Numerical Groundwater Flow Model Research Articles

A Novel Simulation-Optimization Model Built by FloPy: Pollutant Traceability in a Chemical Park in China

Heavy metal pollution of groundwater will not only destroy the ecological environment but also negatively affect the functioning of the human liver. Tracing the source of groundwater pollution is an important way to protect groundwater resources. FloPy is promoting the use of big data in the groundwater field, especially in groundwater resource planning and management and contaminant traceability. This paper takes Mn as an example and codes a simulation-optimization model for solving the groundwater pollutant traceability problem using FloPy. The Bayesian optimization and strengthen elitist genetic algorithm (SEGA) algorithms are then used to optimize the hydraulic conductivity and pollutant sources in the study area. The results show that the model runs in 411 s, which is an acceptable amount of time spent, the slope of the fitted curve between the model-calculated water level and the actual observed water level is 0.914, and the contaminant traceability results can successfully locate the contaminant sources in real engineering problems. The numerical groundwater flow model and solute transport model can be quickly built, modified, and run by writing code, and can be easily and efficiently coupled with various optimization algorithms with FloPy.

Numerical modeling of site-scale groundwater flow with stochastic parameterized hydraulic conductivity fields for geological disposal of high-level radioactive waste in China

Deep geological disposal is internationally accepted as a feasible and safe approach for high-level radioactive waste (HLW) disposal. To evaluate hydrogeological conditions in support of safety assessments for HLW disposal at the Xinchang preselected site in China, stochastic inverse models of site-scale groundwater flow were developed in this study to generate highly parameterized hydraulic conductivity fields for the fractured medium by adopting pilot point and null-space Monte Carlo methods. The hydraulic influence zones of the faults were carefully considered to have homogenous parameter values across the zones. A total of 120 multiple random realizations were generated to characterize the 3D spatial variations in hydraulic conductivity by conditioning to 1218 fixed pilot points. The simulated hydraulic heads of the realizations were in good agreement with observational data. The hydraulic conductivity fields close to the boreholes could be characterized in detail and had relatively low uncertainties. Furthermore, the hydraulic conductivity (K) values around underground research laboratory (URL) at the HLW disposal zone depth were less than 10−9 m/s. The K values obtained for most of the influence zones of these faults at this depth were consistent with hydraulic test data and ranged from 10−10 to 10−9 m/s, thereby indicating that the surrounding rock has low permeability and is suitable for HLW disposal. These findings offer new insights into hydrogeological conditions by providing key information on the permeability characteristics that need further focus on HLW disposal.

Permeability Tests and Numerical Simulation of Argillaceous Dolomite in the Jurong Pumped-Storage Power Station, China

Due to its poor hydro-physical properties and other characteristics, argillaceous dolomite is susceptible to seepage failure under high water pressure, affecting the seepage stability of a rock mass. To ensure the safety of the project, when the argillaceous dolomite is present, it is necessary to study the conditions pertaining to its seepage failure. Taking the argillaceous dolomite of Jurong Pumped Storage Power Station as the research object, the spatial distribution, occurrence, scale, degree of weathering, and mechanical and hydrogeological characteristics of the argillaceous dolomite were studied. Through on-site water pressure tests and laboratory variable head tests, the permeability characteristics of argillaceous dolomite were analyzed, and the hydraulic conductivity of the argillaceous dolomite in the upper reservoir and underground powerhouse areas was quantified. The argillaceous dolomite specimens were collected, and seepage failure tests were conducted to determine the critical water pressure for its seepage failure. Based on the results of the laboratory tests, a numerical model of groundwater flow was established. By changing the water level of the upper reservoir and the measures of the anti-seepage and drainage, the seepage stability of the argillaceous dolomite was discussed. The actual water pressure of argillaceous dolomite in the underground powerhouse area was identified during the operation of the Jurong pumped-storage power station. The calculations show that when fully enclosed anti-seepage and drainage measures are taken for the underground powerhouse, the maximum head of water is 98 m, which is lower than the critical water pressure of seepage failure for the argillaceous dolomite. Therefore, no seepage failure will occur. The results provide a scientific basis for the anti-seepage and drainage design of the underground powerhouse area.

