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.
