Risks due to groundwater contamination at a plutonium processing facility

This is a summary booklet of the main report: Hanford Site Groundwater Monitoring for Fiscal Year 2005. It is the summary section of the main report with a CD of the entire report included. The main report is one of the major products and deliverables of the Groundwater Remediation and Closure Assessment Projects detailed work plan for FY 2006, and reflects the requirements of The Groundwater Performance Assessment Project Quality Assurance Plan (PNNL-15014). This report presents the results of groundwater and vadose zone monitoring and remediation for fiscal year 2005 on the U.S. Department of Energy’s Hanford Site, Washington. The most extensive contaminant plumes in groundwater are tritium, iodine-129, and nitrate, which all had multiple sources and are very mobile in groundwater. The largest portions of these plumes are migrating from the central Hanford Site to the southeast, toward the Columbia River. Carbon tetrachloride and associated organic constituents form a relatively large plume beneath the west-central part of the Hanford Site. Hexavalent chromium is present in plumes beneath the reactor areas along the river and beneath the central part of the site. Strontium-90 exceeds standards beneath all but one of the reactor areas. Technetium-99 and uranium plumes exceeding standards are present in the 200 Areas. A uranium plume underlies the 300 Area. Minor contaminant plumes with concentrations greater than standards include carbon-14, cesium-137, cis-1,2-dichloroethene, cyanide, fluoride, plutonium, and trichloroethene. Monitoring for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 is conducted in 11 groundwater operable units. The purpose of this monitoring is to define and track plumes and to monitor the effectiveness of interim remedial actions. Interim groundwater remediation in the 100 Areas continued with the goal of reducing the amount of chromium (100-K, 100-D, and 100-H) and strontium-90 (100-N) reaching the Columbia River. The objective of two interim remediation systems in the 200 West Area is to prevent the spread of carbon tetrachloride and technetium-99/uranium plumes. Resource Conservation and Recovery Act of 1976 groundwater monitoring continued at 25 waste management areas during fiscal year 2005: 15 under interim or final status detection programs and data indicate that they are not adversely affecting groundwater, 8 under interim status groundwater quality assessment programs to assess contamination, and 2 under final status corrective-action programs. During calendar year 2005, drillers completed 27 new monitoring wells, and decommissioned (filled with grout) 115 unneeded wells. Vadose zone monitoring, characterization, and remediation continued in fiscal year 2005. Remediation and associated monitoring continued at a soil-vapor extraction system in the 200 West Area, which removes gaseous carbon tetrachloride from the vadose zone. DOE uses geophysical methods to monitor potential movement of contamination beneath former waste sites.

This report presents the results of groundwater and vadose-zone monitoring and remediation for fiscal year (FY) 1998 on the Word Site, Washington. Soil-vapor extraction in the 200-West Area removed 777 kg of carbon tetrachloride in FY 1998, for a total of 75,490 kg removed since remediation began in 1992. Spectral gamma logging and evaluation of historical gross gamma logs near tank farms and liquid-disposal sites in the 200 Areas provided information on movement of contaminants in the vadose zone. Water-level monitoring was performed to evaluate groundwater-flow directions, to track changes in water levels, and to relate such changes to evolving disposal practices. Water levels over most of the Hanford Site continued to decline between June 1997 and June 1998. The most widespread radiological contaminant plumes in groundwater were tritium and iodine-129. Concentrations of technetium-99, uranium, strontium-90, and carbon-14 also exceeded drinking water standards in smaller plumes. Plutonium and cesium-137 exceeded standards only near the 216-B-5 injection well. Derived concentration guide levels specified in U.S. Department of Energy Order 5400.5 were exceeded for tritium, uranium, strontium-90, and plutonium in small plumes or single wells. One well completed in the basalt-confined aquifer beneath the 200-East Area exceeded the drinking water standard for technetium-99. Nitrate is the most extensive chemical contaminant. Carbon tetrachloride, chloroform, chromium, cis-l, Z-dichloroethylene, fluoride, and trichloroethylene also were present in smaller areas at levels above their maximum contaminant levels. Cyanide concentrations were elevated in one area but were below the maximum contaminant level. Tetrachloroethylene exceeded its maximum contaminant level in several wells in the 300 Area for the first time since the 1980s. Metals such as aluminum, cadmium, iron, manganese, and nickel exceeded their maximum contaminant levels in filtered samples from numerous wells; they are believed to represent natural components of groundwater. Resource Conservation and Recovery Act of 1976 groundwater monitoring continued at 25 waste management areas during FY 1998: 17 under detection programs and data indicate that they are not adversely affecting groundwater, 6 under interim-status groundwater-quality-assessment programs to assess possible contamination, and 2 under final-status corrective-action programs. Groundwater remediation in the 100 Areas continued to reduce the amount of strontium-90 (100-N) and chromium (100-K, D, and H) reaching the Columbia River. Two systems in the 200-West Area operated to prevent the spread of carbon tetrachloride and technetide uranium plumes. Groundwater monitoring continued at these sites and at other sites where there is no active remediation. A three-dimensional, numerical groundwater model was applied to simulate radionuclide movement from sources in the 200 Areas following site closure in 2050. Contaminants will continue to move toward the southeast and north (through Gable Gap), but the areas with levels exceeding drinking water standards will diminish.

