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K. A. Elrick

Publications and source records attributed to K. A. Elrick.

16 recordsLinked to original sources

Effects of hurricanes Katrina and Rita on the chemistry of bottom sediments in Lake Pontchartrain, Louisiana, USA

The effects of Hurricanes Katrina and Rita and the subsequent unwatering of New Orleans, Louisiana, on the sediment chemistry of Lake Pontchartrain were evaluated by chemical analysis of samples of street mud and suspended and bottom sediments. The highest concentrations of urban-related elements and compounds (e.g., Pb, Zn, polycyclic aromatic hydrocarbons, and chlordane) in bottom sediments exceeded median concentrations in U.S. urban lakes and sediment-quality guidelines. The extent of the elevated concentrations was limited, however, to within a few hundred meters of the mouth of the 17th Street Canal, similar to results of historical assessments. Chemical and radionuclide analysis of pre- and post-Hurricane Rita samples indicates that remobilization of near-shore sediment by lake currents and storms is an ongoing process. The effects of Hurricanes Katrina and Rita on the sediment chemistry of Lake Pontchartrain are limited spatially and are most likely transitory.

Environmental Science & Technology

The prediction of aquatic sediment-associated trace element concentration using selected geochemical factors

Multiple linear regression models calculated from readily obtainable chemical and physical parameters can explain a high percentage (70 per cent or greater) of observed sediment-trace element variance for Cu, Zn, Pb, Cr, Ni, Co, As, Sb, Se, and Hg in a widely divergent suite of 61 sediment samples. The independent variables used in the models may be single parameters, principal component scores, or principal component scores combined with their cross-products. The most useful type of variable must be determined on a case-by-case basis. The independent variables (geochemical parameters) incorporated in the models calculated during this study probably are applicable to many aquatic sediments; albeit, use of a larger data set (>61) could alter the magnitude of the calculated coefficients. The geochemical parameters included in the models were of a physical (e.g. grain size, surface area) and a chemical (e.g. organic matter, amorphous iron oxides) nature. Comparison between actual and predicted trace element concentrations obtained from the models may provide a means of defining ‘average’ sediment-trace element concentrations. In this context, the models may also help identify either naturally or anthropogenically impacted sites for additional study.

Hydrological Processes

Estimating suspended sediment and trace element fluxes in large river basins: Methodological considerations as applied to the NASQAN programme

In 1994, the NASQAN (National Stream Quality Accounting Network) programme was redesigned as a flux-based water-quality monitoring network for the Mississippi, Columbia, Colorado, and Rio Grande Basins. As the new programme represented a departure from the original, new sampling, processing, analytical, and data handling procedures had to be selected/developed to provide data on discharge, suspended sediment concentration, and the concentrations of suspended sediment and dissolved trace elements. Annual suspended sediment fluxes were estimated by summing daily instantaneous fluxes based on predicted suspended sediment concentrations derived from discharge-based log-log regression (rating-curve) models. The models were developed using both historical and current site-specific discharge and suspended sediment concentrations. Errors using this approach typically are less than ?? 10% for the 3-year reporting period; however, the magnitude of the errors increases substantially for temporal spans shorter than 1 year. Total, rather than total-recoverable, suspended sediment-associated trace element concentrations were determined by direct analysis of material dewatered from large-volume whole-water samples. Site-specific intra- and inter-annual suspended sediment-associated chemical variations were less (typically by no more than a factor of two) than those for either discharge or suspended sediment concentrations (usually more than 10-fold). The concentrations, hence the annual fluxes, for suspended sediment-associated phosphorus and organic carbon, determined by direct analyses, were higher than those determined using a more traditional paired, whole-water/filtered-water approach (by factors ranging from 1.5- to 10-fold). This may be important for such issues as eutrophication and coastal productivity. Filtered water-associated (dissolved) trace element concentrations were markedly lower than those determined during the historical NASQAN programme; many were below their respective detection limits. This resulted from the use of clean sampling, processing, and analytical protocols. Hence, the fluxes for filtered water-associated (dissolved) Ag, Pb, Co, V, Be, Sb, and Se, as well as the total (filtered water plus suspended sediment-associated) fluxes for these constituents, could not be estimated.

