Groundwater Contamination Studies Research Articles

Risk assessment and natural attenuation study of groundwater contamination in an oil reservoir in Fuxin

Risk assessment and natural attenuation study of groundwater contamination in an oil reservoir in Fuxin

Assessment of groundwater quality and human health risks of nitrate and fluoride contamination in a rapidly urbanizing region of India

Groundwater contamination studies are important to understand the risks to public health. In this study, groundwater quality, major ion chemistry, sources of contaminants, and related health risks were evaluated for North-West Delhi, India, a region with a rapidly growing urban population. Groundwater samples collected from the study area were analysed for physicochemical parameters - pH, electrical conductivity, total dissolved solids, total hardness, total alkalinity, carbonate, bicarbonate, chloride, nitrate, sulphate, fluoride, phosphate, calcium, magnesium, sodium and potassium. Investigation of hydrochemical facies revealed that bicarbonate was the dominant anion while magnesium was the dominant cation. Multivariate analysis using principal component analysis and Pearson correlation matrix indicated that major ion chemistry in the aquifer under study is primarily due to mineral dissolution, rock-water interactions and anthropogenic factors. Water quality index values showed that only 20% of the samples were acceptable for drinking. Due to high salinity, 54% of the samples were unfit for irrigation purposes. Nitrate and fluoride concentrations ranged from 0.24 to 380.19 mg/land 0.05 to 7.90mg/l, respectively due to fertilizer use, wastewater infiltration and geogenic processes. The health risks from high levels of nitrate and fluoride were calculated for males, females, and children. It was found that health risk from nitrate is more than fluoride in the study region. However, the spatial extent of risk from fluoride is more indicating that more people suffer from fluoride pollution in the study area. The total hazard index for children was found to be more than adults. Continuous monitoring of groundwater and application of remedial measures are recommended to improve the water quality and public health in the region.

An Evaluation Over The Methodological Efficiency In Groundwater Contamination Studies: A Case Study From Wardha Valley Coalfields.

An Evaluation Over The Methodological Efficiency In Groundwater Contamination Studies: A Case Study From Wardha Valley Coalfields.

Groundwater Age Determination- Insight into Groundwater Recharge, Flow Systems and Contamination Studies

Groundwater Age Determination- Insight into Groundwater Recharge, Flow Systems and Contamination Studies

Numerical model of the behavior of chlorinated ethenes in a fractured, karstic limestone aquifer

Characterizing the transport and degradation of chlorinated ethenes in fractured aquifers, as well as the assessment of cleanup times, poses an extreme technical challenge. In the presented study, a method to analyze reactive transport and reductive dechlorination of chlorinated solvents in fractured aquifers is developed. A rough-walled parallel-plate model of nonlinear flow behavior is coupled with random-walk particle tracking, incorporating particle exchange between the mobile and stagnant zones, adsorption processes, and reductive dechlorination reaction pathways. The developed methodology, considering reductive dechlorination processes in a Lagrangian framework, is able to simulate the motion of particles affected by first-order network reactions, so that particles move according to their chemical state, affecting physical transport processes (advection, dispersion, mass-transfer exchange between mobile and stagnant zones). The developed model is applied to a case study of groundwater contamination in the industrial area of Bari and Modugno (Italy), where the limestone aquifer has a fractured, karstic nature. The steady-state distribution of the contamination by chlorinated ethenes from a source at a hot spot is obtained and compared with the observed scenario of contamination, in order to estimate the plausible transport and degradation processes and the mass loading at source. The study represents a valuable tool in deciding the role of natural attenuation as a treatment option, where the natural attenuation capacity of groundwater can be integrated with engineering methods in order to obtain site remediation.

