Determination of the vertical velocity distribution of floatables in CSOs

Abstract

Control of floatables, since April 1994, is one of the nine minimum controls required by the U.S.EPA (United States Environmental Protection Agency) for CSO (Combined Sewer Overflows) control policy compliance. Municipalities must control and intercept floatables at their overflow sites. Efficient interception of these floatables requires prior characterisation. To accomplish this floatables from the Montréal (Canada) region were intercepted during wet weather events. Many characteristics were analysed, but a special emphasis was given to the measurement of the vertical velocity of the floatables. This vertical velocity was measured using a column that could be rotated around its central axis. Results have shown that 80% of the intercepted floatables have a vertical velocity of over 0.07 m/s.