A food producing facility has a discharge with a high BOD $($biochemical oxygen

demand$).$ It must send the discharge through a pipe to a holding pond for treatment. If the

initial BOD concentration is $1500$ mg$/$L$,$ the linear velocity is $0\mathrm{.}05$ meters per second,

and the pipe length is $3500$ meters, what is the concentration when the discharge enters

the pond? The reaction rate for BOD is $0\mathrm{.}3$ per day.