Comparative effects of composted organic waste and inorganic fertilizer on nitrate leachate from the farm soils of northern Guam

The purpose of this study was to quantify the release of nitrate into vadose zone as well as the nitrogen-holding capacity of compost applied on calcareous soils of northern Guam amended with both inorganic fertilizer and composted organic waste, to examine potentially adverse effect of these nutrient materials to groundwater quality. Three different nitrogen levels each of the composted organic waste and the inorganic fertilizer were applied to corn (maize) (farmland) study plots for three consecutive seasons, two dry and one rainy season. During each season, soil organic matter (SOM, w/w%) content and carbon-nitrogen ratio (C/N, w/w%), were determined for analysis of the nitrogen-holding capacity of these calcareous soils. Nitrate levels in soil pore water were also determined for study of potential groundwater contamination. For three seasons, compost plots showed higher SOM% contents and lower C/N% than fertilizer plots. That is, compost-treated soils showed higher SOM content and adsorbed more nitrogen under normalized soil mass than did fertilizer-treated soils. Nitrate levels in pore water were generally higher on compost plots during early stages of corn but were generally higher on fertilizer plots during active leaf, tasseling, and maturity stages. During the rainy season, nitrate leachate seemed to increase, but this trend could not be confirmed because rainfall amounts were not measured. Overall, composted organic waste proved to be a good amendment for soil productivity and agricultural sustainability while reducing nitrate leachate from northern Guam farmland.

Modeling groundwater total dissolved solid from derived electromagnetic data using multiple linear regression analysis: a case study of groundwater contamination

The high concentration of total dissolved solids (TDS) and other physicochemical parameters in groundwater around dumpsites have been used to implicate contamination from decomposed waste materials. A simple multiple linear regression (MLR) TDS model that integrates the TDS data derived from boreholes and hand-dug wells to the geophysical parameters obtained from the frequency-domain electromagnetic (EM) data was developed in this research. This is with a view to efficiently monitor groundwater resources and exploration around the Olusosun dumpsite and its communities. With the aid of the MLR equation, the observed TDS concentration of water samples collected from boreholes and hand-dug wells, and the corresponding estimated ground conductivity data in the vertical dipole mode (VD 40) and horizontal dipole modes (HD 40 and HD 20), obtained from geophysical surveys were regressed in Microsoft Excel software to generate a MLR TDS model. The integrity of the derived TDS model was appraised to examine the possibility of deploying it to investigate the TDS content of groundwater around the study area. The EM data and the resistivity models obtained around the study area confirmed contamination going on around the dumpsite. The developed TDS model can be put to use with high confidence, for groundwater TDS prediction around the study area where there are only terrain conductivity data but with no boreholes parameters. Also, terrain conductivity data alone can be applied to the model to predict the concentration of TDS in groundwater where there are no boreholes and hand-dug wells, therefore reducing the cost and time of determining and monitoring both parameters independently. With the aid of the ArcGIS software, the TDS model was used to generate TDS estimate map for the area. The knowledge of the TDS variability in such a map could give a clue about the integrity of the underground water around the site.

Study of groundwater contamination and drinking suitability in basaltic terrain of Maharashtra, India through PIG and multivariate statistical techniques

Abstract The integration of pollution index of groundwater (PIG), multivariate statistical techniques including correlation matrix (CM), principal component analysis (PCA), cluster analysis (CA) and various ionic plots was applied to elucidate the influence of natural and anthropogenic inputs on groundwater chemistry and quality of the Kadava river basin. A total of 80 groundwater samples were collected and analysed for major ions during pre- and post-monsoon seasons of 2012. Analytical results inferred that Ca, Mg, Cl, SO4 and NO3 surpass the desirable limit (DL) and permissible limit (PL) of Bureau of Indian Standards (BIS) and the World Health Organization (WHO) in both the seasons. The elevated content of total dissolved solids (TDS), Cl, SO4, Mg, Na and NO3 is influenced by precipitation and agricultural dominance. PIG results inferred that 52.5 and 35%, 30 and 37.5%, 12.5 and 20%, 2.5 and 5% groundwater samples fall in insignificant, low, moderate and high pollution category (PC) in pre- and post-monsoon seasons, respectively. PC 1 confirms salinity controlled process due to high inputs of TDS, Ca, Mg, Na, Cl and SO4. Also, PC 2 suggests alkalinity influence by pH, CO3, HCO3 and F content. PIG and statistical techniques help to interpret the water quality data in an easier way.

