Wadi Al-Arab Research Articles

Dam break risk analysis and flood inundation mapping: a case study of Wadi Al-Arab Dam

Dam break risk analysis and flood inundation mapping: a case study of Wadi Al-Arab Dam

Presentation of DeMa (Decision Support Software and Database for Wellfield Management) and Its Application for the Wadi Al Arab Wellfield

This article aims to present the structure and the workflow of a new software DeMa (Decision Support Software and Database for Wellfield Management), to support wellfield managers in their decision-making processes. There is a recognized need to improve the management of groundwater resources, especially with the increased demand for fresh water in arid and semi-arid regions. DeMa differentiates from other available software, by combining data collected for the well’s maintenance, operation, design, installations, and cost data with the collected hydrological field measurements. Additionally, DeMa links the different information and provides an effective graphical representation of the data. We applied the software to the Wadi Al Arab wellfield case study to support wellfield managers in the decision-making process of three typical problems: identification of missing data and information concerning the wells, identification of maintenance needs for a well, and identification of a suitable location for a new well. In the application to the Wadi Al Arab wellfield (Jordan), we collected data and documents from the Yarmouk Water Company (YWC), the Jordan Ministry of Water and Irrigation (MWI), and private drilling companies. The software application highlights the beneficial effects of the digitalization of water resources management by improving data availability and management and achieving data and research-based decisions on the wellfield.

Induced Seismicity by Groundwater Extraction at the Dead Sea Fault, Jordan

AbstractThe earthquake sequence, with a maximum earthquake magnitude of MW 3.8, that occurred during January–February 2022 at the northern Dead Sea fault, is shown to be induced by extensive groundwater abstraction in Wadi Al‐Arab basin. Wadi Al‐Arab basin, which is bordered in the west by the Dead Sea fault, has been overexploited by extensive groundwater abstraction causing significant drawdowns. Relative earthquake relocation indicates an elongated S‐N sequence subparallel to the Dead Sea fault. We simulate the three‐dimensional hydraulic head changes in the past 40 years at Wadi al Arab basin. Results show that the drawdowns at the Dead Sea fault wells reached a value greater than 180 m. We use these results to further model the poroelastic effects of the drawdown on the stability of the Dead Sea fault using a typical fault architecture including fault core surrounded by damage zone. Upward groundwater drainage through the permeable damage zone leads to compaction and strengthening. Failure on the Dead Sea fault is expected to occur on the impermeable fault core or at the protholith where weakening is expected. Groundwater abstraction in Wadi Al‐Arab basin cause changes of a few MPa in the Coulmb Failure Stress (ΔCFS) and trigger seismicity in these sections. This is the second location along the Dead Sea fault where groundwater abstraction was shown to recently induce earthquakes. With growing demand for water and long lasting droughts in the Middle East, seismicity induced by groundwater abstraction might reoccur in the near future.

Effects of the COVID-19 Pandemic Lockdown on the Quality and Pollution of Irrigation Water in the Dams of Jordan

While the world continues to tackle the COVID-19 pandemic and its impacts on public health and the economy, among other issues (e.g., the environment), water, as a major component of the environment, has been significantly affected. This research aims to examine the quality and pollution of irrigation water in six selected vital dams in Jordan, in terms of the Irrigation Water Quality Index (IWQI) and Irrigation Water Pollution Index (IWPI), respectively, in view of determining any changes in the water quality and pollution load between the COVID-19 lockdown and the pre-COVID-19 period. The results of this study revealed that all of the studied dams showed an improvement in the quality of irrigation water and a reduction in pollution levels during the COVID-19 lockdown. This was due to a decrease in industrial, anthropogenic, urban, and agricultural activities, and strict restrictions on mobility and transportation. The improvement percentage in the irrigation water quality during the lockdown based on the IWQI model was in the following order: King Talal dam > Al-Kafrein dam > Al-Wehdeh dam > Kufranja dam > Wadi Al-Arab dam > Zeqlab dam, which is similar to the order of the reduction percentage in pollution based on the IWPI model. Therefore, the results of the IWPI model are consistent with those of the IWQI model. The classification of irrigation water based on the IWQI values indicated that the irrigation water quality of Al-Wehdeh and King Talal dams changed to better categories during the lockdown. All values of physicochemical and biological parameters in the dams’ water were within the Jordanian and international (FAO) standard limits for irrigation, except for the Na concentrations in some dams that were above the FAO standards.