Assessing the Connectivity of a Regional Fractured Aquifer Based on a Hydraulic Conductivity Field Reversed by Multi-Well Pumping Tests and Numerical Groundwater Flow Modeling

Assessing the Connectivity of a Regional Fractured Aquifer Based on a Hydraulic Conductivity Field Reversed by Multi-Well Pumping Tests and Numerical Groundwater Flow Modeling

Effects of a Gravel Pit Lake on Groundwater Hydrodynamic

In Europe, 1132 Mt of sand and gravel were mined in 2019, which causes major changes to the hydrogeological cycle. Such changes may lead to significantly raised or lowered groundwater levels. Therefore, the aggregate sector has to ensure that impacts on existing environmental and water infrastructures are kept to a minimum in the post-mining phase. Such risk assessments are often made by empirical methods, which are based on assumptions that do not meet real aquifer conditions. To investigate this effect, predictions by empirical and numerical methods about hydraulic head changes caused by a pit lake were compared. Wrobel’s equation, which is based on Sichardt’s equation, was used as the empirical method, while a numerical groundwater flow model has been solved by means of the finite-element method in FEFLOW. The empirical method provides significantly smaller ranges of increased/decreased groundwater levels caused by the gravel pit lake as the numerical method. The underestimation of the empirical results was related to the finding that field measurements during pumping tests show a larger extent of groundwater drawdown than calculations with the Sichardt’s equation. Simplifications of the 2D model approach have been evaluated against hydraulic head changes derived from a 3D groundwater model. Our results clearly show that the faster and cheaper empirical method—Wrobel’s equation, which is often preferred over the more expensive and time-consuming numerical method, underestimates the drawdown area. This is especially critical when the assignment of mining permits is based on such computations. Therefore, we recommend using numerical models in the pre-mining phase to accurately compute the extent of a gravel/sand excavation’s impacts on hydraulic head and hence more effective protection of groundwater and other related environmental systems.

Numerical Modelling of Groundwater Flow and Contamination Transport (TDS) in Kaniqurzala Area- Central Basin – Erbil City- Kurdistan - Iraq

Numerical Modelling of Groundwater Flow and Contamination Transport (TDS) in Kaniqurzala Area- Central Basin – Erbil City- Kurdistan - Iraq

Integrated Three‐Dimensional Geological and Numerical Groundwater Model Development

AbstractConceptual site model (CSM) development is a foundational step for numerical groundwater model construction. Tools for reviewing and combining disparate data to develop a CSM have been furthered through software that efficiently integrates multiple data streams, especially when a large amount of information is available at complex sites. Three‐dimensional (3D) interfaces for data visualization and geological modeling are becoming commonly used to compile data, support development of a robust CSM, and create effective visuals that enable project stakeholders to understand site complexity. This article describes a 3D interface workflow applied to a geological and numerical groundwater modeling case study where numerical modeling (i.e., MODFLOW family of codes) was used to assess remedy effectiveness. Specifically, the numerical model was used to overview an in situ solidification (ISS) application, where soil mixing will be conducted with cement, for possible adverse effects to an existing groundwater treatment system. 3D geological modeling allowed for the existing numerical groundwater flow model to be reconstructed to include previously overlooked data on buried infrastructure, which led to a detailed depiction of high‐permeability channels and a more accurate representation of site conditions. Modeling showed that the ISS remedy would not adversely impact the existing groundwater treatment system. Integration of existing data within a 3D interface led to hydrogeological insights that would have been difficult to obtain from two‐dimensional visualization of information, improved numerical modeling efficiency, and informed site remedy decisions. Additionally, the 3D interface created effective visuals that increased internal and external project team conceptual understanding.

Numerical Simulation and Analysis of the Influencing Factors of Foundation Pit Dewatering under a Coupled Radial Well and Curtain

It is crucial to use a suitable dewatering technique to prevent land subsidence and substantial decreases in groundwater levels caused by the dewatering of groundwater during the construction of underground projects. Therefore, in this study, a generalized three-dimensional numerical model of groundwater flow was implemented for an underground station pit project. The dewatering efficiency of the coupled radial well-curtain method was investigated and compared with that of a traditional method. In addition, the influence of different structures and parameters (radial pipe diameter, conductance, number of radial pipes, and shaft drawdown) on the dewatering efficiency was assessed. The results showed the following: (1) radial wells caused less disturbance to the groundwater seepage field and extracted less groundwater during the dewatering process compared with pumping wells; (2) the structure and parameters of the radial wells positively correlated with the dewatering efficiency; (3) the curtain improved the dewatering efficiency, resulting in lower amounts of groundwater discharged and less disturbance to the groundwater flow field; and (4) the coupled radial well-curtain method is an efficient dewatering method that could effectively prevent the lowering of groundwater level outside the foundation pit, thus reducing the risk of land subsidence in the surrounding area.