Analytical Study of Ground Water Contamination in Umarala Taluka of Gujarat

Analytical Study of Ground Water Contamination in Umarala Taluka of Gujarat

Mechanisms of interaction between arsenian pyrite and aqueous arsenite under anoxic and oxic conditions

Pyrite affects the conversion and migration processes of arsenic in soils and waters. Adsorption and redox reactions of arsenite (As(III)) occur on the surface of pyrite, and the interaction processes are influenced by the arsenic incorporated into pyrite. This work examined the effects of arsenic content, pH and oxygen on the interaction between arsenian pyrite and aqueous As(III) and investigated the underlying mechanisms. The results indicated that arsenic incorporation led to a high content of Fe(III) in pyrite, and that As(III) was mainly adsorbed on pyrite surface and part of As(III) was oxidized to As(V) by the newly formed intermediates including hydroxyl radicals and hydrogen peroxide. The oxidation rate increased with increasing arsenic content in the pyrite and the presence of air (oxygen), and first decreased and then increased with increasing pH from 3.0 to 11.0. Hydroxyl radicals and hydrogen peroxide significantly contributed to the oxidation of pyrite and aqueous As(III) in acidic and alkaline solutions, respectively. Although pyrite oxidation increased with increasing arsenic content as indicated by the elevated concentrations of elemental S and SO42−, the percentage of released arsenic in total arsenic of the arsenian pyrite decreased due to the adsorption of arsenic on the surface of newly formed ferric (hydr)oxides, especially the ferric arsenate precipitate formed in high pH solutions. The present study enables a better understanding of the important interaction process of dissolved arsenite and natural pyrites in the study of groundwater contamination, arsenic migration/sequestration, and acid mine drainage formation.

The Study of Groundwater Contamination with Volatile Organic Micropollutants (Trichloroethylene) in Northern Bucharest

The potential severity of some incidents regarding groundwater contamination within urban areas has recently led to the intensification of national concerns for complex identification and assessment of risks in contaminated areas and of their effects on human and environmental health. Urban groundwater protection in line with environmental objectives directly depends on the implementation of the legal and technical regulations in force in a proactive manner, aiming at the appropriate treatment of pollution situations and the effective management of the related risks. Given the massive industrial use of volatile organic compounds, their accumulation in the environment poses a major threat to the environment and public health, including through water pollution. This paper presents the results of a study on the presence of trichlorethylene (TCE) in groundwater and drinking water in a residential area of Bucharest (Pipera-Tunari area), highlighting TCE contamination found in some cases in concentrations well above the required limit set by Law 458 on Drinking Water Quality. The study analyzes the seasonal variations of TCE contamination, while addressing the effectiveness of applicable depollution solutions. The results of the study provide the most useful information for water quality authorities, and can be regarded as a benchmark for similar analyzes in other urban areas.

A case study of groundwater contamination due to open dumping of municipal solid waste in faisalabad pakistan

A case study of groundwater contamination due to open dumping of municipal solid waste in faisalabad pakistan

Gas Well Integrity and Associated Gas Migration Investigations in the Marcellus Shale

The Marcellus Shale is one of the largest natural gas fields in the world and has been the site of a massive natural gas development effort involving hundreds of oil and gas companies. With the onslaught of the “shale revolution,” developers moved into states like Pennsylvania and began drilling/completing natural gas wells by the hundreds. This development occurred so rapidly that attention to issues such as wellbore natural gas intrusion was not initially given the priority it demanded in all cases. This led to instances of alleged natural gas migration and impacts to groundwater supplies in several areas of the region. Although there has been an onslaught ofevaluations geared toward the study of groundwater contamination, the author has researched the natural gaswells themselves. Based on thousands of wellbore integrity studies in the Marcellus and other worldwide shale regions, this paper will summarize the forensic processes, analysis methods, and approaches used in assessing wellbore integrity as part of a natural gas migration investigation. The paper will also present details that pertain to remedial alternatives and approaches to wells requiring attention.

