Barbara J Mahler (Former Employee)
Science and Products
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Contaminant trends in reservoir sediment cores as records of influent stream quality
When reconstructing water-quality histories from lake and reservoir cores, it is sometimes assumed that the chemical signatures in the cores reflect historical water quality in the influent streams. To investigate this assumption, concentrations of metals, PAHs, and organochlorine compounds in sediment cores were compared to those associated with an influent-stream suspended sediment for three res
Authors
P. C. Van Metre, B.J. Mahler
The contribution of particles washed from rooftops to contaminant loading to urban streams
Rooftops are both a source of and a pathway for contaminated runoff in urban environments. To investigate the importance of particle-associated contamination in rooftop runoff, particles washed from asphalt shingle and galvanized metal roofs at sites 12 and 102 m from a major expressway were analyzed for major and trace elements and PAHs. Concentrations and yields from rooftops were compared among
Authors
Peter C. Van Metre, Barbara Mahler
A chronicle of organochlorine contamination in Clear Creek, Galveston and Harris Counties, Texas, 1960-2002, as recorded in sediment cores
Clear Creek flows through the Texas Coastal Plain from its headwaters southeast of Houston, Texas, to Clear Lake, which empties into Galveston Bay. Segments of Clear Creek were on the State of Texas 303(d) list for 1998, 1999, and 2000 as a result of a fish consumption advisory issued by the Texas Department of Health. One of the contaminants for which the fish consumption advisory was issued is t
Authors
Barbara Mahler, Peter Van Metre
A simplified approach for monitoring hydrophobic organic contaminants associated with suspended sediment: Methodology and applications
Hydrophobic organic contaminants, although frequently detected in bed sediment and in aquatic biota, are rarely detected in whole-water samples, complicating determination of their occurrence, load, and source. A better approach for the investigation of hydrophobic organic contaminants is the direct analysis of sediment in suspension, but procedures for doing so are expensive and cumbersome. We de
Authors
B.J. Mahler, P. C. Van Metre
Occurrence, trends, and sources in particle-associated contaminants in selected streams and lakes in Fort Worth, Texas
Several lakes and stream segments in Fort Worth, Texas, have fish consumption bans because of elevated levels of chlordane, dieldrin, DDE, and polychlorinated biphenyls (PCBs). This study was undertaken to evaluate current loading, trends, and sources in these long-banned contaminants and other particle-associated contaminants commonly found in urban areas. Sampling included suspended sediments at
Authors
Peter C. Van Metre, Jennifer T. Wilson, Glenn R. Harwell, Marcus O. Gary, Franklin T. Heitmuller, Barbara Mahler
Chemical quality of water, sediment, and fish in Mountain Creek Lake, Dallas, Texas, 1994-97
The occurrence, trends, and sources of numerous inorganic and organic contaminants were evaluated in Mountain Creek Lake, a reservoir in Dallas, Texas. The study, done in cooperation with the Southern Division Naval Facilities Engineering Command, was prompted by the Navy’s concern for potential off-site migration of contaminants from two facilities on the shore of Mountain Creek Lake, the Naval A
Authors
Peter C. Van Metre, S.A. Jones, J. Bruce Moring, B.J. Mahler, Jennifer T. Wilson
Quality of sediment discharging from the Barton Springs system, Austin, Texas, 2000-2002
Four spring outlets of the Barton Springs system provide the only known habitat for the Barton Springs salamander (Eurycea sosorum), a federally listed endangered species. After heavy rainfall, sediment is flushed through the Barton Springs segment of the Edwards aquifer and springflow often becomes turbid (cloudy). Sediment in urban areas often has high concentrations of hydrophobic contaminants,
Authors
Barbara Mahler
Spatial distribution and trends in trace elements, polycyclic aromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls in Lake Worth sediment, Fort Worth, Texas
In spring 2000, the Texas Department of Health issued a fish consumption advisory for Lake Worth in Fort Worth, Texas, because of elevated concentrations of polychlorinated biphenyls (PCBs) in fish. In response to the advisory and in cooperation with the U.S. Air Force, the U.S. Geological Survey collected 21 surficial sediment samples and three gravity core sediment samples to assess the spatial
Authors
Glenn Richard Harwell, Peter C. Van Metre, Jennifer T. Wilson, Barbara Mahler
