Contamination Sources

Our study reports the first data on mercury (Hg) isotope composition in marine European fish, for seven distinct populations of the European seabass, Dicentrarchus labrax. The use of δ 202 Hg and Δ 199 Hg values in SIBER enabled us to estimate Hg isotopic niches, successfully discriminating several populations. Recursive-partitioning analyses demonstrated the relevance of Hg stable isotopes as discriminating tools. Hg isotopic values also provided insight on Hg contamination sources for biota in coastal environment. The overall narrow range of δ 202 Hg around Europe was suggested to be related to a global atmospheric contamination while δ 202 Hg at some sites was linked either to background contamination, or with local contamination sources. Δ 199 Hg was related to Hg levels of fish but we also suggest a relation with ecological conditions. Throughout this study, results from the Black Sea population stood out, displaying a Hg cycling similar to fresh water lakes. Our findings bring out the possibility to use Hg isotopes in order to discriminate distinct populations, to explore the Hg cycle on a large scale (Europe) and to distinguish sites contaminated by global versus local Hg source. The interest of using Hg sable isotopes to investigate the whole European Hg cycle is clearly highlighted.

Denne rapporten presenterer resultater fra en oppfølgende marinbiologisk undersøkelse i sjøområdet omkring produksjonsanlegget på Mongstad (oljeterminal, raffineri og gassbehandlingsanlegg) i 2013. Anlegget drives av Statoil Petroleum AS. Undersøkelsen følger opp en miljøundersøkelse utført i 2012 som avdekket høye konsentrasjoner av enkelte metaller og oljehydrokarboner i biota ved én av stasjonene ved anlegget, samt stigende nivåer av naftalener og naftalenhomologer i sediment og biota. Metoden brukt for passiv prøvetakning av metallkonsentrasjoner i sjøvann blir sammenliknet med bruk av konvensjonelle spotprøver av sjøvann. Hensikten med den oppfølgende undersøkelsen er å validere funnene fra undersøkelsen i 2012

Artificial recharge (AR) is gaining importance as a management tool in water stressed regions. The need to prove recovery performance requires new monitoring tools for AR systems. A novel combination of environmental isotope tracers (B, Li, O, H stable isotopes) was tested for the monitoring of AR of tertiary treated, desalinated domestic wastewater into a coastal dune aquifer in Flanders, Belgium. No significant isotope fractionation was observed for the treatment process, which includes low pH RO desalination. The wastewater, after infiltration through ponds and before recovery through pumping wells is characterized by low molar Cl/B ratios (3.3 to 5.2), compared to 130 to 1020 in the wider study area, δ 11 B values close to 0‰, rather homogeneous δ 7 Li values (10.3 (1.7‰), and a 18 O and 2 H enrichment with respect to ambient groundwater due to evaporation in the infiltration ponds. This confers to the AR component a unique isotopic and geochemical fingerprint. Immediately downstream of the pumping wells and in the deeper part of the aquifer no evidence of AR wastewater could be found, indicating a high recovery efficiency. In the wider area and in the deeper part of the aquifer, isotopes evidence mixing of coastal rain and a fresh paleo-groundwater component with residual seawater as well as interaction with the aquifer material. Combining several isotope tracers provides independent constraints on groundwater flow and mixing proportions as a complement to hydrodynamic modeling and geochemical studies.

Our study reports the first data on mercury (Hg) isotope composition in marine European fish, for seven distinct populations of the European seabass, Dicentrarchus labrax. The use of δ 202 Hg and Δ 199 Hg values in SIBER enabled us to estimate Hg isotopic niches, successfully discriminating several populations. Recursive-partitioning analyses demonstrated the relevance of Hg stable isotopes as discriminating tools. Hg isotopic values also provided insight on Hg contamination sources for biota in coastal environment. The overall narrow range of δ 202 Hg around Europe was suggested to be related to a global atmospheric contamination while δ 202 Hg at some sites was linked either to background contamination, or with local contamination sources. Δ 199 Hg was related to Hg levels of fish but we also suggest a relation with ecological conditions. Throughout this study, results from the Black Sea population stood out, displaying a Hg cycling similar to fresh water lakes. Our findings bring out the possibility to use Hg isotopes in order to discriminate distinct populations, to explore the Hg cycle on a large scale (Europe) and to distinguish sites contaminated by global versus local Hg source. The interest of using Hg sable isotopes to investigate the whole European Hg cycle is clearly highlighted.

