Continental Cement Co. is seeking a state permit to build additional waste storage at its Hannibal plant.

Approval by the Department of Natural Resources could take two to three years. The cost of the improvements has not been released.

Continental has burned hazardous waste at Hannibal since 1986. The new facilities would be part of Green America Recycling, a Continental-owned firm that shares space at the plant on Highway 79.

Continental wants to build two liquid hazardous waste storage and treatment tanks, one solid hazardous waste storage tank, one solid hazardous waste containment building, three new miscellaneous units and a new direct-burn system.