The Albuquerque Bernalillo County Water Utility Authority (ABCWUA) is supplementing the municipal water supply for Albuquerque, New Mexico, and the surrounding area with water diverted from the Rio Grande. The distribution of surface water for municipal supply has raised questions about the quality of water in the Rio Grande and the possibility of contaminants in the water. The U.S. Geological Survey (USGS), in cooperation with ABCWUA, has compiled existing water-quality data collected on the Rio Grande and its main tributary, the Rio Chama, by various Federal and State agencies to provide a comprehensive overview of water quality in the Rio Grande basin upstream from Albuquerque. This report describes selected water-quality investigations conducted by various Federal and State agencies and 2007 USGS surface-water-quality investigations and data-collection activities and presents a statistical summary of selected water-quality data collected on the Rio Grande and the Rio Chama in central and northern New Mexico