Underground Barrier Walls

A vertical wall that’s constructed of metal, compacted clay or a soil/clay mixture, an underground barrier wall helps prevent the movement of buried wastes or contaminated groundwater beyond the site. At Lowry Landfill, compacted clay and soil/clay walls are anchored into underlying bedrock and extended to approximately 5 feet beneath the ground.

In 1984, while the current cleanup plan was being researched and developed, a compacted clay barrier and collection drain immediately upstream of the barrier were installed at the north end of the site to capture shallow contaminated groundwater. Called the North Boundary Barrier Wall, that system remains in place and operating today.

An additional barrier wall around the east, west and south sides of the site was completed in spring 1998. Made of a soil/clay mixture, it’s 8,800 feet long and approximately 40 to 75 feet deep. Groundwater levels are monitored inside and outside of the wall, and pumping wells were constructed where necessary to maintain inward gradients across the wall. The wall and pumping wells not only prevent contaminated groundwater from escaping the site, but also minimize new contamination that occurs when groundwater from outside the wall flows inward and contacts contaminated materials.

Benefits

  • Prevents exposure to humans and the environment of contaminated groundwater
  • Prevents migration of contaminated groundwater
  • Protects clean surface water
  • Reduces contamination of new groundwater