Effects of climate change on water resources: a case study of the Wadi Al-Arab catchment area in Jordan

Effects of climate change on water resources: a case study of the Wadi Al-Arab catchment area in Jordan

Sentinel 2 analysis of turbidity retrieval models in inland water bodies: The case study of Jordanian dams

AbstractThis study investigates the potential of using Sentinel 2 multispectral satellite images to develop turbidity retrieval models and further estimate the turbidity values of inland water bodies in Jordan. Traditionally, laboratory analysis has been used to assess surface water quality, which is expensive, time‐consuming, and requires accessing the field physically. In contrast, remote sensing technologies can detect the water contaminant level at a consistent spatial and temporal coverage. Turbidity is an essential indicator of inland water quality as it directly reflects under‐water light penetration. This study was held in three Jordanian dams, King Talal Dam, Mujib Dam, and Wadi Al Arab Dam, which vary in their water quality level. Twenty water samples were collected from each dam. Forty samples were used to calibrate the models, and the rest samples were used to validate the predictive models. The results show that Sentinel 2 near‐infrared band to green band (B8/B3) achieved high fitting accuracies with R2 = 0.832 and root mean square error (RMSE) = 1.123 NTU. Overall, this study has demonstrated the ability of Sentinel 2 data to estimate the turbidity in different ranges of inland water bodies’ quality and indicates that remote sensing can be used as an efficient tool for monitoring inland water quality. This study presents empirical data that could act as a platform to extend future work to cover more sites and contexts.

Estimation of the sediment yield using hydrological assessment tool model: a case of Wadi Al-Arab Dam at the northern part of Jordan

Estimation of the sediment yield using hydrological assessment tool model: a case of Wadi Al-Arab Dam at the northern part of Jordan

Hydrochemical Evaluation of Molybdenum Content of the Groundwater Aquifer System in Northern Jordan

The groundwater quality of Wadi Al Arab aquifer, northwest Jordan, was assessed for its high molybdenum concentrations, which reach 1.62 mg/L. This value of Mo-concentration was far beyond the Jordan Institution for Standards and Metrology (JISM) and World Health Organization (WHO) guidelines. Hydro-geochemical studies were carried out in order to assess the chemistry of the groundwater quality focusing on identifying the hydrogeochemical processes and mechanisms that are involved in the high Mo concentration. The water quality data of Wadi Al Arab boreholes (1986-2018) was collected, and the dataset analyzed. Interpretation of hydrochemical data showed that the anions are dominated by with abundance order of , while the main cation is Ca2+, with abundance order of Ca2+ > Mg2+ > Na+ > K+; water type is . The reason is the passage of groundwater through carbonate rocks. The distribution of the sampling points in the Gibbs diagram showed that the majority of samples are plotted within the field of rock weathering, which indicates that the main factor controlling dissolved hydrochemical components of the water samples is the dissolution of the rock-forming minerals. The scattered plot of the Mo with other critical heavy metals shows two different trend lines suggesting initiation of molybdenum to groundwater which is probably derived from oil shale and phosphate. The effects of pH and redox potential on Mo mobility in water are reviewed using the paurbaix diagram. The Mo species of the sampled wells are confined to the field of : anoxic/non-sulfidic condition (Fe reduction) which is located in the unconfined part of the aquifer, and which is sulfidic condition (low and high) in the confined aquifer.

