Forces of Change

Garbage being rearranged at a landfill site.
Garbage being rearranged at a landfill site.
Model soil based on an actual soil sample taken from a landfill in Washington, D.C. Smithsonian Institution

Landfills Affect Soil

We make man-made soils on mining spoil, urban rubble, or landfill. The soil shown here was created between the 1940s and 1970s by filling a floodplain wetland of the Anacostia River with 30 feet of trash. At that time wetlands were often sites for waste disposal or new construction on landfill. Today, wetland soils are usually protected from such uses.

Landfills are one way that humans modify how soils form, by changing the soil-forming factors of climate, exposure, and soil organisms. Today, people are learning how to create healthy new soils and restore soils damaged by human activity. Federal, state, and local agencies are now removing landfill from the banks of the Anacostia River in order to restore tidal wetland soils.