PCBs are transported through the environment in the vapor phase to Lake Superior. Let's assume that the flux to this lake is almost all due to rainfall, which has an average PCB concentration of 30 ng/L. The average depth of Lake Superior is 150 m, and the rainfall averages 80 cm/year. Assume that everything has been at steady state over the last several decades and that the residence time of PCBs in the lake is 3 years. For the moment, don't worry about deposition of PCBs to the sediment of this lake. What is the concentration of PCBs in Lake Superior water?