ERS is currently characterizing the environmental risks associated with an active mining belt in the Andes where mining and ore processing has been done since the early 17th century. ERS was contracted to characterize soil, mine waste, and surface water used for irrigation in an area of approximately 100 square kilometers. To rapidly investigate these materials in a large and remote area, ERS employed field-portable X-ray fluorescence spectroscopy (XRF) to do an initial screening study. Results of that study indicated that soils and surface water used for irrigation of crops are widely affected by heavy metals released by mining activities and mine wastes. ERS created a GIS database to allow integration of results and flexible graphic and data interpretation methods. We are now performing a geochemical study of the broad irrigation system to understand the chemical processes occurring during the transport, reuse, and uptake of irrigation water affected by heavy metals, which is key to evaluating the bioavailability of metals, the risks to health and agriculture, and effective remedial options.