Search USGS⌕ Search

Geology topics

M.S. Davenport

Publications and source records attributed to M.S. Davenport.

5 recordsLinked to original sources
USGS1993

Water-quality and biological data for selected streams, lakes, and wells in the High Point Lake watershed, Guilford County, North Carolina, 1988-89

Water and bottom-sediment samples were collected at 26 sites in the 65-square-mile High Point Lake watershed area of Guilford County, North Carolina, from December 1988 through December 1989. Sampling locations included 10 stream sites, 8 lake sites, and 8 ground-water sites. Generally, six steady-flow samples were collected at each stream site and three storm samples were collected at five sites. Four lake samples and eight ground-water samples also were collected. Chemical analyses of stream and lake sediments and particle-size analyses of lake sediments were performed once during the study. Most stream and lake samples were analyzed for field characteristics, nutrients, major ions, trace elements, total organic carbon, and chemical-oxygen demand. Analyses were performed to detect concentrations of 149 selected organic compounds, including acid and base/neutral extractable and volatile constituents and carbamate, chlorophenoxy acid, triazine, organochlorine, and organophosphorus pesticides and herbicides. Selected lake samples were analyzed for all constituents listed in the Safe Drinking Water Act of 1986, including Giardia, Legionella, radiochemicals, asbestos, and viruses. Various chromatograms from organic analyses were submitted to computerized library searches. The results of these and all other analyses presented in this report are in tabular form.

North Carolina↗
USGS1990

Water-quality trends and basin activities and characteristics for the Albemarle-Pamlico estuarine system, North Carolina and Virginia

The Albemarle-Pamlico estuarine system has a total basin area of nearly 31,000 square miles and includes the Neuse, Tar, Pamlico, Roanoke, Chowan, and Alligator Rivers, and the Albemarle, Pamlico, Currituck, Croatan, and Roanoke Sounds. Albemarle Sound receives the greatest freshwater inflow of all the sounds in the estuarine system. Inflow to this sound averages about 13,500 cubic feet per second. Inflow to Pamlico Sound from the Pamlico River averages around 5,400 cubic feet per second, and average inflow into the Neuse River estuary is about 6,100 cubic feet per second. Approximately one-half of the inflow into the system is from ground-water discharge. The Neuse River basin has had the greatest increases in wastewater discharges (650 percent since the 1950's) and had the greatesttotal wastewater discharges of any of the basins in the study area, averaging about 200 million gallons per day in 1988. Wastewater discharges into the Neuse and Tar Rivers were nearly equal to the 7-day, 10-year low flows for these rivers. Land-use data compiled in 1973 for the lower parts of the Neuse River basin and lower part of the Tar-Pamlico River basin indicate that 25 percent of the area was evergreen forest, 25 percent was forested wetlands, 20 percent was cropland and pasture, 12 percent was mixed forest, 10 percent was nonforested wetland, and 4 percent was urban. The amount of nonforested wetland in the part of the study area along the Outer Banks declined 6.5 percent from 1973 to 1983. The numbers of farms and acreage in agricultural use in the study area have declined since the 1920's. A decrease of more than 60 percentin the number of farms was shown between the early 1950's and 1982. Fertilizer sales increased through the 1970's, but declined in the 1980's. Manufacturing employment has increased in the last 30 years, while agricultural employment has decreased. Data from seven stations of the U.S. Geological Survey National Stream Quality Accounting Network were used to evaluate water quality for the major streams flowing into the Albemarle-Pamlico estuarine system. Water-quality data for 296 stations in the estuarine system were examined for the period 1945-88. The statistical test used for trend analysis was the Seasonal Kendall test (Hirsch and others, 1982). This nonparametric procedure is useful for analyses of water-quality properties that show non-normally distributed frequency distributions. The Seasonal Kendall trend analyses of water-quality data indicate that change has occurred in the water quality of the Albemarle-Pamlico estuarine system from 1945 to 1988. Dissolved-oxygen concentrations increased at a mean rate of 0.1 milligram per liter per year throughout the estuarine system, except in the Chowan River where decreases of approximately 0.06 milligram per liter per year occurred. In general, pH increased in streams throughout the area at a mean rate of 0.04 pH unit per year, except in the Pamlico River where pH decreased by 0.03 pH unit per year. A general increase in pH and dissolved-oxygen concentrations (if daytime measurements) might be indicative of more productive estuary conditions for algal growth. Suspended-solids concentrations decreased throughout the area at a mean rate of 1.1 milligrams per liter per year, probably as a result of a general decrease in suspended inorganic material. Increasing trends of salinity concentrations, as much as 0.1 part per thousand per year, were detected in Albemarle Sound. Total ammonia plus organic nitrogen concentrations decreased (-0.03 milligram per liter per year) in streams throughout most of the area but increased (0.02 milligram per liter per year) in the Pamlico River. However, ammonia nitrogen concentrations decreased (-0.0035 milligram per liter per year) in the Pamlico River; therefore, increases in organic nitrogen probably caused the observed increase in combined ammonia plus organic nitrogen concentrations. This probably results from increas