Hydrological Processes

Annual suspended sediment and trace element fluxes in the Mississippi, Columbia, Colorado, and Rio Grande drainage basins

Suspended sediment, sediment-associated, total trace element, phosphorus (P), and total organic carbon (TOC) fluxes were determined for the Mississippi, Columbia, Rio Grande, and Colorado Basins for the study period (the 1996, 1997, and 1998 water years) as part of the US Geological Survey's redesigned National Stream Quality Accounting Network (NASQAN) programme. The majority (??? 70%) of Cu, Zn, Cr, Ni, Ba, P, As, Fe, Mn, and Al are transported in association with suspended sediment; Sr transport seems dominated by the dissolved phase, whereas the transport of Li and TOC seems to be divided equally between both phases. Average dissolved trace element levels are markedly lower than reported during the original NASQAN programme; this seems due to the use of 'clean' sampling, processing, and analytical techniques rather than to improvements in water quality. Partitioning between sediment and water for Ag, Pb, Cd, Cr, Co, V, Be, As, Sb, Hg, and Ti could not be estimated due to a lack of detectable dissolved concentrations in most samples. Elevated suspended sediment-associated Zn levels were detected in the Ohio River Basin and elevated Hg levels were detected in the Tennessee River, the former may affect the mainstem Mississippi River, whereas the latter probably do not. Sediment-associated concentrations of Ag, Cu, Pb, Zn, Cd, Cr, Co, Ba, Mo, Sb, Hg, and Fe are markedly elevated in the upper Columbia Basin, and appear to be detectable (Zn, Cd) as far downstream as the middle of the basin. These elevated concentrations seem to result from mining and/or mining-related activities. Consistently detectable concentrations of dissolved Se were found only in the Colorado River Basin. Calculated average annual suspended sediment fluxes at the mouths of the Mississippi and Rio Grande Basins were below, whereas those for the Columbia and Colorado Basins were above previously published annual values. Downstream suspended sediment-associated and total trace element fluxes increase in the Mississippi and Columbia Basins, whereas fluxes markedly decrease in the Colorado Basin. No consistent pattern in trace element fluxes was detected in the Rio Grande Basin.

Hydrological Processes

The effect of mining and related activities on the sediment-trace element geochemistry of Lake Coeur d'Alene, Idaho, USA. Part III. Downstream effects: The Spokane River Basin

During 1998/1999, surface and subsurface sediment samples were collected along the entire length of the Spokane River from its outlet at the northern end of Lake Coeur d'Alene (CDA), Idaho, to Lake Roosevelt on the Columbia River, Washington. The study was conducted to determine if the trace element enrichments observed in Lake CDA and on the floodplain and in the CDA River extend through the Spokane River Basin (SRB). As in Lake CDA, surface sediments in the SRB are enriched in Pb, Zn, As, Cd, Sb and Hg relative to local background levels. Pb, Cd and Zn are the most elevated, with maximum enrichment occurring in the upper Spokane River in close proximity to Lake CDA. On average, enrichment decreases downstream, apparently reflecting both increased distance from the inferred source (the CDA River Basin), as well as increased dilution by locally derived but unenriched materials. Only Cd and Zn display marked enrichment throughout the SRB. Pb, Zn and Cd seem to be associated mainly with an operationally defined iron oxide phase, whereas the majority of the As and Sb seem to be matrix-held. Subsurface sediments also are enriched in Pb, Zn, As, Cd, Sb and Hg relative to background levels. Based on 137Cs and excess 210Pb dating, trace element enrichment began in the middle part of the SRB (Long Lake) between 1900 and 1920. This is contemporaneous with similar enrichments observed in Lake CDA, as well as the completion of Long Lake Dam (1913). In the most downstream part of the basin (Spokane River Arm of Lake Roosevelt), enrichment began substantially later, between 1930 and 1940. The temporal difference in enrichment between Long Lake and the River Arm may reflect the latter's greater distance from the presumed source of the enrichment (the CDA River Basin); however, the difference is more likely the result of the completion of Grand Coulee Dam (1934-1941), which formed Lake Roosevelt, backed up the Spokane River, and increased water levels in the River Armby about 30 m.

