Abstract: A sewage collection and separation tank (10) and method of construction is described. The sewage tank is built on a prepared earthen site (21) and is comprised of a tank floor (11) constructed from multiple wedge shaped concrete floor sections (13, 15, 17 and 19) that encase a first elastomeric gasket (37) mounted around the perimeter of a centrally located sump pump pit (23). A second elastomeric gasket (41) is mounted in a side (13c) of the first section so that half of the second gasket remains exposed. The tank floor is completed when the fourth section is poured. By the time the fourth section of the tank floor is poured, the first section has cured to the point that the first section will not seal against the wet concrete of the fourth section. However, a side (19e) of the fourth section, adjacent to the first section, encases the exposed half of the second gasket. This provides a liquid impervious seal between the adjacent first and fourth sections.

Abstract: A sewage collection and separation tank (10) and method of construction is described. The sewage tank is built on a prepared earthen site (21) and is comprised of a tank floor (11) constructed from multiple wedge shaped concrete floor sections (13, 15, 17 and 19) that encase a first elastomeric gasket (37) mounted around the perimeter of a centrally located sump pump pit (23). A second elastomeric gasket (41) is mounted in a side (13c) of the first section so that half of the second gasket remains exposed. The tank floor is completed when the fourth section is poured. By the time the fourth section of the tank floor is poured, the first section has cured to the point that the first section will not seal against the wet concrete of the fourth section. However, a side (19e) of the fourth section, adjacent to the first section, encases the exposed half of the second gasket. This provides a liquid impervious seal between the adjacent first and fourth sections.