Field observation and mathematical representation of the hydrogeological function of alpine landforms in the Canadian Rockies

AbstractGroundwater discharge sustains the baseflow of alpine headwater streams, which is critical for water supply and aquatic environments in mountainous regions. Periglacial landforms typical of alpine headwaters (e.g., talus, moraine, rock glacier, alpine meadows) are important aquifers in alpine watersheds. This study examines the hydrological function of an alpine aquifer complex in a small headwater basin in the Canadian Rockies. The aquifer complex consisting of talus, alpine meadow underlain by a bedrock depression, and recessional moraine provided essentially all baseflow of a 6.5 km2 watershed, even though the upper sub‐watershed containing the aquifer complex occupies only 14% of the watershed. Chemical and isotopic signatures indicated that the recessional moraine serves as a gatekeeper of the upper sub‐watershed, whereby it integrates groundwater components from multiple aquifers and controls the discharge from the outlet springs. Field observation of discharge and the water table in the moraine aquifer showed a nonlinear groundwater storage‐discharge relationship. Numerical groundwater flow models of the upper sub‐watershed showed that the transmissivity feedback resulting from a decrease in hydraulic conductivity with depth was essential for determining the nonlinear storage‐discharge relationship. A simple exponential function was proposed to represent the observed groundwater storage‐discharge relationship, which can be implemented within large‐scale hydrological models to simulate baseflow coming out of alpine headwater regions.

Urbanization effects on the groundwater potential recharge of the aquifers in the southern part of the Basin of Mexico

Abstract Collection, processing, and analysis of GIS and satellite data were performed in this work to estimate temporal groundwater recharge changes, which are needed as input in numerical groundwater-flow models. Layers of geological alignments, land use, drainage network, lithology, topography, and precipitation were collected. This information was spatialized, then layer importance was calculated using an Analytic Hierarchy Process (AHP) based on infiltration capacity to define Potential Recharge (PR) regions. A water budget equation was used to calculate PR volumes. The analysis was done every five years from 1970-19, considering average urban area changes. For all study periods, an increase in urban area was calculated from 16 to 28% of the total study area, while potential recharge decreased from 23 to 19% of the mean precipitation values for each 5-year period. The most significant urban expansion was from 1980-94 and 2010-19, which match periods of potential recharge decrease. However, a slight increase in PR from 2000-09, unrelated to urban area change, may be due to temperature variations. The results account for the spatial and temporal dynamics of the recharge in the study area and can be used as input data to calibrate the actual recharge in a groundwater numerical model.

Multi Model Approach to Study the Effect of Conceptualization and Discretization on Groundwater Model

The objective of the study is to develop multiple steady state conceptual and numerical groundwater flow models for Bhiwadi region of Alwar district of Rajasthan, India. Automated parameter estimation tool (PEST) is used for the calibration of the models. To evaluate and select the best suited conceptual flow model, several statistical criteria such as RMSE (Root Mean Square Error), R-squared (R^2), Nash-Sutcliffe efficiency (NSE), percent bias (PBIAS), multi model information criteria: Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) are used. The result of the study indicates that value R2, NSE and Pbias are almost similar for all the models, hence are insufficient to evaluate the models. Therefore, AIC and BIC statistical criteria are used for accurate evaluation. The result also indicates that grid size and orientation have immense impact on modeling output. For the study area coarse grid size has given better results as compared to finer grid size.

