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.

Arsenic contamination of groundwater:A global synopsis with focus on the Indian Peninsula

More than 2.5 billion people on the globe rely on groundwater for drinking and providing high-quality drinking water has become one of the major challenges of human society.Although groundwater is considered as safe,high concentrations of heavy metals like arsenic(As)can pose potential human health concerns and hazards.In this paper,we present an overview of the current scenario of arsenic contamination of groundwater in various countries across the globe with an emphasis on the Indian Peninsula.With several newly affected regions reported during the last decade,a significant increase has been observed in the global scenario of arsenic contamination.It is estimated that nearly 108 countries are affected by arsenic contamination in groundwater with concentration beyond maximum permissible limit of 10 ppb recommended by the World Health Organization.The highest among these are from Asia(32)and Europe(31),followed by regions like Africa(20),North America(11),South America(9)and Australia(4).More than 230 million people worldwide,which include 180 million from Asia,are at risk of arsenic poisoning.Southeast Asian countries,Bangladesh,India,Pakistan,China,Nepal,Vietnam,Burma,Thailand and Cambodia,are the most affected.In India,20 states and 4 Union Territories have so far been affected by arsenic contamination in groundwater.An attempt to evaluate the correlation between arsenic poisoning and aquifer type shows that the groundwater extracted from unconsolidated sedimentary aquifers,particularly those which are located within the younger orogenic belts of the world,are the worst affected.More than 90%of arsenic pollution is inferred to be geogenic.We infer that alluvial sediments are the major source for arsenic contamination in groundwater and we postulate a strong relation with plate tectonic processes,mountain building,erosion and sedimentation.Prolonged consumption of arsenic-contaminated groundwater results in severe health issues like skin,lung,kidney and bladder cancer;coronary heart disease;bronchiectasis;hyperkeratosis and arsenicosis.Since the major source of arsenic in groundwater is of geogenic origin,the extend of pollution is complexly linked with aquifer geometry and aquifer properties of a region.Therefore,remedial measures are to be designed based on the source mineral,climatological and hydrogeological scenario of the affected region.The corrective measures available include removing arsenic from groundwater using filters,exploring deeper or alternative aquifers,treatment of the aquifer itself,dilution method by artificial recharge to groundwater,conjunctive use,and installation of nano-filter,among other procedures.The vast majority of people affected by arsenic contamination in the Asian countries are the poor who live in rural areas and are not aware of the arsenic poisoning and treatment protocols.Therefore,creating awareness and providing proper medical care to these people remain as a great challenge.Very few policy actions have been taken at international level over the past decade to reduce arsenic contamination in drinking water,with the goal of preventing toxic impacts on human health.We recommend that that United Nations Environment Programme(UNEP)and WHO should take stock of the global arsenic poisoning situation and launch a global drive to create awareness among people/medical professionals/health workers/administrators on this global concern.

GROUNDWATER QUALITY AND CONTAMINATION INDEX MAPPING IN CHANGCHUN CITY,CHINA

Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions.

Acid mine drainage and heavy metal contamination in groundwater of metal sulfide mine at arid territory (BS mine,Western Australia)

The issues of acid mine drainage （AMD） and heavy metals contamination in the metal sulfide mine in the add district were explored, through studying the acidification and the heavy metals distribution and evolution of groundwater in the black swan （BS） nickel sulfide mine （Western Australia）. The groundwater samples were collected from the drilling holes situated in the vicinity of tailings storage facility （TSF） and in the background of the mine （away from TSF）, respectively, and the pH and electric conductivity （Ec） were measured in site and the metal contents were analysed by ICP-MS and ICP-AES, quarterly in one hydrological year. The results disclose that the TSF groundwater is remarkably acidified （.pHmean=5, pHmin=3）, and the average contents of heavy metals （Co, Cu, Zn, Cd） and Al, Mn are of 1-2 orders of magnitude higher in TSF groundwater than in background groundwater. It may be due to the percolation of tailings waste water from miU process, which leads the tailings to oxidize and the deep groundwater to acidify and contaminate with heavy metals. Besides, the heavy metals concentration in groundwater may be controlled by pH mainly.

