More than 1000 precipitation water samples were collected from a number of stations in the Champlain Valley, and six ions were measured (Ca, Na, Mg, K, Cl, SO4). As anticipated, considerable variation existed between rains, and between stations. Concentrations were generally higher in urban locations than in rural stations. The median concentration for all samples were: Ca, 1.25; Na, 0.28; Mg, 0.20; K, 0.19; Cl, 1.7; and SO4, 1.9 mg/l. When concentrations were examined on a seasonal basis, higher concentrations were observed during the winter months with the exception of SO4 which was lowest in the winter. The median monthly loads in kg/sq km were: Ca, 99; Na, 36; Mg, 15; K, 21; Cl, 134; and SO4, 147 kg/sq km. Precipitation brings down about 450 kg/km2/month. The concentrations of the six ions, when compared with a high elevation mountain pond, indicate more Cl in rainfall than in the pond water. (WRSIC abstract)