When the soluble BOD in the influent to the treatment plant rises from 129 mg/L to 201 mg/L, the operator called to ask your advice on a new MLVSS for the plant. It has been operating with an F/M of 0.45 mg/mg-d and the operator would like to continue using the same F/F. The plant data are as follows: flow rate = 7,673 m^3/d; aeration tank volume = 1,157 m^3; mixed liquor volatile suspended solids = 2,601 mg/L