A former MGP gas holder release was located within an area inaccessible for a drill rig.  Conventional vertical advancement of boreholes for characterization purposes could not be performed.

We were able to set up a rig approximately 50 feet adjacent to the area of the suspected release and drill at a shallow angle beneath the former gas holder.  Subsurface material contained urban debris and fill that would have prevented sample collection with split spoons.  We were able to sonically advance boreholes through approximately 80 feet of material, and obtain continuous recovery to characterize impacts beneath the former gas holder location.