$11-2.$ A sampling program at a Superfund site indicated the following DNAPL zones:

A "pool" of free$-$phase DNAPL in a stratigraphic depression in an unfractured clay. The pool is $200f{t}^2$ in area and averages $5$ ft in thickness.

A zone of residual DNAPL extending directly underneath an old pit $100f{t}^2$ in area. The residual zone extends through the $5$ ft thick unsaturated zone and $15$ ft through the saturated zone until it reaches the DNAPL pool.

Other Data: Laboratory tests of mgs of hydrocarbons on the soil and engineering judgment provided the following saturation data:

Residual saturation in the unsaturated zone: $,0\mathrm{.}10$

Residual saturation in the saturated zone: $0\mathrm{.}35$

Saturation in the free$-$phase zone:

$0\mathrm{.}70$

Figure P$11\mathrm{.}2$

Plan View

$($a$)$ What is the estimated total volume of DNAPL at the site?

$($b$)$ How much is pumpable from a theoretical basis?

$($Assume a typical porosity value of $0\mathrm{.}3.$ This should be considered an upper range estimate of the total recoverable volume. Actual volumes are usually much lower$).$