Water Shortage in Jordan

Water shortage in Jordan is considered to be one of the main challenges that face the country throughout the years. In this manuscript all aspects of this issue will be highlighted. In this article, first, the water situation inputs, contests and outputs will be discussed. Secondly, there will be a detailed study about the ‘WADI AL-ARAB’ Project which is funded by the European Investment Bank and managed by the Yarmouk Water Company, its missions, assets and workflow. Finally, the Improvement of Energy Efficiency in the water sector, project aims, framework, and the major findings expected as a result of these analysis will be highlighted. This document presents the essential elements of a work that required a long time, an enormous effort and a hard work to collect all the data from several sources such as the Jordanian Ministry of Water and Irrigation (MWI), the Water Authority of Jordan (WAJ) and the European Commission (EU Official Website) and analyze them. Also, all the information listed about “WADI AL ARAB” Project was collected from multiple site visits.

Groundwater protection under water scarcity; from regional risk assessment to local wastewater treatment solutions in Jordan

The infiltration of untreated wastewater into aquifers highly endangers the availability of fresh-water for human consumption in semi-arid areas. This growing problem of potable water scarcity urgently requires solutions for groundwater protection. Decision support systems for local wastewater treatments in settlements already exist. However, the main challenge of implementing these for regional groundwater protection is to identify where wastewater treatments are most efficient for the whole region. In this paper, we addressed this scale-crossing problem with an interdisciplinary approach that combines regional risk assessment and assessment of local wastewater treatment scenarios. We analysed the impact of polluting the groundwater using vulnerability, hazard, and risk assessments. Thus, we identified the need for semi-arid and karst-related adjustments, defined more suitable standards for wastewater hazard values, and accounted for the groundwater dynamics beyond the vertical flow paths. Using a lateral groundwater flow model, we analysed the impact of the pollution sources and linked the regional and local scale successfully.Furthermore, we combined the geoscientific results with the urban water engineering methods of area and cost assessments for local wastewater scenarios. Based on the example of the Wadi al Arab aquifer in Jordan, we showed that implementing an adapted treatment solution in one of the heavily polluted suburban settlements could reduce 12% of the aquifer pollution, which affects 93% of the potential aquifer users. This novel method helps to identify settlements with significant pollution impact on the groundwater, as well as the users, and also gives specific guidelines to establish the most efficient locally tailored treatment solution.

Implementation of Simple Strategies to Improve Wellfield Management in Arid Regions: The Case Study of Wadi Al Arab Wellfield, Jordan

Groundwater is the main source of drinking water supply in Jordan. Over the past 30 years, many wellfields have been drilled and expanded to cover increasing drinking water demand caused by natural population growth, development of life standards and as a result of the influx of refugees to Jordan. In particular, northern Jordan groundwater resources have been severely depleted. Therefore, water suppliers and utilities have been increasingly challenged to meet water demand and deliver water of adequate quality and quantity to households in a timely manner. Meeting these objectives requires good data management, proper maintenance of groundwater wells, and effective wellfield management plans. We developed a novel monitoring strategy that allows the collection of relevant data for wellfield managers (e.g., yield, static and dynamic water level, as well as energy consumption). The new monitoring system, implemented in 2017, has greatly enhanced data availability in comparison to the situation between 2012 and 2016. The data are used in an operational decision support tool based on simple interpretation of the field observations. The implementation of the project was done using both bottom-up and top-down approaches for the Wadi Al Arab wellfield. Our results evidence that (i) simple strategies can lead to a significant improvement of wellfield management, reducing the maintenance time of the wells though appropriate monitoring (from an average of four days/maintenance/well in 2012 to less than one day/maintenance/well in 2017); (ii) the joint combination of bottom-up and top-down approaches leads to an effective implementation of the monitoring system; (iii) the simplicity of the proposed monitoring strategy makes it suitable for further implementation in other wellfields in Jordan and countries in a similar situation of both data and water scarcity.