Hydrological Processes

Selected laboratory evaluations of the whole-water sample-splitting capabilities of a prototype fourteen-liter Teflon churn splitter

A prototype 14-L Teflon? churn splitter was evaluated for whole-water sample-splitting capabilities over a range of sediment concentratons and grain sizes as well as for potential chemical contamination from both organic and inorganic constituents. These evaluations represent a 'best-case' scenario because they were performed in the controlled environment of a laboratory, and used monomineralic silica sand slurries of known concentration made up in deionized water. Further, all splitting was performed by a single operator, and all the requisite concentration analyses were performed by a single laboratory. The prototype Teflon? churn splitter did not appear to supply significant concentrations of either organic or inorganic contaminants at current U.S. Geological Survey (USGS) National Water Quality Laboratory detection and reporting limits when test samples were prepared using current USGS protocols. As with the polyethylene equivalent of the prototype Teflon? churn, the maximum usable whole-water suspended sediment concentration for the prototype churn appears to lie between 1,000 and 10,000 milligrams per liter (mg/L). Further, the maximum grain-size limit appears to lie between 125- and 250-microns (m). Tests to determine the efficacy of the valve baffle indicate that it must be retained to facilitate representative whole-water subsampling.

Open-File Report

A study of porewater in water saturated sediments of levee banks and marshes in the lower Coeur d'Alene River valley, Idaho: Sampling, analytical methods, and results

This report contains information about the composition of interstitial porewater and solids from water saturated, metal contaminated levee banks at the river's edge and marshes in the lower Coeur d'Alene River valley. Data include pH, alkalinity, and concentrations of sulfate and metals (arsenic [As], cadmium [Cd], copper [Cu], iron [Fe], mercury [Hg], manganese [Mn], lead [Pb], antimony [Sb], and zinc [Zn]) in porewater and sulfur (S), carbon (C), and metal contents of associated solids. The results indicate that the pH of the porewater in all of the sediments is less than the pH of the Coeur d'Alene River. Dissolved concentrations of Mn and Fe are elevated in all of the porewater and levels of sulfate in porewater are below detection limits in almost all marsh sediments and in levee banks at the 2 sites furthest downstream. These observations suggest that levee bank and marsh sediments are suboxic or anoxic below the surface. Concentrations of dissolved Cd are greater in the Coeur d'Alene River than in porewater, while concentrations of As are greater in the porewater relative to the Coeur d'Alene River. Some concentrations of Cu, Pb, Sb, and Zn in porewater are lower, while others are higher, than dissolved concentrations in the Coeur d'Alene River. In addition, leaching experiments (i.e., Standard Elutriate Tests [SET]) were done in the laboratory to evaluate potential water quality impacts resulting from the addition of oxygen and water to these sediments. The intent of the experiments was to simulate how metal concentrations in water may be affected during dredging of contaminated sediments in the lower Coeur d'Alene River valley. The results indicate that there are releases of protons, sulfate, As, Mn, Pb, Sb, and Zn from the majority of levee bank and marsh sediments during leaching by Coeur d'Alene River water. At a water to sediment ratio of 4 to 1, most values of pH and dissolved concentrations of Cd, Fe, Pb, and Zn in the leaching solutions exceed the freshwater aquatic life standards for water of a hardness of 100 mg CaCOa/L. This work was funded by the U.S. EPA and was done to support their Remedial Investigation/Feasibility Study of the Coeur d'Alene and Spokane River basins.

Idaho

A summary of the effects of mining and related activities on the sediment-trace element geochemistry of Lake Coeur d'Alene, Idaho, USA

During 1989 and 1990 a series of 12 gravity cores, and 150 surface grab samples were collected in Lake Coeur d'Alene, Idaho to determine trace element concentrations, partitioning and surface and subsurface distribution patterns in the bed sediments of the lake. In addition, selected subsamples from one core were analyzed for 117 Cs activity to begin to establish a trace element geochemical history for the lake. The intent was to try and relate the trace element concentrations and distributions in the sediment column to past and present mining and mining related activities in the area. Substantial portions of the surface and near-surface sediments in Lake Coeur d'Alene are markedly enriched in Ag, As, Cd, Hg, Pb, Sb and Zn, and somewhat enriched in Cu, Fe and Mn. Surface distribution patterns, as well as variations in the thickness of the trace element-rich subsurface sediments, indicate that the source of much of this enriched material is the Coeur d'Alene River. The similarity between the trace element-rich surface and subsurface sediments with respect to: their location, their bulk chemistry, and their trace element partitioning indicate that the sources and/or concentrating mechanisms causing the trace element enrichment in the lake sediments probably have been the same throughout their depositional history. An estimated 75 million metric tons of trace element-rich sediments have been deposited on or in the lakebed. Based on a Mt. St. Helens' ash layer from the 1980 eruption, ages estimated from 137 Cs activity, and the presence of 80 discernible and presumably annual layers in a core collected near the Coeur d'Alene River delta, indicate that the deposition of trace element-rich sediments began, at least in the Coeur d'Alene River delta, some time between 1895 and 1910, dates consistent with the onset of mining and ore-processing activities that began in the area in the 1880's.

