D.R. Rankin 2000 Bernalillo County officials recognize the importance of monitoring water quality and ground-water levels in rapidly developing areas. For this reason, water-quality and ground-water- level data were collected from 87 wells, 3 springs, and the Ojo Grande Acequia in the east mountain area of Bernalillo County between January 1990 and June 1999. The water samples were analyzed for selected nutrient species; total organic carbon; major dissolved constituents; methylene blue active substances; and dissolved arsenic. Analytical results were used to compute hardness, sodium adsorption ratio, and dissolved solids. Specific conductance, pH, air and water temperature, alkalinity, and dissolved oxygen were measured in the field at the time of sample collection. Ground-water levels were measured at the time of sample collection. From January 1990 through June 1993, water-quality and ground- water-level data were collected monthly from an initial set of 20 wells; these data were published in a 1995 report. During 1995, water samples and ground-water-level data were collected and analyzed from the initial set of 20 wells and from an additional 31 wells, 2 springs, and the Ojo Grande Acequia; these data were published in a 1996 report. Additional water-quality and ground-water-level data have been collected from sites in the east mountain area: 34 wells and the acequia during 1997, 14 wells and 1 spring during 1998, and 6 wells during 1999. Water-quality and ground- water-level data collected in the east mountain area during 1995 through 1999 are presented in tables. In addition, temporal trends for ground-water levels, concentrations of total and dissolved nitrite plus nitrate, concentrations of dissolved chloride, and specific conductance are presented for 20 selected wells in water-quality and water- level hydrographs. application/pdf 10.3133/ofr00476 en U.S. Dept. of the Interior, U.S. Geological Survey ; Information Services [distributor], Water-quality and ground-water-level trends, 1990-99, and data collected from 1995 through 1999, East Mountain area, Bernalillo County, central New Mexico reports