Referring to Table E9 -1 (a), double the flows in Column 11 for each sewer reach and determine the minimum commercially available concrete box sizes required (available, in 1.0-ft increments) for each sewer reach using a minimum box span and rise of 2.0 ft. Keep all elevation, length, slope, and roughness data the same as presented in the table. After sizing the box sewers, recomputed the HGL for the entire system. Evaluate any problems with maintaining a minimum actual velocity of 3fps.