Household wastes may constitute a vector of environmental contamination when buried, in particular through degradation and production of leachates containing significant trace metal (TM) concentrations that may constitute a serious risk to biota. The objectives of this study were to assess the bioavailability and transfer potential of various TMs present in water and sediments in a reservoir receiving landfill leachates. An active biomonitoring approach was adopted consisting of exposing naive laboratory organisms in cages deployed in the field. Aquatic insects such as Chironomus riparius larvae are good candidates since they represent key organisms in the trophic functioning of aquatic ecosystems. The results show that water, suspended particles, and sediments were significantly contaminated by various TMs (As, Cd, Cu, Ni, Pb, and Zn). Their contribution to the transfer of TMs depends, however, on the specific element considered, e.g., Cd in sediments or Pb in both suspended particles and sediments. The internal fate of TMs was investigated according to their fractionation between an insoluble and a cytosolic fraction. This approach revealed different detoxification strategies capable of preventing the induction of deleterious effects at the individual scale. However, the accumulation of several TMs in C. riparius larvae tissues may also represent a significant load potentially transferable to higher trophic levels.

Prosjektleder Asle ØkelsrudBradalsmyra er Nammo Raufoss AS sitt testsenter for utprøving av ny ammunisjon, etablerte serieprodukter, rakettmotorer og andre fremdriftssystemer. Området avvannes av Veltmannåa, og to mindre bekker. Vi fortsetter her rapportering av overvåkingen av metaller, som har pågått siden 1991. Prøvetaking foregår månedlig i den isfrie perioden. For 2020 ble det ikke observert overskridelser av gjeldende miljøkvalitetsstandard (EQS) for prioriterte stoffer (kadmium, bly og nikkel). For kobber og sink ble det påvist enkeltmålinger som tilsvarer overskridelse av MAC-EQS (maksimal verdi) i en av bekkene som avvanner testsenteret, samt i en vannansamling inne på testsenteret. Det ble ikke observert overskridelser av EQS for de vannregionspesifikke stoffene i de utgående bekkene. For arsen forekom enkelte konsentrasjoner tilsvarende tilstandsklasse III i en av bekkene som avvanner testsenteret, nedstrøms i en mindre bekk som renner ut av testsenteret, samt i en av bek...

På oppdrag fra Lillestrøm kommune og Vannområde Leira-Nitelva har vi undersøkt miljøgifter i åtte fiskearter i Nedre Nitelva, innenfor to ulike områder, i den øvre delen av vannforekomsten (strekningen Kjellerholen til Bondetangen) og i den nedre delen av vannforekomsten (strekningen fra Øya til Gullaugvika). Fisk ble fanget i garn den 24-25. august 2020. Miljøgifter som er undersøkt er polysykliske aromatiske hydrokarboner (PAH), perfluorerte alkylforbindelser (PFAS), kvikksølv og andre metaller. Asle Økelsrud og Kine Baek har i fellesskap ledet prosjektet, med ansvar for henholdsvis innsamling/rapportering og kjemiske analyser. Asle Økelsrud og Morten Jartun har samlet inn fisk, Espen Lund og Marthe Torunn Solhaug Jenssen har stått for opparbeiding av prøver og registrering av fiskemorfometridata, Kine Baek har organisert alle kjemiske analyser, og Asle Økelsrud, Morten Jartun og Sigurd Øxnevad har skrevet rapporten.

Recently, groundwater has been the backbone in sustaining the development of many regions in Egypt, especially in Sinai. Growing of population, increasing in water demands and uncertain impacts of climate changes are major challenges for groundwater management in Rafah, Zowayeid, Kharouba and El-Arish areas. In order to assess the effect of previous factors; a mathematical model (Modflow) is used to simulate the groundwater system in the study area. The model is calibrated and consequently three scenarios are proposed to test and predict the response of the aquifer during simulation period. The main objective of the study is to examine the vulnerability of the aquifer to groundwater extraction, Sea water rise as a result of climate changes and the occurrence possibility of sea water intrusion. The results indicated that there is no significant effect of the Sea water rise on the aquifer but it is high vulnerable for both pumping rates and Sea water Intrusion. The most affected area ...

Investment in the coastal resources of Gaza City is vital to various developmental issues and projects. Access to the coast and coastal erosion represent two major geo-environmental problems to the city. This paper describes local engineering works developed by the municipality and local people to overcome such problems. A cliff of calcareous sandstone-Kurkar as it is locally known-(up to 18 m high), is located at a distance of 20-50 m from the water-land contact. People who need to reach the beach must cross this Kurkar cliff. The engineering works used to facilitate access to the beach are: old automobile tires, white waste skeletons (refrigerators) and construction waste, where long stairs were designed using these materials. Meanwhile the engineering works which were used as erosion control measures include: rock gabions, concrete wastes, construction waste, concrete walls and shallow excavations. Such practices are commonly used in third world countries and are characterized by inexpensive transportation and implementation costs. The performance of these methods was evaluated from an economic, environmental and safety point of view. Suggestions were made to improve the performance of these practices in the future.

