Abstract: A secondary containment and drainage system for an above-ground storage tank is described, in which small quantities of leaked or overflowing liquid are temporarily stored in a housing above the internal storage tank. This fluid can be easily removed from the housing for re-use or at least removed without the time consuming process of emptying and cleaning the overfill dike that surrounds the tank. When greater quantities of liquid leak from the input port of the storage tank, the overflowing liquid is drained into the dike through a drainage pipe that extends from the housing, through the internal storage tank, and into the dike. The dike is enclosed by a roofing structure that forms a seal to prevent contamination when liquid is drained into the dike.

Abstract: The present invention is directed to a retrofit underground storage tank (30) and method for making the same. A portion of an underground primary tank (32) its uncovered and an access opening (42) in formed therein. A plurality of trifolds (50, 120, 122, and 124) comprising three folded up and banded together panels (52, 54, 56) which are jointed together by hinges are inserted into the primary tank. A monorail or conveyor (90) is inserted into and suspended from above the primary tank (32). Trolleys (102, 104) on the monorail (90) assist in transporting the trifolds (50, 120, 122 and 124) within the primary tank (32) and then the monorail (90) is removed. Trifolds (50, 120, 122 and 124) are unbanded and unfolded and are arranged circumferentially about the tank. Jack stands are used to hold panels of the trifolds in place.

Abstract: The present invention is directed to a retrofit underground storage tank (30) and method for making the same. A portion of an underground primary tank (32) its uncovered and an access opening (42) in formed therein. A plurality of trifolds (50, 120, 122, and 124) comprising three folded up and banded together panels (52, 54, 56) which are jointed together by hinges are inserted into the primary tank. A monorail or conveyor (90) is inserted into and suspended from above the primary tank (32). Trolleys (102, 104) on the monorail (90) assist in transporting the trifolds (50, 120, 122 and 124) within the primary tank (32) and then the monorail (90) is removed. Trifolds (50, 120, 122 and 124) are unbanded and unfolded and are arranged circumferentially about the tank. Jack stands are used to hold panels of the trifolds in place.