North Carolina, Virginia↗
USGS1989

Water quality in Reedy Fork and Buffalo Creek basins in the Greensboro area, North Carolina, 1986-87

Water and bottom-sediment samples were collected from April 1986 through September 1987 at 19 sites in Guilford County and the City of Greensboro, North Carolina. Sampling locations included 13 stream sites, two lakes that supply the City of Greensboro with drinking water, two City of Greensboro finished drinking-water filtration plants, and effluent from the two municipal wastewater plants prior to outfall into receiving streams. Water sampling consisted of six surveys during various stages of steady ground-water flow at all sites and high-flow-event sampling during two storms at six sites. Bottom-sediment samples were collected at three sites during two routine sampling surveys. A summary of nearly 22, 000 separate chemical or physical analyses of water samples or bottom sediment is presented and discussed as individual values, ranges of values, or median values with respect to the locations of sampling sites, streamflow conditions, or other information bearing on water-quality conditions under discussion. The results include discussions of general water-quality indicators; major ion, nutrient, and trace-element concentrations; acid and base/neutral extractable organic compounds; volatile organic compounds; and organochlorine and organophosphorus pesticides detected at each sampling site. Loadings of selected constituents are also estimated on a yearly and daily basis. The quality of the raw and finished water, municipal effluents, and streams in the Greensboro area are characterized by using State and Federal water-quality standards. Inorganic constituents most commonly found in excess of standards were iron, copper, zinc, arsenic, phosphorus, manganese, cyanide, and mercury. Relatively few organic compounds were detected; however, those consistently reported were phthalate, thihalomethane, organophosphorus pesticide, benzol, and phenolic compounds. Selected inorganic, physical, and total organic carbon data are used in a Wilcoxon test for two independent variables to statistically compare water-quality characteristics in selected rural, semideveloped and urban basins. During low-flow sampling, the constituents that differed significantly among all sites were calcium, magnesium, and chloride. During low flows, concentrations of orthophosphate, fluoride, sulfate, and TOC differed at the urban site from the rural and semideveloped and urban sites. There were no significant differences among sites in concentrations of sodium, suspended sediment, nickel, zinc, copper, and mercury during low flows. The Wilcoxon test performed on high-flow data indicated that concentrations of TOC, chloride, sulfate, suspended sediment, and nickel were not significantly different among the sites.

North Carolina↗
USGS1988

Surface-water and water-quality data from selected streams and treated waters in the Greensboro Area, North Carolina, 1986-87

Water and bottom-sediment samples were collected from April 1986 to September 1987 at 19 sites in Guilford County and the City of Greensboro, North Carolina. Sampling locations included 13 stream sites, two lakes that supply City of Greensboro drinking water, two City of Greensboro finished drinking-water filtration plants, and two municipal wastewater plants where effluents were sampled prior to outfall into the receiving streams. Water sampling consisted of six routine samplings during various stages of steady flow at all sites, and rainfall-event sampling during two storms at six sites. Bottom-sediment samples were collected at three sites during two routine samplings. Samples were analyzed for trace-element, major ion, and nutrient concentrations, as well as general water-quality indicators, such as pH, dissolved oxygen, and specific conductivity. Concentrations of acid and base/neutral extractable, volatile organic compounds, and organochlorine and organophosphorus constituents were also determined. Chromatographs from organic analyses were submitted to computerized library searches, the results of which are included in this report. Results from all analyses are presented in tabular form in the appendices.

North Carolina↗