Prioritization of W. Alarab Sub-Watersheds (North Jordan) for Conservation Measures Using RS, GIS, and Multi-Criteria Analysis

Soil erosion and high sediment flow are of eminent environmental concern in Wadi Alarab catchment, northern Jordan. The objective of this research is to conduct a prioritization scheme using RS, GIS, and multi-criteria analysis approach based on morphometric analysis, land use/land cover (LULC) change analysis, and soil loss modeling based on RUSLE model factors. ASTER GDEM and Arc GIS were utilized to delineate watersheds and extract the drainage networks using the Arc Hydro tool. Five basic morphometric parameters, five linear and five shape parameters, six LULC classes, and five soil erosion risk classes are applied to prioritize 13 sub-watersheds connected to W. Alarab basin. LANDSAT images were subjected to supervised classification (the Maximum Likelihood Method) to determine land use/cover changes and to establish the LULC map/layer. Soil erosion risk classes were estimated using the RULSE model. RULSE factors (R, K, L, S, C, and P) were calculated in a GIS environment, then multiplied together so as to estimate soil loss (ton·ha-1·yr-1) and to establish a soil erosion risk map for the entire watershed and the thirteen sub-watersheds. A GIS-based integration of the three layers compiled for each criterion reveals that six sub-watersheds (1, 5, 8, 9, 10, and 11) are categorized under low priority. Further, three sub-basins (4, 12, and 13) are fall under moderate priority, and four sub-basins (2, 3, 6, and 7) are designated as of high priority. It is obvious that 53.8% of these sub-basins must be prioritized immediately for soil and conservation measures. The validity of the achieved priority classes was tested statistically using Discriminant Analysis (DA), and the results showed that morphometric parameters, LULC analysis, and soil loss are accepted criteria for prioritization. These results are intended to help decision-makers to prepare reliable soil erosion management plans.

Geo-environmental study of heavy metals of the agricultural highway soils, NW Jordan

This study investigated the status and distribution patterns of selected heavy metals in roadside soils along Irbid-North Shooneh Highway, Jordan. This highway has experienced a growing number of vehicles that are likely to influence the levels of heavy metals in the surrounding agricultural lands. The average concentrations of Cr, Co, Cd, Cu, Pb, Zn, and Ni were 16.0, 36.0, 11.0, 4.0, 79.0, 122.0, and 60.0 mg/kg, respectively. Cd, Pb, and Co showed average levels that are higher than the average world soil background values. Elevated levels of heavy metals were measured in surface soil layer which decreased with depth, and with distance from the roadway. The contamination factor (CF), pollution load index (PLI), single ecological risk (Ei), potential ecological risk index (PERI), and geo-accumulation index (Igeo) generally indicated that the roadside soils are contaminated with Cd, Pb, and Ni. Heavy metals in soils are of geogenic and anthropogenic origins. Weathering of parent rocks in Wadi Al-Arab catchment is the primary natural source, whereas agrochemicals, vehicle exhausts, degradation of surface wear and paint of vehicles, vehicle wear debris of tire, and brake lining are the main anthropogenic sources of heavy metals.

Hydrogeochemical investigation of the origin of Molybdenum (Mo) in groundwater resources in Wadi Al Arab area, Northern Jordan

