Variation in precipitation quality during a 40-hour snowstorm in an Urban Environment - Denver, Colorado

Seventeen precipitation samples were collected during a 40-hour snowstorm in the northwestern part of the Denver, Colorado, metropolitan area. Maximum concentrations of barium, calcium, cadmium, chloride, iron, potassium, magnesium, sodium, nitrate, phosphate and sulfate occurred during the initial three hours of the storm. The maximum copper concentrations occurred nearly six hours after the storm began, the maximum strontium concentration occurred 25 hours after the storm began, and the maximum zinc concentration occurred 12 hours after the storm began. Concentrations of beryllium, cobalt, lithium and vanadium were less than the analytical detection limits during the entire storm. Lowest pH values were determined in samples collected during or immediately after periods of normal, maximum automobile traffic.