Geogenic contamination of groundwater in shallow aquifers in Ibadan, south-west Nigeria

Purpose– The purpose of this paper is to examine the presence of geogenic contaminants in groundwater from shallow aquifers of the crystalline basement complex rocks of Ibadan south-western, Nigeria.Design/methodology/approach– A total of 30 drinking water samples, (six samples each from the five major lithologic formations of the study area) were collected from hand dug wells during the rainy season. Atomic absorption spectrophotometry was used to determine concentrations of arsenic, iron and fluoride in drinking water samples and also concentrations of other chemical parameters that could affect the concentrations of the geogenic contaminants including pH, Ca, Mg, Na and SO42−. Descriptive statistics, multiple correlation and analysis of variance were used to examine the relationship between the geogenic contaminants and concentration of other chemical parameters while inverse distance weighting was used to produce risk maps.Findings– The results showed Arsenic concentration exceeding the WHO recommended concentration for drinking water in all the samples within the area. Samples from 16.6 per cent of the wells exceeded the recommended limit for fluoride while iron was present in most of the samples within acceptable limits. The study also revealed no significant difference in concentration of contaminants between the geologic formations.Originality/value– Geogenic contamination has been scarcely studied in Nigeria. This research, therefore, is a paradigm shift in the study of groundwater contamination which had been mainly focused on anthropogenic contaminants. The outcome of this research will engender policy makers and researchers to pay more attention to geogenic contamination than anthropogenic contaminants in Nigeria.

Studies of Geogenic Groundwater Contamination in Southwestern Anatolia, Turkey

The present study provides an overview of the geogenic contamination in Southwestern Anatolia based on its origin, occurrence and impacts. The Isparta, Çeltikçi, Tefenni, Çöl and Sandıklı groundwater basins, whose geogenic contaminations were determined, are considered in this study. Quaternary alluvium and Pliocene units are the most important aquifers. Groundwater is widely used for drinking, domestic and irrigation purposes in these basins. The increase of Al content in groundwater is originates from water-rock interaction as related to feldspar, kaolin and mica minerals within volcanic rocks. Weathering and dissolution of arsenic minerals, water–rock interactions, and geothermal processes cause groundwater to be enriched in As contents in the study area. The increase of Fe and Mn contents in groundwater are caused by magmatic rocks and sandstone levels of the Elmalı formation, which have iron and manganese ores due to water–rock interaction. The increase of F content in surface and groundwater originated from the solution of apatite and more commonly from the solution of fluoride - bearing micas and amphiboles within Miocene clastics, Gölcük pyroclastics and volcanic rocks in the Isparta region. Groundwater quality is supremely important for people's health. In these basins Mn, Al, Fe, As and F contents of groundwater reached up to 433μg/l, 3540μg/l, 6190μg/l, 21.8μg/l and 5620μg/l, respectively. When compared to drinking water guidelines established by WHO [22,23] Turkey and the EPA, these elements are above the critical values in the different sampling time as locally.

Reply to query related to “Study of uranium contamination of ground water in Punjab state in India using X-ray fluorescence technique”

The queries made by Rathore in the preceding Letter to Editor (J Radioanal Nucl Chem, 2013) regarding the “Studies of ground water contamination in Punjab state in India using X-ray fluorescence technique” by Alrakabi et al. (J Radioanal Nucl Chem 294:221–227, 2012. doi: 10.1007/s10967-011-1585-x), are responded. The points raised by Rathore are important in case of sensitive analytical techniques, where only a small fraction (~few hundred μL of water) of the water sample collected in the container is effectively used as analyte. The biasing due to chemical speciation and physical escape of element of interest becomes significant in such rapid techniques if the ionic species of interest in the analyte are not stabilised using suitable additives. In the reported study based on X-ray fluorescence technique, the analyte used for elemental analysis was obtained by drying about 500–1000 mL of water sample. Adequate precautions were taken to minimize possibility of element of interest to escape or adhere to the bottle surface or lost as residue. The onsite acidification of collected water sample to pH 1 with reagent-grade nitric acid for sample preservation is not a pre-requisite in the procedure followed. The contribution of particulate matter to the reported concentrations of uranium was estimated to be insignificant. Also, the query related to effect of co-precipitation of uranium with formation of CaF2 is found to be inconsequential. The comment made by Rathore (J Radioanal Nucl Chem, 2013) stating that ‘proceeding further in the measurement of uranium is a waste of time and has no meaning and results and discussion have no meaning too’ is extraneous.

