A little stream discharges 0.5m3/s of clean water into a large river where the depth is 10m, and the mean velocity 0.6m/s.If0.1kg/sec of some chemical are added to the stream, what will be the maximum...

A little stream discharges 0.5m3/s of clean water into a large river where the depth is 10m, and the mean velocity 0.6m/s.If0.1kg/sec of some chemical are added to the stream, what will be the maximum concentration in the river? Assume that upstream of the confluence the river is free of contaminants, and that instantaneous mixing occurs in the vertical direction.