Students who experience difficulties in learning are the teacher's responsibility to overcome them, one action that can be taken is through providing remedial activities. This research aims to determine the steps, obstacles and solutions for implementing remedial activities by class V-C teachers for students who experience difficulties in adding and subtracting mixed fractions at SDN Rangkah I Surabaya. This research method uses a descriptive qualitative approach with data collection techniques through observation, interviews and documentation. The results of the research show that the steps taken by the teacher include analysis of the results of the diagnosis of student difficulties based on test scores that are below the KKTP 60. Next, the teacher carries out remedial activity planning by arranging the day, date, time, method, media and questions that will be used . After careful planning, the teacher carried out remedial activities for four students who were experiencing difficulties and then assessed the results of the students' work. However, the implementation of remedial activities faces obstacles, such as taking a long time, the physical condition of students who are not enthusiastic, and differences in the characteristics of students' comprehension abilities. To overcome this obstacle, teachers maximize activity time, encourage students, and provide individual explanations to students who do not understand. The results of this research emphasize the importance of careful planning and approaches tailored to the characteristics of each student in remedial activities. Thus, remedial activities can be an effective solution in helping students overcome learning difficulties and achieve better learning outcomes.

PreviousNext No AccessSymposium on the Application of Geophysics to Engineering and Environmental Problems 1994Use of Borehole Electromagnetic‐Induction and Natural‐Gamma Logs to Delineate a Contaminant Plume in Ground WaterAuthors: Thomas J. MackThomas J. MackU.S. Geological Survey, 525 Clinton Street, Bow, New Hampshire 03304https://doi.org/10.4133/1.2922080 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InReddit Abstract Introductory paragraph for this paper is available only in the PDF and GZipped PS filesPermalink: https://doi.org/10.4133/1.2922080FiguresReferencesRelatedDetails Symposium on the Application of Geophysics to Engineering and Environmental Problems 1994ISSN (online):1554-8015Copyright: 1994 Pages: 1082 publication data© 1994 Copyright © 1994 The Environmental and Engineering Geophysical SocietyPublisher:Environmental & Engineering Geophysical Society HistoryPublished Online: 30 Sep 2008 CITATION INFORMATION Thomas J. Mack, (1994), "Use of Borehole Electromagnetic‐Induction and Natural‐Gamma Logs to Delineate a Contaminant Plume in Ground Water," Symposium on the Application of Geophysics to Engineering and Environmental Problems Proceedings : 443-459. https://doi.org/10.4133/1.2922080 Plain-Language Summary PDF DownloadLoading ...

The radioactive contaminant plume in groundwater at the Karachai Lake site has been examined further. The source of pollution is the Karachai Lake which was used as a reservoir for liquid radioactive waste (LRW) from the Radiochemical Production Association “Mayak” (South Urals, Russia). Taking into account that colloid-facilitated transport of radionuclides can substantially increase the contaminant migration velocity, the composition and structure of colloid particles from the groundwater within the contaminant plume were studied. Sampling of groundwater was carried out in the observation well within the contaminant plume. Different fractions of colloid particles were extracted from the groundwater samples by sequential filtration through membranes with decreasing pore size. Chemical and mineralogical compositions of the colloid particles were determined by X-ray photoelectron spectroscopy in combination with ion etching of the particle surfaces. The host rocks were studied using characteristic samples from the surface outcrop nearest to the observation well. The analysis showed that the colloid particles consisted of an inorganic core with a discontinuous organic cover. The inorganic core was close in composition to the host rocks along the flow path with a predominance of layered hydrosilicates.

