Weaver Consultants Group provided engineering oversight during the implementation of the North & South Phosphogypsum Stack Corrective Action project performed at a site in the Chicago area. The project included the excavation of approximately 630,000 CY of phosphogypsum and 150,000 CY of soil from the approximately 23 acre North Phosphogypsum Stack. This material was placed on top of the 175 acre South Phosphogypsum Stack. The excavated area of the North Phosphogypsum Stack was then graded into a surface water management basin. A 60-mil thick HDPE geomembrane was installed over the top of a portion of the South Gypsum Stack to prevent further infiltration of surface water into the stack.
Weaver Consultants Group provided excavation documentation and surveying during the excavation of the North Phosphogypsum Stack. After the removal of the phosphogypsum and soil fill from the North Stack, Weaver Consultants Group collected soil samples on a 125-foot by 125-foot grid to verify that removal operations were complete.
Following the placement of the phosphogypsum on the South Stack, Weaver Consultants Group performed CQA and construction documentation during the installation of over 60 acres of 60-mil thick HDPE geomembrane.