High Mo concentrations have been detected in drinking water pumped from domestic water supply wells located in the Wadi Al Arab area, at the Irbid city, northern Jordan. The main objective of this study is to investigate hydrogeochemical processes responsible for the release of Mo in the groundwater resources. Usually Mo is a metallic element that is naturally present in the earth’s crust. However, the presence of Mo in groundwater is an important potential pollution issue. To achieve the objectives of the study, 34 water samples were collected from the whole catchment area of Wadi Al Arab and were analyzed using ICP-MS for total Mo and the other major cations, anions and heavy metals. The results obtained from the hydrogeochemical investigation show that the groundwater in Wadi Al Arab catchment area is susceptible to Mo contamination due to the chemical reactions of water with clay-rich underlying bedrock that consists mainly of shale and marl rocks. The concentration values measured at the tested wells vary from 46.6 μg/L to 1438.7 μg/L, with an average value of 397.6 μg/L. Therefore, about 70% of the analyzed water samples show Mo levels that exceed the permissible limit of 70 μg/L for drinking water according to World Health Organization. The results of geochemical modeling using VISUAL MINTEQ software show that the most abundant species of Mo mineral is molybdate ion (MoO42-), with a concentration of 30 μg/L, which accounts for more than 50% of the Mo species dissolved in groundwater. The possible source of the Mo in the groundwater in Wadi Al Arab catchment area is due to presence of oil shale and phosphate layers within the geological succession of the aquifer. Through the geochemical model, the saturation indices of the common Mo minerals were calculated. The calculated saturation indices showed that groundwater is under-saturated with respect to Mo mineral speciation, which emphasizes that natural equilibrium will never be reached.

Assessing anthropogenic impacts on limited water resources under semi-arid conditions: three-dimensional transient regional modelling in Jordan

Both increasing aridity and population growth strongly stress freshwater resources in semi-arid areas such as Jordan. The country’s second largest governorate, Irbid, with over 1 million inhabitants, is already suffering from an annual water deficit of 25 million cubic meters (MCM). The population is expected to double within the next 20 years. Even without the large number of refugees from Syria, the deficit will likely increase to more then 50 MCM per year by 2035 The Governorate’s exclusive resource is groundwater, abstracted by the extensive Al Arab and Kufr Asad well fields. This study presents the first three-dimensional transient regional groundwater flow model of the entire Wadi al Arab to answer important questions regarding the dynamic quality and availability of water within the catchment. Emphasis is given to the calculation and validation of the dynamic groundwater recharge, derived from a multi-proxy approach, including (1) a hydrological model covering a 30-years dataset, (2) groundwater level measurements and (3) information about springs. The model enables evaluation of the impact of abstraction on the flow regime and the groundwater budget of the resource. Sensitivity analyses of controlling parameters indicate that intense abstraction in the southern part of the Wadi al Arab system can result in critical water-level drops of 10 m at a distance of 16 km from the production wells. Moreover, modelling results suggest that observed head fluctuations are strongly controlled by anthropogenic abstraction rather than variable recharge rates due to climate changes.

Rare earth elements and uranium geochemistry in the Al-Kora phosphorite province, Late Cretaceous, northwestern Jordan

Sixty-three samples representing the phosphorite deposits of the Al-Kora province in northwest Jordan are analyzed for their major and certain trace elements including the rare earth and uranium. They are collected from the following four sections: Tubna, Dair Abu Sa’id, Wadi Al-Arab, and Wadi Ziglab. The samples studied are mainly phosphorite packstone/grainstone consisting of phosphate intraclasts and vertebrate skeletal fragments (bone and teeth) of varying sizes, associated with minor carbonate wackestones. Laminated, in situ phosphorites, sometimes called pristine phosphorites, are also present. The Al-Kora phosphorites are authigenic, i.e., precipitated from the interstitial solutions enriched with the phosphate ion. Carbonate fluorapatite (CFA) or francolite is the dominant mineral. Geochemical data suggest that the analyzed elements can be grouped into (a) land-derived detrital clay group (Al2O3, Fe2O3, TiO2, K2O, Cr, Ga, Hf, Nb, Rb, Th, and Zr). This group constitutes less than 5 % of the total elemental concentrations in the analyzed samples, (b) marine- or seawater-derived phosphate-carbonate group (P2O5, CaO, MgO, Na2O, Ba, Sr, U, Y, and the 14 rare earth element (REE)), making the bulk of the samples studied, and (c) organic matter/detrital clay group (Cr, Ni, Mo, Cu, Pb, As, Zn, and Sb). Uranium substitutes for Ca in the CFA structure with a range from 1 to 186 ppm for all samples including carbonates, with an average of 58.4 ppm. Average for the phosphate-only samples is 101 ppm. The shale-normalized REE patterns exhibit distinct seawater-derived mineral patterns. The patterns are characterized by an enhanced negative Ce anomaly and an enriched heavy REE. This signal (pattern) seems to have survived the phosphogenesis processes. Average Ce anomaly is −0.76, including the carbonate samples. It indicates the fractionation of Ce3+ into Ce4+ and the deposition of the latter in oxic, or possibly oxygen minimum, seawater. It, thus, confirms the oxic water conditions of the Neo-Tethys Ocean at the time of deposition.