Journal of Geochemical Exploration

The Effect of mining and related activities on the sediment-trace element geochemistry of Lake Coeur d'Alene, Idaho, U.S.A.; Part II, Subsurface sediments

During the summer of 1990, 12 gravity cores were collected in Lake Coeur d'Alene, Idaho, at various depths and in a variety of depositional environments. All core subsamples were analyzed to determine bulk chemistry and selected subsamples were analyzed for trace-element partitioning and (137)Cs activity. The purpose of these analyses was to determine the trace-element concentrations and distributions in the sediment column and to try to establish a trace-element geochemical history of the lake in relation to mining and mining-related discharge operations in the area. Substantial portions of the near-surface sediments in Lake Coeur d'Alene are markedly enriched in Ag, As, Cd, Hg, Pb, Sb, and Zn, and somewhat enriched in Cu, Fe, and Mn. Variations in the thickness of the trace element- rich sediments suggest that the source of much of this material is the Coeur d'Alene River. Calculated estimates indicate that there are some 75 million metric tons of trace element-rich sediments currently on/in the lakebed. Estimated trace-element masses in excess of those caused by non-mining-related sources, range from a high of 468,000 metric tons of Pb to a low of 260 metric tons of Hg. The similarity between the trace element-rich surface and subsurface sediments as regards their: (1) location; (2) bulk chemistry; (3) interelement relationships; and (4) trace-element partitioning indicate that the sources and/or concentrating mechanisms causing the trace-element enrichment in the lake probably have been the same throughout their depositional history. Based on Mt. St. Helens' ash layer from the 1980 eruption, ages estimated from (137)Cs activity, and the presence of 80 discernible and presumably annual layers in a core collected near the Coeur d'Alene River delta, it appears that deposition rates for the trace element-rich sediments varied from 2.1 to 1.3 cm/yr. These data also indicate that the deposition of trace element-rich sediments began, at least in the Coeur d'Alene River delta, sometime between 1895 and 1910, dates consistent with the onset of mining and ore-processing activities in the area which began in the 1880's.

Open-File Report

Effect of membrane filtration artifacts on dissolved trace element concentrations

Among environment scientists, the current and almost universally accepted definition of dissolved constituents is an operational one-only those materials which pass through a 0.45-μm membrane filter are considered to be dissolved. Detailed laboratory and field studies on Fe and Al indicate that a number of factors associated with filtration, other than just pore size, can substantially alter “dissolved” trace element concentrations; these include: filter type, filter diameter, filtration method, volume of sample processed, suspended sediment concentration, suspended sediment grain-size distribution, concentration of colloids and colloidally-associated trace elements and concentration of organic matter. As such, reported filtered-water concentrations employing the same pore size filter may not be equal. Filtration artifacts may lead to the production of chemical data that indicate seasonal or annual “dissolved” chemical trends which do not reflect actual environmental conditions. Further, the development of worldwide averages for various dissolved chemical constituents, the quantification of geochemical cycles, and the determination of short- or long-term environmental chemical trends may be subject to substantial errors, due to filtration artifacts, when data from the same or multiple sources are combined. Finally, filtration effects could have a substantial impact on various regulatory requirements.

Georgia

Arsenopyrite in the bank deposits of the Whitewood Creek-Belle Fourche-Cheyenne River-Lake Oahe system, South Dakota, U.S.A.

