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.

Purpose and Scope

The purpose of this interagency manual is to document/compile field water-sample-collection methods (water column only) commonly used by various "participating" agencies for assessing the water quality of international and transboundary rivers. These agencies include the USEPA-Regions VI and IX, IBWC, USGS, BOR, and State regulatory agencies. This document is intended to provide an objective assessment of the benefits and limitations associated with each sampling method to enable the collector to select the field procedure that is most appropriate for the respective agency's needs or individual project's DQOs. This manual covers only water-column sampling of ambient waters of rivers, streams, lakes, and reservoirs. This manual also is not intended to replace agency-specific, detailed guidelines or sampling instructions provided by the USEPA, IBWC, USGS, BOR or State agencies for various water-quality projects. Users of this manual are advised to contact water-quality personnel within their agency for final determinations on sampling procedures, techniques, and protocols. The development of new and improved field techniques is a continuing process. Therefore, this manual might not contain the most recent information after it is printed and distributed. The user should review their agency protocols if there are any questions.

Field Manual Review and Revision

This interagency manual has been reviewed and revised by the following participants: Forrest B. John, USEPA-Region VI; Yusuf Farran and Yvette McKenna, IBWC; and Lloyd Woosley, USGS. Editorial and technical reviews were completed by USGS personnel. Reviews and opportunities to comment were afforded to the Comisión Nacional del Agua (CNA) through the IBWC, Mexican Section. The use of any trade names or materials in this manual does not constitute an endorsement of the product or material by any participating agencies.


The preparation of this document was made possible by the USEPA. The information included in this manual is based on existing agency manuals, various reference documents, and a broad spectrum of colleague expertise. The manual compilers wish to thank the following individuals for their contributions: Delores Williams, USGS, manuscript preparation and Clarence E. Ranzau, USGS, photographer.

| IFM home page | USGS | EPA |
| Back to Table of Contents | |

Contact Dee Lurry for more information