Landfills

J.A.McDonald, Inc. has extensive experience constructing new Landfill Cells and performing closure services for landfills that have been filled to their capacity.  The scope of work required for construction of a new landfill cell is quite diverse and requires tremendous resource availability and coordination to meet the demanding challenges encountered. These projects are very schedule driven and require a 24/7 commitment during certain phases of the project. New cells are created by the mass excavation, of varying soil types, to create a cell formation, then the installation of a dual level leachate collection system is installed in conjunction with the installation of a dual layer liner system that is separated and covered by a dual layer of imported sand product. 

The dual cell liner system can be comprised of a low premable clay layer of soil, a synthetic clay enpregnated blanket, or a HDPE liner material, or a combination of the above, to ensure that the new cell meets the stringent water tight contract requirements.

The challenges associated with this type of work are contract schedule and the project soil conditions. The installation of the liner system is very weather sensitive, both temperature and moisture dependent. If solid rock is encountered in the excavation an additional ten vertical feet of excavated rock material has to be excavated and replaced with suitable material to meet the contractual requirement of a ten foot separation between the liner system and any rock formation.

Landfill closures encompass a scope of work that involves the regrading of the final surface contours of a landfill that is being closed. The closed landfill is graded so that water can flow from the surface areas. Gas extraction wells are developed and a gas collection piping system is installed to export methane gas that is produced as the landfill material decomposes. A soil cover layer is placed over the regraded site and then a geosynthetic cover is placed with a sand cover placed to project the synthetic layer. The end product is a landfill that is well graded and capped with a synthetic layer that prevents water from penetrating the landfill. J.A.McDonald, Inc. has completed the closure of a Landfill Superfund Site project where all personnel working on the site were required to have successfully completed a 40-hour Hazardous Material / Waste Health and Safety Training Course.