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility in Waverly, Nebraska, from 1952 to 1974. During this time, the grain fumigant '80/20' (carbon tetrachloride/carbon disulfide) was used to preserve stored grain. In 1982, sampling by the U.S. Environmental Protection Agency (EPA) found carbon tetrachloride contamination in the town's groundwater. After an investigation of the contaminant distribution, the site was placed on the National Priority List (NPL) in 1986, and the CCC/USDA accepted responsibility for the contamination. An Interagency Compliance Agreement between the EPA and the CCC/USDA was finalized in May 1988 (EPA 1990). The EPA (Woodward-Clyde Consultants, contractor) started immediate cleanup efforts in 1987 with the installation of an air stripper, a soil vapor extraction system, a groundwater extraction well, and groundwater and soil gas monitoring wells (Woodward-Clyde 1986, 1988a,b). After the EPA issued its Record of Decision (ROD; EPA 1990), the CCC/USDA (Argonne National Laboratory, contractor) took over operation of the treatment systems. The CCC/USDA conducted a site investigation (Argonne 1991, 1992a,b), during which a carbon tetrachloride plume in groundwater was discovered northeast of the former facility. This plume was not being captured by the existing groundwater extraction system. The remediation system was modified in 1994 (Argonne 1993) with the installation of a second groundwater extraction well to contain the contamination further. Subsequently, a detailed evaluation of the system resulted in a recommendation to pump only the second well to conserve water in the aquifer (Argonne 1995). Sampling and analysis after implementation of this recommendation showed continued decreases in the extent and concentrations of the contamination with only one well pumping (Argonne 1999). The CCC/USDA issued quarterly monitoring reports from 1988 to 2009. Complete documentation of the CCC/USDA characterization and remediation efforts, including the quarterly monitoring reports, is on the compact disc inside the back cover of this report. The EPA reported on the progress of the remediation systems in a series of five-year reviews (EPA 1993, 1999, 2004, 2009). These reports and other EPA documentation are also on the compact disc inside the back cover of this report, along with the Woodward-Clyde (1986, 1988a,b) documentation cited. Starting in 2006, the analytical results for groundwater (the only medium still being monitored) showed no carbon tetrachloride concentrations above the maximum contaminant level (MCL) of 5.0 g/L. Because the cleanup goals specified in the ROD (EPA 1990) had been met, the EPA removed the site from the NPL in November 2006 (Appendix A). In 2008 the National Pollutant Discharge Elimination System (NPDES) permit for the remediation system was deactivated, and a year later the EPA released its fourth and final five-year report (EPA 2009), indicating that no further action was required for the site and that the site was ready for unlimited use. In 2011-2012, the CCC/USDA decommissioned the remediation systems at Waverly. This report documents the decommission process and closure of the site.

This purpose of this study was to evaluate the impact of heterogeneity in aquifer hydraulic conductivity on configurations of non-pumped wells filled with reactive media for removing contaminant plumes in groundwater. Among one homogeneous and three heterogeneous simulated aquifers, 2-16 wells were necessary to contain a plume, with no clear relationship between degree of heterogeneity and number of wells. Generally, heterogeneous aquifers with initial plumes having broad rather than narrow downgradient margins required more wells and showed greater tendency for plumes to move around wells. Cleanup time increased up to 181 % with degree of heterogeneity in hydraulic conductivity.

Longitudinal distortion attributable to macroscopic structure can be determined on a scale consistent with the variance of hydraulic conductivity. (Kovacs, 1983) INTRODUCTION Heterogeneity of porous media has been a troublesome topic from the very beginning of groundwater hydrology as a quantitative science. Darcy (1856) recognized the necessity to quantify flow through porous media using a macroscopic, rather than a microscopic, viewpoint; he defined a flux based on an average linear flow path through a representative volume of porous media. Meinzer (1932) called heterogeneity the ‘most formidable difficulty’ in quantifying aquifer parameters. Shortly after this, Theis (1935) offered a solution to the heterogeneity problem by developing a way of calculating effective aquifer parameters. He demonstrated that by measuring the drawdown of water levels in response to pumping, it is possible to use an analytical solution to calculate effective aquifer parameters for average transmission and storage characteristics. Theis' method in essence replaces the heterogeneous aquifer with an equivalent homogeneous porous medium. Theis' technique for dealing with heterogeneity allowed groundwater hydrologists to ignore geological heterogeneity for approximately 40 years. Then, Freeze (1975) called attention to the effect of uncertainty in hydraulic conductivity on the head distribution computed using groundwater models. About the same time, researchers were beginning to attempt to use the advection–dispersion equation to describe the transport of contaminant plumes in groundwater (Bredehoeft & Pinder, 1973; Pinder, 1973), and they were confronted with the problem of quantifying the dispersion coefficient. Slichter (1905) had earlier recognized that the spreading he observed in tracer experiments could not be due solely to the effects of molecular diffusion.

