George Bennett
George Bennett - California Water Science Center
Science and Products
Filter Total Items: 52
Sources of High-Chloride Water to Wells, Eastern San Joaquin Ground-Water Subbasin, California
As a result of pumping and subsequent declines in water levels, chloride concentrations have increased in water from wells in the Eastern San Joaquin Ground-Water Subbasin, about 80 miles east of San Francisco (Montgomery Watson, Inc., 2000). Water from a number of public-supply, agricultural, and domestic wells in the western part of the subbasin adjacent to the San Joaquin Delta exceeds the U.S.
Authors
John A. Izbicki, Loren F. Metzger, Kelly R. McPherson, Rhett R. Everett, George L. Bennett V
A tool for assessing mercury loadings from restored tidal systems
Accurately quantifying net loads in tidal systems is difficult owing to the high variability in constituent concentrations over the vastly different time scales present in these systems. Perhaps most difficult is the measurement of fluxed over the tidal time scale. On this scale, the net export of the constituent is orders of magnitude less than the bulk exchange in either direction because of the
Authors
J.A. Fleck, B.A. Bergamaschi, B.D. Downing, M. A. Lionberger, D. H. Schoellhamer, E. Boss, M. Stephenson
Sources, bioavailability, and photoreactivity of dissolved organic carbon in the Sacramento-San Joaquin River Delta
We analyzed bioavailability, photoreactivity, fluorescence, and isotopic composition of dissolved organic carbon (DOC) collected at 13 stations in the Sacramento-San Joaquin River Delta during various seasons to estimate the persistence of DOC from diverse shallow water habitat sources. Prospective large-scale wetland restorations in the Delta may change the amount of DOC available to the food web
Authors
R. Stepanauskas, M.A. Moran, B.A. Bergamaschi, J.T. Hollibaugh
Suspended sediment fluxes in a tidal wetland: Measurement, controlling factors, and error analysis
Suspended sediment fluxes to and from tidal wetlands are of increasing concern because of habitat restoration efforts, wetland sustainability as sea level rises, and potential contaminant accumulation. We measured water and sediment fluxes through two channels on Browns Island, at the landward end of San Francisco Bay, United States, to determine the factors that control sediment fluxes on and off
Authors
N. K. Ganju, D. H. Schoellhamer, B.A. Bergamaschi
Quantifying the contributions of tidal wetlands to dissolved organic material in the San Francisco Estuary, California, USA
No abstract available.
Authors
B.A. Bergamaschi, B.A Downing, G.A Wheeler, D. H. Schoellhamer, N. Ganju, M.S. Fram, D.E. Erickson, C. Kendall, B.E. Bemis, R. Stepanauskas, J.T. Hollibaugh, R. Fujii
Preliminary assessment of DOC and THM precursor loads from a freshwater restored wetland, an agricultural field, and a tidal wetland in the Sacramento-San Joaquin River Delta
Water exported from the Sacramento-San Joaquin River Delta supplies drinking water to more than 22 million people in California. At certain times of the year, Delta waters contain relatively high concentrations of dissolved organic carbon (DOC) and bromide. During these times, chlorination of Delta water for drinking water disinfection will form disinfection byproducts, such as trihalomethanes (TH
Authors
R. Fujii, B.A. Bergamaschi, N. K. Ganju, J.A. Fleck, K.R. Burow-Fogg, D. Schoellhamer, S. J. Deverel
Evaluation of specific ultraviolet absorbance as an indicator of the chemical composition and reactivity of dissolved organic carbon
Specific UV absorbance (SUVA) is defined as the UV absorbance of a water sample at a given wavelength normalized for dissolved organic carbon (DOC) concentration. Our data indicate that SUVA, determined at 254 nm, is strongly correlated with percent aromaticity as determined by 13C NMR for 13 organic matter isolates obtained from a variety of aquatic environments. SUVA, therefore, is shown to be a
Authors
J.L. Weishaar, George R. Aiken, Brian A. Bergamaschi, Miranda S. Fram, Roger Fujii, K. Mopper
Covariance of bacterioplankton composition and environmental variables in a temperate delta system
We examined seasonal and spatial variation in bacterioplankton composition in the Sacramento-San Joaquin River Delta (CA) using terminal restriction fragment length polymorphism (T-RFLP) analysis. Cloned 16S rRNA genes from this system were used for putative identification of taxa dominating the T-RFLP profiles. Both cloning and T-RFLP analysis indicated that Actinobacteria, Verrucomicrobia, Cytop
Authors
R. Stepanauskas, M.A. Moran, B.A. Bergamaschi, J.T. Hollibaugh
Tannin diagenesis in mangrove leaves from a tropical estuary: A novel molecular approach
Molecular-level condensed tannin analyses were conducted on a series of mangrove (Rhizophora mangle) leaves at various stages of decomposition in a tropical estuary. Total molecular tannin yields ranged from 0.5% ash-free dry weight (AFDW) in the most highly degraded black leaves (6-7 weeks in the water) up to >7% AFDW in fresh leaves (80% procyanidin (PC) with the remainder being prodelphinidin (
Authors
P.J. Hernes, R. Benner, G.L. Cowie, M.A. Goi, B.A. Bergamaschi, J. I. Hedges
Improving water quality in Sweetwater Reservoir, San Diego County, California; sources and mitigation strategies for trihalomethane (THM)-forming carb
No abstract available.