Llano Grande Lake bottom sediments; a chronicle of water-quality changes in the Arroyo Colorado, South Texas, 1989-2001
The Arroyo Colorado, an ancient channel of the Rio Grande, extends 90 miles from Mission, Tex., to the Laguna Madre. The Arroyo Colorado flows through areas of intense agricultural cultivation and through important habitat for migrating birds and other wildlife, including several wildlife sanctuaries and refuges. The above-tidal segment of the Arroyo Colorado is included in the State of Texas 2000
Authors
Barbara June Mahler, Peter C. Van Metre
Occurrence of selected volatile organic compounds and soluble pesticides in Texas public water-supply source waters, 1999-2001
During 1999–2001, the U.S. Geological Survey, in cooperation with the Texas Natural Resource Conservation Commission, collected samples of untreated water from 48 public water-supply reservoirs and 174 public water-supply wells. The samples were analyzed for volatile organic compounds (VOCs) and soluble pesticides; in addition, well samples were analyzed for nitrite plus nitrate and tritium. This
Authors
Barbara June Mahler, Michael G. Canova, Marcus O. Gary
Occurrence of Polychlorinated Biphenyls (PCBs) on Suspended Sediment in the Donna Canal, Hidalgo County, Texas, 1999-2001
Some fish in the Donna Canal contain PCBs at levels that might pose a risk to human health if the fish are eaten. Early attempts to locate the source of PCBs in the canal were unsuccessful. An innovative method of sampling and analyzing suspended sediment helped scientists detect PCBs in suspended sediment and narrowed the probable PCB source area(s) from the entire 11-kilometer canal to a 600-met
Authors
B.J. Mahler, P. C. Van Metre, R.M. Miranda
Transport of suspended solids from a karstic to an alluvial aquifer: The role of the karst/alluvium interface
This study focuses on the coupled transport of dissolved constituents and particulates, from their infiltration on a karst plateau to their discharge from a karst spring and their arrival at a well in an alluvial plain. Particulate markers were identified and the transport of solids was characterised in situ in porous and karstic media, based on particle size analyses, SEM, and traces. Transport f
Authors
N. Massei, M. Lacroix, H.Q. Wang, B.J. Mahler, J.P. Dupont
Science and Products
Filter Total Items: 13
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Filter Total Items: 24
No results found.
Filter Total Items: 106
Contaminant trends in reservoir sediment cores as records of influent stream quality
When reconstructing water-quality histories from lake and reservoir cores, it is sometimes assumed that the chemical signatures in the cores reflect historical water quality in the influent streams. To investigate this assumption, concentrations of metals, PAHs, and organochlorine compounds in sediment cores were compared to those associated with an influent-stream suspended sediment for three res
Authors
P. C. Van Metre, B.J. Mahler
The contribution of particles washed from rooftops to contaminant loading to urban streams
Rooftops are both a source of and a pathway for contaminated runoff in urban environments. To investigate the importance of particle-associated contamination in rooftop runoff, particles washed from asphalt shingle and galvanized metal roofs at sites 12 and 102 m from a major expressway were analyzed for major and trace elements and PAHs. Concentrations and yields from rooftops were compared among
Authors
Peter C. Van Metre, Barbara Mahler
A chronicle of organochlorine contamination in Clear Creek, Galveston and Harris Counties, Texas, 1960-2002, as recorded in sediment cores
Clear Creek flows through the Texas Coastal Plain from its headwaters southeast of Houston, Texas, to Clear Lake, which empties into Galveston Bay. Segments of Clear Creek were on the State of Texas 303(d) list for 1998, 1999, and 2000 as a result of a fish consumption advisory issued by the Texas Department of Health. One of the contaminants for which the fish consumption advisory was issued is t
Authors
Barbara Mahler, Peter Van Metre
A simplified approach for monitoring hydrophobic organic contaminants associated with suspended sediment: Methodology and applications
Hydrophobic organic contaminants, although frequently detected in bed sediment and in aquatic biota, are rarely detected in whole-water samples, complicating determination of their occurrence, load, and source. A better approach for the investigation of hydrophobic organic contaminants is the direct analysis of sediment in suspension, but procedures for doing so are expensive and cumbersome. We de
Authors
B.J. Mahler, P. C. Van Metre
