Chlorine: From Table $3$ below, $99\mathrm{.}9$ percent $(3\mathrm{.}0$ log $)$ inactivation of Giardia cysts and a free chlorine residual of $1\mathrm{.}0m\frac{g}{l}$ is required. Assuming that the temperature is $10C,$ and pH is $7\mathrm{.}5,$ calculate the concentration and pounds of chlorine needed.

Source: Adapted from Guidance Manual for Compliance with the Filtration and Disinfection Requirements for Public Water Systems Using Surface Water Sources. U$.$S$.$ Environmental Protection Agency.