Evaluation of a buried vertical well leachate recirculation system for municipal solid waste landfills.

Vertical liquids addition systems have been used at municipal landfills as a leachate management method and to enhance biostabilization of waste. Drawbacks of these systems include a limitation on pressurized injection and the occurrence of seepage. A novel vertical well system that employed buried wells constructed below a lift of compacted waste was operated for 153 days at a landfill in Florida, USA. The system included 54 wells installed in six clusters of nine wells connected with a horizontally-oriented manifold system. A cumulative volume of 8430 m(3) of leachate was added intermittently into the well clusters over the duration of the project with no incidence of surface seeps. Achievable average flow rates ranged from 9.3 × 10(-4) m(3) s(-1) to 14.2 × 10(-4) m(3) s(-1), which was similar to or greater than flow rates achieved in a previous study using traditional vertical wells at the same landfill site. The results demonstrated that pressurized liquids addition in vertical wells at municipal solid waste landfills can be achieved while avoiding typical operational and maintenance issues associated with seeps.