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<br />Table 10.--sample-collection schedule for water, bottom sediment, <br />and biota, November 1987 and January, March, and July 1988 <br /> <br />Sample medium and analysis <br /> <br />Months samples were collected <br /> <br />Water, inorganic <br />Water, pesticides <br />Bottom sediment, inorganic <br />Bottom sediment, pesticides <br />Birds, inorganic <br /> <br />November, January, March, July <br />July <br />November, January <br />November, January <br />May, June, July <br /> <br />Birds, pesticides <br />Eggs, inorganic <br />Eggs, pesticides <br />Fish, inorganic <br />Fish, pesticides <br /> <br />May, June, July <br />May, June, July <br />May, June, July <br />Julyl <br />July <br /> <br />Invertebrates, inorganic <br />Plants, inorganic <br /> <br />July <br />July <br /> <br />lFish samples also were collected at Sweitzer Lake in March 1989. <br /> <br />Water-quality samples were collected at three sites on the Gunnison <br />River and two sites on the Uncompahgre River (table 9; fig. 2). One site on <br />each stream was selected as a background site and was located upstream from <br />all lands receiving irrigation water from the Uncompahgre Project. Site 2 <br />(Gunnison River below Gunnison Tunnel) is the bac~ground site for the Gunnison <br />River, and water quality at site 2 is equivalent to the quality of the water <br />diverted into the Gunnison Tunnel. Water quality of the Gunnison River <br />immediately upstream from the confluence of the Uncompahgre River at Delta was <br />sampled at site 3 (Gunnison River at Delta). There is irrigation drainage and <br />tailwater from project lands that discharge into the Gunnison River upstream <br />from site 3; however, there also is irrigation drainage and return flow from <br />the Smith Fork basin, from the North Fork basin, and from irrigated land on <br />the north side of the Gunnison River. The outflow site downstream from the <br />entire project area is at site 11, (Gunnison River upstream from Escalante <br />Creek). Site 11 was the nearest site to the Escalante State Wildlife Area <br />where the Gunnison River could be sampled, and samples collected at site 11 <br />represent the quality of water flowing through the Escalante State Wildlife <br />Area (site 10). Much of the inflow into the Gunnison River between the mouth <br />of the Uncompahgre River at Delta and site 11 is from Roubideau Creek, which <br />was estimated to contribute less than 5 percent of the stream discharge of the <br />Gunnison River at site 11. <br /> <br />The background sampling site for the Uncompahgre River was at site 4 <br />(Uncompahgre River at Colona) (fig. 2). Site 9 (Uncompahgre River at Delta) <br />is the outflow sampling site for the Uncompahgre River and is located about <br />1.1 mi upstream [rom the confluence with the Gunnison River near Delta. <br />Water-quality differences between sites 4 and 9 could be attributed to several <br />factors. During the nonirrigation season (November through March), irrigation <br />drainage and shallow ground-water discharge probably have the largest effect <br />on water quality of the river. Runoff in tributaries, such as Happy Canyon, <br /> <br />32 <br />