Access Terminal Design for Horizontal Landfill Conduits

Horizontal landfill conduits are often the primary means for liquid and gas exchange within the bioreactor landfill waste mass. However, operational problems have historically plagued these components. Differential settlement, crushing, and waterlogging have been so common that engineers often treated horizontal conduits as sacrificial infrastructure. Many years of development and experience at projects initially in New York State, and now in many other states, have shown that structurally reinforced conduits have the survivability necessary for long-term use. The remaining design challenge has been development of multi-function access and cleaning terminals to support long-term operations. This paper will describe and give an installation case history of a new, integrated, landfill conduit terminal system that provides easy access for control of all normal functions such as gas extraction or leachate injection, and gives access for high-pressure jet cleaning and excess liquid removal. Air can also be forced into the system if desired. This system is a technological breakthrough, which will provide a new level of control and improved maintenance for permanent horizontal landfill conduits.