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At least 1,351 records · Page 75Linked to original sources
USGS2014

Does water chemistry affect the dietary uptake and toxicity of silver nanoparticles by the freshwater snail Lymnaea stagnalis ?

Silver nanoparticles (AgNPs) are widely used in many applications and likely released into the aquatic environment. There is increasing evidence that Ag is efficiently delivered to aquatic organisms from AgNPs after aqueous and dietary exposures. Accumulation of AgNPs through the diet can damage digestion and adversely affect growth. It is well recognized that aspects of water quality, such as hardness, affect the bioavailability and toxicity of waterborne Ag. However, the influence of water chemistry on the bioavailability and toxicity of dietborne AgNPs to aquatic invertebrates is largely unknown. Here we characterize for the first time the effects of water hardness and humic acids on the bioaccumulation and toxicity of AgNPs coated with polyvinyl pyrrolidone (PVP) to the freshwater snail Lymnaea stagnalis after dietary exposures. Our results indicate that bioaccumulation and toxicity of Ag from PVP-AgNPs ingested with food are not affected by water hardness and by humic acids, although both could affect interactions with the biological membrane and trigger nanoparticle transformations. Snails efficiently assimilated Ag from the PVP-AgNPs mixed with diatoms (Ag assimilation efficiencies ranged from 82 to 93%). Rate constants of Ag uptake from food were similar across the entire range of water hardness and humic acid concentrations. These results suggest that correcting regulations for water quality could be irrelevant and ineffective where dietary exposure is important.

Environmental Pollution↗
USGS2008

Ground-water quality data in the southeast San Joaquin Valley, 2005–2006— Results from the California GAMA program

Ground-water quality in the approximately 3,800 square-mile Southeast San Joaquin Valley study unit (SESJ) was investigated from October 2005 through February 2006 as part of the Priority Basin Assessment Project of Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment project was developed in response to the Ground-Water Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The SESJ study was designed to provide a spatially unbiased assessment of raw ground-water quality within SESJ, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 99 wells in Fresno, Tulare, and Kings Counties, 83 of which were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (grid wells), and 16 of which were sampled to evaluate changes in water chemistry along ground-water flow paths or across alluvial fans (understanding wells). The ground-water samples were analyzed for a large number of synthetic organic constituents (volatile organic compounds [VOCs], pesticides and pesticide degradates, and pharmaceutical compounds), constituents of special interest (perchlorate, N-nitrosodimethylamine, and 1,2,3-trichloropropane), naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, and carbon-14, and stable isotopes of hydrogen, oxygen, nitrogen, and carbon), and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, samples for matrix spikes) were collected at approximately 10 percent of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Assessment of the quality-control data resulted in censoring of less than 1 percent of the detections of constituents measured in ground-water samples. This study did not attempt to evaluate the quality of drinking water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, and (or) blended with other waters to maintain acceptable drinking-water quality. Regulatory thresholds apply to the treated water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with regulatory and other health-based thresholds established by the U.S. Environmental Protection Agency and California Department of Public Health (CDPH) and thresholds established for aesthetic concerns by CDPH. Two VOCs were detected above health-based thresholds: 1,2-dibromo-3-chloropropane (DBCP), and benzene. DBCP was detected above the U.S. Environmental Protections Agency’s maximum contaminant level (MCL-US) in three grid wells and five understanding wells. Benzene was detected above the CDPH’s maximum contaminant level (MCL-CA) in one grid well. All pesticide detections were below health-based thresholds. Perchlorate was detected above its maximum contaminate level for California in one grid well. Nitrate was detected above the MCL-US in six samples from understanding wells, of which one was a public supply well. Two trace elements were detected above MCLs-US: arsenic and uranium. Arsenic was detected above the MCL-US in four grid wells and two understanding wells; uranium was detected above the MCL-US in one grid well and one understanding well. Gross alpha radiation was detected above MCLs-US in five samples; four of them understanding wells, and uranium isotope activity was greater than the MCL-US for one understanding well. Radon-222 was detected above the proposed MCL-US in all wells sampled. Total coliforms were detected in two wells and somatic coliphage was detected in one well.

California↗
USGS2007

Chapter B. Physical, Chemical, and Biological Responses of Streams to Increasing Watershed Urbanization in the Piedmont Ecoregion of Georgia and Alabama, 2003

As part of the U.S. Geological Survey National Water-Quality Assessment Program?s effort to assess the physical, chemical, and biological responses of streams to urbanization, 30 wadable streams were sampled near Atlanta, Ga., during 2002?2003. Watersheds were selected to minimize natural factors such as geology, altitude, and climate while representing a range of urban development. A multimetric urban intensity index was calculated using watershed land use, land cover, infrastructure, and socioeconomic variables that are highly correlated with population density. The index was used to select sites along a gradient from low to high urban intensity. Response variables measured include stream hydrology and water temperature, instream habitat, field properties (pH, conductivity, dissolved oxygen, turbidity), nutrients, pesticides, suspended sediment, sulfate, chloride, Escherichia coli (E. coli) concentrations, and characterization of algal, invertebrate and fish communities. In addition, semipermeablemembrane devices (SPMDs)?passive samplers that concentrate hydrophobic organic contaminants such as polycyclicaromatic hydrocarbons (PAHs)?were used to evaluate water-quality conditions during the 4 weeks prior to biological sampling. Changes in physical, chemical, and biological conditions were evaluated using both nonparametric correlation analysis and nonmetric multidimensional scaling (MDS) ordinations and associated comparisons of dataset similarity matrices. Many of the commonly reported effects of watershed urbanization on streams were observed in this study, such as altered hydrology and increases in some chemical constituent levels. Analysis of water-chemistry data showed that specific conductance, chloride, sulfate, and pesticides increased as urbanization increased. Nutrient concentrations were not directly correlated to increases in development, but were inversely correlated to percent forest in the watershed. Analyses of SPMD-derived data showed that bioassays and certain chemical constituents such as pyrene and benzophenanthrene, both PAHs found in coal tar, were strongly correlated with measures of watershed urbanization. Hydrologic variability metrics indicated that as urban development increased, streams became flashier, with characteristic high flows having shorter duration. The hydrologic effects associated with urbanization were greatest during the fall and least apparent during the winter. No correlations were observed between increasing urbanization and stream temperature or changes in stream habitat. Algal, invertebrate, and fish communities exhibited statistically significant changes as watersheds became increasingly urban, with the strongest responses observed in the invertebrate community followed by fishes, then algal diatom communities. Invertebrate communities were the most responsive to increasing urbanization with Ephemeroptera, Plecoptera, and Tricoptera taxa, especially Plecoptera (stoneflies) responding negatively and most strongly to increasing urbanization. Invertebrate communities were influenced more significantly by water quality, although significant responses to altered hydrology also were noted. In terms of the fish community, the percentage of cyprinids present in the stream was the only Index of Biotic Integrity metric that responded negatively to increases in watershed urbanization. Fish community response to urbanization was intermediate relative to algae and invertebrates with respect to significant metric responses as well as the overall community response to increasing urbanization. Measures of hydrologic variability were the most influential environmental variables affecting the algal community. Although sites were originally chosen to represent a gradient of increasing urbanization, a cluster analysis performed on the component metrics of the urban index categorized sites into four distinct groups. Multivariate analysis based on nonmetric MDS and related analyses of data ma

