Federal environmental regulators said they expect to decide this year on a controversial proposal that would allow Tampa-based Fortune 500 mining company Mosaic to test its phosphate waste as an ingredient in road construction. Federal environmental regulators said they expect to decide this year on a controversial proposal that would allow Tampa-based Fortune 500 mining company Mosaic to test its phosphate waste as an ingredient in road construction. Environment Phys.org – latest science and technology news stories