Groundwater discharge and saltwater-freshwater mixing in a mangrove wetland over tidal cycles: A field and modeling study

Material transport and transformations in mangrove wetlands are closely related to seawater-groundwater mixing processes, which can influence mangrove growth and development. Therefore, a clearer understanding of groundwater and salt transport dynamics in aquifers beneath mangrove wetlands is needed to accurately estimate chemical fluxes to mangrove ecosystems. We established a multi-level groundwater monitoring profile in a mangrove wetland and constructed a numerical model of tidally-driven groundwater flow and salt transport that was calibrated to salinity and pore water pressure. Model results indicated that 99% of groundwater discharge to the mangrove wetland was saltwater and that this discharge accounted for 33% of total discharge over a spring-neap tidal cycle. Tidal creeks that cross-cut the wetland received the remaining 67% of total discharge. Seawater infiltration from tidal action across the wetland formed a subsurface saltwater-freshwater mixing zone with a geometry that followed the undulation of a high permeably layer at depth. Model sensitivity tests showed that salinity distributions and groundwater discharge patterns were controlled strongly by wetland topography and anisotropy. Model cases with a gently sloping and flat mangrove platform led to substantially less salt mass in the subsurface compared to the base case with mangrove topographic relief. Models with lower anisotropy allowed salt to penetrate through the high-permeability layer to the base of the aquifer. The spatial patterns of fresh and saline groundwater discharge and mixing processes within mangrove wetlands as shown in this study may have implications for mangrove tree nutrient availability and for the prevalence and spatial distribution of mangroves along coastlines.

Simulating spatial variability of groundwater table in England and Wales

AbstractGroundwater is a vital natural resource that affects human life and the environment. Groundwater supplies drinking water, supports irrigation for food production, and helps to sustain flow of water in streams and wetlands during dry periods. Therefore, it is important to assess the variability of groundwater resources and consider it in freshwater management. Numerical modelling is widely used for understanding the variability of groundwater table. However, there is still a lack of large‐scale groundwater flow models. For instance, in the United Kingdom, groundwater modelling efforts so far have focused on aquifer to regional scales. A national scale model would aid the quantification of the available groundwater storage and the assessment of the impacts of climate change and anthropogenic activities on this crucial resource. In this study, we evaluate a numerical groundwater flow modelling approach for entire England and Wales. This model operates at 1 km spatial and 1 day temporal resolution. We force the model with precipitation and potential evapotranspiration, parameterise the subsurface using our estimation of transmissivity and specific yield based on available information, and simulate steady‐state groundwater heads over England and Wales. The results demonstrate that the model can reproduce spatial variability of groundwater table in the region. Because of a two‐dimensional numerical representation of groundwater flow, the computational demand of this model is low, facilitating multiple simulations required for calibration, sensitivity analysis, and quantification of the impacts of environmental changes on groundwater resources.

The role of Canadian research in advancing groundwater hydrology: historical sketches from the past 75 years

Canadian hydrologists have played important roles in advancing the scientific understanding of groundwater flow in the hydrologic cycle. This article highlights some of the major episodes that made fundamental contributions to groundwater hydrology, rather than attempt a comprehensive review of all Canadian advances in groundwater research. The early years of groundwater research were driven by the need to find water supplies and to evaluate the capacity of wells and aquifers using the well hydraulics theories. The research focus shifted to the understanding of groundwater flow in drainage basins in the late 1950s and the 1960s through field observations using piezometer networks, rigorous mathematical analysis, and the development of numerical groundwater flow models. These researchers established a new conceptual framework and mathematical tools to describe groundwater flow systems in the context of topographic features and geological heterogeneity. In the 1970s, Canadian researchers made important contributions in establishing the new paradigm of hillslope hydrology by field observations and numerical modelling of storm runoff generation, development of tracer-based hydrograph separation techniques, and the demonstration of the role of the capillary fringe. The groundwater research group at the University of Waterloo pioneered contaminant hydrogeology research in the 1970s and 1980s, which generated new knowledge of groundwater flow and transport processes and developed increasingly sophisticated numerical models capable of simulating coupled surface and subsurface flow and transport. The scope of groundwater hydrology diversified in the 1990s onward including the interaction of surface water and groundwater as well as the interaction between hydrological and ecological systems. Climate-change impacts on groundwater are a major topic of current and future research. To address this and other challenging problems, it is important to establish and maintain long-term monitoring sites. The history has shown that the scientific advances presented in this article would have been impossible without high-quality field data.