Contamination source identification in water distribution network has got serious attention during last two decades, especially in developed countries. The same effort is almost absent in developing countries. This paper introduces a contamination source identification methodology where EPANET is used for hydraulic and water quality simulation and genetic algorithm (GA) is used for the optimization. The methodology has been tested on two networks with increasing complexity. Sensitivity analysis on GA parameters shows the robustness of the methodology.<br>

The water pollution trends in the Ambewela reservoir at the uppermost catchment of Kotmale River was assessed through a study on chemical and bio monitoring programme that carried out from March to October 2008. The mean average value (mean ± SD) of the nitrate, nitrite, phosphate and ammonia concentrations in Ambewela reservoir were 0.780 ± 1.386 mg/l, 0.103 ± 0.223mg/l, 0.051 ± 0.061mg/l and 0.218± 0.261 mg/l whereas values for the streams selected from Dambagasthalawa Oya were 0.985 ± 0.902 mg/l, 0.099  ± 0.207mg/l, 0.038 ± 0.026 mg/l and 0.085± 0.077 mg/l respectively. Average Chlorophyll- a values of the reservoir were 17.85 ± 17.858 mg/m3 and 8.30 ± 4.686 mg/m3for other two streams accordingly. Average BOD values of the reservoir were 8.06 ± 3.494 and 4.25 ± 2.251 for other two streams correspondingly. The bio monitoring studies also clearly showed sudden records of huge colonies of  Hydra(approximately 258/cm3) in the reservoir from time to time. This phenomenon was found in ...

Egypt is mainly covered by desert and only 4% of total lands is arable, mainly the alluvial plain of the Nile and its delta. In order to cope with the increasing population, the government of Egypt has been pressed into the development of Sinai Peninsula. So, it is indispensable to evaluate the potential groundwater resources for the development of the Sinai Peninsula. The key components are a conceptual model and a groundwater model with certain mathematical components. The conceptual model is a system analysis of the hydrogeological understanding of how water flows into, through and out of a groundwater system. Based on available borehole data, the study area is characterized to reach to the most representative conceptual models. Finally, a finite difference groundwater model was applied utilizing the graphic user interface GMS were used. In order to handle problems at regional scale, automated parameter estimation (PEST) was used in GMS. Moreover, recharge was parameterized using zones by defining these zones several factors were considered; for example, surface geology, density of vegetation, general land use, and LANDSAT image. However, Groundwater flow model successfully calibrated. Calibrated groundwater model helped to identify the heterogeneity in the aquifer.

Contamination source identification in water distribution network has got serious attention during last two decades, especially in developed countries. The same effort is almost absent in developing countries. This paper introduces a contamination source identification methodology where EPANET is used for hydraulic and water quality simulation and genetic algorithm (GA) is used for the optimization. The methodology has been tested on two networks with increasing complexity. Sensitivity analysis on GA parameters shows the robustness of the methodology.<br>

The Quaternary aquifer system in the northern coast of Sinai contains a productive but highly vulnerable unconfined reservoirs used for irrigation, drinking and domestic supply. Rafah City totally relies on these aquifers to cover the excessive water needs for its growing population. A comprehensive hydrogeochemical and hydrogeological studies of these aquifers has shown severe deterioration in the groundwater quality (pollution and salinization). Nitrate, faecal coliform counts and some heavy metal contents are commonly exceeds the drinking water standards. The deteriorated sites and sources of contamination are defined using graphical and statistical hydrogeochemical techniques. The main sources of groundwater contamination at Rafah environs are the leakage from undeveloped sewage system, liquid waste disposal of food industry factory and agricultural activities. The leakage from sewage system is confined to the city center and along the international border zone, where there are ...

Bomuruella Reservoir in Nuwara Eliya is an important water source in the area which indirectly contributes to the drinking water supply of the downstream people. Many agricultural lands obtain water from this reservoir and consume its water for washing and cleaning purposes. This research was focused on identifying the contamination sources of Bomuruella reservoir and to investigate the suitability of the reservoir as a drinking water source. According to the water quality analysis, BOD5 and CODMn values of most sample points did not satisfy the specified standards of Cen-tral Environmental Authority, Sri Lanka. Municipal wastewater stream and the stream from the cultivated area re-corded high BOD5 levels of 7.65 mg/l and 6.55 mg/l respectively in the period of low water level of the reservoir. The stream from the cultivated area reported a high CODMn value of 595.74 mg/l during March and the stream from Kan-dapola plantation recorded a CODMn value of 74.44 mg/l during May. This con...