Mining, milling, and processing wastes containing quantities of arsenopyrite were produced around Lead, South Dokata, from 1875 to 1977. Much of this material was discharged into Whitewood Creek, and from there portions of the waste were transported to the Belle Fourche River, thence to the Cheyenne River, and finally to the Missouri River. In 1958, the Missouri River was dammed at Pierre, forming Lake Oahe. Analyses of cores collected from the lake bottom showed the presence of arsenic-rich layers in the bed sediments; substantial portions of the arsenic are due to arsenopyrite in the 8-16 and 16-32 ??m size fractions of the sediments. In addition, suspended-sediment samples collected from the Cheyenne River above Lake Oahe contain detectable quantities of arsenopyrite in the 8-16 and 16-32 ??m fractions. Solid material collected from the banks and floodplains of the Belle Fourche River and Whitewood Creek contains reduced and oxidized phases. The reduced phases have arsenic maxima in the 16-32 and 32-63 ??m size ranges. These fractions also contribute the most arsenic to the samples; the major source being arsenopyrite. The oxidized segments have arsenic maxima in the < 2 and > 63 ??m size ranges. The < 2 ??m maxima are associated with widely disseminated, arsenic-bearing iron oxide coatings. However, the > 63 ??m fractions contribute the most arsenic to the oxidized samples. This arsenic, despite the oxidized nature of the samples, is associated with arsenopyrite coated with thin iron oxide rinds. It has been calculated that 80% of the arsenic in these deposits is associated with sulfides (in the form of arsenopyrite), while 20% is associated with iron oxides. The arsenopyrite found in the banks and floodplains of Whitewood Creek and the Belle Fourche River are the likely source of the arsenopyrite found in the suspended sediments of the Cheyenne River and in the bed sediment of Lake Oahe.

Conference Paper

The effect of mining on the sediment - trace element geochemistry of cores from the Cheyenne River arm of Lake Oahe, South Dakota, U.S.A.

Six cores, ranging in length from 1 to 2 m, were collected in the Cheyenne River arm of Lake Oahe, South Dakota, to investigate potential impacts from gold-mining operations around Lead, South Dakota. Sedimentation rates in the river arm appear to be event-dominated and rapid, on the order of 6-7 cm yr.-1. All the chemical concentrations in the core samples fall within the wide ranges previously reported for the Pierre Shale of Cretaceous age and with the exception of As, generally are similar to bed sediment levels in the Cheyenne River, Lake Oahe and Foster Bay. Based on the downcore distribution of Mn, it appears that reducing conditions exist in the sediment column of the river arm below 2-3 cm. The reducing conditions do not appear to be severe enough to produce differentiation of Fe and Mn throughout the sediment column in the river arm. Cross-correlations for high-level metal-bearing strata within the sediment column can be made for several strata and for several cores; however, cross-correlations for all the high-level metal-bearing strata are not feasible. As is the only element which appears enriched in the core samples compared to surface sediment levels. Well-crystallized arsenopyrite was found in high-As bearing strata from two cores and probably was transported in that form from reducing sediment-storage sites in the banks or floodplains of Whitewood Creek and the Belle Fourche River. It has not oxidized due to the reducing conditions in the sediment column of the Cheyenne River arm. Some As may also be transported in association with Fe- and Mn-oxides and -hydroxides, remobilized under the reducing conditions in the river arm, and then reprecipitated in authigenic sulfide phases. In either case, the As appears to be relatively immobile in the sediment column. ?? 1988.

Chemical Geology

The relation of stream sediment surface area, grain size and composition to trace element chemistry

Intensive studies of 17 geographically and hydrologically diverse stream bed sediments provide information on the relation between grain size, surface area, and operationally defined geochemical phases (e.g. Mn oxides, amorphous Fe oxides) to trace element concentrations. Of the size fractions investigated (<2, <16, <63and<125 μm), the strongest correlation with trace elements occurs with the percent <63 μm or<125 μm fractions. As the proportion of these size fractions increases in the samples, so do the trace element concentrations. When surface area (as defined by nitrogen adsorption and the BET equations) increases, trace element levels also increase. Correlations between bulk sediment chemistry and surface area are as strong as those between sediment chemistry and the proportion of the <63or<125 μm fractions. Surface area appears to serve as a proxy for grain size. The strongest correlations between grain size and surface area are the same as for trace elements and grain size (with the <63or<125 μm fractions). Surface area also is affected by geochemical phase, as are the trace elements associated with sediments. Of the phases considered (carbonates, Mn oxides, reactive Fe, amorphous Fe, organic matter), amorphous Fe oxides appear to exert the greatest control over both surface area and trace element levels. The concentrations of various geochemical phases affect surface area, grain size, and trace element chemistry. However, the effect of phase is grain-size dependent. For material with mean grain sizes in the fine sand range and coarser (> 125 μm), each of the various phases contribute to overall sample surface area. For material having mean grain sizes in the very fine sand range and finer (<125 μm), the same phases act as surface-area inhibitors by cementing fine grains together to form aggregates. This increases the mean grain size of the sample and reduces the surface area. The presence of these aggregates may explain why the <63 μm or<125 μm size fractions are more important to sediment-trace element levels and surface area than other finer fractions.

Applied Geochemistry