Based on the provided data, plot a figure showing the chlorine demand curve. Be sure to

label the axes.

a$.$ What is the breakpoint dosage?

b$.$ What chlorine dose should be used to achieve a $2\mathrm{.}1m\frac{g}{L}$ free residual chlorine

concentration?

c$.$ What is the total residual at the dose in part b$?$

Consult Table $16\mathrm{.}2($in LO$2\_$Disinfection$\_$Droste.pdf$)$ to find C$.$t values for $99\mathrm{.}9\%$ reduction in

Giardia lamblia with a free Cl concentration of $2\mathrm{.}0m\frac{g}{L}.($Assume conservatively that the

residual chlorine is $2\mathrm{.}0$ rather than the $2\mathrm{.}1$ we are designing the dosage for.$)$

a$.$ Calculate the required retention time in minutes for a proposed contact tank.

b$.$ Explain which temperature value you used and why.

c$.$ Calculate the size of detention tank needed to achieve this retention time for the design

flowrate. Give your answer in gallons.

Calculate the mass of chlorine gas $(C{l}_2)$ per day needed to treat the system's design flow

$[$lb$/$day$].$