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M. A. Sylvester

Publications and source records attributed to M. A. Sylvester.

7 recordsLinked to original sources
USGS1994

Bioaccumulation of selenium from natural geologic sources in western states and its potential consequences

Ecological impacts of water-quality problems have developed in the western United States resulting from the disposal of seleniferous agricultural wastewater in wetland areas. Overt effects of selenium toxicosis occurred at five areas where deformities of wild aquatic birds were similar to those first observed at Kesterson National Wildlife Refuge in the west-central San Joaquin Valley of California. These areas are: Tulare Lake Bed Area, California, Middle Green River Basin, Utah, Kandrick Reclamation Project Area, Wyoming, Sun River Basin, Montana, and Stillwater Wildlife Management Area, Nevada. Potential for ecological damage is indicated at six more sites in Oregon, Colorado, the Colorado/Kansas border, and South Dakota out of 16 areas in 11 states where biological tissue data were collected. This conclusion is based on the fact that selenium bioaccumulated in bird livers to median levels that had exceeded or were in the range associated with adverse reproductive effects. Selenium concentrations in samples of fish and bird eggs support these conclusions at a majority of these areas. Reason for concern is also given for the lower Colorado River Valley, although this is not exclusively a conclusion from these reconnaissance data. Biogeochemical conditions and the extent of selenium contamination of water, bottom sediment, and biota from which this assessment was made are given here. In a companion paper, the biogeochemical pathway postulated for selenium contamination to take place from natural geologic sources to aquatic wildlife is defined.

Environmental Management↗
USGS1993

Concentrations, distribution, and sources of selenium from irrigated lands in western United States

Concentrations, distribution, and sources of selenium from irrigated lands were studied between 1986 and 1990 at 20 reconnaissance project areas in 17 western states under the Department of Interior's National Irrigation Water Quality Program. Samples of water, bottom sediment, whole‐body fish, and bird livers for analysis of selenium concentrations were collected before, during, and after irrigation season from streams, canals, lakes, and ground water in each project area. Selenium concentrations in water ranged from less than the detection limit of 1 μg/L in 42% of the 586 samples collected to 4,800 μg/L from a well in the Pine River Area, in southern Colorado. Selenium concentrations in 223 samples of bottom sediment ranged from less than the detection limit of 0.1 μg/g to 85 μg/g in a sample from the Middle Green River Basin, in Utah. Selenium concentrations in whole‐body fish (all species) ranged from 0.1 μg to 50 μg per gram dry weight, with the maximum concentration observed in a carp from the Gunnison River Basin, in western Colorado. Selenium concentrations in bird livers (all species) ranged from less than 0.32 μg to 170 μg per gram dry weight with the maximum concentration observed in the liver of an avocet from the Kendrick Reclamation Project, in Wyoming. Cretaceous‐age marine shales probably are the original sources for selenium in 16 of the 20 areas studied. In several areas, evaporative concentration of applied irrigation water and drainage of this water to wetlands, canals, streams, and lakes appears to be responsible for elevated concentrations of selenium.

Colorado, Utah, Wyoming↗
USGS1988

Water quality of the Lexington Reservoir, Santa Clara County, California, 1978-80

Analysis of water samples from Lexington Reservoir and Los Gatos Creek upstream from the reservoir from June 1978 through September 1980 showed that water generally met water-quality objectives identified by California Regional Water Quality Control Board, San Francisco Bay Region. Water-temperature profiles show that Lexington Reservoir is a warm monomictic lake. During summer, dissolved-oxygen concentrations generally were not reduced below 5.0 mg/L in the hyplimnion; only once during the study did bottom waters become anoxic. Water transparency decreased with depth. The euphotic zone ranged from 1.0 to 5.4 m, depending on suspended solids and algae, and was greater in summer than in spring. Calcium and bicarbonate were dominant ions at all stations except during spring, following the rainy season, when waters were a mixed cation bicarbonate type. Nitrogen concentrations were greater in samples from reservoir stations than in those from Los Gatos Creek, with most of the nitrogen in ammonia and organic forms. The amount of dissolved nitrate appeared to be related to phytoplankton abundance. Phosphorus and trace-element concentrations were low at all stations. Estimates of net primary productivity and Carlson 's trophic-state index, based on chlorophyll-a concentrations, indicated that reservoir classification ranges from oligotrophic to mesotrophic. Blue-green algae generally were predominant in reservoir samples. (USGS)

Water-Resources Investigations Report↗
USGS1983

Land application of wastewater and its effect on ground-water quality in the Livermore-Amador Valley, Alameda County, California

Ground-water quality, ground-water level, and rainfall data collected during the 1975 water year through the 1980 water year were analyzed to determine the effects of land application of effluent from wastewater treatment plants on ground-water quality in the Livermore-Amador Valley. Annual rainfall varied markedly during the study: 1976 and 1977 water years had less than one half the normal rainfall; 1978 and 1980 water years had greater than normal rainfall; and 1975 and 1979 water years had nearly normal rainfall. The direction ground-water movement in the valley was found to be generally that of surface water. Dissolved nitrate concentrations were generally much less in areas not receiving wastewater applications than in areas that do. Specific conductance, dissolved solids, dissolved chloride, and dissolved nitrate were substantially less in the lower aquifers than in the upper aquifer in the Livermore wastewater application areas. In the Castlewood, Pleasanton, Veterans Administration Hospital, and Livermore wastewater applications areas ground-water quality was similar to the quality of effluent from wastewater treatment plants in the valley. Rainfall, soil, and geology appeared to be the main determinants of ground-water quality in the Castlewood and Dublin-San Ramon and Camp Parks Military Reservation areas. Wastewater application appeared to be the main determinant of ground-water quality in Pleasanton, Veterans Administration Hospital, and Livermore Municipal Airport areas. Comparison of ground-water quality in wastewater application areas with proposed State water-quality objectives for ground water in the Livermore-Amador Valley showed impaired water quality in all areas.

California↗