The elemental concentration over time of sediments from four trenches from the Aztec drinking water reservoir #1. The source of water to the reservoir is the Animas River, which has historical mining sites in the watershed. In order to evaluate the geochemical record in the sediments, several types of data were collected. Bulk chemical analysis of sediments with depth in the reservoir as well as X-ray fluorescence measurements provide information about the sediment total chemistry. Batch experiments where sediments are reacted with different reagents provide information about the mobility of major and trace elements from the sediments into the reservoir water or environment. Sediment field descriptions provide information about the grain size, degree of sorting, redox conditions, and reaction with hydrochloric acid or hydrogen peroxide.