area that drain into tributaries of the Bay, researchers say.

The Maryland Department of the Environment says it is watching the pilot project closely, since there are numerous landfills statewide that would benefit from this alternative closure approach.

Vegetative caps are gaining acceptance from state agencies as a sustainable practice, and the Environmental Protection Agency sees the Maryland project as a potential model, the USDA release said.