A Reconnaissance Study of Mercury and Base Metal Concentrations in Water, and Stream- and Lake-Sediment Samples along the Pecos River, Eastern New Mexico

Virginia T. McLemore, Lynn A. Brandvold, New Mexico Bureau of Mines and Mineral Resources, and Donald K. Brandvold, New Mexico Institute of Mining and Technology


Water quality of the Pecos River has become a major concern as population in eastern New Mexico increases together with a corresponding increase in multiple uses for agriculture, municipal, domestic, and recreational purposes. Samples of fish, waterfowl and small mammals have been found to contain elevated levels of certain metals and other pollutants. In this study, water and stream- and lake-sediments were collected along the Pecos River during a five-day period in September 1992 and were analyzed for mercury, lead, copper, and zinc. Sediments were also analyzed for chromium. Mercury, lead, copper, and zinc concentrations in sediments are elevated above and immediately below the Pecos mine waster dumps, suggesting that the waste dumps, outcropping zones of mineralization and the outcropping rocks may be potential sources. However, elsewhere in the Pecos drainage basin other sources for these metals should be considered as well.