Alabama, Georgia↗
USGS2013

Fate(s) of injected CO2 in a coal-bearing formation, Louisiana, Gulf Coast Basin: Chemical and isotopic tracers of microbial-brine-rock-CO2 interactions

Coal beds are one of the most promising reservoirs for geologic carbon dioxide (CO₂) sequestration, as CO₂ can strongly adsorb onto organic matter and displace methane; however, little is known about the long-term fate of CO₂ sequestered in coal beds. The "2800' sand" of the Olla oil field is a coal-bearing, oil and gas-producing reservoir of the Paleocene–Eocene Wilcox Group in north-central Louisiana. In the 1980s, this field, specifically the 2800' sand, was flooded with CO₂ in an enhanced oil recovery (EOR) project, with 9.0×10⁷m³ of CO₂ remaining in the 2800' sand after injection ceased. This study utilized isotopic and geochemical tracers from co-produced natural gas, oil and brine from reservoirs located stratigraphically above, below and within the 2800' sand to determine the fate of the remaining EOR-CO₂, examining the possibilities of CO₂ migration, dissolution, mineral trapping, gas-phase trapping, and sorption to coal beds, while also testing a previous hypothesis that EOR-CO₂ may have been converted by microbes (CO₂-reducing methanogens) into methane, creating a microbial "hotspot". Reservoirs stratigraphically-comparable to the 2800' sand, but located in adjacent oil fields across a 90-km transect were sampled to investigate regional trends in gas composition, brine chemistry and microbial activity. The source field for the EOR-CO₂, the Black Lake Field, was also sampled to establish the δ¹³C-CO₂ value of the injected gas (0.9‰ +/- 0.9‰). Four samples collected from the Olla 2800' sand produced CO₂-rich gas with δ¹³C-CO₂ values (average 9.9‰) much lower than average (pre-injection) conditions (+15.9‰, average of sands located stratigraphically below the 2800' sand in the Olla Field) and at much higher CO₂ concentrations (24.9 mole %) than average (7.6 mole %, average of sands located stratigraphically below the 2800' sand in the Olla Field), suggesting the presence of EOR-CO₂ and gas-phase trapping as a major storage mechanism. Using δ¹³C values of CO₂ and dissolved organic carbon (DIC), CO₂ dissolution was also shown to be a major storage mechanism for 3 of the 4 samples from the Olla 2800' sand. Minor storage mechanisms were shown to be migration, which only affected 2 samples (from 1 well), and some EOR-CO₂ conversion to microbial methane for 3 of the 4 Olla 2800' sand samples. Since methanogenesis was not shown to be a major storage mechanism for the EOR-CO₂ in the Olla Field (CO₂ injection did not stimulate methanogenesis), samples were examined from adjacent oil fields to determine the cause of the Olla microbial "hot-spot". Microbial methane was found in all oil fields sampled, but indicators of methanogenesis (e.g. alkalinity, high δ¹³C-DIC values) were the greatest in the Olla Field, and the environmental conditions (salinity, pH, temperature) were most ideal for microbial CO₂ reduction in the Olla field, compared to adjacent fields.

Thesis↗
USGS1987

Water-quality data-collection activities in Colorado and Ohio; Phase II, Evaluation of 1984 field and laboratory quality-assurance practices

Serious questions have been raised by Congress about the usefulness of water-quality data for addressing issues of regional and national scope and, especially, for characterizing the current quality of the Nation's streams and ground water. In response, the U.S. Geological Survey has undertaken a pilot study in Colorado and Ohio to (1) determine the characteristics of current (1984) water-quality data-collection activities of Federal, regional, State, and local agencies, and academic institutions; and (2) determine how well the data from these activities, collected for various purposes and using different procedures, can be used to improve our ability to answer major broad-scope questions, such as: A. What are (or were) natural or near-natural water-quality conditions? B. What are existing water-quality conditions? C. How has water quality changed, and how do the changes relate to human activities? Colorado and Ohio were chosen for the pilot study largely because they represent regions with different types of waterquality concerns and programs. The study has been divided into three phases, the objectives of which are: Phase I--Inventory water-quality data-collection programs, including costs, and identify those programs that met a set of broad criteria for producing data that are potentially appropriate for water-quality assessments of regional and national scope. Phase II--Evaluate the quality assurance of field and laboratory procedures used in producing the data from programs that met the broad criteria of Phase I. Phase III--Compile the qualifying data and evaluate the adequacy of this data base for addressing selected water-quality questions of regional and national scope. Water-quality data are collected by a large number of organizations for diverse purposes ranging from meeting statutory requirements to research on water chemistry. Combining these individual data bases is an appealing and potentially cost-effective way to attempt to develop a data base adequate for regional or national water-quality assessments. However, to combine data from diverse sources, field and laboratory procedures used to produce the data need to be equivalent and need to meet specific qualityassurance standards. It is these factors that are the focus of Phase II, which is described in this report. In the first phase of this study, an inventory was made of all public organizations and academic institutions that undertook water-quality data-collection activities in Colorado and Ohio in 1984. Water-quality programs identified in Phase I were tested against a set of broad screening criteria. A total of 44 waterquality programs in Colorado and 29 programs in Ohio passed the Phase-I screen and were examined in Phase II. These programs accounted for an estimated 165,000 analyses in Colorado and 76,300 analyses in Ohio for 20 selected constituents and properties. Although qualifying programs included both surface- and ground-water sampling, they emphasized surface waters and produced few groundwater analyses (3,660 for Colorado and 470 for Ohio). For Phase II, information about field and laboratory qualityassurance practices was provided by each organization and its supporting laboratories through questionnaires. This information was evaluated against a set of specific criteria for field and laboratory practices. The criteria were developed from guidelines published by public agencies and professional organizations such as the American Public Health Association, the U.Sc, Environmental Protection Agency, and the U.S. Geological Survey. Each of the eight criteria that comprise the Phase-II screen fall into one of two major categories--field practices or laboratory practices.

