The migration of arsenic and lead in surface sediments at Three Kids Mine, Henderson, Nevada

This study focused on the distribution of arsenic and lead in surface sediments at Three Kids Mine in Henderson, Nevada. The mine site encompasses approximately 470 acres of desert and is situated above two developing communities (Lake Las Vegas and Calico Ridge) and the Las Vegas Valley's water source (Lake Mead).;Transport of arsenic and lead appears to have occurred within a limited range in both the eastern and western washes on the eastern and western sides of Three Kids Mine. Concentrations of arsenic range between 20 mg/kg (ppm) and 1130 mg/kg and between 20 mg/kg and 8400 mg/kg for lead. Samples gathered from the north side of the site indicate a mixing of the natural soils which are low in arsenic and lead with much higher arsenic and lead levels which apparently originated from the milling process employed on the site. This migration of arsenic and lead apparently resulted from the transport of sediments containing arsenic and lead down gradient in surface runoff during storm events. Sorption of arsenic and lead onto the surfaces of soil particles is postulated to be the major source of transport during wet periods for this site. As a result, transport of arsenic and lead from the Three Kids Mine could possibly pose a threat to Lake Las Vegas if a catastrophic storm event or repeated storm events were to occur within a short period of time.