Acesulfame allows the tracing of multiple sources of wastewater and riverbank filtration

Aquifers providing drinking water are increasingly threatened by emerging contaminants due to wastewater inputs from multiple sources. These inputs have to be identified, differentiated, and characterized to allow an accurate risk assessment and thus ensure the safety of drinking water through appropriate management. We hypothesize, that in climates with seasonal temperature variations, the sweetener acesulfame potassium (ACE) provides new pathways to study wastewater inputs to aquifers. Specifically, this study investigates the temperature-driven seasonal oscillation of ACE to assess multiple sources of wastewater inputs at a riverbank filtration site. ACE concentrations in the river water varied from 0.2 to 1 μg L−1 in the cold season (T < 10 °C) to 0–0.1 μg L−1 in the warm season (T > 10 °C), due to temperature-dependent biodegradation during wastewater treatment. This oscillating signal could be traced throughout the aquifer over distances up to 3250 m from two different infiltration sources. A transient numerical model of groundwater flow and ACE transport was calibrated over hydraulic heads and ACE concentrations, allowing the accurate calculation of mixing ratios, travel times, and flow-path directions for each of the two infiltration sources. The calculated travel time from the distant infiltration source was of 67 days, while that from the near source was of 20 days. The difference in travel times leads to different potential degradation of contaminants flowing into the aquifer from the river, thus demonstrating the importance of individually assessing the locations of riverbank infiltration. The calibrated ACE transport model allowed calculating transient mixing ratios, which confirmed the impact of river stage and groundwater levels on the mixing ratio of the original groundwater and the bank filtrate. Therefore, continuous monitoring of ACE concentrations can help to optimize the management of the water works with the aim to avoid collection of water with very short travel times, which has important regulative aspects. Our findings demonstrate the suitability of ACE as a transient tracer for identifying multiple sources of wastewater, including riverbank filtration sites affected by wastewater treatment plant effluents. ACE seasonal oscillation tracking thus provides a new tool to be used in climates with pronounced seasonal temperature variations to assess the origins of contamination in aquifers, with time and cost advantages over multi-tracer approaches.

Data scarce modelling the impact of present and future groundwater development on Jordan multiaquifer groundwater resources

Rapidly growing demands and climate change stresses water resources worldwide and leads to highly competitive situations between the environment and socio-economic development of a region, calling for a smart and modelling driven water resources management. However, data scarcity often prevents the realisation of a comprehensive, nation-wide resources model, which provides reliable and spatially discretized results of water resources development.We present a workflow approach to set up a large-scale multi-aquifer model, overcoming data shortage by stepwise calibration and integrating hydrological and numerical groundwater flow modelling into a coupled system. The study aims to develop such a system to assess how groundwater resources react on anthropogenic impacts on the example of the Kingdom of Jordan, one of the water poorest countries on globe.Simulated heads reliably resembled the monitored ones in >70 % of the observation wells. That makes us confident, the model represents all the states well from 1970, prior to the intense development of the country until 2015. The water balance shows an annual deficit of 1.16 million cubic meter (MCM) due to an overdraft. The discharge to the Dead Sea increased from 564 MCM/yr to 696 MCM/yr over the time period. Regional drawdowns of >250 m and groundwater depression with an extension of approx.100 km are observable in both large aquifer complexes. Most severe areas in the upper calcareous aquifer are located in the north of Amman and practically in all urban and agricultural agglomerations across the country. Groundwater tables in the deeper sandstone aquifer are particularly affected in the south as well as in the wider vicinity of the Dead Sea as consequence of its continuous dropping. Simulations of the future development of the groundwater tables indicate a severe deterioration of the situation with further declines in groundwater levels of up to 70 m.

Effect of Ecological Water Supplement on Groundwater Restoration in the Yongding River Based on Multi-Model Linkage

Evaluating the effect of ecological water supplement on groundwater restoration quantitatively could produce positive contributions to both water cycle theory and surface–groundwater conjunctive management. Therefore, in this paper, a groundwater flow numerical model has been established after calculating the river section seepage rate using a fuzzy mathematical method in the Yongding River channel. The simulated results show that the model could accurately reflect the real groundwater dynamic features. Then, a data-driven random forest(RF) model has been established to quantitatively evaluate the contributions of the factors which influence the groundwater level variation. The Nash-Sutcliffe efficiency coefficient(NSE) of the RF model is 0.93. It shows excellent ability to identify the rising zone of groundwater level. The study shows that the infiltration capacity is strong in the upstream area of the Yongding River, and the seepage rate is over 0.7. The lowest seepage rate is 0.19 at the downstream end, while the seepage rate in the middle area is basically between 0.4 and 0.7. From 2018 to 2019, the ecological water supplement of the Yongding River has played a significant role in raising the groundwater level along the river channel. Additionally, its contribution analyzed by the RF model to the change of groundwater level is 25%. Groundwater exploitation is the most important variable affecting the groundwater level variation. The impact depth of groundwater level fluctuation reaches about 10 m. The impact range where the groundwater level average uplifts 1.86 m is 502.13 km2. The influence direction gradually changes from around the ecological water supplement section to along the Yongding River channel. The groundwater level variation along the tangential direction of the Yongding River is slowing down. The groundwater level would entirely uplift with 170 × 106 m3/year ecological water supplement of the Yongding River and 35.77 × 106 m3/year groundwater mining reduction in the downstream area until 2035.