The importance of transects for characterizing aged organic contaminant plumes in groundwater

Aqueous benzene, toluene, ethylbenzene and xylene (BTEX) removal using core-shell structure activated carbon ball as a permeable reactive barrier material

Geochemical characteristics and arsenic content of groundwater in the Kurdistan and West Azerbaijan provinces (west of Iran) were analyzed. Groundwater is the local source of drinking water and travertine springs are mainly used for bathing and balneological purposes. The results indicate that total arsenic in travertine springs and groundwater range between 212 to 986.9 and 0.4 to 688.9 μg/L, respectively. Speciation of arsenic suggests arsenite the dominant arsenic species in travertine spring (68.2 to 98.9%). The variations of Br/Cl and B/Cl ratio, negative ORP (Oxygen Redox Potential) and high concentrations of Cl, Na, Cs, Li, Rb, Sr, B, Br and Rb in travertine spring samples confirm deep groundwater circulation in the volcanic basement. The results of saturation indices show that groundwater samples are supersaturated with respect to iron oxides, calcite, dolomite and aragonite and undersaturated with respect to gypsum and halite. In spite of gold mineralization, dissolution of arsenic-containing sulfide minerals is not the main source of arsenic contamination in groundwater. Spatial coincidence between the arsenic anomaly in groundwater and the travertine springs distribution illustrates they are the main source of arsenic in groundwater. The present study is useful in addressing future measures in groundwater resource management, in the volcanic regions in the west of Iran.

This study aimed to assess the impact of remedial activities on students' mathematics competences in public secondary schools in Ngororero District, Rwanda. This study aimed to assess the impact of remedial activities on students' mathematics competences in public secondary schools in Ngororero District, Rwanda. The research used both quantitative and qualitative approaches, with 117 respondents, including students, teachers, the dean of study, and head teachers. The study used purposive sampling and simple random sampling to select teachers and students. Data collection methods include questionnaires and interviews. Instruments used to collect data were questionnaires and interviews. Quantitative data was analyzed using statistical methods such as SPSS 2021 and Microsoft Excel. Therefore, tabulation with frequency tables, graphs, and percentages was adopted. The findings indicate that digital numeracy is the most commonly used remedial activity by teachers in Ngororero District, Rwanda. A majority of respondents agree that digital numeracy is used to develop competencies such as critical thinking. Additionally, the study identifies the level of students' competences required in mathematics in Ngororero District, Rwanda, which includes creativity, innovation, critical thinking, problem-solving, and cooperation and collaboration. The study also highlights the importance of cooperation and life skills in the teaching and learning process. Teachers use digital numeracy to provide learners with access to graphs, tables, and charts related to their mathematical course. Collaboration and life skills are also used to facilitate learners' discovery in the mathematics subject. The researcher recommends implementing remedial activities that are suitable for the learners, ensuring that the remedial activities are suitable for their needs.

About 50 million tonnes/year of waste rock from coal-mining is generated in the limited area of the thickly populated Upper Silesian Coal Basin (USCB) in Poland. There are 380 coal-mining waste dumps, including 76 active dump sites covering over 2,000 ha. About 15-16 million tonnes/year of waste rock is being reused for civil engineering purposes in the same area. This brings about a problem of ground water deterioration by constituents leached from waste rock exposed to atmospheric conditions. The major factors determining the ground water contamination potential from waste rock are chloride salinity, sulfur content and acid generation potential. The concept behind the presented studies was to provide data for correct evaluation and prediction of contaminant release from the waste rock, based on the characterization of coal-mining waste properties, as well as on long-term laboratory, lysimetric and field studies. The results show that coal-mining waste dumps can be a long-term source of ground water contamination, lasting for decades and increasing with time. Ground water down-gradient from the disused 15–30-years-old part of the studied dump displays high and increasing acidification, high TDS, SO4, and the highest, still increasing concentrations of Mn, Fe and Zn. Cost-effective and efficient pollution control measures, similar to the presented design and construction elements of the dump site, can mitigate the negative environmental impacts.

