A stormwater treatment system designed to separate floating pollutants, liter,
and contaminated settling solids from drainage discharge. The system uses a cylindrical
tank, buried below the ground, which enables separation of the pollutants. The
stormwater flows around the inside perimeter of the tank until it flows into an
inner cylinder through a weir (or weirs). This causes a delayed flow due to the
limited entry point through the vertical weir. The extended amount of resonance
time allows for separation of pollutants, liter, and contaminated solids. The stormwater
continues to separate itself as it flows around the inner cylinder, up through
a vertical pipe and out an outlet pipe. The solid contaminants which are left behind
are stored and able to be removed later.
