In this exercise we will measure several water quality (chemistry) parameters at the same site where we measured stream discharge. We will combine the water quality and discharge to estimate the flux of dissolved species in the stream. Water managers and regulators commonly make these types of measurements to determine the flux of contaminants into drinking water supplies. The development of a ``Dead Zone'' in the Gulf of Mexico annually is related to nitrate runoff via the Mississippi River. Researchers are urging a nitrate reduction program to reduce the adverse effects on fisheries from this phenomenon.