Project Description

The Riley Group, Inc. (RGI) conducted an assessment of the horizontal and vertical extent of the former City of Monroe municipal solid waste landfill. The former City of Monroe landfill occupies 3 to 4 acres of an undeveloped, approximately 11-acre parcel located within the Monroe city limits. RGI’s assessment began with a thorough review of the available City of Monroe, Snohomish County Health Department (SHD), and Washington State Department of Ecology (Ecology) files regarding the history of the landfill. RGI also reviewed available aerial photographs showing the landfill area. To better estimate the area, thickness, and boundaries of the landfill RGI recommended a geophysical survey. The geophysical survey findings were used to map and field-flag the approximate edge of the landfill. RGI prepared a work plan to confirm the extent and thickness of the landfill material using an excavator and a sonic drilling rig.