The establishment of new communities and land reclamation projects in the Egyptian desert areas is one of the most important national targets. One of these areas is the 10 th of Ramadan city. The main goal of the study is concerned with delineation of groundwater contaminants plume in the future. The results show that; the ions concentration of most samples from the oxidation ponds resources contain concentrations of Al 3+ , Cr 2+ , Fe 2+ , Ni 2+ and Sr 2+ exceeding the acceptable limit of WHO (1996) standards. Also, most of the groundwater samples are polluted with Al 3+ and Fe 2+ and Sr 2+ ions. The infiltration from the oxidation ponds and expansion of reclaimed lands irrigated with wastewater reflect critical environmental hazards. The results of the groundwater flow and transport simulation reveal contamination plume expansion. It will travel 1.8, 2.1 and 2.3 km due NE direction after for Al 3+ , Fe 2+ and Sr 2+ contaminants respectively. It is strongly recommended that wastes from oxidation ponds must not be used in irrigation without tertiary treatment. The oxidation ponds to minimize the pollution of groundwater with heavy metals is highly recommended.

There are some sources of pollution of the groundwater such as the industrial, agriculture, domestic activities and the oxidation ponds that are considered collection points for waste disposal plants. The motivations to do this work were: (1) investigating the concentrations of pollutants in the oxidation ponds and well surrounding the 10th Ramadan city and (2) predicting the groundwater flow and the pollutant transport to the groundwater from the pollution source using a numerical simulation (MODFLOW-2000 with MT3D code). The samples of groundwater were collected from the wells that spread around the studied area as well as many samples were collected from the oxidation ponds to investigate the concentrations of pollutants in these samples and predict the pollutant transport to the groundwater over 30 years. The results illustrated that the ion concentration of most samples from the oxidation ponds resources contained Al 3+ , Fe 2+ , Sr 2+ , Ni 2+ , and Cr 2+ which were exceeding the acceptable limit of WHO (International standards for drinking water, WHO, Geneva, 1996) standards. The results also demonstrated that most of the analyzed groundwater samples are polluted with strontium (Sr 2+), aluminum (Al 3+), and iron (Fe 2+). The simulation predicted that the pollutants movements toward the northeast of the study zone over a long-term period (30 years).

Bomuruella Reservoir in Nuwara Eliya is an important water source in the area which indirectly contributes to the drinking water supply of the downstream people. Many agricultural lands obtain water from this reservoir and consume its water for washing and cleaning purposes. This research was focused on identifying the contamination sources of Bomuruella reservoir and to investigate the suitability of the reservoir as a drinking water source. According to the water quality analysis, BOD5 and CODMn values of most sample points did not satisfy the specified standards of Central Environmental Authority, Sri Lanka. Municipal wastewater stream and the stream from the cultivated area recorded high BOD5 levels of 7.65 mg/l and 6.55 mg/l respectively in the period of low water level of the reservoir. The stream from the cultivated area reported a high CODMn value of 595.74 mg/l during March and the stream from Kandapola plantation recorded a CODMn value of 74.44 mg/l during May. This concludes that the reservoir was contaminated with significant loads of organic wastes. Furthermore, the effluent from the leachate treatment plant recorded higher conductivity, nitrate and CODMn values which indicated that the leachate treatment plant was malfunctioning.The main cause of pollution of the reservoir is the discharge of agricultural runoff, raw sewage and wastes which include domestic, industrial and hospital waste directly into the feeder streams. It can be concluded that if the reservoir is to be used as a source of drinking water stringent measures have to be taken to control effluents.

The impact of individual septic tank effluent on groundwater quality was investigated in the rural area of the Ain Soltane municipality in Algeria. This area has an important number of individual septic tanks, and it is devoid of a drinking water supply and sewerage systems. The septic tank is a pre-treatment solution of sewage by bacteria living without oxygen (anaerobic). The alluvial aquifer in this area is covered by a layer of good permeability on the surface, which can pollute groundwater by vertical transport of pollutants through the soil, including microbial contamination. Groundwater samples were collected from 33 wells in the dry period of 2016. The monitoring of groundwater quality has shown a significant degree of organic and inorganic pollution in the majority of wells, with very high concentrations of sulphate and chloride exceeding 450 mg/l and 250 mg/l respectively. The analyzes also show the presence of bacterial germs in the groundwater of which the origin is faecal (faecal coliform densities are above 10 organisms per 100 ml, and the Total Streptococcus is more than 240 colonies per 100 ml). Monitoring confirms the contamination of these wells from septic tanks and that it was moving into groundwater, which makes it unfit for drinking due to the pathogenic germs. This poses a major problem for public health. This study has identified the effects of septic tank effluent on groundwater quality in this area.