The Combined Approach When Assessing and Mapping Groundwater Vulnerability to Contamination

In early 1980’s, the Italian scientific community, together with a number of institutional decision-makers, realized how urgent it was to protect natural and environmental resources. They agreed that an adequate level of scientifically organized knowledge allows the accurate planning and development of environment systems through the management and direction of the effective development process, but without stopping it. Since the special VAZAR1 project was first set up in 1984, as part of the GNDCI-CNR2 scientific context it has been the cardinal center point of Research National Program “Aquifer Vulnerability Assessment”. The problem of groundwater contamination was examined in this program for the very first time in Italy in an organic and extensive manner as a key for forecasting and prevention purposes. The Italian approaches to assessing and mapping groundwater vulnerability to contamination are essentially based on two main methodologies: 1) the GNDCI Basic Method [1,2] a HCS type approach that can be used for any type of Italian hydrogeologic situation, even where there is a limited number of data. A unified legend and symbols are also defined for each hydrogeologic level. 2) The SINTACS method [2,3], a PCSM developed for use prevalently in areas with a good data base coverage. The methodological approaches described in this paper now make up the Italian standard which has been dealt with in the recent very important Italian Law (152/993) and which are now ratified in the national guidelines [4] produced by ANPA, the Italian National Agency for Environment Protection. The methods, besides Italy [5] have been applied in several other Countries [6–10] and others.

Fluoride contamination in groundwater resources of Alleppey,southern India

Alleppey is one of the thickly populated coastal towns of the Kerala state in southern India.Groundwater is the main source of drinking water for the 240,991 people living in this region.The groundwater is being extracted from a multi-layer aquifer system of unconsolidated to semi-consolidated sedimentary formations,which range in age from Recent to Tertiary.The public water distribution system uses dug and tube wells.Though there were reports on fluoride contamination,this study reports for the first time excess fluoride and excess salinity in the drinking water of the region.The quality parameters,like Electrical Conductivity（EC） ranges from 266 to 3900 μs/cm,the fluoride content ranges from 0.68 to2.88 mg/L,and the chloride ranges between the 5.7 to 1253 mg/L.The main water types are Na-HC03,NaCO3 and Na-Cl.The aqueous concentrations of F- and CO32- show positive correlation whereas F- and Ca2＋ show negative correlation.The source of fluoride in the groundwater could be from dissolution of fluorapatite,which is a common mineral in the Tertiary sediments of the area.Long residence time,sediment-groundwater interaction and facies changes（Ca-HCO3 to Na-HCO3） during groundwater flow regime are the major factors responsible for the high fluoride content in the groundwater of the area.High strontium content and high EC in some of the wells indicate saline water intrusion that could be due to the excess pumping from the deeper aquifers of the area.The water quality index computation has revealed that 62%of groundwater belongs to poor quality and is not suitable for domestic purposes as per BIS and WHO standards.Since the groundwater is the only source of drinking water in the area,proper treatment strategies and regulating the groundwater extraction are required as the quality deterioration poses serious threat to human health.

Groundwater modelling to help diagnose contamination problems

Aquifer remediation for a contaminated site is complex, expensive, and long-term. Groundwater modelling is often used as a tool to evaluate remedial alternatives and to design a groundwater remediation system. Groundwater modelling can also be used as a useful process to identify aquifer characteristics and contaminant behaviour that are not realized prior to modelling, to help diagnose what happened and why it happened at contaminant sites. Three real-world modelling cases are presented to demonstrate how groundwater modelling is applied to help understand contamination problems and how valuable the improved understanding is to decision-making and/or to remedial design.