Colorado, Ohio↗
USGS2022

Potential effects of energy development on environmental resources of the Williston Basin in Montana, North Dakota, and South Dakota—Water resources

The Williston Basin has been a leading oil and gas producing area for more than 50 years. While oil production initially peaked within the Williston Basin in the mid-1980s, production rapidly increased in the mid-2000s, largely because of improved horizontal (directional) drilling and hydraulic fracturing methods. In 2012, energy development associated with the Bakken Formation was identified as a priority requiring collaboration toward improved timeliness of issuing permits for new wells combined with reasonable measures to maintain environmental quality. Shortly thereafter, the Bakken Federal Executive Group was created to address common challenges associated with energy development. The Bakken Federal Executive Group partner agencies identified a gap in current understanding of the cumulative environmental challenges attributed to energy development throughout the area, resulting in an effort to aggregate scientific data and identify additional research and information needs related to natural resources within areas of energy development in the Williston Basin. As part of this effort, water resources in the area (including groundwater; streams and rivers; and lakes, reservoirs, and wetlands) were characterized and described in terms of physical occurrence, flow characteristics, recharge, water quality, and water use. Similarly, waters produced during energy-development activities also were characterized even though these waters are not considered usable resources within the area. Groundwater resources were characterized by the major hydrogeologic units, or aquifers, identifying the units that supply most groundwater used for domestic, stock, agricultural, and industrial purposes. The groundwater characterization included other deeper hydrogeologic units in the Williston Basin that may be a useable source of water with treatment, have utility as a reservoir for reinjection of produced waters, or be a source of minerals and energy resources. A generalized groundwater budget and flow system identifying the sources of recharge (stream infiltration, precipitation, and movement [leakage] from other aquifers) and the general groundwater flow direction is included for each of the major hydrogeologic units. Rivers and streams within the Williston Basin with 10 or more years of continuous streamflow data were identified. For a subset of these sites, streamflow characteristics, including the monthly and annual mean flow, were generated to identify seasonal and interannual changes in streamflow and thus provide information on the drivers and reliability of streamflow at the seasonal or multiyear scale. Daily streamflow and annual extreme flows (peak and low flow) also were estimated for the subset of sites. The daily streamflow and annual extreme flow values provide information on short-term or extreme events that are relevant to infrastructure design and evaluating spills, leaks, or accidental discharges of water or petroleum products. Surface-water features (lakes, ponds, and wetlands) were classified using the Cowardin system and identified on the National Wetlands Inventory maps generated by the U.S. Fish and Wildlife Service. The spatial distribution of the surface-water features was analyzed by State, county, and specifically in comparison to the Prairie Pothole Region. The proximity of the surface-water features to energy development infrastructure (specifically oil or gas well pads) was evaluated. It was determined that, although oil or gas wells are often near a surface-water feature, most surface-water features do not have wells nearby, with the exception of wells in the Prairie Pothole Region. Water-quality data were aggregated from two data sources: (1) the Water-Quality Portal, sponsored by the U.S. Geological Survey (USGS), U.S. Environmental Protection Agency (EPA), and National Water Quality Monitoring Council; and (2) a data compilation completed as part of the USGS National Water-Quality Assessment project. The Water-Quality Portal integrates publicly available water-quality data from databases maintained by the USGS, EPA, and U.S. Department of Agriculture, including water-quality data from Tribal, State, and local databases. Water-quality data for 15 commonly measured water-quality constituents were aggregated for groundwater, rivers and streams, and lakes and reservoirs. For each aggregated dataset (groundwater, rivers and streams, and lakes and reservoirs), analyses of the water-quality data included summary statistics, maps of spatial distribution of constituent values, boxplots of constituent values by timeframe or hydrogeologic unit, spatial comparisons of site locations and constituent values to petroleum well density, and comparisons of the constituent values measured to EPA drinking-water standards/guidelines. Produced water includes all fluids brought to the surface along with the targeted hydrocarbons as part of the oil and gas exploration and extraction processes. These fluids may include formation water (waters that co-exist with rock/oil/gas), hydraulic fracturing fluids, and other combinations of water and chemicals used during oil and gas well drilling, development, treatments, recompletions, and workovers. Produced water datasets were aggregated from two sources: the USGS National Produced Waters Geochemical database (ver. 2.1) and a series of projects focused specifically on sampling produced water in the Williston Basin from 2010 to 2014. The National Produced Waters Geochemical database was useful for a general understanding of produced-water chemistry. Produced waters are characterized by extreme salinity and contain elevated concentrations of other constituents (including arsenic, barium, cadmium, lead, zinc, radium-226/radium-228, and ammonium) that could negatively affect water and aquatic resources if released. Produced waters also have a generally unique chemical (isotopic) signature that may be useful in tracking water from different geologic units; for example, the oxygen/deuterium and strontium ratio values measured in brine waters from the Bakken Formation are distinct from brines collected from other geologic units in the Williston Basin. Water-use information related to energy production in the area also was aggregated and summarized. The summary of water use is not limited to oil and gas production but includes water used to produce all types of energy resources in the Williston Basin, including coal/lignite, thermoelectric power, oil and gas, hydropower, biomass and biofuels, wind, geothermal, and solar. Each State has its own methods for regulating and reporting water usage within its jurisdiction. These methods can introduce problems when examining water use from sources, such as the Missouri River or Fox Hills aquifer, that are shared across political boundaries. Without the one-to-one match for usage types and amounts used from a water source, it is difficult to develop a comprehensive water budget for the water source being evaluated. A large amount of freshwater is required to prepare a well for oil and gas well production; in some cases, 3 to 7 million gallons of water are needed per well. The EPA estimates that hydraulic fracturing in the Williston Basin uses between 70 to 140 billion gallons per year. Water also is used for myriad other purposes related to ancillary oil and gas extraction. In addition to water used for immediate energy development, the expanded human workforce migrating into the area and other support staff who have moved into the area during the development also use water. Research and information needs were identified that could be relevant in the evaluation of the effects of energy development on water resources. Information needs related to the evaluation of groundwater resources include the following: improved potentiometric-surface maps for glacial units; availability of a uniform stream network digital geographic coverage that spans the international boundary with Canada; enhanced surface-water use information with regards to the gain and loss of streamflow to shallow groundwater, which would increase understanding groundwater and surface-water interactions; and expanded geophysical assessments. Gaps in the availability of streamflow data include the lack of information on ice-jam flooding despite potential for effects to infrastructure (pipelines, roads, and facilities) and an understanding of the cumulative effects of largely undocumented stock and diversion dams. Although this study resulted in the aggregation of a large quantity of water-quality data, the availability of consistently collected, systematically processed and reported data over large parts of the Williston Basin is sparse. Few samples have been analyzed for constituents that may indicate the effect of energy development on water resources. Constituents that could be considered include boron, chloride, bromide, iodine, fluoride, manganese, lithium, radium, strontium isotopes, volatile organic compounds, and isotopes of inorganic ions (such as hydrogen and carbon). Collaboration between Tribal, Federal, State, and local entities to identify a common study design, common monitoring constituents, and consistent sampling locations would generate datasets with broad utility and would likely result in overall cost savings for monitoring over time. Similarly, there is a need for standardized sample collection, processing, laboratory analytical methods, and the collection of ancillary data for produced waters sampling. Additional characterization of the range of chemical, microbial, and isotopic compositions and quantities of “end-member” produced waters, and the collection of time-series datasets to document the changes in produced waters during and after well development also were needs identified during this study. Water-use estimates would be improved through the implementation of comprehensive studies of water use from groundwater and surface-water sources using consistent methodologies across the Williston Basin. The submission of chemical and water data related to hydraulic fracturing collected by the oil and gas industry would add to the quantity of available data. Consistent implementation of regulations and monitoring controls across political boundaries (State, county, and international) would further improve the consistency of data available for the estimates of water use.

