Leachate treatment system using constructed wetlands, Town of Fenton sanitary landfill, Broome County, New York. Final report

Abstract

Municipal sanitary landfills generate leachate that New York State regulations require to be collected and treated to avoid contaminating surface water and groundwater. One option for treating leachate is to haul it to a municipal wastewater treatment facility. This option may be expensive, may require excessive energy for transportation, and may require pretreatment to protect the receiving facility'sprocesses. An alternative is onnsite treatment and discharge. Personnel from the Town of Fenton, New York; Hawk Engineering, P.C.; Cornell University; and Ithaca College designed, built, and operated a pilot constructed wetland for treating leachate at the Town of Fenton's municipal landf'dl. The system, consisting of two overland flow beds and two subsurface flow beds, has been effective for 18 months in reducing levels of ammonia (averaging 85% removal by volatilization and denitrification) and total iron (averaging 95% removal by precipitation and sedimentation), two key constituents of the Fenton landfill's leachate.The system effects these reductions with zero chemical and energy inputs and minimal maintenance.A third key constituent of the leachate, manganese, apparently passes through the beds with minimal removal.This report documents and discusses the Fenton system's design and performance. Also covered are two companion laboratory experiments using Fenton landfill leachate: 1) a microcosm experiment which examined the effects of leachate pretreatment on plant growth and the effects of plants and leachate on maintenance of soil permeability and removal of chemicals from the leachate; and 2) a floating plant experiment which examined the toxicity of leachate sampled at different stages of the constructed wetland treatment process.