Groundwater Nitrate Contamination and Driving Forces from Intensive Cropland in the North China Plain

High nitrate in groundwater is a serious problem especially in highly active agricultural areas.In this paper,the concentration and spatial distribution of groundwater nitrate in cropland area in the North China Plain were assessed by statistical and geostatistical techniques.Nitrate concentration in groundwater reached a maximum of 526.58 mg/L,and 47.2%,21.33%and 11.13%of samples had levels in excess of nitrate safety threshold concentration(50 mg/L)in shallow,middle-deep and deep groundwater,respectively.And NO-3 content significantly decreased with groundwater depth.Groundwater nitrate concentrations under vegetable area are significantly higher than ones under grain and orchard.And there are great differences in spatial distribution of nitrate in the North China Plain and pollution hotspot areas are mainly in Shandong Province.Based on both multiple regressions combined with principal component analysis(PCA),significant variables for nitrate variation in three types of ground water were found:population per unit area,percentage of vegetable area,percentage of grain crop area,livestock per unit area,annual precipitation and annual mean temperature for shallow groundwater;population per unit area and percentage of vegetable area for middle-deep groundwater;percentage of vegetable area,percentage of grain crop area and livestock per unit area for deep groundwater.

Assessment of Health Risks Related to Contamination of Groundwater by Trace Metal Elements (Hg, Pb, Cd, As and Fe) in the Department of Zouan-Hounien (West Côte d’Ivoire)

In the department of Zouan-Hounien, gold mining is booming. This activity, marked by the excavation of rocks and the use of chemicals such as mercury, is likely to contaminate the region’s groundwater resources and expose populations to serious diseases. This study aims to assess the health risks associated with the consumption of this water by the population. To this end, 72 groundwater samples were taken in eight (08) villages of the department at the rate of forty-six (46) well water samples and twenty-six (26) borehole water samples. A total of twenty-twenty-three wells and thirteen boreholes were sampled during two campaigns. An atomic absorption spectrometer (AAS) was used to determine the concentrations of metallic trace elements (MTEs), such as mercury (Hg), lead (Pb), cadmium (Cd), Arsenic (As), and iron (Fe) in the different samples. The daily exposure doses for oral ingestion (CDIing) and skin contact (Expderm) were calculated. The non-carcinogenic (HQ) and carcinogenic risks (CR) were estimated. The results show that the mean concentrations of Fe, Pb, Hg, As and Cd are respectively 2233.48 > 3.10 > 0.60 > 1.18 > 0.08 μg·L-1 in the wells and 2427.94 > 4.08 > 1.27 > 1.76 > 0.08 μg·L-1 in boreholes. Evaluating the risks to human health reveals that the mean values of hazard quotient (HQ) and cancer risk (CR) for all the elements in the wells and boreholes are lower than 1 and 10-4 respectively in children and adults for oral and dermal exposure. However, at the oral exposure level, 9 wells and 6 boreholes recorded HQ and CR above the defined critical limits. These values indicate that the occurrence of non-cancerous and cancerous diseases in populations consuming these waters by contamination with mercury and arsenic is not excluded. Dermal exposure to MTEs also poses no potential health risk to the population.

Remediation of BTEX-Contaminated Groundwater by Air Sparging:A Simulation Study

BTEX contaminants in groundwater seriously impact the ecological environment and human health that has become one of the urgent problems needed to be solved.Due to its low density,low solubility and strong volatility,BTEX in groundwater usually form non-aqueous phase liquid(NAPL) contaminants and exist in three phases:gas,aqueous and oil phase.Air sparging(AS) is an in situ treatment technology

A Simplified Method for the Assessment of Groundwater Vulnerability to Contamination

In this study, an attempt was made to develop a new simplified groundwater vulnerability to contamination index (SGVI). Nine experts in the fields of groundwater, surface water, soil, landuse and GIS were interviewed to develop the new index. They were asked to agree on new parameters that could be used to investigate groundwater vulnerability. Data about such parameters must be affordable and inexpensive. Subsurface parameters were excluded due to the fact that most researchers might not have adequate data about them. The experts agreed that depth to groundwater, soil texture, lineament density, rainfall, topographic slope, drainage density and landuse/land cover parameters should be included in the new vulnerability index. The experts were also asked to give a weight and the ratings for each parameter. The weights given by the experts were subjected to AHP analysis to determine the exact weight for each parameter. An area of 3200 km2 in the northern part of Jordan was selected to test the SGVI. The final map of the SGVI showed that most of the area (more than 96%) had moderate-low and moderate-high vulnerability to contamination. The new index was also subjected to statistical analysis, map removal test and map removal sensitivity analysis. The outcomes of these analyses showed that the new index was applicable and could be used in areas where subsurface data was limited or not available.

