Construction: Methane Mitigation System in Washington County, MD

Resh Road Landfill, Hagerstown, MD

methane mitigation plansBackground
A methane gas study determined the existence and extent of methane gas migration at the Resh Road Landfill, which opened in in 1960 and closed in 1982. The landfill consultant recommended the installation of the Methane Mitigation System as part of the County’s Capital improvement plan. This is the second mitigation performed for Washington County; SCS completed a similar project using the One-Pass Trenching method at the Hancock landfill establishing a sound working relationship with the client.

The challenge was to construct a 20-25 ft. deep, 2’ wide, and 2200 ft. long bentonite clay filled trench during a harsh winter with subzero conditions, and at times with 16″ of snow.  SCS brought in a specialized trenching system with capabilities unique to the trenching industry.

The system of trenching, mixing and redepositing a mixed bentonite/clay mix with the designed permeability requirements to form an impenetrable gas seal and venting system in a one pass technique. The system works better than open trench method, manual excavation techniques, which get bogged down when rain and snow impact the site.

Outcomes and Benefits
SCS completed the methane mitigation project on time and on budget despite adverse weather conditions. The One Pass Trenching method allowed us to achieve a consistent Bentonite/Clay mix for our client which is far superior to conventional mixing methods. Landfill gases were prevented from migrating from capture at the landfill site.