Problem
The wastes at the WestLake Landfill EPA site are described as follows
"In 1973, about 8,700 tons of leached barium sulfate cake residue was mixed with 39,000 tons of soil and deposited in the West Lake Landfill as fill material during landfill operations."
What is leached barium sulfate cake residue and how does it relate to radioactive wastes?