$4-3)$

The "contaminant" concentration has been found to be $200$m for the area of a site represented in plan view in the following figure. The groundwater contours are spaced at intervals of about $50$ m$.$ From test borings, the average thickness of the aquifer is $5$ m and the hydraulic conductivity is estimated to be $110-2$s$.$ For each meter of length as measured parallel to the river, what is the contaminant loading rate in kg$/$yr$?$