Montana, North Dakota, South Dakota↗
USGS1999

Environmental setting and natural factors and human influences affecting water quality in the White River Basin, Indiana

The White River Basin drains 11,349 square miles of central and southern Indiana and is one of 59 Study Units selected for water-quality assessment as part of the U.S. Geological Survey's National WaterQuality Assessment Program. Defining the environmental setting of the basin and identifying the natural factors and human influences that affect water quality are important parts of the assessment. Interrelated natural factors help determine the quality of surface and ground water in a river basin. The White River Basin has a humid continental climate, characterized by well-defined winter and summer seasons. Geologic features in the basin include glaciated and nonglaciated areas; a region of karst geomorphology that is characterized by caves and sinkholes; and a thick, sedimentary bedrock sequence underlying the entire basin. Unconsolidated glacial deposits of clay, silt, sand and gravel cover more than 60 percent of the basin. Soils developed in unconsolidated glacial deposits are typically fertile, naturally or artificially well drained, and farmed. Soils in the unglaciated south-central part of the basin are thin, have low fertility, and are best suited for forest or pasture. Agriculture is the principal land use in the White River Basin. Approximately 70 percent of the basin is used for agriculture, and about 50 percent of the basin is cropland. Corn and soybeans are the major crops. Other significant land uses are forest (22 percent) and urban and residential (7 percent). The population of the basin was 2.1 million in 1990. Water use in the White River Basin totaled 1,284 million gallons per day in 1995, of which 84.5 percent was surface water and 15.5 percent was ground water. Despite the predominant use of surface water, ground water was the primary source of drinking water for approximately 56 percent of the population. The general water chemistry in the White River Basin is determined by natural factors such as soils and geologic materials that water contacts as it moves through the hydrologic system. In the southern part of the basin, bedrock upland areas are dominated by non-carbonate bedrock, thin soils, and high runoff-rainfall ratios. These areas have small chemical concentrations in streamwater. Conversely, in the northern part of the basin where glacial deposits are thick and in the southwestern part of the basin where loess deposits are thick, water has longer periods of time to react with soils and aquifers and to acquire substantial quantities of dissolved constituents. As a result, streams in the till plain and glacial lowland have higher concentrations of most constituents than streams in the unglaciated parts of the basin. Water quality is significantly modified by human influences. Water quality is affected locally by point sources of contamination that include combined-sewer overflows, power-generation-plant cooling stations, and wastewater-treatment-plant effluents that are generally associated with densely populated areas. Water quality is additionally affected by non-point sources of contamination related to agriculture, urban runoff, and mining. Six hydrogeomorphic regions of the White River Basin are delineated on the basis of distinct and relatively homogeneous natural characteristics. These six regions are used in the White River Basin study as a framework for examining the effects of natural factors on water quality in the basin. Bedrock is exposed or near the surface in three hydrogeomorphic regions the bedrock uplands, bedrock lowland and plain, and karst plain; streams and shallow aquifers in these regions are susceptible to contamination, especially in the karst plain, and show rapid response to rainfall. The other three hydrogeomorphic regions the fluvial deposits, till plain, and glacial lowland are in the glaciated part of the basin. Where thick fine-grained unconsolidated sediments are present, primarily in the till plain, ground-water supplies are protected from contamination, and extreme high and low streamflows are moderated.

Indiana↗
USGS2025

Evaluation of 6PPD-quinone lethal toxicity and sublethal effects on disease resistance and swimming fitness in coastal cutthroat trout (Oncorhynchus clarkii clarkii)

6PPD-quinone (6PPDQ), derived from the tire-protectant 6PPD reacting with ozone, is an emerging contaminant of concern owing to its role in coho salmon ( Oncorhynchus kisutch ) deaths via urban runoff mortality syndrome (URMS). Given the impact of 6PPDQ on aquatic life in urban streams, we addressed the acute toxicity of 6PPDQ exposure on coastal cutthroat trout (CCT) ( Oncorhynchus clarkii clarkii ), a species sympatric with coho salmon in natal watersheds. Using static exposures coupled with analytical chemistry, we determined the 24-h LC 50 values for alevin (297.2 ng/L), swim-up fry (39.6 ng/L), 5-month parr (103.3 ng/L), and 13-month juveniles (185.9 ng/L)─values similar to toxicity observed in coho salmon. Additionally, the 96-h LC 50 (77.6 ng/L) was 2.4 times more lethal for juvenile CCT. We assessed potential effects of sublethal 6PPDQ exposure on disease resistance to infectious hematopoietic necrosis (IHN), an endemic viral disease of Pacific salmon, and to swimming performance. Sublethal 6PPDQ (53.6 ng/L) did not affect survival of parr exposed to IHN virus compared to virus alone. Conversely, 6PPDQ exposure as low as 72.2 ng/L significantly reduced 15- and 24-month juvenile swimming performance, and 120.5 ng/L 6PPDQ increased blood hematocrit. Overall, CCT are the second most sensitive species tested to date for 6PPDQ sensitivity which further emphasizes the need for identifying alternatives to 6PPD.

Environmental Science and Technology↗
USGS2000

Stanford-USGS shrimp-RG ion microprobe: A new approach to determining the distribution of trace elements in coal

The distribution of Cr and other trace metals of environmental interest in a range of widely used U.S. coals was investigated using the Stanford-USGS SHRIMP-RG ion microprobe . Using the oxygen ion source, concentrations of Cr (11 to 176 ppm), V (23 to 248 ppm), Mn (2 to 149 ppm), Ni (2 to 30 ppm), and 13 other elements were determined in illite/smectite, a group of clay minerals commonly present in coal. The results confirm previous indirect or semi-quantitative determinations indicating illite/smectite to be an important host of these metals. Calibration was achieved using doped aluminosilicate-glass synthetic standards and glasses prepared from USGS rock standards. Grains for analysis were identified optically, and confirmed by 1) precursory electron microprobe analysis and wavelength-dispersive compositional mapping, and 2) SHRIMP-RG major element data obtained concurrently with trace element results. Follow-up investigations will focus on the distribution of As and other elements that are more effectively ionized with the cesium primary beam currently being tested.

ACS Division of Fuel Chemistry, Preprints↗
USGS2019

Reactivity of As and U co-occurring in mine wastes in northeastern Arizona

The reactivity of co-occurring arsenic (As) and uranium (U) in mine wastes was investigated using batch reactors, microscopy, spectroscopy, and aqueous chemistry. Analyses of field samples collected in proximity to mine wastes in northeastern Arizona confirm the presence of As and U in soils and surrounding waters, as reported in a previous study from our research group. In this study, we measured As (<0.500 to 7.77 μg/L) and U (0.950 to 165 μg/L) in waters, as well as mine wastes (<20.0 to 40.0 mg/kg As and <60.0 to 110 mg/kg U) and background solids (<20.0 mg/kg As and <60.0 mg/kg U). Analysis with X-ray fluorescence (XRF) and electron microprobe show the co-occurrence of As and U with iron (Fe) and vanadium (V). These field conditions served as a foundation for additional laboratory experiments to assess the reactivity of metals in these mine wastes. Results from laboratory experiments indicate that labile and exchangeable As(V) was released to solution when solids were sequentially reacted with water and magnesium chloride (MgCl 2 ), while limited U was released to solution with the same reactants. The predominance of As(V) in mine waste solids was confirmed by X-ray absorption near edge (XANES) analysis. Both As and U were released to solution after reaction of solids in batch experiments with HCO 3 − . Both X-ray photoelectron spectroscopy (XPS) and XANES analysis determined the predominance of Fe(III) in the solids. Mössbauer spectroscopy detected the presence of nano-crystalline goethite, Fe(II) and Fe(III) in (phyllo)silicates, and an unidentified mineral with parameters consistent with arsenopyrite or jarosite in the mine waste solids. Our results suggest that As and U can be released under environmentally relevant conditions in mine waste, which is applicable to risk and exposure assessment.

Arizona↗
USGS1988

Element concentrations in soils and other surficial materials of Alaska

Mean concentrations of 35 elements, ash yields, and pH have been estimated for samples of sils and other unconsolidated surficial materials from 266 collection locations throughout Alaska. These background values can be applied to studies of environmental geochemistry and health, wildlife management, and soil-forming processes in cold climates and to computation of element abundances on a regional or worldwide scale. Limited data for an additoinal eight elements are also presented. Materials were collected using a one-way, three-level, analysis-of-variance samplling design in which collecting procedures were simplified for the convenience of the many volunteer field workers. The sample collectors were asked to avoid locations of known mineral deposits and obvious contamination, to take samples at a depth of about 20 cm where possible, and to take a replicate sample about 100 m distant from the first sample collected. With more than 60 percent of the samples replicated and 14 percent of the samples split for duplicate laboratory analyses, reliable estimates were made of the variability in element concentrations at two geographic scales and of the error associated with sample handling and laboratory procedures. Mean concentrations of most elements in surficial materials from the state of alaska correspond well with those reported in similar materials from the conterminous United STatess. Most element concentrations and ranges in samples of stream and lake sediments from Alaska, however, as reported in the literature, do not correspond well with those found in surficial materials of this study. This lack of correspondence is attributed to (1) a merger of two kinds ofsediments (stream and lake) for calculating means; (2) elimination from the sediment mean calculations of values below the limit of quantitative determination; (3) analytical methods different from those of the surficial materials study; and (4) most importantly, the inherent differences in chemistry of the materials. The distribution of variability in element concentrations o Alaskan surficial-material samples was, for most elements, largely among sampling locations, with only a samll part of the variability occurring between replicate samples at a location. The geochemical uniformity within sampling locations in Alaska is an expression of uniform geochemical cycling processes within small geographic areas. The concentration values for 35 elements in 266 samples were plotted on maps by symbols representing classes of concentration frequency distributions. These plotted symbols form patterns that may or may not be possible to interpret but nevertheless show differences that are observable at several geographical scales. The largest pattern is one generally low concentrations of many elements in materials from arctic and oceanic tundra regions, as contrasted to their often high concentrations in samples from interior and southeastern Alaska. The patttern for sodium isespecially pronounced. Intermediate-sized patterns are shown, for example, by the generally high values for magnesium and low values for silicon in the coastal forest region of southeastern Alaska. Many elements occur at low concentratoins in samples from the Alaskan peninsula and the Aleutian Islands. The degree of confidence in patterns of element abundance is expected to be in direct proportion to the number of samples included in the area. As the patterns become smaller, the probability increases that the patterns are not reproducible.

Alaska↗
USGS1985

Sorption of lead onto two gram-negative marine bacteria in seawater

Laboratory adsorption experiments performed at environmentally significant lead (Pb) and cell concentrations indicate that the marine bacteria examined have significant binding capacities for Pb. However, the behavior governing Pb sorption onto gram-negative bacteria in seawater may be quite complex. The sorption kinetics appear to involve two distinct phases, i.e., a rapid removal of Pb from solution within the first few minutes, followed by a slow but nearly constant removal over many hours. Also, the average binding coefficient, calculated for Pb sorption onto bacteria and a measure of binding intensity, increases with decreasing sorption density (amounts of bacteria-associated Pb per unit bacterial surface) at low cell concentrations (10 5 cells ml −1 ), but decreases with decreasing sorption density at higher cell concentrations (10 7 cells ml −1 ). The latter effect is apparently due to the production of significant amounts of extra-cellular organics at high cell concentrations that compete directly with bacterial surfaces for available lead. Lead toxicity and active uptake by marine bacteria did not appear significant at the Pb concentrations used.

Marine Chemistry↗
USGS2007

Best management practices for nutrient and sediment retention in urban stormwater runoff

Stormwater management infrastructure is utilized in urban areas to alleviate flooding caused by decreased landscape permeability from increased impervious surface cover (ISC) construction. In this study, we examined two types of stormwater detention basins, SDB-BMPs (stormwater detention basin-best management practice), and SDB-FCs (stormwater detention basin-flood control). Both are constructed to retain peak stormwater flows for flood mitigation. However, the SDB-BMPs are also designed using basin topography and wetland vegetation to provide water quality improvement (nutrient and sediment removal and retention). The objective of this study was to compare SDB (both SDB-BMP and SDB-FC) surface soil P concentrations, P saturation, and Fe chemistry with natural riparian wetlands (RWs), using sites in Fairfax County, Virginia as a model system. The SDB-BMPs had significantly greater surface soil total P (Pt) concentrations than the RWs and SDB-FCs (831.9 ?? 32.5 kg ha-1, 643.3 ?? 19.1 kg ha-1, and 652.1 ?? 18.8 kg ha-1, respectively). The soil P sorption capacities of SDB-BMPs were similar to the RWs, and were greater than those of SDB-FCs, appearing to result in greater soil P removal and retention in SDB-BMPs compared with SDB-FCs. Increased Fe concentrations and relatively greater amounts of more crystalline forms of Fe in SDB-BMP soils suggested increased sediment deposition compared with RW and SDB-FC soils. Data suggest that SDB nutrient and sediment retention is facilitated in SDB-BMPs. When stormwater management is necessary, use of SDB-BMPs instead of SDB-FCs could foster more responsible urban development and be an appropriate mitigation action for receiving aquatic ecosystems. ?? ASA, CSSA, SSSA.

Journal of Environmental Quality↗
USGS2008

Ground-water quality data in the San Fernando-San Gabriel study unit, 2005— Results from the California GAMA program

Ground-water quality in the approximately 460 square mile San Fernando-San Gabriel study unit (SFSG) was investigated between May and July 2005 as part of the Priority Basin Assessment Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Assessment Project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The San Fernando-San Gabriel study was designed to provide a spatially unbiased assessment of raw ground-water quality within SFSG, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 52 wells in Los Angeles County. Thirty-five of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (grid wells), and seventeen wells were selected to aid in the evaluation of specific water-quality issues or changes in water chemistry along a historic ground-water flow path (understanding wells). The ground-water samples were analyzed for a large number of synthetic organic constituents [volatile organic compounds (VOCs), pesticides and pesticide degradates], constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), 1,2,3-trichloropropane (1,2,3-TCP), and 1,4-dioxane], naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, and carbon-14, and stable isotopes of hydrogen, oxygen, and carbon), and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, samples for matrix spikes) were collected at approximately one-fifth (11 of 52) of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Assessment of the quality-control results showed that the data had very little bias or variability and resulted in censoring of less than 0.7 percent (32 of 4,484 measurements) of the data collected for ground-water samples. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, or blended with other waters to maintain acceptable water quality. Regulatory thresholds apply to treated water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH) and thresholds established for aesthetic concerns (secondary maximum contaminant levels, SMCL-CA) by CDPH. VOCs were detected in more than 90 percent (33 of 35) of grid wells. For all wells sampled for SFSG, nearly all VOC detections were below health-based thresholds, and most were less than one-tenth of the threshold values. Samples from seven wells had at least one detection of PCE, TCE, tetrachloromethane, NDMA, or 1,2,3-TCP at or above a health-based threshold. Pesticides were detected in about 90 percent (31 of 35) grid wells and all detections in samples from SFSG wells were below health-based thresholds. Major ions, trace elements, and nutrients in samples from 17 SFSG wells were all below health-based thresholds, with the exception of one detection of nitrate that was above the USEPA maximum contaminant level (MCL-US). With the exception of 14 samples having radon-222 above the proposed MCL-US, radioactive constituents were below health-based thresholds for 16 of the SFSG wells sampled. Total dissolved solids in 6 of the 24 SFSG wells that were sampled ha

California↗
USGS2008

Ground-water quality data in the middle Sacramento Valley study unit, 2006— Results from the California GAMA program

Ground-water quality in the approximately 3,340 mi 2 Middle Sacramento Valley study unit (MSACV) was investigated from June through September, 2006, as part of the California Groundwater Ambient Monitoring and Assessment (GAMA) program. The GAMA Priority Basin Assessment project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The Middle Sacramento Valley study was designed to provide a spatially unbiased assessment of raw ground-water quality within MSACV, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 108 wells in Butte, Colusa, Glenn, Sutter, Tehama, Yolo, and Yuba Counties. Seventy-one wells were selected using a randomized grid-based method to provide statistical representation of the study unit (grid wells), 15 wells were selected to evaluate changes in water chemistry along ground-water flow paths (flow-path wells), and 22 were shallow monitoring wells selected to assess the effects of rice agriculture, a major land use in the study unit, on ground-water chemistry (RICE wells). The ground-water samples were analyzed for a large number of synthetic organic constituents (volatile organic compounds [VOCs], gasoline oxygenates and degradates, pesticides and pesticide degradates, and pharmaceutical compounds), constituents of special interest (perchlorate, N-nitrosodimethylamine [NDMA], and 1,2,3-trichloropropane [1,2,3-TCP]), inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, and carbon-14, and stable isotopes of hydrogen, oxygen, nitrogen, and carbon), and dissolved noble gases also were measured to help identify the sources and ages of the sampled ground water. Quality-control samples (blanks, replicates, laboratory matrix spikes) were collected at approximately 10 percent of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a noticeable source of bias in the data for the ground-water samples. Differences between replicate samples were within acceptable ranges, indicating acceptably low variability. Matrix spike recoveries were within acceptable ranges for most constituents. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, or blended with other waters to maintain acceptable water quality. Regulatory thresholds apply to treated water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with health-based thresholds established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH) and thresholds established for aesthetic concerns (secondary maximum contaminant levels, SMCL-CA) by CDPH. Comparisons between data collected for this study and drinking-water thresholds are for illustrative purposes only and are not indicative of compliance or noncompliance with regulatory thresholds. Most constituents that were detected in ground-water samples were found at concentrations below drinking-water thresholds. VOCs were detected in less than one-third and pesticides and pesticide degradates in just over one-half of the grid wells, and all detections of these constituents in samples from all wells of the MSACV study unit were below health-based thresholds. All detections of trace elements in samples from MSACV grid wells were below health-based thresholds, with the exceptions of arsenic and boron. Arsenic concentrations were above the USEPA maximum contaminant level (MCL-US) threshold in eight grid wells, and boron concentrations were above the CDPH notification level (NL-CA) in two grid wells. Arsenic was detected above the MCL-US in two flow-path wells. Arsenic, barium, boron, molybdenum, strontium, and vanadium were detected above health-based thresholds in a few of the RICE wells; these wells are not used to supply drinking water. All detections of radioactive constituents were below health-based thresholds, although six samples had activities of radon-222 above the lower proposed MCL-US threshold. Most of the samples from the MSACV wells had concentrations of major elements, total dissolved solids, and trace elements below the non-enforceable thresholds set for aesthetic concerns. Chloride and sulfate concentrations exceeded SMCL-CA thresholds in two and one grid well, respectively. Iron, manganese, and total dissolved solids concentrations were above the SMCL-CA thresholds in 1, 12, and 6 grid wells, respectively. Nitrate (nitrite plus nitrate, as dissolved nitrogen) concentrations from two grid wells were above the MCL-US threshold. There were no detections of microbial indicators in MSACV.

California↗
USGS2008

Drier forest composition associated with hydrologic change in the Apalachicola River floodplain, Florida

Forests of the Apalachicola River floodplain had shorter flood durations, were drier in composition, and had 17 percent fewer trees in 2004 than in 1976. The change to drier forest composition is expected to continue for at least 80 more years. Floodplain drying was caused by large declines in river levels resulting from erosion of the river channel after 1954 and from decreased flows in spring and summer months since the 1970s. Water-level declines have been greatest at low and medium flows, which are the most common flows (occurring about 80 percent of the time). Water levels have remained relatively unchanged during large floods which continue to occur about three times per decade. A study conducted by the U.S. Geological Survey compared temporal changes in hydrologic conditions, forest composition, forest characteristics, and individual species of trees, as well as estimated the potential for change in composition of floodplain forests in the nontidal reach of the Apalachicola River. The study was conducted with the cooperation of the Florida Department of Environmental Protection and the Northwest Florida Water Management District. Forest composition and field observations from studies conducted in 1976-1984 (termed “1976 data”) were used as baseline data for comparison with data from plots sampled in 2004-2006 (“2004 data”). Flood durations were shorter in all periods subsequent to 1923-1976. The periods of record used to calculate flood durations for forest data were subsets of the complete record available (1923-2004). At sampled plots in all forest types and reaches combined, flood durations changed an average of more than 70 percent toward the baseline flood duration of the next drier forest type. For all forest types, changes in flood durations toward the next drier type were greatest in the upper reach (95.9 percent) and least in the lower reach (42.0 percent). All forests are expected to be 38.2 percent drier in species composition by 2085, the year when the median age of surviving 2004 subcanopy trees will reach the median age (99 years) of the 2004 large canopy trees. The change will be greatest for forests in the upper reach (45.0 percent). Forest composition changes from pre-1954 to 2085 were calculated using Floodplain Indices from 1976 and 2004 tree-size classes and replicate plots. Species composition in high bottomland hardwood forests is expected to continue to change, and some low bottomland hardwood forests are expected to become high bottomland hardwood forests. Organisms associated with floodplain forests will be affected by the changes in tree species, which will alter the timing of leaf-out, fruiting, and leaf-drop, the types of fruit and debris produced, and soil chemistry. Swamps will contain more bottomland hardwood species, but will also have an overall loss of tree density. The density of trees in swamps significantly decreased by 37 percent from 1976 to 2004. Of the estimated 4.3 million (17 percent) fewer trees that existed in the nontidal floodplain in 2004 than in 1976, 3.3 million trees belonged to four swamp species: popash, Ogeechee tupelo, water tupelo, and bald cypress. Water tupelo, the most important tree in the nontidal floodplain in terms of basal area and density, has declined in number of trees by nearly 20 percent since 1976. Ogeechee tupelo, the species valuable to the tupelo honey industry, has declined in number of trees by at least 44 percent. Greater hydrologic variability in recent years may be the reason swamps have had a large decrease in tree density. Drier conditions are detrimental for the growth of swamp species, and periodic large floods kill invading bottomland hardwood trees. The loss of canopy density in swamps may result in the swamp floor being exposed to more light with an increase in the amount of ground cover present, which in turn, would reduce tree replacement. The microclimate of the swamp floor would become warmer due to the decrease in shade and inundation. Soils would become dehydrated more quickly in dry periods and debris would decompose more quickly. A loss of tree density in swamps would lead to a decrease in tree and leaf litter biomass, which would have additional effects on swamp organisms. The loss of litter would result in a loss of substrate for benthic organisms in the floodplain and, ultimately, in the downstream waters of the river and estuary.

Florida↗
USGS2008

Ground-water quality data in the coastal Los Angeles Basin study unit, 2006: Results from the California GAMA Program

Ground-water quality in the approximately 860 square-mile Coastal Los Angeles Basin study unit (CLAB) was investigated from June to November of 2006 as part of the Statewide Basin Assessment Project of the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment was developed in response to the Ground-Water Quality Monitoring Act of 2001, and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The Coastal Los Angeles Basin study was designed to provide a spatially unbiased assessment of raw ground-water quality within CLAB, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 69 wells in Los Angeles and Orange Counties. Fifty-five of the wells were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (?grid wells?). Fourteen additional wells were selected to evaluate changes in ground-water chemistry or to gain a greater understanding of the ground-water quality within a specific portion of the Coastal Los Angeles Basin study unit ('understanding wells'). Ground-water samples were analyzed for: a large number of synthetic organic constituents [volatile organic compounds (VOCs), gasoline oxygenates and their degradates, pesticides, polar pesticides, and pesticide degradates, pharmaceutical compounds, and potential wastewater-indicators]; constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), 1,4-dioxane, and 1,2,3-trichloropropane (1,2,3-TCP)]; inorganic constituents that can occur naturally [nutrients, major and minor ions, and trace elements]; radioactive constituents [gross-alpha and gross-beta radiation, radium isotopes, and radon-222]; and microbial indicators. Naturally occurring isotopes [stable isotopic ratios of hydrogen and oxygen, and activities of tritium and carbon-14] and dissolved noble gases also were measured to help identify the sources and ages of the sampled ground water. Quality-control samples (blanks, replicates, and samples for matrix spikes) were collected at approximately one-fourth of the wells, and the results for these samples were used to evaluate the quality of the data for the ground-water samples. Field blanks rarely contained detectable concentrations of any constituent, suggesting that contamination was not a significant source of bias. Differences between replicate samples were within acceptable ranges, indicating acceptably low variability. Matrix spike recoveries were within acceptable ranges for most compounds. Assessment of the quality-control information resulted in applying ?V? codes to approximately 0.1 percent of the data collected for ground-water samples (meaning a constituent was detected in blanks as well as the corresponding environmental data). This study did not attempt to evaluate the quality of drinking water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, and (or) blended with other waters to maintain acceptable drinking-water quality. Regulatory thresholds are applied to the treated drinking water that is served to the consumer, not to raw ground water. However, to provide some context for the results, concentrations of constituents measured in the raw ground water were compared with regulatory and non-regulatory health-based thresholds established by the U.S. Environmental Protection Agency (USEPA), California Department of Public Health (CDPH, formerly California Department of Health Services [CADHS]) and thresholds established for aesthetic concerns (secondary maximum contaminant levels, SMCL-CA) by CDPH. Comparisons between data collected for this study and drinking-water thresholds are for illustrative purposes only, and are not indicative of compliance or non-compliance with those thresholds. VOCs were detected in alm

California↗
USGS2010

Depositional setting, petrology and chemistry of Permian coals from the Paraná Basin: 2. South Santa Catarina Coalfield, Brazil

In Brazil economically important coal deposits occur in the southern part of the Paraná Basin, where coal seams occur in the Permian Rio Bonito Formation, with major coal development in the states of Rio Grande de Sul and Santa Catarina. The current paper presents results on sequence stratigraphic interpretation of the coal-bearing strata , and petrological and geochemical coal seam characterization from the South Santa Catarina Coalfield, Paraná Basin. In terms of sequence stratigraphic interpretation the precursor mires of the Santa Catarina coal seams formed in an estuarine-barrier shoreface depositional environment , with major peat accumulation in a high stand systems tract (Pre-Bonito and Bonito seams), a lowstand systems tract (Ponta Alta seam, seam A, seam B) and a transgressive systems tract (Irapuá, Barro Branco and Treviso seams). Seam thicknesses range from 1.70 to 2.39 m, but high proportions of impure coal (coaly shale and shaley coal), carbonaceous shale and partings reduce the net coal thickness significantly. Coal lithoypes are variable, with banded coal predominant in the Barro Branco seam, and banded dull and dull coal predominantly in Bonito and Irapuá seams, respectively. Results from petrographic analyses indicate a vitrinite reflectance range from 0.76 to 1.63 %Rrandom (HVB A to LVB coal). Maceral group distribution varies significantly, with the Barro Branco seam having the highest vitrinite content (mean 67.5 vol%), whereas the Irapuá seam has the highest inertinite content (33.8 vol%). Liptinite mean values range from 7.8 vol% (Barro Branco seam) to 22.5 vol% (Irapuá seam). Results from proximate analyses indicate for the three seams high ash yields (50.2 – 64.2 wt.%). Considering the International Classification of in-Seam Coals, all samples are in fact classified as carbonaceous rocks (> 50 wt.% ash). Sulfur contents range from 3.4 to 7.7 wt.%, of which the major part occurs as pyritic sulfur. Results of X-ray diffraction indicate the predominance of quartz and kaolinite (also pyrite). Gypsum , gibbsite , jarosite and calcite were also identified in some samples. Feldspar was noted but is rare. The major element distribution in the three seams (coal basis) is dominated by SiO 2 (31.3 wt.%, mean value), Al 2 O 3 (14.5 wt.%, mean value) and Fe 2 O 3 (6.9 wt.%, mean value). Considering the concentrations of trace elements that are of potential environmental hazards the Barro Branco, Bonito and Irapuá seams (coal base) are significantly enriched in Co (15.7 ppm), Cr (54.5 ppm), Li (59.3 ppm), Mn (150.4 ppm), Pb (58.0 ppm) and V (99.6 ppm), when compared to average trace elements contents reported for U. S. coals. Hierarchical cluster analysis identified, based on similarity levels, three groups of major elements and seven groups of trace elements. Applying discriminant analyses using trace and major element distribution, it could be demonstrated that the three seams from Santa Catarina show distinct populations in the discriminant analyses plots, and also differ from the coals of Rio Grande do Sul analyzed in a previous study.

Santa Catarina↗