US Patent 9464451 Holding tanks, systems and methods

A concrete holding tank and related systems and methods, including a monolithic concrete sewage holding tank created with two separate pours of concrete where an encased-in-place seal (water stop) is positioned at a pour joint between a tub of the tank and a cover of the tank, and where in some aspects the second pour also forms a structural column contacting a bottom of the tank and supporting the cover. The structural column and resulting larger cover presents a tank having a low profile while still providing desired capacity.