Formulation of the problem. To date, a large number of environmental problems remain unsolved.Moreover, their number increases year after year. First of all, this is due to the impact of man on a balanced nature, the expansion of industrial and agricultural production. Kharkiv region, whose industry plays a significant role in Ukraine's production and gives a tenth of all industrial production in the country, was investigated in the article to assess the impact of technogenic sources of groundwater contamination. There are more than 1200 industrial enterprises located here, indicating an extremely high level of industrialization, which results in the formation of significant volumes of industrial waste and negatively affects the environment. Powerful heavy industry enterprises on the territory of Kharkiv region, which have worn-out and technically outdated workshops and production in their structure, produce large volumes of industrial waste, which, in turn, causes an unfavorable environmental condition in the cities of the region, such as chemical pollution of air, soils, groundwater. The purpose of the article is to assess the impact of technogenic sources of groundwater pollution on the territory of Kharkiv region. Presenting main material. The article gives a description of the influence of the most significant objects of Kharkiv region, which pose a possible threat to groundwater, and therefore to the water intakes they operate. The sources of concentrated groundwater contamination in the investigated area are mainly large industrial enterprises, which, by their nature, use water in significant volumes and, as a result, have large amounts of waste water. Such sites are on the territory involved in the production cycle. These are septic tanks, sludges, heat exchangers, quarries, access platforms, warehouses, burial sites of various wastes, etc. Conclusions. Several significant sites are located on the territory of Kharkiv region, which pose a possible threat to underground waters, and therefore to water intakes that operate them. These are, first of all, Zmiiv heat-station, Pervomaisky Khimprom, Balakliya cement-slate intergated works, Shebelinka gas-extraction, the point of radioactive waste disposal in the village of Dergachi, Dergachi District Solid Waste Management and some other active industrial enterprises.Based on the data of groundwater aquifers’ chemical composition in the zone of influence of technogenic sources for the long period of observations, appropriate conclusions were drawn regarding pollution.

This study investigated the characterization of borehole sediment and the impact of contaminants on groundwater quality in the Rukpokwu Community in the delta of Nigeria. The investigation supported by spatial data supported by GIS techniques provides a data baseline for the monitoring of organo-contaminants in groundwater quality in Rukpokwu. This low pH of the groundwater and irritation of the throat and mouth became a concern to the residents. This study is necessary because of the limited data on the level of organic contamination in groundwater in this section of the delta of Niger in Nigeria. So, there was a need to track the source of contamination in this part of the delta of Niger in Nigeria. These previous studies have suggested a highly permeable open aquifer in similar deltaic terrain. Ten (10) samples of borehole sediment and water collected at 30 m depth were being analyzed for textural and physicochemical characteristics. The parameters analyzed include Iron (Fe), Total Petroleum Hydrocarbon &Total Hydrocarbon Content (i.e., TPH and THC respectively) of borehole sediment in association with groundwater quality. Ten (10) sediment samples collected at a depth of 30m and were being analyzed for mean, sorting, skewness and kurtosis, using standard laboratory procedures. Coarse silt, poorly sorted and negatively skewed were the characteristics of the borehole silt. The Kurtosis suggested the leptokurtic and platykurtic nature of the sediment. The TPH and THC range from 0.58 to 0.85 mg/L and 1.26 to 2.84 mg/L respectively. The Fe and pH range in the sediment were 0.85 to 2.46 mg/L and 4.43 to 6.02 respectively. However, Fe in the groundwater ranges from 0.12 to 0.21 mg/L. The results were above the World Health Organization's acceptable contaminant level. Based on the piece of evidence provided by spatial data mapping and textural parameters, the characteristics of the borehole sediment significantly controlled the ingress of contaminants into the groundwater. The source of groundwater contamination is the abnormal concentrations of organic contaminants. These results significantly impact human health in the food chain. This study provides information to the environmental agency for a clean-up process.