Geology topics

A. C. Sedam

Publications and source records attributed to A. C. Sedam.

4 recordsLinked to original sources

USGS1991

Geologic setting and water quality of selected basins in the active coal-mining areas of Ohio, 1987-88

This report presents hydrologic data from selected drainage basins in the active coal-mining areas of Ohio from July 1987 through October 1988. The study area is mostly within the unglaciated part of eastern Ohio along the western edge of the Appalachian Plateaus physiographic province. The 1987-88 work is the second phase of a 7-year study to assess baseline water quality in Ohio's coal region. The data collection network consisted of 41 long-term surface-water sites in 21 basins. The sites were measured and sampled twice yearly at low flow. In addition, six individual basins (three each year) selected for a more detailed representation of surface-water and ground-water quality. In 1987, the Sandy Creek, Middle Tuscarawas River and Sugar Creek, and Lower Tuscarawas River basins were chosen. In 1988, the Short and Wheeling Creeks, Upper Wills Creek, and Upper Raccoon Creek basins were chosen. Because of their proximity to the glaciated region and outwash drainage, the basins studied intensively in 1987 contain more shallow productive aquifers than do the basins studied in detail for 1988, in which shallow ground-water sources are very localized. Chemical analyses for 202 surface-water and 24 ground-water samples are presented. For field measurements made at surface-water sites, the specific conductance ranged from 295 to 3150 ? S/cm (microsiemens per centimeter at 25 degrees Celsius). For pH, the range was 2.8 to 8.6. Alkalinity ranged from 5 to 305 mg/L (milligrams per liter) as CaCO3.

Water-Resources Investigations Report↗

USGS1989

Ground-water levels, water quality, and potential effects of toxic-substance spills or cessation of quarry dewatering near a municipal ground-water supply, southern Franklin County, Ohio

A newly completed municipal ground-water supply that produces from a sand and gravel aquifer in southern Franklin County, Ohio, may be susceptible to potential sources of pollution. Among these are spills of toxic substances that could enter recharge areas of the aquifer or be carried by surface drainage and subsequently enter the aquifer by induced infiltration. Ground water of degraded quality also is present in the vicinity of several landfills located upstream from the municipal supply. Local dewatering by quarrying operations has created a ground-water divide which, at present, prevents direct movement of the degraded ground water to the municipal supply. In addition, the dewatering has held water levels at the largest landfills below the base of the landfill. Should the dewatering cease, concern would be raised regarding the rise of water levels at this landfills and transport of contaminants through the aquifer to the Scioto River and subsequently by the river to the well field. From June 1984 through July 1986, the U.S. Geological Survey, in cooperation with the City of Columbus, Ohio, investigated the relations among the ground-water supply and potential sources of contamination by means of an observation-well network and a program of measuring water levels and sampling for water quality. Sample collections included those made to determine the baseline levels of organic chemicals and metals, as well as periodic sampling and analysis for common constituents to evaluate any changes taking place in the system. Finally, a steady-state, three-dimensional numerical model was used to determine ground-water flow directions and average ground-water velocities to asses potential effects of toxic-substance spills. The model also was used to simulate changes in the ground-water flow system that could result if part or all of the quarry dewatering ceased. Few of the organic-chemical and metal constituents analyzed for were present at detectable levels. With respect to chemical analysis of water and soil materials reported in earlier studies, no new problem areas were discovered as a result of either the baseline or periodic samplings. Model simulations suggest that, under March 1986 conditions, a toxic-substance spill along the major highways in the northern two-thirds of the study area eventually could discharge into one of the two quarries being dewatered or into the Scioto River. A toxic-substance spill in the southern one-third of the study area ultimately may discharge into the Scioto River, Big Walnut Creek, or possibly into the municipal ground-water supply. Model simulations also indicate that concentrated landfill leachate probably would not reach the municipal ground-water supply under current or well-field pumping conditions if dewatering ceased at either or both of the quarries.

Ohio↗

USGS1985

Ground-water quality and geochemistry of aquifers associated with coal in the Allegheny and Monongahela formations, southeastern Ohio

Ground water from aquifers associated with coal beds in the Allegheny and Monongahela Formations in southeastern Ohio is predominantly a calcium magnesium bicarbonate type. Sodium bicarbonate type water is less common. Isolated areas of sodium chloride and calcium sulfate types also are present. The water is predominantly very hard, and has a median hardness concentration of 258 milligrams per liter as calcium carbonate and a median dissolved-solids concentration of 436 milligrams per liter. Few wells contain water with dissolved-solids concentrations in excess of 1,000 milligrams per liter. Bicarbonate concentration in ground water was found to be significantly different among coals, whereas concentrations of bicarbonate, hardness, calcium, magnesium, sodium, iron, manganese, and strontium were significantly different between ground water in the Allegheny and Monongahela Formations. Many constituents are significantly correlated, but few correlation coefficients are high. The presence of sulfate or iron is attributed to the kinetic mechanism operating during the oxidation of pyrite. The position along the sulfide or ferrous-iron oxidation pathways controls the reaction products of pyrite found in solution, and the formation of either the sulfate of iron constituents. The availability and rate of diffusion of oxygen in the formations exerts control on the water quality. Discriminant-function analysis correctly classifies 89 percent of the observations into the Allegheny or Monongahela Formations. As a verifications, 39 of 41 observations from another study were correctly classified by formation. The differences in water chemistry between the Allegheny and the Monongahela Formations are gradational and are attributed the oxidation of iron sulfide. The diffusion and availability of oxygen, which controls the chemical reaction, is regulated by the porosity and permeability of the rock with respect to oxygen and the presence or absence of carbonates, which controls the pH.

Water-Resources Investigations Report↗

USGS1984

Occurrence of uranium in ground water in the vicinity of the U.S. Department of Energy Feed Materials Production Center, Fernald, Ohio

Process wastes are stored on site in rubber-lined and clay-lined pits and in large tanks at the U.S. Department of Energy Feed Materials Production Center (FMPC), where purified uranium and uranium compounds are produced. Water samples collected from off-site domestic and commercial wells in December 1981 and in August 1982, contained concentrations of dissolved uranium that ranged from < 0.4 to 430 micrograms/L (ug/L). The wells whose samples contained unusual concentrations of uranium (> 10 ug/L) lie roughly along a line extending about 2000 ft south from the southern boundary of FMPC. The offsite area affected by these concentrations is probably < 100 acres. It is not possible to determine the exact point of origination of contaminants in the groundwater on the basis of available data. (Author 's abstract)

Open-File Report↗