Rating System

LEED BD+C: New Construction

Rating System Version

v2 - LEED 2.2

Inquiry

Our project requires the construction of a perimeter retaining wall for our building due to the urban location of our site. Our site has abutting buildings, all of which border our lot lines. The geotechnical and engineering consultants have specified slurry wall construction. The specifications call for a bentonite slurry containing recycled foundry sand. As you know, bentonite is a clay and the slurry is used to stabilize the trench walls prior to the pouring of the concrete, essentially replacing concrete forming. We would like a determination on the bentonite slurry. Does the USGBC consider bentonite a soil or a construction material? As a followup, if the bentonite is determined to be a construction material, our plan is to move the spent bentonite to a facility where bentonite slurry is aggregated and dried in sedimentation ponds to be recycled at some time in the future, when the recycling/reprocessing technology has become more efficient. Would this plan be acceptable as diversion from the landfill per MR2.1 and MR2.2?