A well with a pump is located $230$ m to the west of an impermeable boundary that prevents water from flowing horizontally. The aquifer has a storage coefficient of $0\mathrm{.}002$ and a transmissivity of $0\mathrm{.}63$ m$2$ min$-1.$ The flow rate from the well is $0\mathrm{.}26$ m$3$ min$-1.$ Calculate the drawdown in an observation well located $118$ m to the west of the impermeable boundary after $9$ days of continuous pumping.

Solve pretending there $isan$ imaginery well $230m$ east $of$ the impermeable boundary. Use the formula:

s $=($Q$/4$piT$)($W$(u_r$