Abstract: Various embodiments disclosed relate to a sealed storage tank. The sealed storage tank includes a first polymeric layer. The sealed storage tank further includes a second polymeric layer continuously welded to the first polymeric layer to form the sealed storage tank. The sealed storage tank further includes an optional vent formed in the first polymeric layer or the second polymeric layer. The sealed storage tank can be configured to hold at least 13,000 liters of liquid.

Abstract: A system comprises a negative-pressure apparatus comprising one or more fans, at least one manifold pipe coupled to the fan, and one or more a suction pipes coupled to and extending from the manifold pipe down a wall of the retention pond, each suction pipes including one or more structures for drawing air into an interior of the suction pipe. A flexible cover is positionable over at least a portion of the suction pipes and over at least a portion of a material in the retention pond. The fans draw air from the suction pipe interiors through the manifold pipe to create a negative pressure at the wall proximate to each suction pipe to hold the flexible cover to the wall when the one or more fans are activated.