Occurrence, trends, and sources in particle-associated contaminants in selected streams and lakes in Fort Worth, Texas
Several lakes and stream segments in Fort Worth, Texas, have fish consumption bans because of elevated levels of chlordane, dieldrin, DDE, and polychlorinated biphenyls (PCBs). This study was undertaken to evaluate current loading, trends, and sources in these long-banned contaminants and other particle-associated contaminants commonly found in urban areas. Sampling included suspended sediments at
Authors
Peter C. Van Metre, Jennifer T. Wilson, Glenn R. Harwell, Marcus O. Gary, Franklin T. Heitmuller, Barbara Mahler
Chemical quality of water, sediment, and fish in Mountain Creek Lake, Dallas, Texas, 1994-97
The occurrence, trends, and sources of numerous inorganic and organic contaminants were evaluated in Mountain Creek Lake, a reservoir in Dallas, Texas. The study, done in cooperation with the Southern Division Naval Facilities Engineering Command, was prompted by the Navy’s concern for potential off-site migration of contaminants from two facilities on the shore of Mountain Creek Lake, the Naval A
Authors
Peter C. Van Metre, S.A. Jones, J. Bruce Moring, B.J. Mahler, Jennifer T. Wilson
Quality of sediment discharging from the Barton Springs system, Austin, Texas, 2000-2002
Four spring outlets of the Barton Springs system provide the only known habitat for the Barton Springs salamander (Eurycea sosorum), a federally listed endangered species. After heavy rainfall, sediment is flushed through the Barton Springs segment of the Edwards aquifer and springflow often becomes turbid (cloudy). Sediment in urban areas often has high concentrations of hydrophobic contaminants,
Authors
Barbara Mahler
Spatial distribution and trends in trace elements, polycyclic aromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls in Lake Worth sediment, Fort Worth, Texas
In spring 2000, the Texas Department of Health issued a fish consumption advisory for Lake Worth in Fort Worth, Texas, because of elevated concentrations of polychlorinated biphenyls (PCBs) in fish. In response to the advisory and in cooperation with the U.S. Air Force, the U.S. Geological Survey collected 21 surficial sediment samples and three gravity core sediment samples to assess the spatial
Authors
Glenn Richard Harwell, Peter C. Van Metre, Jennifer T. Wilson, Barbara Mahler
Llano Grande Lake bottom sediments; a chronicle of water-quality changes in the Arroyo Colorado, South Texas, 1989-2001
The Arroyo Colorado, an ancient channel of the Rio Grande, extends 90 miles from Mission, Tex., to the Laguna Madre. The Arroyo Colorado flows through areas of intense agricultural cultivation and through important habitat for migrating birds and other wildlife, including several wildlife sanctuaries and refuges. The above-tidal segment of the Arroyo Colorado is included in the State of Texas 2000
Authors
Barbara June Mahler, Peter C. Van Metre
Occurrence of selected volatile organic compounds and soluble pesticides in Texas public water-supply source waters, 1999-2001
During 1999–2001, the U.S. Geological Survey, in cooperation with the Texas Natural Resource Conservation Commission, collected samples of untreated water from 48 public water-supply reservoirs and 174 public water-supply wells. The samples were analyzed for volatile organic compounds (VOCs) and soluble pesticides; in addition, well samples were analyzed for nitrite plus nitrate and tritium. This
Authors
Barbara June Mahler, Michael G. Canova, Marcus O. Gary
Occurrence of Polychlorinated Biphenyls (PCBs) on Suspended Sediment in the Donna Canal, Hidalgo County, Texas, 1999-2001
Some fish in the Donna Canal contain PCBs at levels that might pose a risk to human health if the fish are eaten. Early attempts to locate the source of PCBs in the canal were unsuccessful. An innovative method of sampling and analyzing suspended sediment helped scientists detect PCBs in suspended sediment and narrowed the probable PCB source area(s) from the entire 11-kilometer canal to a 600-met
Authors
B.J. Mahler, P. C. Van Metre, R.M. Miranda
Transport of suspended solids from a karstic to an alluvial aquifer: The role of the karst/alluvium interface
This study focuses on the coupled transport of dissolved constituents and particulates, from their infiltration on a karst plateau to their discharge from a karst spring and their arrival at a well in an alluvial plain. Particulate markers were identified and the transport of solids was characterised in situ in porous and karstic media, based on particle size analyses, SEM, and traces. Transport f
Authors
N. Massei, M. Lacroix, H.Q. Wang, B.J. Mahler, J.P. Dupont