Identifying Well Contamination through the use of 3-D Fluorescence Spectroscopy to Classify Coalbed Methane Produced Water

Production of unconventional gas resources commonly requires the use of hydraulic fracturing and chemical production well additives. Concern exists for the use of chemical compounds in gas wells due to the risk of groundwater contamination. This study focuses on a proposed method of identifying groundwater contamination from gas production. The method focuses on the classification of naturally occurring organic signatures of coalbed methane (CBM) produced water compared to anthropogenic organic compounds. The 3-D fluorescence excitation-emission matrix (EEM) spectra of coalbed methane produced water samples revealed four peaks characteristic of coalbed methane produced water: Peak P (aromatic proteins region), Peak M(1) (microbial byproducts region), Peak M(2) (microbial byproducts region), and Peak H (humic acid-like region). Peak H is characteristic of the coal-water equilibria present in all basins, while peaks P and M(2) correlate with microbial activity in basins with biogenic methane generation pathways. Anthropogenic well additives produce EEM signatures with notable flooding of peaks P, M(1), M(2), and H, relatively higher overall fluorescence intensity, and slightly higher DOC concentrations. Fluorescence spectroscopy has the potential to be used in conjunction with groundwater contamination studies to determine if detected organic compounds originate from naturally occurring sources or well production additives.

Analytical hydrologic models and the design of policy instruments for groundwater-quality management

This paper explores how analytical hydrologic models can inform the effective design and choice of policy instruments to manage groundwater quality by coupling a social-planner’s problem of optimal groundwater-quality management with analytical solutions from the hydrology literature. A theoretical analysis is performed in order to characterize the properties of an optimal emissions policy. The model is then applied in a numerical analysis of groundwater contamination by chloride from highway deicers, demonstrating the relevance of the theoretical results to practical management settings. This analytical approach can help determine which policy instruments are likely to be effective in controlling groundwater pollution, especially if costly numerical groundwater models are not available for the aquifer in question. Unlike previous economic studies of groundwater contamination, this approach defines optimal emissions policies as a function of geophysical parameters employed by hydrologists such as distance between source and sink, groundwater velocity, and aquifer dispersivity. The theoretical section of this paper also demonstrates that the relationship between geophysical parameters and optimal emissions levels may be ambiguous.

Radioactive contamination of groundwater at the Andreeva Bay Shore Technical Base, Northwest Russia

The Andreeva Bay Shore Technical Base is one of the largest, most contaminated nuclear legacy sites in Northwest Russia. Radioactive contamination at the site stems from servicing and maintenance activites for Russian Northern Fleet nuclear submarine. Studies of groundwater contamination have been conducted using measurements taken at different boreholes around the site. Results indicate that groundwater contamination has occurred in some areas of the Andreeva Bay facility. These areas are primarily located near Building 5 where accidental releases occurred in 1982 during storage of spent nuclear fuel (SNF) and near the liquid and solid radioactive waste (LRW and SRW) storage facilities which have been infiltrated by precipitation waters.

Aquifer Vulnerability Zoning, an Indicator of Atmospheric Pollutants Input? Vanadium in the Salamanca Aquifer, Mexico

Aquifer vulnerability assessments can be incorporated in groundwater contamination studies. Atmospheric pollutants as vanadium, V, can reach aquifers after soil deposition if the system is vulnerable. Vanadium concentrations were detected in soil and groundwater in Salamanca Mexico. V origin is related mainly to particulate emissions from a thermoelectric plant that is using fuel oil number 6 with high V content. To determine the V origin in groundwater, a soil and groundwater monitoring was carried out. A SINTACS vulnerability zoning was done. Vanadium in soil, emissions and groundwater is well correlated. The V input is associated to aquifer vulnerable zones.