Hydrodynamic separator for stormwater treatment

A hydrodynamic separator assembly configured for installation within a stormwater drainage infrastructure, wherein the hydrodynamic separator has substantially circular walls with a top, with one or more access openings, a bottom, at least one inlet opening and at least one outlet opening;

• wherein said hydrodynamic separator, contains three flow weirs each serving a specific function including a flow splitter, an oil-floatables skimmer, and an outlet weir;
• wherein said flow splitter is attached to a wall of said hydrodynamic separator, adjacent to said inlet opening, such that water entering via the inlet pipe encounters the said flow splitter and water is directed outward along the walls of the hydrodynamic separator through the flow splitter's side openings,
• wherein directed water travels along said walls toward the oil-floatables skimmer and said directed water is directed toward the center of the hydrodynamic separator and then back toward the flow splitter and continues in two circular motions,
• wherein water must flow downward and pass under the bottom of the oil-floatables skimmer, said oil-floatables skimmer bottom is positioned below the invert of the outlet pipe and top is positioned above the invert of the outlet pipe so that all water must pass under the oil-floatables skimmer and in doing so trap floatables, said oil-floatables skimmer is attached to walls of said hydrodynamic separator,
• wherein said water that travels under said oil-floatables skimmer, must travel back upward and pass over the wall of the outlet weir to make it to the outlet opening, said outlet weir attached to said wall of hydrodynamic separator, and positioned so that the wall of the outlet weir is disposed across the outlet opening horizontally level so that water must pass over the said weir wall in an even fashion to create laminar flow conditions with minimal velocity to aid the capture of particulates.