An activated sludge process $\text{(ASP)}$ is designed for secondary treatment of $7500\:m^{3}/$day of municipal wastewater. After primary clarifier, the ultimate $\text{BOD}$ of the influent, which enters into $\text{ASP}$ reactor is $\text{200 mg/L}$. Treated effluent after secondary clarifier is required to have an ultimate $\text{BOD}$ of $\text{20 mg/L}$. Mix liquor volatile suspended solids $\text{(MLVSS)}$ concentration in the reactor and the underflow is maintained as $\text{3000 mg/L}$ and $\text{12000 mg/L}$, respectively. The hydraulic retention time and mean cell residence time are $0.2$ day and $10$ days, respectively. A representative flow diagram of the $\text{ASP}$ is shown below.

The underflow volume (in $m^{3}$/day, $\textit{round off to one decimal place}$) of sludge wastage is _______________________