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Orville B. Lloyd

Publications and source records attributed to Orville B. Lloyd.

5 recordsLinked to original sources
USGS1995

Water-quality assessment of the Albemarle-Pamlico drainage basin, North Carolina and Virginia environmental setting and water-quality issues

The Albemarle-Pamlico drainage study unit is one of 60 units of the U.S. Geological Survey's National Water-Quality Assessment Program, and includes the large river basins which drain into the Albemarle and Pamlico Sounds-the Chowan, Roanoke, Tar-Pamlico, and Neuse River Basins. The study unit includes about 28,000 square miles and has an interrelated set of environmental characteristics which strongly influence water quality. The chemical and physical nature of these characteristics are the dominant controls on baseline water quality in the study area. About 50 percent of the study area is forested, slightly more than 30 percent is agricultural, about 15 percent is wetlands, and less than 5 percent is developed. Three million people live in the study area, and activities related to agriculture and development have caused increased concentrations of constituents such as nutrients, pesticides, and suspended sediment. About two-thirds of the 36 to 52 inches of precipitation in the area reenters the atmosphere by evapotranspiration. About one-third of the remaining precipitation reaches streams by overland runoff; the remainder recharges the water table aquifer, where much of the water eventually discharges to streams as ground water. Thus, ground-water quality has a substantial influence on surface-water quality, particularly during dry weather. In 1990, about 152,900 tons of elemental nitrogen and 10,500 tons of elemental phosphorus either were applied to crops as fertilizer or fixed by biological processes, and in 1987, about 43,500 tons of nitrogen and 12,200 tons of phosphorus were produced as animal wastes. In addition, about 1,300 tons of selected herbicides and 400 tons of selected insecticides were applied to crops in 1990. Some 249 permitted point sources discharged 410 million gallons per day, containing an annual load of 5,800 tons of nitrogen and 1,800 tons of phosphorus, to the study area in 1990. Data from 1970-79 indicate that mean annual suspended-sediment yields for selected forested, agricultural, and developed urban basins in North Carolina are 50, 250, and 550 tons per square mile, respectively. In order to facilitate comparisons, much of the data were compiled by hydrologic unit. Homogeneous areas, or strata, representing the most prevalent combinations of environmental factors, such as land use, soils, and geology, were defined. Future data collection and analyses will be designed to answer objective-related concerns about the relations between important water-quality conditions and these study-unit strata.

North Carolina, Virginia↗
USGS1979

Ground-water resources of Monroe County, Pennsylvania

Monroe County is on the eastern border of Pennsylvania and includes much of the area popularly called the Poconos. It is an area long used for outdoor recreation and includes a part of the Delaware Water Gap National Recreation Area. Water resources in the county are derived from precipitation. The Lehigh and Delaware Rivers, bordering the northwestern and southeastern parts, respectively, are the drains for surface-water and ground-water discharge and are essentially unused for water supply. Water budgets were calculated for average conditions when annual precipitation is 45 in. Sixty percent of this or 27 in. runs off and 65 percent of that runoff or 17 in. moves through the ground-water reservoir. Evapotranspiration varies little between wet and dry years and averages 18 in. Bedrock consists of Silurian and Devonian sedimentary rocks, which are intensely deformed by folding in the southeastern third of the county and are moderately deformed in the remainder. During the Pleistocene Epoch, glaciers repeatedly advanced across most of the county. The last of these advances deposited a terminal moraine that extends across the southwestern part of the county. The glaciers eroded pre-existing deposits, veneered the upland, and filled valleys with unconsolidated deposits that changed surface-water drainage and altered ground-water gradients. Water occurs in fractures and solution openings in the consolidated rocks and in intergranular openings in the unconsolidated rocks and weathered calcareous sandstones. Water that reaches the water table moves down the hydraulic gradient to points of discharge, moving both laterally and vertically away from ground-water divides and toward streams. The thickness of the fresh-water system is 800 ft or more, but little water is yielded to wells by aquifers more than 500 ft below land surface. Ground-water recharge is 600 to 650 (gal/min)/mi 2 ; and about 1.6 billion gallons per square mile is stored in the ground-water reservoir. Currently the most productive wells are in consolidated-rock aquifers; however, specific-capacity data suggest that wells in the unconsolidated deposits have potentially larger yields. Well yield is affected primarily by the distribution, size, and interconnection of the water-bearing openings and by topographic location, available recharge, well-depth, location within the flow system, pumping rate and duration of pumping, and interference from other pumping wells. Potential yields of properly located, drilled, and developed wells have been calculated for the aquifers. The median yields calculated from specific capacity data from the unconsolidated deposits, are 200 gal/min; from the Bloomsburg Formation, 100 gal/min; and from the Poplar Gap Member of the Catskill Formation, 70 gal/min. Median yields of the other units range from 15 to 40 gal/min. In general, enough water for domestic use can be obtained throughout the county. Large-scale development and consumptive use of the ground water will diminish baseflow of the streams. The temperature of water measured in wells ranges from 44° to 57°F and is largely dependent on altitude of the land surface and depth to the producing zone. Hardness of water in the noncarbonate rocks averages 3 to 4 grains per gallon, or about half that of the carbonate rocks. Water from most of the bedrock aquifers is low in dissolved solids, acidic, and soft. In carbonate rocks, the water tends to be hard and slightly alkaline. Excessive amounts of iron and manganese are encountered in water from the unconsolidated deposits and, locally, from the Catskill and Shawangunk Formations.

Pennsylvania↗
USGS1979

Geology and groundwater resources of Monroe County, Pennsylvania

Monroe County is on the eastern border of Pennsylvania and includes much of the area popularly called the Poconos. It is an area long used for outdoor recreation and includes a part of the Delaware Water Gap National Recreation Area. Water resources in the county are derived from precipitation. The Lehigh and Delaware Rivers, bordering the northwestern and southeastern parts, respectively, are the drains for surface-water and groundwater discharge and are essentially unused for water supply.

Pennsylvania↗
USGS1968

Ground-water supply of Cape Hatteras National Seashore recreational area, North Carolina, Part 4

In 1957, the National Park Service requested that the U. S. Geological Survey determine the quality and quantity of available ground water at selected sites within the Cape Hatteras National Seashore Recreational Area. A series of reports, Ground-Water Supply of Cape Hatteras National Seashore Recreational Area" by P. M. Brown (1960), "Ground-Water Supply of Cape Hatteras National Seashore Recreational Area, Part 2" by J. 0. Kimrey (1960), and "Ground -Water Supply of Cape Hatteras National Seashore Recreational Area, Part 3" by W. H. Harris and H. B. Wilder (1964), have been prepared and transmitted to the National Park Service in compliance with their request.

North Carolina↗