Client Name: Departamento Administrativo del Medio Ambiente (DAMA)

The Doña Juana Landfill is a privately operated landfill that handles over 4,500 tons/day of municipal solid waste, en­compassing 90% of the waste generated by the City of Bogotá (population – 6 million). In September 1997, a recently filled section of the landfill slid down the side of the mountain, carrying over 800,000 cubic meters of waste, and came to a rest at the valley floor, blocking a small river. This is the largest reported mass movement of solid waste in history.

Edgeboro International Inc. was approached to design, manage, and coordinate the construction of an Emergency Stabilization Extraction system. The system was designed to reduce the pore pressure within the adjacent portion of the landfill to help stabilize the section that earlier failed.

Preceding firms experienced several setbacks and failures. Prior attempts to extract leachate proved difficult due to the intense methane gasification of the leachate, which caused the leachate to foam and the electric pumps to aerate. Other attempts to stabilize the landfill also proved unsuccessful due to the high leachate levels found in the landfill. This high level of leachate resulted in the gas being inaccessible, as well as incapable of working with conventional methane systems. These were the two key reasons the landfill experienced incredible pore pressure, which in turn, was the grounds for a major portion of the landfill to fail.

EII was retained by DAMA to stabilize the landfill. EII approached the situation with a two-step method. First, EII installed a series of methane extraction wells and second, constructed a two-part system that sealed off and restricted gas flow to cause positive pressure. This system included pumping leachate levels down with specially designed pneumatic pumps, and next, utilizing a secondary system to control the methane gas with special wellheads. The entire field was then placed under a vacuum enabling the flaring of the methane gas. The extraction wells were then piped together with HDPE leachate discharge lines, methane extraction lines, and pneumatic air lines to collect, contain and power the entire well field.

The result was the significant reduction in pore pressure and stabilization of the adjacent portion of the landfill.

Note: Due to the severity of the problem, EII was requested to mobilize at an accelerated pace. EII pre-assembled the necessary equipment and construction materials in the United States, which were then packaged and shipped in containers for assembly in the city of Bogotá. EII then began construction of the methane wells by hiring and training local manpower and materials.