Degree Of Groundwater Contamination Research Articles

Potentially toxic elements in groundwater of the upper Brahmaputra floodplains of Assam, India: water quality and health risk.

This paper presents the groundwater quality assessment of the upper Brahmaputra floodplains of Assam on a seasonal basis. A total of 88 samples were analyzed for the presence of potentially toxic elements in two seasons. In addition, an attempt is made to identify any possible associated health risks to the residents via the drinking water pathway. The study reveals the presence of various potentially toxic elements, in particular, manganese, iron, nickel, and fluoride concentration exceeding the drinking water specifications set by BIS and WHO drinking water standards. The degree of groundwater contamination was assessed using the Water Quality Index, Heavy metal Pollution Index, Heavy metal Evaluation Index, and Degree of Contamination. The spatial distribution maps of groundwater quality were prepared using geographical information system. The non-carcinogenic health risk was evaluated using hazard quotients and hazard index as per the United States Environmental Protection Agency methodology. The hazard quotient of fluoride and manganese have values > 1, which exceeds USEPA recommended benchmark. The health risk assessment identified that the risk was highest during the pre-monsoon season, and the child population is more vulnerable to non-carcinogenic risk than the adults. Findings of cancer risk identified that pre-monsoon groundwater samples from the Golaghat District pose the highest health risks in the upper Brahmaputra floodplains. The risk is highest in the southwest of the study area, followed by the south and then by the north.

Impact of Informal Auto-Mobile Mechanic Workshops Activities on Groundwater Quality in Ibadan, Nigeria

The detrimental effect of the activities in informal auto-mobile mechanic workshops is a major public health concern; and its impact on groundwater contamination cannot be ignored. We assessed the effect of activities of mechanics in auto-mobile workshops on the quality of groundwater sources. Water samples were collected from hand dug wells situated within 0 to 50 metres in twenty auto-mobile workshops randomly selected across three zones. A residential area was selected as the control site. Analysis of water for some physico-chemical parameters (pH, TDS, Electrical Conductivity, Alkalinity, Oil and Grease) and the heavy metals (Cu, Cd, Cr, and Pb) was done using standard methods. Sanitary inspection was also carried out at each well location. Results were compared with the control and regulatory standards Nigerian Industrial Standard for Drinking Water Quality (NISDQW) and World Health Organization (WHO) guidelines for drinking water quality. Results revealed that mean values of pH, TDS and Electrical conductivity for the three zones, Alphonso, Temidire, and Ojoo were within WHO limits. The concentrations of Cu, Cd Cr and Pb in the water samples ranged from 0.02 - 6.12 mg/l, 0.1 - 2.19 mg/l, 0.2 - 0.79 mg/l and 0.02 - 35.8 mg/l across the three zones respectively. Mean concentrations of Cu (mg/l) were significantly higher in Alphonso (2.5 ± 2.06) than in other zones. Mean concentration of Cr (mg/l) was 0.34 ± 0.28, 0.37 ± 0.13 and 0.31 ± 0.3 for Alphonso, Temidire and Ojoo respectively. Cadmium was also present in all the zones but Pb was only detected in Alphonso. The mean concentrations for heavy metals were significantly higher when compared with the permissible limits for both NISDQW and WHO. The degree of groundwater contamination indicates poor water quality in the study area, and this requires regular monitoring. Enforcement of environmental regulations guiding activities of auto-mechanics should be done so that they can embrace environmentally friendly practices to reduce pollution.

Impact of Informal Auto-Mobile Mechanic Workshops Activities on Groundwater Quality in Ibadan, Nigeria

The detrimental effect of the activities in informal auto-mobile mechanic workshops is a major public health concern; and its impact on groundwater contamination cannot be ignored. We assessed the effect of activities of mechanics in auto-mobile workshops on the quality of groundwater sources. Water samples were collected from hand dug wells situated within 0 to 50 metres in twenty auto-mobile workshops randomly selected across three zones. A residential area was selected as the control site. Analysis of water for some physico-chemical parameters (pH, TDS, Electrical Conductivity, Alkalinity, Oil and Grease) and the heavy metals (Cu, Cd, Cr, and Pb) was done using standard methods. Sanitary inspection was also carried out at each well location. Results were compared with the control and regulatory standards Nigerian Industrial Standard for Drinking Water Quality (NISDQW) and World Health Organization (WHO) guidelines for drinking water quality. Results revealed that mean values of pH, TDS and Electrical conductivity for the three zones, Alphonso, Temidire, and Ojoo were within WHO limits. The concentrations of Cu, Cd Cr and Pb in the water samples ranged from 0.02 - 6.12 mg/l, 0.1 - 2.19 mg/l, 0.2 - 0.79 mg/l and 0.02 - 35.8 mg/l across the three zones respectively. Mean concentrations of Cu (mg/l) were significantly higher in Alphonso (2.5 ± 2.06) than in other zones. Mean concentration of Cr (mg/l) was 0.34 ± 0.28, 0.37 ± 0.13 and 0.31 ± 0.3 for Alphonso, Temidire and Ojoo respectively. Cadmium was also present in all the zones but Pb was only detected in Alphonso. The mean concentrations for heavy metals were significantly higher when compared with the permissible limits for both NISDQW and WHO. The degree of groundwater contamination indicates poor water quality in the study area, and this requires regular monitoring. Enforcement of environmental regulations guiding activities of auto-mechanics should be done so that they can embrace environmentally friendly practices to reduce pollution.

