The smallest (size), mono-media (sand depth = 3-ft) filter system to treat a flow rate of Q = 80 MGD with the constraints below that will accommodate a head loss of 6-ft across the filter has a total filter area of?  (Assume 2 filtration units per filter box)

Constraints:

SLR = 4.5 gpm/ft^2

Filtration unit L:W = 3:1

Gullet Width = 12 ft.

Max. Allowable filtration unit surface area = 750 ft^2

Filter Bottom Depth = 1 ft.

Freeboard = 3 ft.