Authors
M.S. Fram, B.A. Bergamaschi, Roger Fujii
Pesticides associated with suspended sediments entering San Francisco Bay following the first major storm of water year 1996
Estuaries receive large quantities of suspended sediments following the first major storm of the water year. The first-flush events transport the majority of suspended sediments in any given year, and because of their relative freshness in the hydrologic system, these sediments may carry a significant amount of the sediment-associated pesticide load transported into estuaries. To characterize sedi
Authors
Brian A. Bergamaschi, Kathryn Kuivila, Miranda S. Fram
Trihalomethanes formed from natural organic matter isolates: Using isotopic and compositional data to help understand sources
Over 20 million people drink water from the Sacramento-San Joaquin Delta despite problematic levels of natural organic matter (NOM) and bromide in Delta water, which can form trihalomethanes (THMs) during the treatment process. It is widely believed that NOM released from Delta peat islands is a substantial contributor to the pool of THM precursors present in Delta waters. Dissolved NOM was isolat
Authors
Brian A. Bergamaschi, Miranda S. Fram, Roger Fujii, George R. Aiken, Carol Kendall, Steven R. Silva
Science and Products
Filter Total Items: 52
Sources of High-Chloride Water to Wells, Eastern San Joaquin Ground-Water Subbasin, California
As a result of pumping and subsequent declines in water levels, chloride concentrations have increased in water from wells in the Eastern San Joaquin Ground-Water Subbasin, about 80 miles east of San Francisco (Montgomery Watson, Inc., 2000). Water from a number of public-supply, agricultural, and domestic wells in the western part of the subbasin adjacent to the San Joaquin Delta exceeds the U.S.
Authors
John A. Izbicki, Loren F. Metzger, Kelly R. McPherson, Rhett R. Everett, George L. Bennett V
A tool for assessing mercury loadings from restored tidal systems
Accurately quantifying net loads in tidal systems is difficult owing to the high variability in constituent concentrations over the vastly different time scales present in these systems. Perhaps most difficult is the measurement of fluxed over the tidal time scale. On this scale, the net export of the constituent is orders of magnitude less than the bulk exchange in either direction because of the
Authors
J.A. Fleck, B.A. Bergamaschi, B.D. Downing, M. A. Lionberger, D. H. Schoellhamer, E. Boss, M. Stephenson
Sources, bioavailability, and photoreactivity of dissolved organic carbon in the Sacramento-San Joaquin River Delta
We analyzed bioavailability, photoreactivity, fluorescence, and isotopic composition of dissolved organic carbon (DOC) collected at 13 stations in the Sacramento-San Joaquin River Delta during various seasons to estimate the persistence of DOC from diverse shallow water habitat sources. Prospective large-scale wetland restorations in the Delta may change the amount of DOC available to the food web
Authors
R. Stepanauskas, M.A. Moran, B.A. Bergamaschi, J.T. Hollibaugh
Suspended sediment fluxes in a tidal wetland: Measurement, controlling factors, and error analysis
Suspended sediment fluxes to and from tidal wetlands are of increasing concern because of habitat restoration efforts, wetland sustainability as sea level rises, and potential contaminant accumulation. We measured water and sediment fluxes through two channels on Browns Island, at the landward end of San Francisco Bay, United States, to determine the factors that control sediment fluxes on and off
Authors
N. K. Ganju, D. H. Schoellhamer, B.A. Bergamaschi
Quantifying the contributions of tidal wetlands to dissolved organic material in the San Francisco Estuary, California, USA
No abstract available.