Geostatistical techniques to evaluate groundwater contamination and its sources in Miryang City, Korea

Miryang City has high seasonal variations in precipitation and small number of surface reservoirs. It uses much groundwater for living and irrigation purposes. This study delineates the characteristics and the controlling factors of groundwater contamination using multivariate statistical analyses and kriging method. GIS spatial maps showed that groundwater contamination was occurred mainly in the central and southern areas and partly in the southwestern and northern areas. It may be attributed to the effect of residual saline water, irrigation, livestock wastes and municipal sewage. Ca-HCO3 water type was the most predominant in the groundwater of the study area. Ca-Cl2, Na-Cl and Na-HCO3 water types were dominant in order, due to the influence of residual saline water and anthropogenic activity. Geostatistical techniques were applied to classify the groundwater samples and to identify the geochemical processes and sources controlling the groundwater geochemistry. The scatter diagrams of factor score versus topographic elevation and groundwater level represented that groundwater was influenced by saline water and NO3-N at <85 m of well elevation. The areas and degrees of groundwater contamination were understood from the spatial distribution maps of factor scores versus groundwater level. Chemical characteristics and contamination sources of groundwater were identified from cluster and factor analyses. Kriging method was useful for the production of distribution maps showing the degree and location of groundwater contamination. Thus, geostatistical techniques including factor analysis, cluster analysis and kriging method played very important roles in evaluating groundwater contamination and identifying contamination sources.

Factors influencing groundwater quality: towards an integrated management approach.

The safety of groundwater resources is a serious issue, particularly when these resources are the main source of water for drinking, irrigation and industrial use in coastal areas. In Italy, 85% of the water used by the public is of underground origin. The aim of this report is to analyze the main factors that make groundwater vulnerable. Soil characteristics and filtration capacity can promote or hinder the diffusion of environmental contaminants. Global climate change influences the prevalence and degree of groundwater contamination. Anthropic pressure causes considerable exploitation of water resources, leading to reduced water availability and the progressive deterioration of water quality. Management of water quality will require a multidisciplinary, dynamic and practical approach focused on identifying the measures necessary to reduce contamination and mitigate the risks associated with the use of contaminated water resources.

Hydraulic fracturing: a toxicological threat for groundwater and drinking-water?

This paper deals with the possible impact of hydraulic fracturing (fracking), employed in the exploitation of unconventional shale gas and tight gas reservoirs, on groundwater, which is the most important source of drinking-water in Germany and many other European countries. This assessment, which is part of an interdisciplinary study by a panel of neutral experts on the risks and environmental impact of hydraulic fracturing, is based mainly on data obtained from three ExxonMobil drilling sites in northern Germany. First, the basic technical aspects of fracking and its relevant water fluxes are explained. The type, purpose and fate of the constituents of the fracking fluids are discussed. The chemicals used in the fracking fluids are assessed with regard to their hazardous properties according to the Regulation (EC) No. 1272/2008 of the European Parliament and of the Council on the classification, labelling and packaging of substances and mixtures (CLP regulation) and the German “Water Hazard Classes”. Contamination of groundwater by ingredients of fracking fluids may occur from under ground or may result from above-ground accidents associated with the transport, storage and handling of hazardous substances used as additives in fracking fluids. The degree of groundwater contamination cannot be predicted in a general way. Therefore, different dilutions of the fracking fluid in groundwater are considered. It is shown that the concentrations of most ingredients resulting from a 1:10,000 up to 1:100,000 dilution of the fracking fluid in groundwater are below health-based reference values such as the limit values of the European Drinking Water Directive, the WHO Guideline Values for Drinking-water Quality, and other health-based guide values for drinking-water. Regarding the salinity of fracking fluids, a dilution of 1:1,000 is sufficient to reach concentrations which are acceptable for drinking-water. From the human-toxicological point of view, the constituents of flowback water are more problematic with respect to drinking-water produced from groundwater than those of the fracking fluids. The few reliable data which have become available, as well as hydrogeological considerations, point in the direction of considerable salt concentrations and toxic constituents, e.g., Hg, As, Pb, Zn, Cd, BTX, PAHs, or even radioactive elements. The identification and assessment of reaction products and metabolites, which are produced as a result of the fracking operation and the metabolic activity of microorganisms, are important topics for further research. The recommendations include the need for a better understanding of the environmental impact of fracking operations, especially with regard to the development of sustainable rules for planning, permission, performance and management of fracking, and for the monitoring of groundwater quality around fracked drilling sites.