Sustainable development in El Arish area of North Sinai, Egypt, is retarded by serious environmental problems, where the land-use and land cover of the region is changing over present time. The impact of human activities in the study area is accompanied by the destruction and over-exploitation of the environment. This study applies multivariate statistics (factor and cluster analyses) and GIS techniques to identify both anthropogenic and natural processes affecting the groundwater quality in the Quaternary sands aquifer. The aim of this study was to investigate the impacts on groundwater resources, the potential pollution sources, and to identify the main anthropogenic inputs of both nutrients and trace metal. Since the depth to the water table is shallow especially in the northern part (<4 m), and the aquifer was exposed on the ground surface, it has poor buffering capacity and the pollution risk is very high. Groundwater chemistry in this coastal region has complex contaminant ...

There are some sources of pollution of the groundwater such as the industrial, agriculture, domestic activities and the oxidation ponds that are considered collection points for waste disposal plants. The motivations to do this work were: (1) investigating the concentrations of pollutants in the oxidation ponds and well surrounding the 10th Ramadan city and (2) predicting the groundwater flow and the pollutant transport to the groundwater from the pollution source using a numerical simulation (MODFLOW-2000 with MT3D code). The samples of groundwater were collected from the wells that spread around the studied area as well as many samples were collected from the oxidation ponds to investigate the concentrations of pollutants in these samples and predict the pollutant transport to the groundwater over 30 years. The results illustrated that the ion concentration of most samples from the oxidation ponds resources contained Al 3+ , Fe 2+ , Sr 2+ , Ni 2+ , and Cr 2+ which were exceeding the acceptable limit of WHO (International standards for drinking water, WHO, Geneva, 1996) standards. The results also demonstrated that most of the analyzed groundwater samples are polluted with strontium (Sr 2+), aluminum (Al 3+), and iron (Fe 2+). The simulation predicted that the pollutants movements toward the northeast of the study zone over a long-term period (30 years).

Geoindicators have been developed as tools for integrated assessments of natural environments and ecosystems, and tracking and reporting on the state of the environment. This paper examines groundwater geoindicators in Río Cuarto city, Argentina, and focusses on piezometric levels and water quality indicator parameters. Since 1988, there has been a progressive rise of the water table caused by cesspool effluents and an increasing trend of rainfall excess in the water balance. In certain neighborhoods this has caused serious damage. Water quality indicators include nitrogen species, total dissolved solids (TDS) and chloride (Cl), which indicate contamination due to sanitary systems. Nitrate (NO 3) and dissolved iron were used to assess the redox state of groundwater. The neighborhoods under study present different contamination scenarios. Where oxidizing conditions prevail, NO 3 was found in all the samples, and those with the highest values showed an increase in TDS and Cl. Where reducing conditions prevail, NO 3 was not found. There was an increase in dissolved iron and in TDS and Cl in the most microbiologically contaminated samples. Taking into consideration that a great number of people are affected by these groundwater problems, the municipality has provided more than 500 families with piped running water and/or sewerage systems, and installed dewatering wells to control the high water table.

Bomuruella Reservoir in Nuwara Eliya is an important water source in the area which indirectly contributes to the drinking water supply of the downstream people. Many agricultural lands obtain water from this reservoir and consume its water for washing and cleaning purposes. This research was focused on identifying the contamination sources of Bomuruella reservoir and to investigate the suitability of the reservoir as a drinking water source. According to the water quality analysis, BOD5 and CODMn values of most sample points did not satisfy the specified standards of Central Environmental Authority, Sri Lanka. Municipal wastewater stream and the stream from the cultivated area recorded high BOD5 levels of 7.65 mg/l and 6.55 mg/l respectively in the period of low water level of the reservoir. The stream from the cultivated area reported a high CODMn value of 595.74 mg/l during March and the stream from Kandapola plantation recorded a CODMn value of 74.44 mg/l during May. This concludes that the reservoir was contaminated with significant loads of organic wastes. Furthermore, the effluent from the leachate treatment plant recorded higher conductivity, nitrate and CODMn values which indicated that the leachate treatment plant was malfunctioning.The main cause of pollution of the reservoir is the discharge of agricultural runoff, raw sewage and wastes which include domestic, industrial and hospital waste directly into the feeder streams. It can be concluded that if the reservoir is to be used as a source of drinking water stringent measures have to be taken to control effluents.

