[en] There is an increasing demand for independent analytical methods which can control the geographical origin of food. The EU project TRACE was started with the aim to develop a general understanding of the relation between the geo-bio-climatic environment and the isotope and elemental signature in food commodities. Beside mineral water the agricultural products wheat, honey, olive oil and lamb meat are investigated. As one part of the study a detailed δ¹⁸O map for ground water will be generated by the isotope results of 600 samples of European mineral waters. These isotope ground water maps provide a multitude of applications not only for authenticity of food, but for groundwater recharge and climate studies, criminal forensics as well as archaeology. (author)

[en] The objective of the study is to determine the groundwater potential of La Digue Island in the Seychelles Archipelago by mapping out the total extent of the aquifer available for abstraction of fresh water and estimating the recharge to the aquifer, including possible recharge enhancement, thereby estimating the safe yield of the resource. The proposed methodology to achieve the above task is discussed including the use of isotopic signature related to the precipitation inputs and their tracing through the aquifer. Moreover, the previous studies on the same plateau and similar areas are reviewed in order to identify the information gaps and thus, the required additional studies that can be proposed to evaluate the impact of sea water intrusion with or without artificial recharge to the aquifer in relation to various water abstraction scenarios. All possible contamination sources due to the human activities are examined from the available water quality data. (author)

[en] Geochemical and isotopic techniques are applied to evaluate the origin of submarine springs in the southern and northern shoreline in Lebanon. Submarine springs have different geochemistry reflecting a difference in the specific geology of southern and northern shoreline. Environmental isotopes including ²H, ¹⁸O, ³⁴S and ¹⁸O in sulfate have proved the different geological features. A more enriched isotopic composition of submarine groundwater is investigated in the south where submarine springs are primarily artesian flows. The deep circulation of groundwater is affected by a high geothermal gradient. Also a high sulfate content is related to a fractionation in ³⁴S isotopic composition. This is due to the dissolution of gypsum minerals and its reduction of marly limestones of the Upper Cretaceous and Lower Eocene in the confined aquifers. In the northern part, a slightly depleted isotopic composition is found for submarine and groundwater. The highly karstified northern region induces a fast infiltration of groundwater till its discharge as submarine springs

[en] Fluid and gas monitoring can be used to confirm the security and integrity of geological CO₂ storage. The distinct carbon isotopic composition of CO₂ from many industrial sources that process or combust hydrocarbons allows the use of isotopic and chemical analyses of produced fluids and gases to trace the injected CO₂ and quantify CO₂ storage processes in the subsurface. Our four year monitoring programme at the International Energy Agency Weyburn CO₂ Monitoring and Storage Project in Saskatchewan, Canada, featured frequent chemical and isotopic measurements of produced fluids and gases from around forty wells. Over the four year period, over four million tonnes of CO₂ were injected for storage and enhanced hydrocarbon recovery in the Weyburn oilfield. CO₂ concentration and carbon isotopic measurements of produced fluids and gases trace CO₂, and confirm that the order of magnitude increase in the amount of CO₂ in the subsurface resulted from CO₂ injection. The amount of CO₂ stored as HCO₃^- can be quantified using HCO₃^- concentration and carbon isotopic measurements, while concentration and isotope data for SO₄^2- and H₂S indicate that bacterial sulfate reduction was not a major source of HCO₃^- . To allow widespread application of geological CO₂ storage, reliable, cost effective monitoring of storage integrity will be essential. The produced fluid and gas monitoring techniques described here are based on chemical and isotopic techniques that are already widely employed and well understood by environmental isotope hydrologists, and have the potential to play an essential role in future geological CO₂ storage monitoring programmes. (author)

[en] The ¹⁴C natural isotope has been used to monitored exploitation effects within a 10 year interval between 1995 to 2005 in Bontang groundwater basing east Borneo- Indonesia. Exploitation of the groundwater of Bontang basin has occurred since 1981 and at the present the groundwater abstraction for Bontang basin is about 59,000 m³/day to fulfill the necessity of liquid natural gas and fertilizer industries from more than 20 wells. Isotope investigation of the groundwater Bontang basin have been done through water sources sampling like rivers, cold spring deep wells sea water and rain water in 1995 and 2005. The ¹⁸O and D isotope data show that deep groundwater originates from local rain water that infiltrates through the slope of mount Lobang Batik. Along the hilly slope zone, it is layered by the sedimentary Kampung Baru Formation. There is no indication that the Mahakam river water infiltrates and sea water intrusion to the deep groundwater. The ¹⁴C of isotope data from deep wells show that the average age of 4 wells with distance 2-3 km located from the outcrop of Kampung Baru in 1995 is about 2300 a. There is a decrease of groundwater age since exploitation to around 500 a. Decreasing of groundwater age is possible due to mixing with recent recharge through the Kampung Baru formation. (author)

