Landfill Closure and Waste Capping

In accordance with OEPA regulations and facility phasing plans, the landfill must be closed with an impermeable cap which is constructed on top of final grades, after waste is placed up to the permitted waste grades. Final cover grades within the landfill is limited to a maximum slope of 3 horizontal to 1 vertical (3H: 1V) waste slopes grading into a five percent (5%) slope at a maximum top elevation.

Several alternative BAT designs for capping systems exist. A typical capping system includes:

  • 12 inches of intermediate cover soils
  • 12 to 24 inches recompacted clay
  • 40-mil HDPE liner or a geosynthetic clay liner
  • 40-mil HDPE liner
  • A Drainage layer
    • (12 inches of sand or geocomposite)
    • 18 to 24 inches of protective cover soils
    • 6 inches of vegetative soils
All final slope surfaces are re-vegetated for long-term protection. Areas are revegetated for long-term erosion protection in order to:

  1. Provide adequate soil-seed contact to enhance seed germination.
  2. Enhance plant root penetration and development.
  3. Retard soil erosion.
  4. Improve water availability within the root zone.

Other components of the final capping system include installation of downslope channels, final diversion berms, rock channels and other surface management ancillary components in accordance with American Landfill's engineering design.

Closure and Post-Closure Care (Financial Assurance)

The Ohio EPA regulations require that solid waste disposal facilities maintain a financial assurance instrument such as bonds or certificate of insurance to adequately fund the closure and post-closure maintenance and monitoring of the site. The post-closure period is 30 years after closure is completed and certified by the OEPA. The OEPA also requires the facilities to adjust the closure and post-closure cost if there is an increase or decrease in disposal area. In addition, these closure and post-closure funds are adjusted on an annual basis to reflect cost increases due to inflation.

For American Landfill, the cost of this insurance is submitted to the OEPA and the Stark County Health Department each year.