Investigators collected water, bottom-sediment, soil, and biological samples at more than 50 sites in the San Juan River area during 1993-94. Sample sites included (1) sites located within Department of the Interior irrigation project service areas, or areas that receive drainage from irrigation projects; (2) reference sites for comparison with irrigation project sites; and (3) sites located within the reach of the San Juan River from Navajo Dam to 10 miles downstream from the dam.
United States Geological Survey, "Physical, Chemical, and Biological Data for Detailed Study of Irrigation Drainage in the San Juan Area, New Mexico, 1993-94, with Supplemental Data, 1991-95" (1997). All U.S. Government Documents (Utah Regional Depository). Paper 160.