sustainable coastal aquifer management in urban areas

Proceedings of the Resilient Cities 2013 congress

Session: B4 Adapting Urban Water Management

Presentation: Sustainable coastal aquifer management in urban areas:

The role of groundwater quality indices

El-Fadel, M.; