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I.G. Krapac

Publications and source records attributed to I.G. Krapac.

At least 19 recordsLinked to original sources

Characterizing near-surface CO2 conditions before injection - Perspectives from a CCS project in the Illinois Basin, USA

The Midwest Geological Sequestration Consortium is conducting a large-scale carbon capture and storage (CCS) project in Decatur, Illinois, USA to demonstrate the ability of a deep saline formation to store one million tonnes of carbon dioxide (CO 2 ) from an ethanol facility. Beginning in early 2011, CO 2 will be injected at a rate of 1,000 tonnes/day for three years into the Mount Simon Sandstone at a depth of approximately 2,100 meters. An extensive Monitoring, Verification, and Accounting (MVA) program has been undertaken for the Illinois Basin Decatur Project (IBDP) and is focused on the 0.65 km2 project site. Goals include establishing baseline conditions to evaluate potential impacts from CO 2 injection, demonstrating that project activities are protective of human health and the environment, and providing an accurate accounting of stored CO 2 . MVA efforts are being conducted pre-, during, and post- CO 2 injection. Soil and net CO 2 flux monitoring has been conducted for more than one year to characterize near-surface CO 2 conditions. More than 2,200 soil CO 2 flux measurements have been manually collected from a network of 118 soil rings since June 2009. Three ring types have been evaluated to determine which type may be the most effective in detecting potential CO 2 leakage. Bare soil, shallow-depth rings were driven 8 cm into the ground and were prepared to minimize surface vegetation in and near the rings. Bare soil, deep-depth rings were prepared similarly, but were driven 46 cm. Natural-vegetation, shallow-depth rings were driven 8 cm and are most representative of typical vegetation conditions. Bare-soil, shallow-depth rings had the smallest observed mean flux (1.78 μmol m −2 s −1 ) versus natural-vegetation, shallow-depth rings (3.38 μmol m −2 s −1 ). Current data suggest bare ring types would be more sensitive to small CO 2 leak signatures than natural ring types because of higher signal to noise ratios. An eddy covariance (EC) system has been in use since June 2009. Baseline data from EC monitoring is being used to characterize pre-injection conditions, and may then be used to detect changes in net exchange CO 2 fluxes (Fc) that could be the result of CO 2 leakage into the near-surface environment during or following injection. When injection at IBDP begins, soil and net CO 2 monitoring efforts will have established a baseline of near-surface conditions that will be important to help demonstrate the effectiveness of storage activities.

Illinois↗

Applying monitoring, verification, and accounting techniques to a real-world, enhanced oil recovery operational CO2 leak

The use of carbon dioxide (CO 2 ) for enhanced oil recovery (EOR) is being tested for oil fields in the Illinois Basin, USA. While this technology has shown promise for improving oil production, it has raised some issues about the safety of CO 2 injection and storage. The Midwest Geological Sequestration Consortium (MGSC) organized a Monitoring, Verification, and Accounting (MVA) team to develop and deploy monitoring programs at three EOR sites in Illinois, Indiana, and Kentucky, USA. MVA goals include establishing baseline conditions to evaluate potential impacts from CO 2 injection, demonstrating that project activities are protective of human health and the environment, and providing an accurate accounting of stored CO 2 . This paper focuses on the use of MVA techniques in monitoring a small CO 2 leak from a supply line at an EOR facility under real-world conditions. The ability of shallow monitoring techniques to detect and quantify a CO 2 leak under real-world conditions has been largely unproven. In July of 2009, a leak in the pipe supplying pressurized CO 2 to an injection well was observed at an MGSC EOR site located in west-central Kentucky. Carbon dioxide was escaping from the supply pipe located approximately 1 m underground. The leak was discovered visually by site personnel and injection was halted immediately. At its largest extent, the hole created by the leak was approximately 1.9 m long by 1.7 m wide and 0.7 m deep in the land surface. This circumstance provided an excellent opportunity to evaluate the performance of several monitoring techniques including soil CO 2 flux measurements, portable infrared gas analysis, thermal infrared imagery, and aerial hyperspectral imagery. Valuable experience was gained during this effort. Lessons learned included determining (1) hyperspectral imagery was not effective in detecting this relatively small, short-term CO 2 leak, (2) even though injection was halted, the leak remained dynamic and presented a safety risk concern during monitoring activities and, (3) the atmospheric and soil monitoring techniques used were relatively cost-effective, easily and rapidly deployable, and required minimal manpower to set up and maintain for short-term assessments. However, characterization of CO 2 distribution near the land surface resulting from a dynamic leak with widely variable concentrations and fluxes was challenging.

Illinois, Indiana, and Kentucky↗

The path to a successful one-million tonne demonstration of geological sequestration: Characterization, cooperation, and collaboration

The development of the Illinois Basin-Decatur USA test site for a 1 million tonne injection of CO 2 into the Mount Simon Sandstone saline reservoir beginning in 2011 has been a multiphase process requiring a wide array of personnel and resources that began in 2003. The process of regional characterization took two years as part of a Phase I effort focused on the entire Illinois Basin, located in Illinois, Indiana, and Kentucky, USA. Seeking the cooperation of an industrial source of CO 2 and site selection within the Basin took place during Phase II while most of the concurrent research emphasis was on a set of small-scale tests of Enhanced Oil Recovery (EOR) and CO 2 injection into a coal seam. Phase III began the commitment to the 1 million-tonne test site development through the collaboration of the Archer Daniels Midland Company (ADM) who is providing a site, the CO 2 , and developing a compression facility, of Schlumberger Carbon Services who is providing expertise for operations, drilling, geophysics, risk assessment, and reservoir modelling, and of the Illinois State Geological Survey (ISGS) whose geologists and engineers lead the Midwest Geological Sequestration Consortium (MGSC). Communications and outreach has been a collaborative effort of ADM, ISGS and Schlumberger Carbon Services. The Consortium is one of the seven Regional Carbon Sequestration Partnerships, a carbon sequestration research program supported by the National Energy Technology Laboratory of the U.S. Department of Energy.

Illinois↗

A Multi-Level Approach to Outreach for Geologic Sequestration Projects

Public perception of carbon capture and sequestration (CCS) projects represents a potential barrier to commercialization. Outreach to stakeholders at the local, regional, and national level is needed to create familiarity with and potential acceptance of CCS projects. This paper highlights the Midwest Geological Sequestration Consortium (MGSC) multi-level outreach approach which interacts with multiple stakeholders. The MGSC approach focuses on external and internal communication. External communication has resulted in building regional public understanding of CCS. Internal communication, through a project Risk Assessment process, has resulted in enhanced team communication and preparation of team members for outreach roles. ?? 2009 Elsevier Ltd. All rights reserved.

Conference Paper↗

The feasibility of applying immature yard-waste compost to remove nitrate from agricultural drainage effluents: A preliminary assessment

Nitrate is a major agricultural pollutant found in drainage waters. Immature yard-waste compost was selected as a filter media to study its feasibility for removing nitrate from drainage water. Different operation parameters were tested to examine the denitrification efficiency, including the amounts of compost packed in columns, the flow rate, and the compost storage periods. The experimental results suggested that hydraulic retention time was the major factor to determine the extent of nitrate removal, although the amount of compost packed could also contribute to the nitrate removal efficiency. The effluent nitrate concentration increased as the flow rate decreased, and the compost column reduced nitrate concentrations from 20 mg/L to less than 5 mg/L within 1.5 h. The solution pH increased at the onset of experiment because of denitrification, but stabilized at a pH of about 7.8, suggesting that the compost had a buffering capacity to maintain a suitable pH for denitrification. Storing compost under air-dried conditions may diminish the extent nitrate removed initially, but the effects were not apparent after longer applications. It appeared that immature yard-waste compost may be a suitable material to remove nitrate from tile drainage water because of its relatively large organic carbon content, high microbial activity, and buffering capacity. ?? 2006 Elsevier B.V. All rights reserved.

Journal of Hazardous Materials↗

Monitoring and source tracking of tetracycline resistance genes in lagoons and groundwater adjacent to swine production facilities over a 3-year period

To monitor the dissemination of resistance genes into the environment, we determined the occurrence of tetracycline resistance (Tcr) genes in groundwater underlying two swine confinement operations. Monitoring well networks (16 wells at site A and 6 wells at site C) were established around the lagoons at each facility. Groundwater (n = 124) and lagoon (n = 12) samples were collected from the two sites at six sampling times from 2000 through 2003. Total DNA was extracted, and PCR was used to detect seven Tcr genes [tet(M), tet(O), tet(Q), tet(W), tet(C), tet(H), and tet(Z)]. The concentration of Tcr genes was quantified by real-time quantitative PCR. To confirm the Tcr gene source in groundwater, comparative analysis of tet(W) gene sequences was performed on groundwater and lagoon samples. All seven Tcr genes were continually detected in groundwater during the 3-year monitoring period at both sites. At site A, elevated detection frequency and concentration of Tcr genes were observed in the wells located down-gradient of the lagoon. Comparative analysis of tet(W) sequences revealed that the impacted groundwater contained gene sequences almost identical (99.8% identity) to those in the lagoon, but these genes were not found in background libraries. Novel sequence clusters and unique indigenous resistance gene pools were also found in the groundwater. Thus, antibiotic resistance genes in groundwater are affected by swine manure, but they are also part of the indigenous gene pool. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

Applied and Environmental Microbiology↗

Potential soil cleanup objectives for nitrogen-containing fertilizers at agrichemical facilities

Accidental and incidental chemical releases of nitrogen-containing fertilizers occur at retail agrichemical facilities. Because contaminated soil may threaten groundwater quality, the facility may require some type of site remediation. The purpose of this study was to apply the concepts of the Soil Screening Levels of the U.S. Environmental Protection Agency to derive soil cleanup objectives (SCO) that are protective of groundwater quality in Illinois for nitrogen as nitrate and as ammonium. The Soil Screening Levels are based on the solute transport mechanisms of sorption, volatilization, and groundwater dilution, and the contaminant-specific groundwater cleanup objective used to derive the SCO. Because nitrate is relatively unreactive, only groundwater dilution could be taken into account in the derivation of a SCO. Using a default groundwater objective for potable groundwater, an SCO of 38 mg N-NO3/kg was derived. For ammonium, however, the extent of sorption was measured using an uncontaminated, surface-soil sample (0 to 15 cm) of 10 different soil types that occur in Illinois and three gravel-fill samples from three different agrichemical facilities. Using a default groundwater objective, an SCO was derived for each soil type. The median SCO was 989 mg N-NH4/kg. The SCO calculated for each of the 10 soil and 3 fill samples was positively correlated with cation exchange capacity, clay content, and surface area. It was concluded that this approach can be used to derive either default of site-specific SCOs for nitrogen as nitrate and as ammonium for chemical releases. Copyright ?? Taylor & Francis Group, LLC.

Soil and Sediment Contamination↗

Characterization and identification of Na-Cl sources in ground water

Elevated concentrations of sodium (Na+) and chloride (Cl -) in surface and ground water are common in the United States and other countries, and can serve as indicators of, or may constitute, a water quality problem. We have characterized the most prevalent natural and anthropogenic sources of Na+ and Cl- in ground water, primarily in Illinois, and explored techniques that could be used to identify their source. We considered seven potential sources that included agricultural chemicals, septic effluent, animal waste, municipal landfill leachate, sea water, basin brines, and road deicers. The halides Cl-, bromide (Br-), and iodide (I-) were useful indicators of the sources of Na+-Cl- contamination. Iodide enrichment (relative to Cl-) was greatest in precipitation, followed by uncontaminated soil water and ground water, and landfill leachate. The mass ratios of the halides among themselves, with total nitrogen (N), and with Na+ provided diagnostic methods for graphically distinguishing among sources of Na+ and Cl- in contaminated water. Cl/Br ratios relative to Cl- revealed a clear, although overlapping, separation of sample groups. Samples of landfill leachate and ground water known to be contaminated by leachate were enriched in I- and Br-; this provided an excellent fingerprint for identifying leachate contamination. In addition, total N, when plotted against Cl/Br ratios, successfully separated water contaminated by road salt from water contaminated by other sources. Copyright ?? 2005 National Ground Water Association.

Ground Water↗

Geochemical transformations and modeling of two deep-well injected hazardous wastes

Two liquid hazardous wastes (an alkaline brine-like solution and a dilute acidic waste) were mixed with finely ground rock samples of three injection-related lithologies (sandstone, dolomite, and siltstone) for 155 to 230 days at 325°K-10.8 MPa. The pH and inorganic chemical composition of the alkaline waste were not significantly altered by any of the rock samples after 230 days of mixing. The acidic waste was neutralized as a consequence of carbonate dissolution, ion exchange, or clay-mineral dissolution, and hence was transformed into a nonhazardous waste.

Groundwater↗

Long-term behavior of water content and density in an earthen liner

An extensively instrumented compacted earthen liner was constructed at the Illinois State Geological Survey facility in Champaign, III. in 1987. A pond of water 0.31 m deep was maintained on top of the 7.3 m ?? 14.6 m ?? 0.9 m thick liner for 14 years. One of the goals of the project was to evaluate the long-term performance of a compacted earthen liner by monitoring the long-term changes in water content and density. The water content of the earthen liner showed no trend with depth or time. The liner density remained essentially constant from construction through excavation in 2002. The liner did not become fully saturated. Upon excavation of the liner, the degree of saturation was 80.0??6.3% after 14 years of ponding under a hydraulic head of 0.31 m. The results imply that properly designed and constructed earthen liners may reduce the possibility of pollutants leaching from municipal solid waste containment facilities by remaining partially saturated for years and maintaining the placement density. Journal of Geotechnical and Geoenvironmental Engineering ?? ASCE.

Journal of Geotechnical and Geoenvironmental Engin↗

Evaluation of multidimensional transport through a field-scale compacted soil liner

A field-scale compacted soil liner was constructed at the University of Illinois at Urbana-Champaign by the U.S. Environmental Protection Agency (USEPA) and Illinois State Geological Survey in 1988 to investigate chemical transport rates through low permeability compacted clay liners (CCLs). Four tracers (bromide and three benzoic acid tracers) were each added to one of four large ring infiltrometers (LRIs) while tritium was added to the pond water (excluding the infiltrometers). Results from the long-term transport of Br - "> Br - from the localized source zone of LRI are presented in this paper. Core samples were taken radially outward from the center of the Br - "> Br - LRI and concentration depth profiles were obtained. Transport properties were evaluated using an axially symmetric transport model. Results indicate that (1) transport was diffusion controlled; (2) transport due to advection was negligible and well within the regulatory limits of k sat ⩽ 1 × 10 - 7 cm / s ; "> k sat ⩽ 1 × 10 − 7 cm / s; (3) diffusion rates in the horizontal and vertical directions were the same; and (4) small positioning errors due to compression during soil sampling did not affect the best fit advection and diffusion values. The best-fit diffusion coefficient for bromide was equal to the molecular diffusion coefficient multiplied by a tortuosity factor of 0.27, which is within 8% of the tortuosity factor (0.25) found in a related study where tritium transport through the same liner was evaluated. This suggests that the governing mechanisms for the transport of tritium and bromide through the CCL were similar. These results are significant because they address transport through a composite liner from a localized source zone which occurs when defects or punctures in the geomembrane of a composite system are present.

Journal of Geotechnical and Geoenvironmental Engin↗

Impacts of swine manure pits on groundwater quality

Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and ??15N and ??18O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human health. Fecal streptococcus bacteria were detected at least once in groundwater from all monitoring wells at both sites. Fecal streptococcus was more common and at greater concentrations than fecal coliform. The microbiological data suggest that filtration of bacteria by soils may not be as effective as commonly assumed. The presence of fecal bacteria in the shallow groundwater may pose a significant threat to human health if the ground water is used for drinking. Both facilities are less than 4 years old and the short-term impacts of these manure storage facilities on groundwater quality have been limited. Continued monitoring of these facilities will determine if they have a long-term impact on groundwater resources. ?? 2002 Elsevier Science Ltd. All rights reserved.

Environmental Pollution↗

Long-term tritium transport through field-scale compacted soil liner

A 13-year study of tritium transport through a field-scale earthen liner was conducted by the Illinois State Geological Survey to determine the long-term performance of compacted soil liners in limiting chemical transport. Two field-sampling procedures (pressure-vacuum lysimeter and core sampling) were used to determine the vertical tritium concentration profiles at different times and locations within the liner. Profiles determined by the two methods were similar and consistent. Analyses of the concentration profiles showed that the tritium concentration was relatively uniformly distributed horizontally at each sampling depth within the liner and thus there was no apparent preferential transport. A simple one-dimensional analytical solution to the advective-dispersive solute transport equation was used to model tritium transport through the liner. Modeling results showed that diffusion was the dominant contaminant transport mechanism. The measured tritium concentration profiles were accurately modeled with an effective diffusion coefficient of 6 ?? 10-4 mm2/s, which is in the middle of the range of values reported in the literature.

Journal of Geotechnical and Geoenvironmental Engin↗

Pesticide storage and release in unsaturated soil in Illinois, USA

The chemical fate and movement of pesticides may be subject to transient storage in unsaturated soils during periods of light rainfall, and subsequent release into shallow groundwater by increased rainfall. The objective of this study was to conduct field-scale experiments to determine the relative importance of transient storage and subsequent release of agrichemicals from the vadose zone into potential aquifers. Two field-scale experiments were conducted under a rain exclusion shelter. In the 1 x experiment, atrazine and chlorpyrifos were applied at application-rate equivalents (1.6 kg ha-1 and 1.3 kg ha-1, respectively). In the 4x experiment, atrazine was applied in an amount that was four times greater than that usually applied to fields (6.7 kg ha-1). Water was either applied to simulate rain or withheld to simulate dry periods. In the 1 x experiment, atrazine was detected in the water samples whereas chlorpyrifos was not detected in the majority of the samples. The dry period imposed on the treatment plot did not appear to result in storage of the chemicals, whereas the wet period resulted in greater leaching of atrazine, although the concentrations remained less than the Maximum Contaminant Level of 3 ?? L-1. Both chemicals were detected in soil samples collected from a 20- to 30-cm depth, but it appeared that both chemicals dissipated before the field experiment was concluded. It appeared that the one-time application of atrazine and chlorpyrifos at the label rates did not result in a sufficient mass to be stored and flushed in significant concentrations to the saturated zone. When atrazine was applied at 4x and a longer drought period was imposed on the treatment plot, the resulting concentrations of dissolved atrazine were still less than 3 ??g L-1. Atrazine was detected in only the near-surface (0 to 15 cm) soil samples and the herbicide dissipated before the onset of the dry period in the treatment plot. The results of this field study demonstrated that atrazine and chlorpyrifos were not sufficiently persistent to be stored and then released in significantly large concentrations to the saturated zone. The dissipation half-life of atrazine in the 4x application was about 44 days. This study, in addition to others, suggested that atrazine may be less persistent in surface soil than has been generally reported.

Journal of Environmental Science and Health - Part↗

Impact of urban development on the chemical composition of ground water in a fen-wetland complex

A 15-month-long hydrogeologic investigation of a fen-wetland complex in northeastern Illinois, USA indicated the encroachment of ground-water-borne anthropogenic contaminants into two of three high quality fens. Ground-water flow directions and chemical evidence indicated that plumes of ground water with anomalously large concentrations of Na − and Cl − originated from a private septic system and from rock salt spread on an adjacent road. The contamination, in turn, had an adverse effect on fen vegetation; within the plumes, diverse vegetation was replaced by the more salt-tolerant narrow-leaf cattail ( Typha angustifolia ). Ground water of the third fen contained large concentrations of SO 4 2− as high as 516 mg/L. The SO 4 2− anomaly was observed on a transient and/or seasonal basis in the fen ground water and in an adjacent marsh and pond. Isotopically light δ 34 S values in these waters indicated that the addition of SO 4 2− resulted from the oxidation of pyrite within underlying peat and/or pyritic gravel. However, the large SO 4 2− concentrations had no discernible effect on fen vegetation. The results of this investigation indicate how easily construction of houses with private septic systems and deicing agents from roadway maintenance can contaminate fen ground water with relatively large concentrations of Na + and Cl − , resulting in a significant loss of biodiversity in fens.

Illinois↗

A new device for collecting time-integrated water samples from springs and surface water bodies

A new device termed the 'seepage sampler' was developed to collect representative water samples from springs, streams, and other surface-water bodies. The sampler collects composite, time-integrated water samples over short (hours) or extended (weeks) periods without causing significant changes to the chemical composition of the samples. The water sample within the sampler remains at the ambient temperature of the water body and does not need to be cooled. Seepage samplers are inexpensive to construct and easy to use. A sampling program of numerous springs and/or streams can be designed at a relatively low cost through the use of these samplers. Transient solutes migrating through such flow systems, potentially unnoticed by periodic sampling, may be detected. In addition, the mass loading of solutes (e.g., agrichemicals) may be determined when seepage samplers are used in conjunction with discharge measurements.

Environmental & Engineering Geoscience↗

Off-site movement of pesticide-contaminated fill from agrichemical facilities during the 1993 flooding in Illinois

Twenty retail agrichemical facilities were flooded. There was a concern that pesticide-contaminated road fill at these facilities had been transported into residential areas by the flooding. Forty fill and flood-related sediment samples were collected at six facilities. No significant accumulation of sediments was present at any of the six facilities. At five of the six facilities, it did not appear that road fill had been transported off-site. Pesticides were detected in sediment samples collected off-site adjacent to five of the facilities. Of the 21 samples collected off-site, atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazide) and metolachlor (2-chloro-6′-ethyl- N -(2-methoxy-1-methylethyl)acet- o -toluidine) were detected in 86 and 81% of the samples, respectively. When compared with on-site concentrations, off-site pesticide concentrations were either at similar levels, or were as much as three orders of magnitude less. The interpretation of the pesticide data was difficult and often inconclusive, because there were no background data on the occurrence and distribution of pesticides at each site before flooding.

Journal of Environmental Quality↗

Adsorption and desorption of atrazine and deethylatrazine by low organic carbon geologic materials

The adsorption and desorption of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and a primary metabolite, deethylatrazine (2-amino-4-chloro-6-isopropylamino-s-triazine; DEA), by low organic C (≤ 3.3 g kg −1 ) materials were measured by batch-equilibrium techniques. The adsorbents were samples of glacial outwash sand, till, and stream sediments. The adsorption of both atrazine and DEA conformed to linear isotherms. The adsorption of atrazine by most of the adsorbents yielded apparent K oc values that were in excess of those based on surface agricultural soils. Adsorption correlated with only the pH of the sand-water suspensions. The desorption of atrazine was hysteretic under the conditions of the measurement. DEA had a lower affinity for the same adsorbents; the mean ratio of K d values of DEA to those of atrazine was 0.37 ± 0.20. DEA adsorption did not correlate with organic C, surface area, clay content of the adsorbents, or with the pH of the suspensions. DEA adsorption, unlike atrazine, tended to be reversible. There was a linear relationship between the adsorption constants of atrazine and those of DEA.

Journal of Environmental Quality↗