$7-33.$ The Big Bear town council has asked that you determine whether the

discharge of the town's wastewater into the Salmon River will reduce

the DO below the state standard of $5\mathrm{.}00m\frac{g}{L}$ at Alittlebit, $5\mathrm{.}79$ km $-$

downstream, or at any other point downstream. The pertinent data are

as follows:

Answers: DO at Alittlebit $=4\mathrm{.}79m\frac{g}{L}$

Critical DO $=4\mathrm{.}74m\frac{g}{L}$ at $t_c=0\mathrm{.}3113d$