Charles A Cravotta, III, PhD, PG (Former Employee)
Science and Products
Filter Total Items: 89
Assessing mine drainage pH from the color and spectral reflectance of chemical precipitates
The pH of mine impacted waters was estimated from the spectral reflectance of resident sediments composed mostly of chemical precipitates. Mine drainage sediments were collected from sites in the Anthracite Region of eastern Pennsylvania, representing acid to near neutral pH. Sediments occurring in acidic waters contained primarily schwertmannite and goethite while near neutral waters produced fer
Authors
D.J. Williams, J.M. Bigham, C.A. Cravotta, S.J. Traina, J.E. Anderson, J.G. Lyon
Water-quality trends for a stream draining the Southern Anthracite Field, Pennsylvania
Stream flow, chemical and biological data for the northern part of Swatara Creek, which drains a 112 km2 area in the Southern Anthracite Field of eastern Pennsylvania, indicate progressive improvement in water quality since 1959, after which most mines in the watershed had been flooded. Drainage from the flooded mines contributes substantially to base flow in Swatara Creek. Beginning in 1995, a va
Authors
C.A. Cravotta, Michael D. Bilger
Detecting change in water quality from implementation of limestone treatment systems in a coal-minded watershed
During 1996-97, a variety of limestone-based treatment systems were implemented to neutralize acidic mine drainage and reduce the transport of dissolved metals in the northern part of the Swatara Creek watershed, which drains a 43-mi2 (112-km2) area in the Southern Anthracite Field upstream from Ravine, Pa. Since 1996, the current project has monitored water quality upstream and downstream of each
Authors
Charles A. Cravotta, Jeffrey B. Weitzel
Relations among sulfate, metals, sediment, and streamflow data for a stream draining a coal-mined watershed in East-Central Pennsylvania
Streamflow and water-quality data for the northern part of Swatara Creek, which drains a 112-km2 area in the Southern Anthracite Field of east-central Pennsylvania, indicate iron, copper, and lead, and to a lesser extent manganese and zinc, are transported with suspended particles during stormflow conditions. During stormflow conditions, concentrations of these constituents typically peak prior to
Authors
Charles A. Cravotta
Geochemical investigations by the U.S. Geological Survey on uranium mining, milling, and environmental restoration
Recent research by the U.S. Geological Survey has characterized contaminant sources and identified important geochemical processes that influence transport of radionuclides from uranium mining and milling wastes. 1) Selective extraction studies indicated that alkaline earth sulfates and hydrous ferric oxides are important hosts of 226Ra in uranium mill tailings. The action of sulfate-reducing and
Authors
Edward R. Landa, Charles A. Cravotta, David L. Naftz, Philip L. Verplanck, D. Kirk Nordstrom, Robert A. Zielinski
Hydrobiogeochemical interactions in 'anoxic' limestone drains for neutralization of acidic mine drainage
Processes affecting neutralization of acidic coal mine drainage were evaluated within `anoxic' limestone drains (ALDs). Influents had pH≤3.5 and dissolved oxygen <2 mg/l. Even though effluents were near neutral (pH>6 and alkalinity>acidity), two of the four ALDs were failing due to clogging. Mineral-saturation indices indicated the potential for dissolution of calcite and gypsum, and precipitation
Authors
E. I. Robbins, C.A. Cravotta, C.E. Savela, Gordon L. Nord
Oxic limestone drains for treatment of dilute, acidic mine drainage
Limestone treatment systems can be effective for remediation of acidic mine drainage (AMD) that contains moderate concentrations of dissolved O2 , Fe3+ , or A13+ (1‐5 mg‐L‐1 ). Samples of water and limestone were collected periodically for 1 year at inflow, outflow, and intermediate points within underground, oxic limestone drains (OLDs) in Pennsylvania to evaluate the transport of dissolved metal
Authors
Charles A. Cravotta
Effect of sewage sludge on formation of acidic ground water at a reclaimed coal mine
Data on rock, ground water, vadose water, and vadose gas chemistry were collected for two years after sewage sludge was applied at a reclaimed surface coal mine in Pennsylvania to determine if surface-applied sludge is an effective barrier to oxygen influx, contributes metals and nutrients to ground water, and promotes the acidification of ground water. Acidity, sulfate, and metals concentrations
Authors
C.A. Cravotta
Oxygen transport and pyrite oxidation in unsaturated coal-mine spoil
