A tank has ruptured and a pool of benzene has formed. The pool is approximately rectangular with dimensions of \(20 \mathrm{ft}\) by \(30 \mathrm{ft}\). Estimate the evaporation rate and the distance affected downwind. Define the plume boundary using \(10 \mathrm{ppm}\). It is an overcast day with a \(9 \mathrm{mph}\) wind. The temperature is \(90^{\circ} \mathrm{F}\).