Along the United States-Mexico border region, numerous Federal, State, and local agencies; nongovernmental organizations (NGO); and researchers collect water-quality data for many purposes. The water community uses a number of documented and undocumented procedures, some of which have specific data-quality objectives (DQO) and data-information objectives. This mix of procedures results in uncertainties by data users as to data validity and quality. These uncertainties limit the use of the data by the U.S. Environmental Protection Agency (USEPA); International Boundary and Water Commission (IBWC) United States and Mexico; U.S. Geological Survey (USGS); State environmental agencies; NGOs; and the public, as well as their counterparts in Mexico.

The USEPA, IBWC, USGS, and Texas Natural Resource Conservation Commission (TNRCC) have been working cooperatively to establish a Water-Quality Monitoring Council for the international reach of the Rio Grande (Río Bravo). A similar effort is occurring along the western international boundary with interested partners including the U.S. Bureau of Reclamation (BOR), Arizona Department of Environmental Quality (ADEQ), and the California Regional Water Quality Control Board (CRWQCB). As of February 1997, the partners agreed to work towards greater cooperation, specifically: 1. to revise the 1977 Joint Report of IBWC Engineers as specified in IBWC Minute No. 289; 2. to implement a binational Intergovernmental Task Force for Water-Quality Monitoring (ITFM) workgroup by inviting the participation of cooperators from Mexico; 3. to review and revise each agency’s existing monitoring network to reduce interagency redundancy; 4. to develop a bilingual manual for water-quality monitoring that would describe various field methods used for sampling water, aquatic biology, and sediment, and for assessing stream habitat; and selection of methods on the basis of DQOs, representativeness, and limitations; 5. to establish a common, easily accessible water-quality database; and 6. to hold joint training programs in water-quality monitoring and data management. Part of the fourth goal—to develop a field manual for water-sample-collection methods—will be accomplished with the publication of this manual.