Integrating Lithostratigraphic Units and GIS-Analysis Techniques to Modified Surface Water Quality Index

The purpose of this study is to investigate the effect of using Bicarbonate and Calcium parameters as alternatives to the lithostratigraphic units covered the catchment area, on water quality index (WQI) values that have been implemented with GIS technique at Wadi Al-Arab Dam. The analyzed results (by WQI method) have been used to depict water quality for the two approaches. Based on physico-chemical parameters, the calculated values for WQI over the 3-year for study period were 169, 168, and 157, respectively. While the WQI values were 184, 183 and 172, respectively, as a result of incorporated Bicarbonate and Calcium parameters in WQI calculations that significantly contributed to increasing the WQI. The elevated values may be attributed to the influence of carbonate stone dissolution and mechanical erosion under weathering conditions that are prevalent during winter season in the catchment area. As a consequence of lithostratigraphic unites product and GIS technique integration and normalization processes, most of water quality ranks are good and only autumn season has poor water quality in the 2012 and 2013, while in 2014 it has good water quality in the same season. The WQI values increase in general trend from winter to autumn seasons during the study period that may be referred to outflow by daily consumption, evaporation rising, and seepage water. The analysis shows that the modified water quality values of the Wadi Al-Arab Dam Reservoir (WADR) vary after using Bicarbonate and Calcium parameters by constant value. Generally, the results signify that the WADR is not polluted based on the physical and chemical characteristics of water.

Sediment fingerprinting in northern Jordan: element-specific correction factors in a carbonatic setting

Water reservoirs around the world suffer from accelerated sediment loads and, consequently, contamination. Notably, in water-scarce regions such as Jordan, this poses a threat to an important water source, and identifying the sediment sources is an important task. Thus, a sediment fingerprinting study in the Wadi Al-Arab catchment of northern Jordan was implemented with special attention directed to the development of suitable correction factors necessary to improve the comparability of source and sink sediments. The selection of seven conservative elements for the sediment fingerprinting was made, with specific attention directed to the chemical environment of the reservoir. Thirty-six samples from six different surface and subsurface sources and 38 sink samples from the Wadi Al-Arab reservoir were collected. In total, 27 organic and inorganic elements as well as radionuclides were analysed. Two vertical physicochemical water profiles provided information on the pH and Eh conditions and common element concentrations. The stepwise multiple regression analysis model (SMRAM) was developed to explore parameters that influence the element concentrations and their interrelations, and to calculate an element-specific correction factor. The standard selection procedure was expanded by the comparison of water and sink sediment element concentrations, a literature review concerning the pH and Eh conditions and, in selected cases, a correlation analysis. The combination of Al, Cr, Mn, Fe, 232Th, 228Th and 137Cs provided the best source discrimination, and based on Monte Carlo simulations, the mixing model revealed the existence of three major sediment source areas. These are as follows: (i) olive orchards on slopes, which delivered 59 ± 8 % of the sediments in the sink; (ii) cultivated fields on plateau and saddle positions contributed 11 ± 9 %; and (iii) slopes with natural vegetation used for grazing contributed 29 ± 15 % of the deposited sediment. With a mean residual error of 1.04 %, the sum of the source concentrations differs only slightly from sink concentrations and proves that the model is reliable. The SMRAM model revealed that the different inorganic (total inorganic carbon, TIC) and organic (total organic carbon, TOC) carbon contents and the clay/sand content influence the element concentrations of the sediment samples. Due to the carbonatic environment, it was mainly necessary to correct for TIC. Applying an expanded literature review regarding the chemical environment under investigation, in addition to the standard mass conservation and Kruskal-Wallis test, prevented possible non-conservative elements from entering the discriminant analysis.

