1. What region of the U.S. has the greatest number of landfill facilities? According to U.S. EPA's latest Municipal Solid Waste Characterization Report (2012), the West region has the greatest number of landfill facilities: 718. The South is next, with 668; then the Midwest, with 394; then the Northeast, with 128.
2. What is the term used to describe the solid material added to hydraulic fracturing fluid to keep new fractures open? Proppant. Sand is often used for this purpose.