통계적 분석 방법을 이용한 국가지하수수질측정망의 오염 등급 정량화 및 평가

This study suggests a method to grade groundwater quality quantitatively using statistical approaches for evaluating the quality of groundwater in wells included in the Groundwater Quality Monitoring Network (GQMN). The proposed analysis method is applied to GQMN data from 2001 to 2008 for nitrate nitrogen, chloride, trichloroethylene, potential of hydrogen (pH), and electrical conductivity. The analysis results are obtained as groundwater quality grades of the groundwater representing each of the monitoring stations. The degree of groundwater contamination is analysed for water quality parameters, district, and usage. The results show that the degree of groundwater contamination is relatively high by nitrate nitrogen, bacteria and electrical conductivity and at Seoul, Incheon, Gwangju, Gyeonggido and Jeollado. The degree of contamination by nitrate nitrogen and trichloroethylene is especially high when the groundwater is used for agricultural and industrial water, respectively. It is evaluated that potable groudnwater in GQMN is significantly vulnerable to nitrate nitrogen and bacteria contamination.

Appropriate sampling strategy and analytical methodology to address contamination by industry. Part 2: Geochemistry and speciation analysis

Abstract The degree of contamination in soils, sediments and dusts can be assessed based on knowledge of a variety of factors, such as industrialization, type of contaminants, deposition conditions, contamination-control techniques, along with the characteristics of the recipient environmental compartments, which include pathways for contamination transport, depth of infiltration, and degree of groundwater contamination. The impact of contaminants also depends on the quantity, mobility and speciation of contaminants/wastes as well as on the sensitivity of the recipient compartments. With sufficient knowledge of these factors, a number of conclusions can be drawn concerning the status of contamination in industrialized areas. This literature review aims to scrutinize some of the methods used to analyse the occurrence, speciation, mobility, bioavailability and likely the toxic effects of contaminants in the environment.

Two-dimensional numerical simulation of groundwater contamination in the highway environment

There are many factors that affect the groundwater contamination in the highway environment. This paper reports a two-dimensional numerical simulation of the movement of contamination with water into the sub-grade and water table beneath a road to determine the major factors affecting transport of contaminants. The modelling parameters were assembled from various literature sources and eight scenarios were adopted to simulate the possible controlling conditions. Analyses were undertaken to simulate 2–4 years of water percolation through the pavement sub-structure, some contamination arriving at an underlying ground water table and other arriving at a lateral drain. Overall, the potential for ground water table contamination above probable limit values is very low except in extreme permeability and low sorption cases. Results show, firstly, that the sorption capacity of aggregates should be taken into account, especially as the runoff is likely to be a more important consideration than the possibility of leaching from the pavement's construction layers. Secondly, they show that the permeability of sub-grade soil, the suction-water content characteristics and the partitioning coefficient are the major factors affecting the degree of groundwater contamination in the highway environment. Of these, the sorptive capacity appears to be the key issue. Thirdly, it is shown that the rainfall pattern has little effect if the quantity of rainfall is the same.

Groundwater Contamination with NO 3-N in a Wheat-Corn Cropping System in the North China Plain

The North China Plain, where summer corn ( Zea mays L.) and winter wheat ( Triticum aestivum L.) are the major crops grown, is a major agricultural area in China. Permeable soils make the region susceptible to groundwater pollution by NO 3-N, which is applied to fields in large amounts of more than 400 kg NO 3-N ha −1 as fertilizer. A field experiment was established in 2002 to examine the relationship among N fertilization rate, soil NO 3-N, and NO 3-N groundwater contamination. Two adjacent fields were fertilized with local farmers' N fertilization rate (LN) and double the normal application rate (HN), respectively, and managed under otherwise identical conditions. The fields were under a traditional summer corn/winter wheat rotation. Over a 22-month period, we monitored NO 3-N concentrations in both bulk soil and soil pore water in 20{40 cm increments up to 180 cm depth. We also monitored NO 3-N concentrations in groundwater and the depth of the groundwater table. No significant differences in soil NO 3-N were observed between the LN and HN treatment. We identified NO 3-N plumes moving downward through the soil profile. The HN treatment resulted in significantly higher groundwater NO 3-N, relative to the LN treatment, with groundwater NO 3-N consistently exceeding the maximum safe level of 10 mg L −1, but groundwater NO 3-N above the maximum safe level was also observed in the LN treatment after heavy rain. Heavy rain in June, July, and August 2003 caused increased NO 3-N leaching through the soil and elevated NO 3-N concentrations in the groundwater. Concurrent rise of the groundwater table into NO 3-N- rich soil layers also contributed to the increased NO 3-N concentrations in the groundwater. Our results indicate that under conditions of average rainfall, soil NO 3-N was accumulated in the soil profile. The subsequent significantly higher-than-average rainfalls continuously flushed the soil NO 3-N into deeper layers and raised the groundwater table, which caused continuous groundwater contamination with NO 3-N. The results suggest that under common farming practices in the North China Plain, groundwater contamination with NO 3-N was likely, especially during heavy rainfalls, and the degree of groundwater contamination appeared to be proportional to the N application rates. Decreasing fertilization rates, splitting fertilizer inputs, and optimizing irrigation scheduling had potential to reduce groundwater NO 3-N contamination.