Spatial distribution patterns of molybdenum (Mo) concentrations in potable groundwater in Northern Jordan.

Two hundred and three groundwater samples were collected during March 2011 to June 2012 from the B2/A7 aquifer water supply wells of northern part of Jordan. The physicochemical properties were analyzed in situ for the major cations, anions, while certain heavy metals were analyzed in the laboratory. Some oilshale rock samples were geochemically analyzed. The Upper Cretaceous aquifer (B2/A7) is used as water supply for most of the communities in the study area. It consists of limestone, marly limestone, bedded chert, and minor phosphorite. Hydrochemical results from the B2/A7 aquifer indicate two main water types: alkaline-earth water (CaHCO3) and alkaline-earth water with high alkaline component (NaHCO3 (-), Na2SO4). Standard column leaching experiments on oilshale rock samples and the R-mode factor analysis suggest that the sources for elevated Mo concentrations in the groundwater of certain parts of northern Jordan are attributed to water-oilshale interaction, mobility of Mo down to the groundwater and the extensive use of fertilizers within these areas. Molybdenum (Mo) concentrations in the groundwater water range from 0.07 to 1.44 mg/L with an average value of 98 μg/L. They are found to exceed the JISM and WHO guidelines in two areas in northern part of Jordan. Spatial distribution of Mo, using ordinary kriging techniques and the resulting map, shows high Mo concentration in the northwestern part near Wadi Al Arab area reaching concentrations of 650 μg/L and in the southeastern corner of the investigated area, south of Al Ukaydir village, with an average concentration of 468 μg/L. Both areas are characterized by extensive oilshale exposures with average concentration of 11.7 mg/kg Mo and intensive agricultural activities. These two areas represent approximately 33 % of the groundwater in the northern part of Jordan. Mobility of Mo to the groundwater in northern part of Jordan is attributed to two mechanisms. First, there is reductive dissolution of Fe-oxide, which releases substantial adsorbed Mo concentrations. Secondly, there is oxidation of Mo into dissolved forms in sulfide organic-rich system.

Semi-volatile organic pollutants in Jordanian surface water

Jordan relies heavily on rainwater stored in reservoirs because it has extremely limited alternative water resources. These reservoirs are essential for drinking water and irrigation, so monitoring their water quality is extremely important. In this study we monitored 55 semi-volatile organic chemicals (SVOCs) in monthly samples from the Zarqa River and three reservoirs between April and August 2010, and also screened the samples for non-target pollutants. Twelve SVOCs were detected and quantified at King Talal Dam followed by ten at Zarqa River and four each at Wadi Al-Arab and Mujib dams. Phenol and phthalate esters were detected at wide range concentrations (0.01–25μg/L) in all water samples. Phenol has the highest level at the Zarqa River (18.5±5.5μg/L) followed by King Talal (12.5±2.5μg/L) and Wadi Al-Arab (2.5±0.63μg/L). Phthalate esters (total) were detected at the Zarqa River, King Talal, Wadi Al-Arab, and Mujib dams at levels 3.85, 3.75, 1.03 and 0.12μg/L. Other contaminants, including polyaromatic hydrocarbons (PAHs), were detected at low concentrations in the King Talal Dam reservoir and Zarqa River samples. Two non-targeted phosphate plasticizers, tri-n-butylphosphate and tris(2-chloroethyl)phosphate were identified in the July and August Zarqa River samples. A comparison study reveals that SVOC pollution of surface water in Jordan is within acceptable international limits, but long-term monitoring programs should be implemented.