Building energy consumption simulation and its application in underground-water source thermal energy management system

In order to analyze the rationality of the compound well structure and the degree of heat penetration of groundwater in a groundwater ground source heat pump project in a certain district of a city, the author proposed a method for building energy consumption simulation and groundwater flow numerical model. The variation trend of groundwater temperature under different heat transfer temperature difference is simulated and predicted. The experimental results show that the fitting points where the error between the simulated predicted temperature and the actual measured temperature does not exceed 0.5?C account for 51.7%, the fitting points where the error is 0.5~1?C account for 28.7%, the fitting points where the error is 1~2?C account for 18.1%, and the fitting points where the error is greater than 2?C account for 1.5%. The dynamic change trend of the simulated predicted temperature curve is basically consistent with that of the actual measured temperature curve. It is proved that the building energy consumption simulation and the numerical model of groundwater flow can effectively analyze the rationality of the compound well structure of the groundwater ground source heat pump project and the degree of groundwater heat penetration.

Numerical Modeling of Transboundary Groundwater Flow in the Bug and San Catchment Areas for Integrated Water Resource Management (Poland–Ukraine)

On the Polish–Ukrainian borderlands, there is the Lublin–Lviv transboundary groundwater aquifer system, which is of key importance in shaping strategic groundwater resources. Due to the particular importance of this aquifer system, the two neighboring countries are obliged to undertake joint actions to protect it. The integrated management of the Lublin–Lviv aquifer system seems difficult due to the significant spatial and temporal scale of groundwater flows in the region. To support internationally integrated management, a transboundary geological model was developed. Based on this model, a hydrogeological conceptual model has been developed, which allowed for a numerical model of groundwater flow to be calculated. The model research helped diagnose potential problems by determining the scope of the area with cross-border flows and quantifying the flows between Poland and Ukraine. In addition, the numerical model was used to define the optimal cross-border management unit and the conditions needed to sustainably exploit the Lublin–Lviv aquifer system. Basing on the research results it was concluded that groundwater flows in transboundary aquifers very on a regional scale and that the range of areas of importance for transboundary groundwater flows is much smaller than the pre-selected partial catchments of the Bug and San Rivers. The results of this study may significantly contribute to the preparation of joint water management plans.

Numerical modeling of groundwater flow and nitrate transport using MODFLOW and MT3DMS in the Karaj alluvial aquifer, Iran.

Nitrate is one of the most dangerous pollutants in groundwater, being regarded as a severe environmental hazard and a global-scale problem. The present study aims to analyze the groundwater flow and nitrate contamination in the Karaj unconfined aquifer, Central Iran. Simulation of the quantitative and qualitative status was performed using MODFLOW and MT3DMS. Sampling was done to model groundwater flow for eight seasonal time periods and nitrate pollution transport for four time periods (a total of 420days), and calibration was carried out by trial-and-error method. Due to the predominance of advection term in the transport of nitrate pollution, the total variation diminishing method was used in transport modeling. The groundwater flow modeling showed a reservoir deficit of - 33 MCUM and 67cm decrease in the water year 2016-2017 and 173cm in the entire modeling period (2016-2018) in groundwater level. Also, the RMSE in the calibration and validation stages was obtained from 24.9 to 0.72 and 0.84, respectively. The nitrate contamination transport modeling indicated that there are three nitrate contamination concentration parts with more than safe concentration of nitrate (50mg/l). The most pollution is in the urban areas in the east of the aquifer. The nitrate pollution is primarily anthropogenic due to industrial and especially domestic wastewater and then fertilizers used in agricultural activities. It can be predicted that with the full implementation of a municipal wastewater collection network, the nitrate pollution concentration in urban areas would reduce significantly to the range of 20 to 25mg/l.