The groundwater resources in North Sinai area are affected by salt water up-coning due to overpumping
phenomenon beside seawater intrusion. To protect these salt-affected ecosystems, an optimum water
resources management is carried out by applying mathematical modeling techniques in this paper. The chosen
area for study is located in the northern coastal zone of Sinai Peninsula of Egypt and covers about 1750 km2.
It is bounded by the Mediterranean Sea to the North and Gebel El-Maghara and Arish-Rafah highway to the
south. Its climate is hot in summer and rainy in winter. Field investigations show that the Quaternary Aquifer
in the North Sinai Area (QANSA) is highly affected by salt water up-coning due to over-pumping phenomenon
beside seawater intrusion. El Arish airport area, El-Maazar village, El-Taweel village and El-Kharouba area are
greatly affected by the groundwater level decline which reaches 15 m at its maximum value. The methodological
approach to simulate the groundwater flow is based on the mathematical modeling techniques applying 3D
finite element software (FEFLOW model). The total surface area of the model domain reaches 600 km2. The two
aquifer zones are discretized into 2 layers and 3 slices. Three management scenarios are applied to detect the
future predictions in the drawdown of groundwater levels under different extraction rates and seawater intrusion
phenomenon. In addition, the methodology of seawater intrusion study is based on applying two-dimensional
finite element simulation algorithm (SINM) depending on the calibrated outputs of the MODFLOW code. The
results of groundwater flow simulation show optimum groundwater extractions of 26 million m3/year from the
cultivated areas. Moreover, Simulation results indicate that the seawater/freshwater interface will migrate, after
15 years, 5.5 Km landward from its initial position if the present groundwater production policy (19 million m3/yr)
continues operating in the investigated area. The predicted interface toe positions will migrate 13 Km from its
initial position after 15 years in case of increasing the groundwater production by 4%. While the climate change
will cause its migration by 5.3 Km landward from its initial position assuming a rise of sea water level by 0.5m.
To conserve the QANSA storage for longer time, it is recommended to reduce the number of the pumping wells
(less than 300 wells), reduce the initial and running time (does not exceed 10 hours) and achieving the objective
of implementing the developing policy without any increase (500 m3/day/well). Otherwise, to mitigate the
migration of the interface toe position, subsurface flow toward sea of 144443 m3/day is needed. It is highly
recommended to carry out geophysical exploration study and constructing monitoring network to verify the
results of the applied model.

This study aims to evaluate the quantity and quality of potential groundwater resources, their mode of occurrence in the different geologic formations and potential sustainable development. The evaluation of groundwater potentialities is done for the north eastern area of Sinai Peninsula. The study is mainly based on filed survey for groundwater wells, and interpretation of the measured hydrogeological data (i.e. Water level, well yield and analyzing groundwater quality). Three aquifers were recognized in the study area based on their lithostratigraphy, hydrogeological setting and water quality, these are : Quaternary aquifer, Fracture Limestone Aquifer, Lower Cretaceous Sandstone Aquifer. The Quaternary sediments cover most the area of study especially the central and northern parts where the thickness of the wadi deposits increase while they decrease in the southern part, generally the aquifer composed of sand, clay, silt and kurkar. The fracture limestone aquifer is considered one of the most important aquifer at the north east Sinai, generally the aquifer composed of dolomitic, chalky and fracture limestone with some strikes of shale and silt, this aquifer it is difficult to evaluate and led to more intensive studies. The lower cretaceous bearing formation is composed of ferruginous, vari-colored sandstone alternating with thin shale beds and common by Malaha formation, this aquifer is consider the promising aquifer in middle and north middle Sinai due to its highly production and good water quality.

Contamination source identification in water distribution network has got serious attention during last two decades, especially in developed countries. The same effort is almost absent in developing countries. This paper introduces a contamination source identification methodology where EPANET is used for hydraulic and water quality simulation and genetic algorithm (GA) is used for the optimization. The methodology has been tested on two networks with increasing complexity. Sensitivity analysis on GA parameters shows the robustness of the methodology.

