Methodology
Storm Events for Settling Tank Performance
Simulation
To simulate performance of the two-compartment settling tank,
precipitations, flows, and PSDs of grab samples for 16 storm
events 1.5–71.4 mm total event rainfall measured during 2002–
2003 wet season at three highway runoff sites in west Los Angeles
were used. PSDs were measured using a Nicomp Particle
Sizing Systems AccuSizer 780 optical particle sizer module
Santa Barbara, Calif., which quantifies the number of particles
in 512 intervals over the size range of 2–1,000 m. The Accu-
Sizer 780 utilizes light scattering or obscuration to detect particles
passing through the sensing zone. The detected pulses by the
sensor have different pulse height and detect frequency depending
on the mean particle diameter and particle numbers, which are
directly converted to PSD using a calibration curve previously
prepared.