An understanding of the mechanisms of oxygen (02) transport in unsaturated mine spoil is necessary to design and implement effective measures to exclude 02 from pyritic materials and to control the formation of acidic mine drainage. Partial pressure of oxygen (Po2) in pore gas, chemistry of pore water, and temperature were measured at different depths in unsaturated spoil at two reclaimed surface
Authors
Weixing Guo, Charles A. Cravotta
Use of stable isotopes of carbon, nitrogen, and sulfer to identify sources of nitrogen in surface waters in the Lower Susquehanna River basin, Pennsylvania
Stable isotopes of carbon (C), nitrogen (N), and sulfur (S) in nitrogen sources and nearby samples of topsoil, subsoil, runoff water, and stream water were measured to evaluate the feasibility of using isotopic data to identify nitrogen sources in stream water from forested, agricultural, or suburban land-use areas. Chemical and isotopic compositions were measured for six N-source types consisting
Authors
C.A. Cravotta
Effects of selective handling of pyritic, acid-forming materials on the chemistry of pore gas and ground water at a reclaimed surface coal mine in Clarion County, PA, USA
A change from dragline to “selective handling” mining methods at a reclaimed surface coal mine in western Pennsylvania did not significantly affect concentrations of metals in ground water because oxidation of pyrite and dissolution of siderite were not abated. Throughout the mine, placement of pyritic material near the land surface facilitated the oxidation of pyrite, causing the consumption of o
Authors
Charles A. Cravotta, Diana L. Dugas, Keith Brady, Thomas E. Kovalchuck
Geochemical and geohydrological characteristics of bedrock and spol from two methods of mining at a reclaimed surface coal mine, Clarion County, PA, USA
Two methods of mining caused subtle differences in geochemical and geohydrological characteristics of spoil at a reclaimed surface coal mine in western Pennsylvania. A dragline was used in the southern area of the mine, and bulldozers and front-end loaders were used in the northern area. Mining methods used in the intervening, middle area are uncertain. In general, overburden at the mine consisted
Authors
Charles A. Cravotta, Keith Brady, Linda C. Gustafson-Minnich, Michael R. DiMatteo
Science and Products
Filter Total Items: 89
Assessing mine drainage pH from the color and spectral reflectance of chemical precipitates
The pH of mine impacted waters was estimated from the spectral reflectance of resident sediments composed mostly of chemical precipitates. Mine drainage sediments were collected from sites in the Anthracite Region of eastern Pennsylvania, representing acid to near neutral pH. Sediments occurring in acidic waters contained primarily schwertmannite and goethite while near neutral waters produced fer
Authors
D.J. Williams, J.M. Bigham, C.A. Cravotta, S.J. Traina, J.E. Anderson, J.G. Lyon
Water-quality trends for a stream draining the Southern Anthracite Field, Pennsylvania
Stream flow, chemical and biological data for the northern part of Swatara Creek, which drains a 112 km2 area in the Southern Anthracite Field of eastern Pennsylvania, indicate progressive improvement in water quality since 1959, after which most mines in the watershed had been flooded. Drainage from the flooded mines contributes substantially to base flow in Swatara Creek. Beginning in 1995, a va
Authors
C.A. Cravotta, Michael D. Bilger
Detecting change in water quality from implementation of limestone treatment systems in a coal-minded watershed
During 1996-97, a variety of limestone-based treatment systems were implemented to neutralize acidic mine drainage and reduce the transport of dissolved metals in the northern part of the Swatara Creek watershed, which drains a 43-mi2 (112-km2) area in the Southern Anthracite Field upstream from Ravine, Pa. Since 1996, the current project has monitored water quality upstream and downstream of each
Authors
Charles A. Cravotta, Jeffrey B. Weitzel
Relations among sulfate, metals, sediment, and streamflow data for a stream draining a coal-mined watershed in East-Central Pennsylvania
Streamflow and water-quality data for the northern part of Swatara Creek, which drains a 112-km2 area in the Southern Anthracite Field of east-central Pennsylvania, indicate iron, copper, and lead, and to a lesser extent manganese and zinc, are transported with suspended particles during stormflow conditions. During stormflow conditions, concentrations of these constituents typically peak prior to
Authors
Charles A. Cravotta
