Abstract: A method of constructing a moveable storage tank for the temporary storage of liquids at a fixed location, including the steps of obtaining a moveable shipping container having a bottom section, a top section, two side sections and two end pieces, and removing the end pieces to form a container housing having two end openings. The method further includes installing a shaped floor panel over the bottom section of the container housing to form a reservoir bottom, followed by installing a pair of side panels to the shaped floor panel and two side sections of the container housing to form the reservoir sidewalls. The method also includes the step of installing a pair of bulkheads to the shaped floor panel and the side panels at the two end openings to form a liquid-tight liquids reservoir that is integrated within and substantially conforms to the box-like shape of the container housing.