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T. A. Ehlke

Publications and source records attributed to T. A. Ehlke.

12 recordsLinked to original sources
USGS2002

Comparison of dialysis membrane diffusion samplers and two purging methods in bedrock wells

Collection of ground-water samples from bedrock wells using low-flow purging techniques is problematic because of the random spacing, variable hydraulic conductivity, and variable contamination of contributing fractures in each well's open interval. To test alternatives to this purging method, a field comparison of three ground-water-sampling techniques was conducted on wells in fractured bedrock at a site contaminated primarily with volatile organic compounds. Constituent concentrations in samples collected with a diffusion sampler constructed from dialysis membrane material were compared to those in samples collected from the same wells with a standard low-flow purging technique and a hybrid (high-flow/low-flow) purging technique. Concentrations of trichloroethene, cis-1,2-dichloroethene, vinyl chloride, calcium, chloride, and alkalinity agreed well among samples collected with all three techniques in 9 of the 10 wells tested. Iron concentrations varied more than those of the other parameters, but their pattern of variation was not consistent. Overall, the results of nonparametric analysis of variance testing on the nine wells sampled twice showed no statistically significant difference at the 95-percent confidence level among the concentrations of volatile organic compounds or inorganic constituents recovered by use of any of the three sampling techniques.

Conference Paper↗
USGS1987

Hydrology of area 8, eastern Coal Province, West Virginia and Ohio

The hydrology of Area 8 in the Ohio River basin in northwestern West Virginia and southeastern Ohio, is influenced by geology and geologic structure. Rocks underlying the area consist of alternating beds of sandstone, siltstone, shale, limestone, and mudstone. Minable coal is contained within the Pennsylvania and Permian rocks. Coal production in 1980 totaled 6.7 million tons from underground mines and one million tons from surface mines. There is a wide range of soil types (29 soil associations) in five land-resource areas. Precipitation averages about 41 inches annually and is greatest at higher altitudes along the eastern boundary of the area. Average annual runoff ranges from 13 to 29 inches per year. The principal land uses are forest and agriculture. Estimated water use during 1980 was 1,170 million gallons per day. Surface-water quality ranges from excellent to poor. The highest iron, manganese and sulfate concentrations were present in mined areas. Well yields range from less than 1 to 350 gallons per minute. Groundwater from the Mississippian rocks contain lesser amounts of dissolved solids than water from the Lower Pennsylvanian rocks. Water high in chloride content is present in some valley areas. (USGS)

Open-File Report↗
USGS1987

Movement and fate of chlorinated solvents in ground water; research activities at Picatinny Arsenal, New Jersey

The USGS, through its Toxic Waste--Ground-Water Contamination Program, is undertaking an interdisciplinary research study of contaminants. The purpose of the study is to gain a better understanding of the chemical, physical, and biological processes that affect the movement and fate of these contaminants in groundwater. The study is being conducted at Picatinny Arsenal, New Jersey, where metal plating and metal etching wastes have contaminated part of the glacial stratified drift aquifers. Major areas of research at the site are described, including: (1) distribution and movement of chlorinated solvents in groundwater, (2) behavior of chlorinated solvents in the unsaturated zone, (3) geochemistry of the contaminated groundwater, and (4) microbial transformations of chlorinated solvents. (Author 's abstract)

Open-File Report↗
USGS1984

Water resources data, West Virginia, water year 1983

Water resources data for the 1983 water year for West Virginia consist of records of stage, discharge, and water quality of streams and springs, and water levels of ground water. This report contains discharge records for 83 gaging stations; stage only records for 15 gaging stations; contents for 1 reservoir; change in contents for 1 reservoir; water quality for 27 gaging stations; and water levels for 31 observation wells. Also included are 2 crest-stage partial-record stations and 1 low-flow partial record station. Locations of these sites are shown on figures 2 and 3. Additional water data were collected at various sites, not involved in the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in West Virginia.

West Virginia↗
USGS1983

Water resources data West Virginia, water year 1982

Water resources data for the 1982 water year for West Virginia consist of records of stage, discharge, and water quality of streams and springs; stage and contents of lakes and reservoirs; and water levels in wells. This report contains discharge records for 116 gaging stations; stage only records for 9 gaging stations; stage and contents for 8 lakes and reservoirs; contents for 1 reservoir; change in contents for 1 reservoir; water quality for 55 gaging stations; and water levels for 29 observation wells. Also included are 2 crest-stage partial-record stations, and 1 low-flow partial record station. Additional water data were collected at various sites, not part of the systematic data collections program, and are published as miscellaneous measurements and analyses. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal Agencies in West Virginia.

West Virginia↗
USGS1979

Biological and microbiological assessment of the upper Chattahoochee River basin, Georgia

Biological and microbiological studies were conducted by the U.S. Geological Survey as a part of the Intensive River-Quality Assessment studies of the upper Chattahoochee River basin, Georgia. Phytoplankton concentrations in cells per milliliter (cells/mL) were generally higher downstream from Atlanta than upstream. The highest concentrations, mostly blue-green algae, occurred in West Point Lake with an average of 90,000 cells/mL for the sampling period. The lowest concentrations, 1,000 cells/mL, occurred upstream of Lake Sidney Lanier. Dissolved orthophosphate and nitrite plus nitrate concentrations were highest in the river reaches and upper reaches of the two lakes and were lowest at the dam pools of both lakes. The high nitrite plus nitrate concentrations downstream from Atlanta were primarily a result of nitrification by Nitrosomonas and Nitrobacter bacteria. Algal growth potential was highest downstream from Atlanta, 25 milligrams per liter (mg/L) at Whitesburg, and was the lowest in the headwaters and at the dam pools of Lake Sidney Lanier and West Point Lake. The rate of nitrification in the Atlanta to Franklin reach of the river was comparatively low, 0.02 mg/L per hour. Nitrification was an important cause of dissolved-oxygen consumption in a 45-mi reach of the river downstream from the Atlanta wastewater treatment facilities. Dissolved-oxygen consumption as a result of nitrification may be greatest during low flow. (Woodard-USGS)

Alabama, Georgia↗
USGS1977

Methods for collection and analysis of aquatic biological and microbiological samples

Chapter A4 contains methods used by the U.S. Geological Survey to collect, preserve, and analyze waters to determine their biological and microbiological properties. Part 1 discusses biological sampling and sampling statistics. The statistical procedures are accompanied by examples. Part 2 consists of detailed descriptions of more than 45 individual methods, including those for bacteria, phytoplankton, zooplankton, seston, periphyton, macrophytes, benthic invertebrates, fish and other vertebrates, cellular contents, productivity, and bioassays. Each method is summarized, and the application, interferences, apparatus, reagents, collection, analysis, calculations, reporting of results, precision and references are given. Part 3 consists of a glossary. Part 4 is a list of taxonomic references.

Techniques of Water-Resources Investigations↗