Water chemistry is measured annually in 11 monitoring wells to characterize regional groundwater chemistry in the Trout Lake area. The chemical parameters measured include pH, conductivity, total alkalinity, dissolved inorganic and organic carbon, total nitrogen, nitrate, ammonia, total phosphorus, calcium, magnesium, sodium, potassium, chloride, sulfate, iron, manganese, total silica and dissolved reactive silica. Chemical data are available at a quarterly sampling frequency for some years. In addition (see related data set - Groundwater Level), water levels in 37 monitoring wells are measured several times per year. The wells are scattered throughout the Trout Lake hydrological basin and the data are used to calibrate and test regional groundwater flow models. Sampling Frequency: annually - with some earlier data from quarterly sampling Number of sites: 11