Assessing Groundwater Contamination Risk and Detection of Unknown Sources Using a Multi-Component Reactive Transport Model

One of the most serious and important environmental issues related to the mining sector in Central Queensland is the contamination of abandoned mine sites. Representative of this issue is the abandoned Mount Morgan gold mine. The potential dispersal of acid mine drainage (AMD), a product of more than 100 million tons of sulphide-rich waste rock, into the surrounding environment, is the most challenging environmental problem currently facing this abandoned mine site. The abandoned Mount Morgan gold mine has multiple pollutant species that involve complex geochemical processes. The present study simulated the flow and transport processes founded on hydrological and geochemical conditions of the real-life field at the mine site. To assess the groundwater contamination risk and detect unknown pollution sources, few chemical species such as Iron and Sulphur were considered as the contaminants. The flow model was simulated using the computer code MODFLOW, and PHT3D was used for the simulation of advection, dispersion and chemical reactions of constituents dissolved in this groundwater system, and to mimic the reactive chemical transport processes in the polluted groundwater. To improve on results from other studies (Datta et al., 2017;Scotney, 2016;Doyle, 2016), a calibrated model was a main focus for this study. Field concentration measurements were matched with the flow simulation outcomes to calibrate the model. The results obtained showed a great potential to model transport of contaminants in the groundwater system using a real-world situation.

Groundwater Contamination Prediction Using Finite Element Derived Geoelectric Parameters Constrained by Chemical Analysis around a Sewage Site, Southwestern Nigeria

Vertical Electrical Sounding, the Finite Element Technique (FET) and chemical analysis of soil samples were used to map the pollution plume around two oxidation sewage ponds in Ile-Ife, Southwestern Nigeria. The elemental concentrations of the soil samples at 5 m depth around the sewage ponds were obtained using partial extraction of exchangeable metals ions of (0.05 HCl + 0.025 N H2SO4) or 0.075 N acid mixture. The VES interpreted results delineated three to four geoelectric subsurface layers comprising topsoil, laterite, weathered layer and the fresh basement. The elemental concentration of Cu, Zn, Pb and Cr in the soil samples located at the periphery of the sewage ponds are much higher than those of the control sample point indicating pollution. The finite element generated isopach map of the overburden indicates easterly direction of groundwater flow and weathered layer isoresistivity map generated using the finite element technique identifies low resistivity zone characteristic of pollution zone in the eastern flank. The study concluded that the groundwater in the area around the sewage ponds may have been polluted.

Assessing Fecal Contamination in Groundwater from the Tulum Region, Quintana Roo, Mexico

The Yucatan Peninsula’s groundwater is experiencing increases in degradation due to swelling population and tourism;yet little is known about sources and transport of contaminants in drinking water supplies. The karst allows for rapid transport of microbial and chemical contaminants to the subsurface, resulting in significantly increased potential for pollution of groundwater. The objective of this research is to determine the occurrence, source, and extent of fecal contamination in the Tulum region of the Peninsula. A multi-analytical approach was undertaken in impacted and unimpacted groundwater locations;measurements included physicochemical parameters, total coliform and E. coli, Bacteroides (human vs total) and caffeine. The results indicate a variation in geochemistry from impacted to protected sites. The total coliform and E. coli show fecal contamination is wide spread. However, the presence of human Bacteriodes and caffeine in the water in the Tulum well field indicates that the recent human activities next to the well field are impacting the drinking water supply. This project is an assessment of the area’s current water quality conditions and the probable impact that the aforementioned growth would have on the area’s water supply. By applying multiple source parameter measurements, including molecular microbiology and chemical indicators it was confirmed the extent of fecal contamination of human origin covered the entire sampling region.