[en] A combined use of carbon and chlorine stable isotopes was applied to evaluate the origin of TCE (trichloroethene) in a contaminated groundwater plume. The TCE at the site can be associated to a primary source of TCE and a separate (off-site) source associated to biodegradation of PCE. The TCE concentration pattern showed that the two sources of TCE formed a comingled plume in the downgradient part of the study site. The ¹³C and ³⁷Cl data on TCE showed a very significant difference in the isotopic fingerprint of the primary TCE source compared to the TCE originated by biodegradation of PCE. This difference is clearly observed in the comingled plume, which permit to demonstrate that the TCE is this part of the plume is indeed associated to the two TCE sources. This study showed the potential of the combined use of ¹³C and ³⁷Cl for fingerprinting chlorinated compounds in groundwater even in situations where biodegradation of these compounds is taking place in the groundwater. (author)

[en] Karst and other sensitive aquifers contribute up to 90% to the total drinking water supply in some European regions. However, they are more vulnerable to contamination than other aquifers due to short transfer times from recharge to source. Therefore, the main objective of this paper is to show possibilities to quantify the impact, even small of long distance air pollution on sensitive water resources (e.g. karst) even in relatively pristine and remote areas as the front-range of the Northern Calcareous Alps in Austria. The monthly precipitation (May and September 2005) samples show ¹⁸O-rich nitrate and sulphate ions, whereas the soil nitrate shows variable contribution of atmospheric nitrogen with depth. Sulphate in the soil profile changes in the direction to lower ¹⁸O and higher ³⁴S values with depth. Assuming the values of precipitation and soil for nitrate and precipitation and the dolomite rocks for sulphate and end-members the contribution of atmospheric nitrate and sulphate in the groundwater are estimated in the range of 20-40%. In addition, strontium isotopes support that up to 25% more atmospheric radiogenic Sr is added to the groundwater. Isotope data confirm that considerable amounts of atmospheric pollution is added to sensitive karst-groundwater by preferential flow. (author)

[en] To study the impact on water quality of changes in land-use, climate, or other factors, the residence times of water within the watershed must be understood. One manner of addressing this issue is through the use of tritium data. It has been over 50 years since thermonuclear weapons began producing tritium in large quantities, and over 40 years since the peak production of tritium by weapons testing in 1962. Since then, the tritium concentrations in the atmosphere have decreased and leading to a perception that tritium is no longer useful for determining physical parameters of surface waters. However, surface waters are frequently composed of a mixture of recent precipitation and base flow, the latter of which can have residence times on the order of weeks to decades, or higher. The fraction of groundwater in surface flow and its age impacts the tritium concentrations of the surface flow. If the residence time of the waters composing base flow is decades or longer, it is frequently possible to estimate the age of the active groundwater component in the river basin. Data from the Rocky Mountain area of Colorado is analyzed during three timespans: 1. The four years immediately after the bomb tests; 2. the decades after the tests (1970-2000); 3. 2000 to the present, The early time period is found to be the best time to estimate the fraction of base flow in a system. Using the ratio of tritium concentration in precipitation/tritium concentration (C_p/C_r) in surface water, it is possible to estimate the residence times of water within watersheds both on historical and recent data. (author)

[en] 24 samples of Mollusc shells from Shatt AL-Arab river and Khor AL-Zubair estuary were analyzed in order to determine the concentration of carbon stable isotope and also to clarify the factors that control the geochemical distribution of carbon isotopes in these two different environments. The carbon stable isotope were measured using the dosed tube method, in which shell samples are combusted to carbon dioxide for carbon isotope analysis. The carbon dioxide samples are analyzed on a Finnigan Mat 251 isotope ratio mass spectrometer equipped with a triple collector and controlled by an Apple He microcomputer. Measurements are made relative to several working standards {Norit (-24 per mille),NBS-22 (-29 per mille)}, and several secondary light methane standards at -43.4 per mille and -62.6 per mille. All values are reported versus PDB. These analyses are conducted in the department, of Oceanography in Texas A and M University. This study indicates that the differences in carbon stable isotopes were due to three factors: environmental conditions, under which these three molluscs are lived, chemistry of the water in Shatt AL-Arab and Khor AL-Zubair and feeding quality of these of these molluscs. The factors are close related with another important factor that it. is the pollution present in these two different environments. (author)

[en] Kairouan plain, big endorheic sedimentary basin of 3000 km², contains the most important aquifer of Central Tunisia. The importance of this aquifer is due first to its groundwater reservoir dimension, and then to the high recharge rates by the main wadies (Zeroud and Merguellil) floods and by direct rainfall infiltration. However, since the building of the great dam of Sidi Saad on oued Zeroud to protect the plain against Hooding, natural recharge decreases. Even if regulated dam releases are carried out, a regular depletion of water level is observed due to over exploitation by high anthropic needs. Geochemical and isotopic studies have been conducted in order to quantify the efficiency of artificial recharge. A short time-interval sampling campaign (15 days) has been carried out during the dam release in May 2005 in order to follow up the impact of dam water, whose geochemical and isotopic signatures are well identified on groundwater characteristics. (author)