Environmental Impacts of Acid Leachate Derived from Coal-Storage Piles upon Groundwater

Leachate emanating from a coal-storage area at an electricutility plant in Northwest Indiana (U.S.A.) is impacting groundwater quality. This assessment is based on results of along-term groundwater monitoring program conducted at Purdue University's Wade Utility Plant where a monthly average of 32,000metric tons of both high- and low-sulfur coal are stored. Groundwater from both a perched and major aquifer (the WabashValley Aquifer) as well as surface water from a large retentionpond were sampled monthly for 34 consecutive months. Such a long-term, continuous sampling scheme proved beneficial in identifying seasonal trends and anomalies within the chemistryof ground- and surface waters. Data show elevated concentrationsof sulfate and hardness in the perched zones and the WabashValley Aquifer (WVA). Lead in the WVA has also been reported ata concentration greater than the state maximum contaminant level, while several metals (Be, Cd, Cu, Pb, Ni, Se, and Zn) containedwithin retention-pond sediments have the highest concentrationsin aquatic sediments ever reported within the State of Indiana.Due to the buffering capacity of carbonate minerals in underlyingunconsolidated deposits, the acidic pH of coal-pile leachate is raised to values typical for groundwater in carbonate terrain common in Northwest Indiana. Further ameliorating the input of acid percolation is the dilution capabilities of both the WVA and the recharge pond. Hence, sites without such advantages would exhibit a greater degree of groundwater contamination than what is observed at Purdue's coal-storage facility.

Pollution control of alluvial aquifers infiltrated by diesel oil: impact of fluctuating water level on the degree of groundwater contamination: O. Razakarisoa, P. Muntzer, G. Schafer, L. Zilliox, J. Ducreux & C. Arnaud, in: Groundwater quality: remediation and protection. Proc. conf, Prague, May 1994, ed K. Kovar & J. Krasny, (IAHS; Publication, 225), 1995, p 139

Pollution control of alluvial aquifers infiltrated by diesel oil: impact of fluctuating water level on the degree of groundwater contamination: O. Razakarisoa, P. Muntzer, G. Schafer, L. Zilliox, J. Ducreux & C. Arnaud, in: Groundwater quality: remediation and protection. Proc. conf, Prague, May 1994, ed K. Kovar & J. Krasny, (IAHS; Publication, 225), 1995, p 139

Pre-plant slow-release fertilization of strawberry plants before fertigation

The advantages of pre-plant fertilization were studied by using a slow-release fertilizer (nitrophoska permanent) with strawberry plants (Fragaria ananassa, cv Chandler) before fertigation. A sandy soil was used in the experiment in conditions of abundant rain. When the slow-release NPK was mixed with soil, the leachate analysis of a glasshouse crop showed a lower loss of N and therefore a lower degree of ground water contamination compared with the traditional NPK fertilizer. However, when the fertilizer in question was placed at 10 cm from the surface, as in the case of ornamental plants, the results were less favourable. Consequently, the slow-release fertilizer mixed with the soil not only increases the N uptake by the plant as well as the leaf and root weight, but it also produces higher yields.

MANAGING GROUND WATER QUALITY IN RELATION TO AGRICULTURAL ACTiVITIES1

ABSTRACT: Ground water quality is an environmental issue of national concern. Agricultural activities, because they involve large land areas, often are cited as a major contributor of ground water contaminants. It appears that some degree of ground water contamination from agricultural land use is inevitable, especially where precipitation exceeds evapotranspiration. For this reason, and because agriculture differs significantly from point sources of pollution, farmers, policymakers, and scientists need alternative management strategies by which to protect ground water. Mathematical models coupled to geographic information systems to form expert systems can be important management tools for both policymakers and agricultural producers. An expert system can provide farmers, researchers, and environmental managers with information by which to better manage agricultural production systems to minimize ground water contamination. Significant research is necessary to perfect such a system, necessitating interim ground water management strategies that include not only a strong research program, but educational and public policy components as well.