Geochemical investigations by the U.S. Geological Survey on uranium mining, milling, and environmental restoration
Recent research by the U.S. Geological Survey has characterized contaminant sources and identified important geochemical processes that influence transport of radionuclides from uranium mining and milling wastes. 1) Selective extraction studies indicated that alkaline earth sulfates and hydrous ferric oxides are important hosts of 226Ra in uranium mill tailings. The action of sulfate-reducing and
Authors
Edward R. Landa, Charles A. Cravotta, David L. Naftz, Philip L. Verplanck, D. Kirk Nordstrom, Robert A. Zielinski
Hydrobiogeochemical interactions in 'anoxic' limestone drains for neutralization of acidic mine drainage
Processes affecting neutralization of acidic coal mine drainage were evaluated within `anoxic' limestone drains (ALDs). Influents had pH≤3.5 and dissolved oxygen <2 mg/l. Even though effluents were near neutral (pH>6 and alkalinity>acidity), two of the four ALDs were failing due to clogging. Mineral-saturation indices indicated the potential for dissolution of calcite and gypsum, and precipitation
Authors
E. I. Robbins, C.A. Cravotta, C.E. Savela, Gordon L. Nord
Oxic limestone drains for treatment of dilute, acidic mine drainage
Limestone treatment systems can be effective for remediation of acidic mine drainage (AMD) that contains moderate concentrations of dissolved O2 , Fe3+ , or A13+ (1‐5 mg‐L‐1 ). Samples of water and limestone were collected periodically for 1 year at inflow, outflow, and intermediate points within underground, oxic limestone drains (OLDs) in Pennsylvania to evaluate the transport of dissolved metal
Authors
Charles A. Cravotta
Effect of sewage sludge on formation of acidic ground water at a reclaimed coal mine
Data on rock, ground water, vadose water, and vadose gas chemistry were collected for two years after sewage sludge was applied at a reclaimed surface coal mine in Pennsylvania to determine if surface-applied sludge is an effective barrier to oxygen influx, contributes metals and nutrients to ground water, and promotes the acidification of ground water. Acidity, sulfate, and metals concentrations
Authors
C.A. Cravotta
Oxygen transport and pyrite oxidation in unsaturated coal-mine spoil
An understanding of the mechanisms of oxygen (02) transport in unsaturated mine spoil is necessary to design and implement effective measures to exclude 02 from pyritic materials and to control the formation of acidic mine drainage. Partial pressure of oxygen (Po2) in pore gas, chemistry of pore water, and temperature were measured at different depths in unsaturated spoil at two reclaimed surface
Authors
Weixing Guo, Charles A. Cravotta
Use of stable isotopes of carbon, nitrogen, and sulfer to identify sources of nitrogen in surface waters in the Lower Susquehanna River basin, Pennsylvania
Stable isotopes of carbon (C), nitrogen (N), and sulfur (S) in nitrogen sources and nearby samples of topsoil, subsoil, runoff water, and stream water were measured to evaluate the feasibility of using isotopic data to identify nitrogen sources in stream water from forested, agricultural, or suburban land-use areas. Chemical and isotopic compositions were measured for six N-source types consisting
Authors
C.A. Cravotta
Effects of selective handling of pyritic, acid-forming materials on the chemistry of pore gas and ground water at a reclaimed surface coal mine in Clarion County, PA, USA
A change from dragline to “selective handling” mining methods at a reclaimed surface coal mine in western Pennsylvania did not significantly affect concentrations of metals in ground water because oxidation of pyrite and dissolution of siderite were not abated. Throughout the mine, placement of pyritic material near the land surface facilitated the oxidation of pyrite, causing the consumption of o
Authors
Charles A. Cravotta, Diana L. Dugas, Keith Brady, Thomas E. Kovalchuck
Geochemical and geohydrological characteristics of bedrock and spol from two methods of mining at a reclaimed surface coal mine, Clarion County, PA, USA
Two methods of mining caused subtle differences in geochemical and geohydrological characteristics of spoil at a reclaimed surface coal mine in western Pennsylvania. A dragline was used in the southern area of the mine, and bulldozers and front-end loaders were used in the northern area. Mining methods used in the intervening, middle area are uncertain. In general, overburden at the mine consisted
Authors
Charles A. Cravotta, Keith Brady, Linda C. Gustafson-Minnich, Michael R. DiMatteo
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government