Abstract: A secondary containment structure for the safe storage of hazardous materials held in primary containers, such as drums, cans and bottles. In large sizes, the containment structure is adapted to function as a pallet or as the floor of a building or shelter for primary containers. The structure includes a core formed of an end-grain balsa wood base and a rectangular frame placed thereover formed of the same or similar material to define the bed and the side walls of a sump. The inner edges at the upper end of the frame are indented to create a ledge to accommodate a fiberglass grating. The containers to be stored are seated on the grating, whereby leakage or spillage from the containers are collected in and confined to the sump. Laminated to the exposed surfaces of the core is a layer of a fiberglass-reinforced plastic material, whereby the resultant laminate, though light in weight, is of exceptional strength.

Abstract: An odor control system for a settling tank containing a pool of wastewater to be clarified in which suspended particles are removed by gravitational settling and the water at the surface of the pool is clarified. Supported within the tank is an elongated effluent trough having a weir at one side thereof which extends upwardly therefrom to permit clarified water from the pool to spill over into the trough. Mounted over the trough along its full length is a hood having a side wall which extends into the pool at a position displaced from the weir the hood being constituted by a series of sections. The hood acts to capture noxious gases emitted into a region above the surface of the water therebelow as the clarified water spills over into the trough.

Abstract: A gasketed hatch cover usable in an odor control system in a wastewater treatment plant or in other installations provided with a hatch opening which when closed by the cover is then sealed to prevent the escape of fumes into the atmosphere. The hatch opening is bordered by parallel side walls each having a ledge projecting therefrom. The cover is formed by a rectangular plate whose long edges are turned down to form rims that rest on the ledges and are spaced from the side walls of the opening when the cover is closed. Fitting on each rim is a replaceable gasket of compressible material having a J-shaped section defining a channel to snugly accommodate the rim between the parallel short and long legs of the J, and a D-shaped section whose straight leg is common with the long leg of the J-section. When the gasketed cover is closed, the D-shaped section of each gasket is then compressed within the space between the rim and the side wall, thereby sealing the opening.

Abstract: An outlet for extracting noxious gases generated in a settling tank containing a pool of wastewater, the outlet including an effluent trough supported at a raised position in the pool against the tank wall. The trough is provided with a side wall parallel to the tank wall and lying somewhat below the surface of the pool, a weir being supported on this side wall and extending upwardly therefrom to permit clarified water from the surface region of the pool to spill over into the trough. Overlying the trough and the weir is a flat walk plate that extends horizontally from the tank to the upper edge of a vertical sidewall which extends downwardly into the pool, the sidewall together with the walk plate acting to confine noxious gases emitted into the region above the trough and the weir to prevent their discharge into the atmosphere. The walk plate includes a hatch cover section providing access to the weir when it becomes necessary to scrub and clean the weir.