Authors
B.A. Bergamaschi, B.A Downing, G.A Wheeler, D. H. Schoellhamer, N. Ganju, M.S. Fram, D.E. Erickson, C. Kendall, B.E. Bemis, R. Stepanauskas, J.T. Hollibaugh, R. Fujii
Preliminary assessment of DOC and THM precursor loads from a freshwater restored wetland, an agricultural field, and a tidal wetland in the Sacramento-San Joaquin River Delta
Water exported from the Sacramento-San Joaquin River Delta supplies drinking water to more than 22 million people in California. At certain times of the year, Delta waters contain relatively high concentrations of dissolved organic carbon (DOC) and bromide. During these times, chlorination of Delta water for drinking water disinfection will form disinfection byproducts, such as trihalomethanes (TH
Authors
R. Fujii, B.A. Bergamaschi, N. K. Ganju, J.A. Fleck, K.R. Burow-Fogg, D. Schoellhamer, S. J. Deverel
Evaluation of specific ultraviolet absorbance as an indicator of the chemical composition and reactivity of dissolved organic carbon
Specific UV absorbance (SUVA) is defined as the UV absorbance of a water sample at a given wavelength normalized for dissolved organic carbon (DOC) concentration. Our data indicate that SUVA, determined at 254 nm, is strongly correlated with percent aromaticity as determined by 13C NMR for 13 organic matter isolates obtained from a variety of aquatic environments. SUVA, therefore, is shown to be a
Authors
J.L. Weishaar, George R. Aiken, Brian A. Bergamaschi, Miranda S. Fram, Roger Fujii, K. Mopper
Covariance of bacterioplankton composition and environmental variables in a temperate delta system
We examined seasonal and spatial variation in bacterioplankton composition in the Sacramento-San Joaquin River Delta (CA) using terminal restriction fragment length polymorphism (T-RFLP) analysis. Cloned 16S rRNA genes from this system were used for putative identification of taxa dominating the T-RFLP profiles. Both cloning and T-RFLP analysis indicated that Actinobacteria, Verrucomicrobia, Cytop
Authors
R. Stepanauskas, M.A. Moran, B.A. Bergamaschi, J.T. Hollibaugh
Tannin diagenesis in mangrove leaves from a tropical estuary: A novel molecular approach
Molecular-level condensed tannin analyses were conducted on a series of mangrove (Rhizophora mangle) leaves at various stages of decomposition in a tropical estuary. Total molecular tannin yields ranged from 0.5% ash-free dry weight (AFDW) in the most highly degraded black leaves (6-7 weeks in the water) up to >7% AFDW in fresh leaves (80% procyanidin (PC) with the remainder being prodelphinidin (
Authors
P.J. Hernes, R. Benner, G.L. Cowie, M.A. Goi, B.A. Bergamaschi, J. I. Hedges
Improving water quality in Sweetwater Reservoir, San Diego County, California; sources and mitigation strategies for trihalomethane (THM)-forming carb
No abstract available.
Authors
M.S. Fram, B.A. Bergamaschi, Roger Fujii
Pesticides associated with suspended sediments entering San Francisco Bay following the first major storm of water year 1996
Estuaries receive large quantities of suspended sediments following the first major storm of the water year. The first-flush events transport the majority of suspended sediments in any given year, and because of their relative freshness in the hydrologic system, these sediments may carry a significant amount of the sediment-associated pesticide load transported into estuaries. To characterize sedi
Authors
Brian A. Bergamaschi, Kathryn Kuivila, Miranda S. Fram
Trihalomethanes formed from natural organic matter isolates: Using isotopic and compositional data to help understand sources
Over 20 million people drink water from the Sacramento-San Joaquin Delta despite problematic levels of natural organic matter (NOM) and bromide in Delta water, which can form trihalomethanes (THMs) during the treatment process. It is widely believed that NOM released from Delta peat islands is a substantial contributor to the pool of THM precursors present in Delta waters. Dissolved NOM was isolat
Authors
Brian A. Bergamaschi, Miranda S. Fram, Roger Fujii, George R. Aiken, Carol Kendall, Steven R. Silva