WSP07583

• File Number: 8270.200
• Description: Selenium
• State: CO
• Basin: Gunnison
• Water Division: 4
• Date: 1/1/1996
• Author: USGS
• Title: Detailed Study of Selenium and Other Constituents in Water-Bottom Sediment-Soil-Alfalfa and Biota Associated with Irrigation Drainage - Uncompahgre Project Area and in the Grand Valley - 1991-93
• Water Supply Pro - Doc Type: Report/Study

(0013~8

2,680 11g!L in a new (when the sample was collected
in the 1930's) drain near Mack in the Grand Valley.
The USGS has collected selenium and other trace-
constituent data since 1975 for the Gunnison and
Colorado Rivers. These selenium data are
summarized later in this report in the "Selenium
Concentrations and Loads in the Gunnison and
Colorado Rivers" section. The U.S. Department
of Energy (1986) collected trace-constituent data,
including selenium, from some wells near a uranium
mill-tailings pile in Grand Junction.
Because of a suspected problem concerning
human consumption of fish that had high levels of
selenium, the Colorado Division of Wildlife collected
selenium data for fish from Sweitzer Lake near Delta
in 1974 and 1977 (Colorado Division of Wildlife,
written commun., 1987). A summary of the data is in
Butler and others (1991). Because of results of the
fish sampling, a sign was posted in 1977 at Sweitzer
Lake that warned about high selenium concentrations
in fish in the lake.
A reconnaissance investigation of the Gunnison
and Uncompahgre Rivers and Sweitzer Lake (Butler
and others, 1991) was done in 1988-89 to determine
if irrigation drainage from the Uncompahgre Project
was affecting water, fish. and wildlife resources.
Butler and others (1991) reported high selenium
concentrations in some water, bottom-sediment,
and biota samples and that the Uncompahgre
Project was a significant source of selenium,
dissolved solids, and sulfate to the Uncompahgre
River. The maximum selenium concentration in
water samples was 320 11g!L from the Garnet
Canal diversion into Sweitzer Lake. A bottom-
sediment sample from Sweitzer Lake had 41 l1g1g
of selenium. Selenium concentrations in whole-
body fish samples from Sweitzer Lake ranged
from 15.2 to 50.0 l1g1g dry weight. There also
were large selenium concentrations in some of
the bird samples collected from Sweitzer Lake
and from the Escalante State Wildlife Area, which
is along the Gunnison River downstream from Delta
(fig. I). However, the reconnaissance investigation
did not document adverse effects of selenium on fish
and birds.
Selenium concentrations in soil, water,
vegetables, and field crops in irrigated areas of the
Uncompahgre Project and the Grand Valley were
reported in Follett and others (1990). Sampling was
limited to a few sites in each area. Follett and others

(1990) reported low selenium concentrations in
vegetables (broccoli and sweet com) and in field
crops (alfalfa and wheat).
Considerable dissolved-solids and major-
constituent data were collected in the study area
for salinity studies and other studies related to
agriculture. A study of irrigation-retum-flow water
quality in the Grand Valley was done by Duke and
others (1976). Salinity data collected for a salinity-
control demonstration project in the Grand Valley
were reported by Binder and others (1978). The
BOR has done several investigations concerning
salinity studies in the Uncompahgre Project (Bureau
of Reclamation, 1984, 1987) and in the Grand Valley
(Bureau of Reclamation, 1978,1983,1985). The
report by the BOR (1983) described a detailed water
budget for the Grand Valley. The USGS collected
dissolved-solids and major-ion data for several
streams and washes in the Grand Valley between 1973
and 1983 for the salinity investigations. Whittig and
others (1983) did a salinity investigation in the West
Salt Creek Basin, located west of irrigated areas in the
Grand Valley.
An early survey of soils in the Uncompahgre
Valley was done in 1910 by the U.S. Department of
Agriculture (Nelson and Kolbe, 1912). A more recent
soil survey of the Uncompahgre Project area was done
by Cline and others (1967). A study of soil in saline
areas of the Grand Valley was done by Fireman and
others (1951). Spears and Kleven (1978) did a soil
survey of Mesa County, which includes the Grand
Valley. Lusby (1978) described results of a long-
term study of grazing effects on sediment runoff in
a nonirrigated area in the western end of the Grand
Valley.
Meeks (1950) investigated geology and ground
water in the irrigated areas of the Uncompahgre
Valley. Another investigation of ground water in the
Uncompahgre Valley was done by Craig (1971). A
reconnaissance study of ground-water resources in the
lower Gunnison River Basin was described by Brooks
and Ackerman (1985). Lohman (1965) described the
geology and hydrology of artesian aquifers in the
Grand Valley. Uranium and selenium-indicator plants
that were used for uranium prospecting in the
Colorado Plateau are described by Cannon (1954).
The BOR did several water-resource and
hydrogeologic investigations of the Uncompahgre
Project and the Grand Valley as part of the salinity-
control projects in each area. A report by the BOR

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