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David P. Brown

Publications and source records attributed to David P. Brown.

8 recordsLinked to original sources
USGS1998

Summary of ground-water quality in West Virginia

Water-quality data for the 28 sites in the West Virginia ambient ground-water-quality network and for wells in the U.S. Geological Survey National Water Information System (NWIS) data base for West Virginia were analyzed statistically to identify any water-quality trends and relations and to compare data from the two data sets. Data for 10 selected properties and constituents (pH, fecal coliform, iron, manganese, sulfate, hardness, nitrate plus nitrite, chloride, fluoride, and dissolved solids) were grouped by geologic unit, topographic setting, well depth, and season; simple statistical descriptors such as mean, median, maximum, minimum, standard deviation, and 10th and 90th percentiles were computed for each property and constituent and are summarized in tables. Analysis of the data for wells from the NWIS data base showed that highest median concentrations of dissolved iron and dissolved manganese are in samples from the Lower Pennsylvanian units, which are found mainly in the low-sulfur coal fields of southern West Virginia; the highest median concentration of dissolved sulfate is in samples from the Quaternary alluvium along the Ohio and Kanawha Rivers; and the highest median hardness and concentrations of dissolved nitrate plus nitrite are in samples from the Cambrian and Ordovician karst limestone units found mainly in the Eastern Panhandle. The highest median concentrations of dissolved iron and dissolved manganese are in samples from valley wells and wells of shallow depth, and hardness is greatest in samples from hilltop wells. Analysis of data for all wells and springs in the ambient network corroborated statistics for the NWIS data set in that median concentration of total iron is highest in samples from the Lower Pennsylvanian units, median concentration of dissolved sulfate is highest in samples from the Quaternary alluvium, and hardness and median concentrations of total nitrate plus nitrite are highest in samples from the Cambrian and Ordovician units. Data from the ambient network did not show any significant seasonal variations in groundwater quality. Of the additional constituents sampled for in the ambient network, median concentrations of metals were less than U.S. Environmental Protection Agency drinking-water standards, and organic chemical constituents were rarely detected. Statistical comparisons of data from the NWIS data base and the ambient network data set showed no significant differences except for fecal coliform, iron, and manganese. Median concentrations of these three constituents were several times greater for samples from wells and springs in the ambient network. Statistical differences in values for these constituents could be attributed to differences in the state of constituents sampled (dissolved concentrations of iron and manganese for the NWIS data set as opposed to total concentrations for the ambient network data set) and the smaller number of sites in the ambient network. Statistical resolution could be improved by sampling a greater number of wells and springs that have a greater diversity of geologic and topographic conditions for the ambient network. The present ambient network does not include sites in Silurian or Middle Pennsylvanian geologic units nor sites in hilltop settings. The statistical validity of the ambient network could be improved by sampling additional sites, especially those for aquifers underrepresented in the data set.

West Virginia↗
USGS1983

Water resources of Manatee County, Florida

Rapid development of Manatee County in southwest Florida is creating water-resource problems. This report presents an evaluation of the water resources and potential effects of water-resource developments. Most streams in the county have small drainage basins and minimal flow. Streamflow is variable with the base flow occurring from November to May. The Manattee River and its largest tributary, the Braden River, are the principal sources of public supplies. Surface water is generally of good quality and less mineralized than ground water except in the tidally affected and coastal area. The principal aquifers in the county are the surficial, minor artesian, and the Floridan. The Floridan aquifer is the major source of irrigation water in the county. The minor artesian aquifer is a highly developed source of water for small rural supplies. Withdrawals of 20 to 50 million gallons per fay from the Floridan aquifer since the 1950 's have caused declines in the potentiometric surface of about 20 to 50 feet. The quality of ground water is good except in the coastal and southern parts of the county. Water in the Floridan aquifer is generally more mineralized than the other aquifers, generally increasing in mineral content with depth and from the northeast towards the southwest. (USGS)

Water-Resources Investigations Report↗
USGS1982

Water resources and data-network assessment of the Manasota Basin, Manatee and Sarasota Counties, Florida

The average annual rainfall in the Manasota Basin is 53.7 inches , and annual evapotranspiration is about 39 inches. Annual runoff from gaged parts of the Basin ranges from about 13 to 17 inches per year. Streamflow in the upland areas diminishes rapidly following the end of the rainy season and approaches zero during extended dry periods. Generally, surface water is of good quality except in tidally affected, coastal areas. Its quality varies seasonally, generally becoming more mineralized during the dry season. The principal hydrogeologic units are the surficial aquifer, the upper confining beds and minor artesian aquifers, the Floridan acquifer, and the lower confining bed. The quality of ground water is generally good except in the western and southern parts where saltwater intrusion or incomplete flushing of residual seawater has occurred. Land-use changes and stream impoundments and diversions require reassessment of the type and use of data collected by the surface-water network. Such changes may require modification of existing sites and establishment of new ones. Development and completion of the monitoring plan could provide most of the data necessary to define the groundwater system. (USGS)

Water-Resources Investigations Report↗
USGS1980

Geologic and hydrologic data from a test-monitor well at Fernandina Beach, Florida

A 2,102-foot observation well was drilled at Fernandina Beach, Florida, to obtain geologic and hydrologic data. Drill cuttings, water samples, and water-level measurements were collected. Geologist's, driller's, and geophysical logs were completed. The well is constructed with 12-inch diameter casing to a depth of 515 feet and 6-inch diameter casing from 515 to 2,000 feet. The remainder is open hole. The uppermost 500 feet of material penetrated by the well consists of sand, clay, limestone, and dolomite. In the remainder of the hole, the material consists of fragmental and granular limestone and massive to finely crystalline dolomite, which comprise the Floridan aquifer in the area. After the well was completed, water levels in the monitored zone, 2,000 to 2,102 feet, were above land surface. During July and August 1979, water levels ranged from about 8 to 13 feet above land surface. Chloride concentrations of water sampled through the drill stem from a depth of 632 to 2,039 feet ranged from 25 to 710 milligrams per liter. Chloride increased markedly below 2,039 feet to a maximum of 7,800 milligrams per liter at 2,094 feet. After completion of the well, chloride was 8,100 milligrams per liter.

Florida↗
USGS1979

Results of testing landspreading of treated municipal wastewater at St. Petersburg, Florida

Chlorinated secondary-treated effluent was used to irrigate a grassed 4-acre site at rates of 2 and 4 inches per week for periods of 11 and 14 weeks, respectively. Part of the site was drained by tile lines 5 feet below land surface. Irrigation of the drained plot resulted in rapid passage of the applied wastewater through the soil and, consequently, poor nitrogen removal. The rapid percolation permitted nitrification but prevented denitrification. Total phosphorus in the shallow ground water at the site increased from a maximum of 1.4 milligrams per liter before irrigation to as much as 5 milligrams per liter in the ground water 5 feet below land surface. Concentrations of nitrogen and phosphorus did not increase in ground water downgradient from the site, although increased chloride concentrations demonstrated downgradient migration of the applied wastewater. Prior to irrigation, total coliform bacteria were not detected in ground water at the site. After irrigation, total and fecal coliforms were detected in the ground water at the site and downgradient. (Woodard-USGS)

Water-Resources Investigations Report↗