Permeable Reactive Treatment Wall Design $(+15)$

The saturated zone under an air force base in Albuquerque, New Mexico, is contaminated with $670m\frac{g}{L}$

trichloroethene $($TCE$)$ from years of cleaning jets over uncontained pavement. The saturated depth of the

aquifer in the location of the contamination is $120$ feet, it has a porosity of $0\mathrm{.}28,$ and an average linear

groundwater velocity of $0\mathrm{.}5f\frac{t}{?}$ day. The plume of contamination extends throughout the saturated depth of

the aquifer and is $83$ feet wide. An in situ permeable reactive treatment wall of zero valent iron $(Fe)$ is

selected to treat the contamination.

a$.$ Calculate the minimum amount of $Fe$ in metric tons needed to degrade the plume down to the drinking

water MCL of $5u\frac{g}{L}.$

Answer: $M=349$ metric tons

b$.$ Determine the required thickness and residence time of your treatment wall.

Answers: Thickness $=0\mathrm{.}43$ feet; residence time $=44hr$