A Comparative Investigation of Groundwater Contamination in Typical Dumpsites and Cemetery Using Ert and Physicochemical Analysis of Water in Benin Metropolis, Nigeria

This paper investigated the comparative analysis of groundwater contamination in Third Cemetery and Costain Dumpsite in Benin Metropolis, South South of Nigeria, using Electrical Resistivity Tomography (ERT) and Physicochemical analysis of water. The implications of land utilization for burial of dead human bodies in the form of cemeteries, many cases associated with coffin and caskets used for interment of remains and the location of refuse dump have received no consideration in Nigeria. Interment of bodies in cemeteries and dumping of refuse in dumpsites remain widespread practice and the only alternative endpoint to dead bodies and disposal of wastes in Nigeria. In Nigeria, this practice had not been perceived as having a significant potential contaminant effect in the environment and especially the groundwater component as search of literature attracted no such study to the country. In Benin City and Nigeria in general, the major cemeteries and dumpsites are located close to human residential areas and virtually all the populace within this locality depends on groundwater as the primary water source for various domestic purposes. Res2Dinv was employed in both sites as the geophysical method. The investigation of cemeteries is always difficult and challenging task in geoforensic prospective. Most researchers assess the impact of interment on the environment by comparing study results from cemeteries with data from reference sites. This study is based on this premise. The 2-D Geological Models showed that both Third Cemetery and Costain Dumpsite contained leachate plumes of various degrees as indicated by the low resistivity values, which infiltrated into the groundwater. The values of Water Quality Index (WQI) of groundwater samples in Third Cemetery and Costain Dumpsite were found to be 13.40 and 21.58 respectively which indicated that the quality of water at both Third Cemetery and Costain Dumpsite were good for drinking and other domestic purposes though with some degrees of contamination.

Comparative analysis of bacterial contamination in tap and groundwater: A case study on water quality of Quetta City, an arid zone in Pakistan

Water is an essential element on earth,which provides human a variety of services in domestic use,agriculture,or industries.However,some serious health risks of drinking water are associated with microbial contamination,particularly with fecal matter.Therefore,microbial quality assessment is considered to be a necessary component of water quality assessment.This study investigates microbial contamination of water distributary system around the city by comparing groundwater(GW)and tap water(TW)quality in Quetta city.31 GW samples and 31 TW samples were collected in the study area during the months of September,October,and November.Fecal coliform test was carried out in laboratory and their average total coliform contamination was computed.Results showed that the TW sample were all contaminated by coliform except for Chiltan town,hence are not considered suitable for drinking without any treatment according to WHO drinking water quality standards.The average coliform concentrations were 12 in Quetta main city,11.6 in Jinnah town,5.3 in Satallite town,10 in Shahbaz town and 5 in Brewery town(0/100 mL CFU)and the TW samples from the three towns were even more contaminated with E.coli.Whereas among the GW,average microbial concentrations were 1.8 in Quetta main city,2 in Satallite town,1.4 in Shahbaz town,and 0.4 in Chiltan town(0/100 mL CFU),respectively,which shows that the contamination is occurring within the water distributary pipeline system when the water flows through the pipelines.Moreover,this research will be valuable for researchers and administrative authorities to conduct elaborative studies,and develop new policies to prevent further deterioration of drinking water in the water distribution system by pathogenic microorganisms and ensure safe drinking water to the public of Quetta city.

Groundwater Quality and Arsenic Contamination in Amphoe Khemmarat, Ubon Ratchathani, Thailand

