Abstract: A large capacity immiscible liquid separator adapted for placement in the ground, rather than under the sinks of food processing facilities. The liquid separator has a large oil compartment that can be vacuum suctioned to empty the contents thereof. Large volumes of the immiscible liquid influent can be processed without the use of a ball-type valve. A large circumference weir allows a large volume of separated waste water to overflow to the sewer system. The weir can be H-shaped to provide a large circumference and thus accommodate large separated waste water flows thereover.