In the last few decades hydrochemistry has contributed significantly to the understanding of ground water systems by using the hydrochemical facies and the application of equilibrium concepts. Hydrochemical information is used to interpret the origin and mode of ground water occurrence and recharge. The aim of this study is the investigation of the geochemical characteristics and processes of ground water in Al Arish area, Sinai (Egypt). To achieve this aim; Geographic Information System, geochemical modeling and statistical analyses were used. The ground water chemical analyses, the geochemical parameters and the concentration of different elements enabled the characterization of salinity sources and the identification of the different geochemical processes affecting ground water chemistry in the area. Ground water types include alkaline earth to alkaline water. Ion exchange, reverse ion exchange and mixing processes represent the main geochemical processes in the ground water. The saturation indices and inverse geochemical modeling resulted in the deposition of calcite and aragonite in the pore spaces of the sand sediments forming Kurkar deposits, and vice versa gypsum and anhydrite are dissoluted. Cluster Q-mode dendrogram was interpreted by three clusters reflecting recharge sources, distances of flow path, percolation depths and lateral flow of ground water. Factor analysis represents four main factors affecting ground water chemistry (evaporation, dissolution, biodegradation, and mixing processes).

Groundwater is endangered by agricultural activities, wastes disposal, aquifer over exploitation and seawater intrusion. The pollution risk is high, as the depth to the water table is shallow and the aquifers are highly permeable and have poor buffering capacity. Intensive farming activities have also put stress on groundwater quality due to intensive use of fertilizers and pesticides. As a result, concentrations of NO3 -, SO4 2and PO4 -2 are very high. Most of the house owners do not have access to public sewers, which poses another risk for the aquifers. More than 71.2% of the aerial distribution of nitrate concentration is greater than 44.29 mg/L, thus causing a serious problem. Static water level maps from 1983 to 2000 show the declining of the water level with time. The discharge from Quaternary aquifers exceeds the recharge rates after 1988 resulting in both upward leakage of the deeper high saline water and seawater intrusion. Factor analyses were used to define the factors that affect the groundwater quality. Dissolution and deposition of several minerals, evaporation from the groundwater, human impact on the aquifers, cation exchange, mixing between different waters and rainfall recharge were identified as the main factors impacting the ground waters.

Geoindicators have been developed as tools for integrated assessments of natural environments and ecosystems, and tracking and reporting on the state of the environment. This paper examines groundwater geoindicators in Río Cuarto city, Argentina, and focusses on piezometric levels and water quality indicator parameters. Since 1988, there has been a progressive rise of the water table caused by cesspool effluents and an increasing trend of rainfall excess in the water balance. In certain neighborhoods this has caused serious damage. Water quality indicators include nitrogen species, total dissolved solids (TDS) and chloride (Cl), which indicate contamination due to sanitary systems. Nitrate (NO 3 ) and dissolved iron were used to assess the redox state of groundwater. The neighborhoods under study present different contamination scenarios. Where oxidizing conditions prevail, NO 3 was found in all the samples, and those with the highest values showed an increase in TDS and Cl. Where reducing conditions prevail, NO 3 was not found. There was an increase in dissolved iron and in TDS and Cl in the most microbiologically contaminated samples. Taking into consideration that a great number of people are affected by these groundwater problems, the municipality has provided more than 500 families with piped running water and/or sewerage systems, and installed dewatering wells to control the high water table.

Nitrate pollution is a worldwide problem in groundwater, as it may limit water supply and increase health risk when high concentrations are present. The North Maresme coastal alluvial groundwater-dependent agrosystem, one of the most heavily nitrate polluted aquifers in Spain, is located 70 km northeast from Barcelona. Field monitoring campaigns performed in this aquifer yielded nitrate concentrations up to ten times the permitted limit for drinking water suggested by the World Health Organization (50 mg/l), with a maximum concentration of 567 mg/l and a mean of 137.5 mg/l. Nitrate contamination was quantified by means of a mass balance, taking into account the main hydrogeological and anthropogenic processes that control the behavior of this ion in the aquifer, such as recharge, groundwater extraction, irrigation and fertilizer application to crops. Nitrate balance is an integrative approach for assessing nitrate loading based on linking different sources of nitrates to a groundwat...

A hydrogeochemical survey involving collection and analysis of 51 well, spring and stream water samples from an area of about 216 km2 was carried out over a part of the Arabo-Nubian Shield of southern Sinai (locally known as St. Catherine area). The distribution and relationships of major and trace constituents of water with sulphide occurrences were described. Only six major chemical parameters, including high electric conductivity, Ca, Mg, SO4, Cl and low HCO3 contents, can be used as prospecting guides in the search for sulphide minerals. Trace element anomalies, including Fe, Pb. Cr, and Mn, are distributed over, the mineralized zones owing to their relative immobility in this arid environment. On the other hand, the relatively mobile elements; including Cu, Mo, Ni and Zn; are significantly increased in waters as the distance increased away from the mineralized zone. As a result of the present research, two hydrogeochemical anomalies were delineated; those suggest the presence o...

