The Watson Road Landfill is a closed municipal solid waste landfill located near Newark, Ohio. Burgess & Niple (B&N) was retained to design repairs to address leachate discharging into two adjacent surface water tributaries that exceeded the discharge limits set by the city’s NPDES permit.
Following a detailed site investigation, B&N submitted a conceptual design solution that included: reducing surface water infiltration through the existing pre-1976 landfill cap, landfill cap repairs, wetland removal, drainage improvements, stream restoration to minimize erosion and waste relocation.
The design also included phytoremediation – a green solution that uses trees to remove or neutralize contaminants in polluted soil or water. B&N retained subcontractor Ecolotree, Inc. to plant approximately 2,900 hybrid poplar and willow trees at the Watson Road Landfill as part of the phytoremediation system. Planted on the landfill cap and adjacent to the streams, the trees will help reduce the levels of saturation within the subsurface and treat on-site leachate prior to discharge. This cost-saving solution was $1 million less than a previous consultant recommendation.
A buffer was installed at the convergence of the two tributaries to remove saturation from the subsurface and treat contaminants in place prior to reaching surface water. A cap was installed that also will remove saturation and treat contaminants, as well as minimize precipitation that gets into the subsurface, which could generate more leachate.
The need for wetland mitigation was eliminated by establishing a preservation program for the remaining onsite wetlands. Leachate surface seeps have been eliminated by redirecting subsurface flow through a collection trench and discharging through a controlled single point discharge pipe. Once the planted trees mature, water quality treatment, extraction of water from the subsurface, and prevention of precipitation infiltration, will follow.