Arsenic （As） is one of the most important elemental pollutants in groundwater and drinking water because it causes health problem of arsenicosis after consumption of drinking arsenic-rich water more than 5-10 years. Arsenic contamination of groundwater is an emerging issue in Mekong Basin including Cambodia, Vietnam, and Thailand. In Thailand, information about arsenic contamination in drinking water resources are quite rare due to that arsenic is not the main element in water qualification assay. The objective of this study is to determine groundwater quality and arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Groundwater samples were collected from 20 different sampling points, between August 2009 and February 2010 in Amphoe Khemmarat, Ubon Ratchathani, Thailand. Physical and chemical characteristics of groundwater were determined. It was observed that the groundwater was 27.9-30.3 ~C, pH 5.7-6.9. The conductivity was 707-767 p.S.cm＂. Dissolved oxygen was 2.04-5.12 mg.L-1 and TDS was 352-384 mg.L~. The samples showed soft- to very hardness-water properties. In some area, few parameters like CI, Fe, Mn, and As exceeded the WHO guideline limits. This result represents basic information for quality of groundwater and the arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Thus, it is probably useful for arsenic standard level assignment and public health authorities. Moreover, it also leads to establish research activity in treatment of arsenic-contaminated groundwater for different purposes

Assessing Localized Contamination Hazard and Groundwater Quality Challenges in Water-Stressed Peri-Urban Accra, Ghana

The study assesses the quality of hand dug wells in relation to distance from soakaway septic tanks in three selected peri-urban communities in the Ga West Municipality near Accra, Ghana. Water quality analyses of bio-physico-chemical variables (pH, Temperature, EC, turbidity, DO, BOD, TSS, TDS, sodium, potassium, nitrate, nitrite, ammonia, sulphate, chloride, salinity, total alkalinity, total coliform, fecal coliforms and isolation of E. coli) were determined. Concentrations of the major nutrient anion sulphate, nitrate, phosphate, and chlorides in water samples at distances between 0 - 30 m radial distances from the septic tank were above the WHO permissible limit of drinking water compared to the control. All the water samples had high fecal and total coliform counts that exceeded the international standard of 0 per 100 mL of potable water with counts ranging from 0 - 143 cfu/100 ml and 53 - 463/100 ml for FC and TC respectively. High fecal coliform and detection of E. coli in most samples is an indication of fecal pollution possibly from their close proximity to soak away septic sewage. The high nutrient levels detected in samples at distances between 0 - 30 m as compared to the controls may also be attributed to its close proximity to septic tanks. This study, therefore, accentuates the need for the owners of the water points to site their water source at least 30m away from localized sources of pollution as well as treatment of groundwater before use.

Contamination of Groundwater Sources with Common Waterborne Pathogens and Heficobacter pylori in the West Bank： Case Study of Wadi AI Arroub, Tulkarem and Jericho

Detection of waterborne pathogens in drinking water via rapid DNA amplification assays is an important and crucial public health method. The aim of this study is to investigate the presence of waterborne pathogens in groundwater resources in Al Arroub, Tulkarem and Jericho areas using direct PCR （polymerase chain reaction） analysis. Forty-six groundwater samples were collected. The total DNA was extracted from each sample and subjected to PCR analysis directed to specific genes of enteric bacteria, β-lactamases producing bacteria, L. pneumophila （Legionella pneumophila） and H. pylori （Helicobacter pylori）. Enteric bacteria were detected with high frequency in Palestinian water sources followed by 13% occurrence of β-lactamases producing bacteria, 9% of H. pylori and 4% of L. pneumophila. The study shows that shallow groundwater wells and water taped from karstic aquifer is potential for contamination and could not be reliable sources of potable water.

Soil Explorations and Groundwater Monitoring to Evaluate Subsurface Contamination Due to Chromium in District Kasur, Pakistan

Due to improper tannery wastewater management in district Kasur Pakistan, groundwater has been reported to be highly contaminated. It was aimed to find out the extent up to which subsurface has contaminated due to chromium in areas adjacent to the tannery units. Eight （8） soil bores were conducted up to the depth of 30.5 meters and soil samples were tested for total and hexavalent chromium concentrations retained in soil by aqua regia digestion at the every depth of 1.5 meters. Afterwards monitoring wells were installed in these eight （8） bores so as to monitor chromium concentrations in the groundwater on monthly basis. The main source of contamination was considered to be the four （4） drains carrying tanneries effluent therefore samples were collected from these drains so as to observe seasonal variation in chromium concentration.