The current study introduces the geological subsurface
cross-sections in the southern part of the Gaza Strip to
show the structure of the aquifer in the area. The crosssections
give evidence of four subaquifers of the coastal
aquifer in the southern part of the Gaza Strip. These crosssections
give the natural reasons for the deterioration of the
groundwater in the study area. The results show presence of
clay lenses that prevent the replenishment processes of the
aquifer of fresh water from the rainfall and returns flow from
agricultural activities. Lithological formation was evident as
one of the natural causes which accelerate destroying process
of the coastal aquifer. The results also show that the structure
of the aquifer causes the increase of the groundwater salinity
in the Gaza Strip. The cross-sections had shown the shortage
of storage capacity of high quantities of fresh water in the
coastal aquifer in these areas. The role of lithological formation
was evident as one of the natural causes to accelerate the
process of destroying the coastal aquifer.

Groundwater is endangered by agricultural activities, wastes disposal, aquifer over exploitation and seawater intrusion. The pollution risk is high, as the depth to the water table is shallow and the aquifers are highly permeable and have poor buffering capacity. Intensive farming activities have also put stress on groundwater quality due to intensive use of fertilizers and pesticides. As a result, concentrations of NO3 -, SO4 2and PO4 -2 are very high. Most of the house owners do not have access to public sewers, which poses another risk for the aquifers. More than 71.2% of the aerial distribution of nitrate concentration is greater than 44.29 mg/L, thus causing a serious problem. Static water level maps from 1983 to 2000 show the declining of the water level with time. The discharge from Quaternary aquifers exceeds the recharge rates after 1988 resulting in both upward leakage of the deeper high saline water and seawater intrusion. Factor analyses were used to define the factors that affect the groundwater quality. Dissolution and deposition of several minerals, evaporation from the groundwater, human impact on the aquifers, cation exchange, mixing between different waters and rainfall recharge were identified as the main factors impacting the ground waters.

A stochastic approach is proposed, aiming at the optimal allocation of increasing sets of monitoring stations for the early detection of the intentional contamination of water distribution networks. The approach is based on the use of the Monte Carlo technique for the generation of a number of timevarying hydraulic scenarios, each consisting of a succession of steady conditions related to different users' water demands. Given a time-varying hydraulic scenario, and chosing an injection node, the spreading of the contaminant through the network is evaluated by means of a Lagrangian advection model, and the arrival times to all the potential monitoring stations are calculated. If these operations are accomplished for all the source nodes, and for each of the time-varying hydraulic scenarios, a statistical analysis allows for the allocation of the monitoring stations which maximise the number of upstream nodes characterised by arrival times less than a pre-assigned value (early warning time).

Egypt is mainly covered by desert and only 4% of total lands is arable, mainly the alluvial plain of the Nile and its delta. In order to cope with the increasing population, the government of Egypt has been pressed into the development of Si-nai Peninsula. So, it is indispensable to evaluate the potential groundwater resources for the development of the Sinai Peninsula. The key components are a conceptual model and a groundwater model with certain mathematical compo- nents. The conceptual model is a system analysis of the hydrogeological understanding of how water flows into, through and out of a groundwater system. Based on available borehole data, the study area is characterized to reach to the most representative conceptual models. Finally, a finite difference groundwater model was applied utilizing the graphic user interface GMS were used. In order to handle problems at regional scale, automated parameter estimation (PEST) was used in GMS. Moreover, recharge was parameterized using zones by defining these zones several factors were considered; for example, surface geology, density of vegetation, general land use, and LANDSAT image. How-ever, Groundwater flow model successfully calibrated. Calibrated groundwater model helped to identify the heteroge-neity in the aquifer.

Groundwater is the main water source for St. Katherine city inhabitants, South Sinai. The rapid population growth, high levels of tourism and poor sewage waste disposal (at least for the foreseeable future) in St. Katherine have resulted in potential contamination of groundwater and subsequent high risk to human health. To evaluate the safety of well water for human use in St. Katherine, water samples were collected from 14 different wells covering various inhabited locations in the area. These samples were subjected to extensive physical, chemical and microbiological analysis. Nitrate values of the majority of the studied wells water exceeded the accepted limits recommended by the Egyptian environmental legislations and the World Health Organization for drinking water standards. Counts of faecal indicators (faecal coliform and faecal streptococci) ranged between 2-142 cfu/100ml in wells. Bacterial pathogens including Salmonella, Shigella and Vibrio spp. were detectable in all wells, indicating heavy contamination of the groundwater with domestic sewage. We discuss the impact of the geological structure of the aquifers and human activities on the safety of groundwater for human use in St. Katherine, as well as possible solutions.