Oil/grit interceptor

A concrete interceptor tank in the form of a right parallelepiped comprising three interconnected chambers formed by a first and second upstanding concrete walls in said tank,

• sloping conduit means in said tank, passing completely through said tank and each of said walls,
• said first wall having a screened opening therein at a first predetermined height for communication between said first and second chambers,
• said second wall having at least one siphon means mounted therein at a second predetermined height for communication between said second and third chambers,
• hatch means provided on said tank for access to each chamber of said tank,
• said sloping conduit means having an input and output, a first orifice in said conduit means near said input and being in communication with said first chamber,
• a second orifice in said conduit means near the output and being in communication with said third chamber at a liquid level,
• said first orifice being at a predetermined height above said second orifice in said tank.

A method of preventing turbulence in an interceptor tank comprising;

• providing a tank having a plurality of interconnected chambers which includes at least an inlet and outlet chamber for separating water borne pollutants from an inlet stream,
• providing a sloping conduit in said tank near the top thereof, and passing therethrough,
• providing an outlet orifice in said conduit in communication with said outlet chamber of said tank for controlling the level of liquid in said tank chambers by providing an escape for liquid in said outlet chamber,
• providing an inlet orifice in said conduit in communication with said inlet chamber at a predetermined height above said outlet orifice,
• controlling the flow of water to a predetermined maximum quantity with said inlet orifice permitting any water in excess of the predetermined maximum to flow past said inlet orifice and past said second orifice in said conduit to exit said tank.

A concrete interceptor tank in the form of a right parallel piped, comprising a first, second and third interconnected chambers separated by a first and second upstanding interior walls,

• said first wall having a screened opening therein at a first predetermined height for communication between said first and second chambers,
• said second wall having at least one siphon means mounted at a second predetermined height for communication between said second and third chamber,
• hatch means provided on said tank to provide access to the chambers of said tank,
• sloping conduit means located near the top of said tank to provide an input for liquid to said tank,
• said conduit means sloping downwardly through said tank from the input at the entrance at an exterior wall of said first chamber and subsequently passing through said first and second interior walls and terminating in an output in said third chamber,
• said sloping conduit having an orifice located in said first chamber downstream from said input,
• said orifice being located a third predetermined height above the liquid in said first chamber,
• exit means for the liquid in said third chamber being located at a fourth predetermined height in one of the exterior walls of said third chamber.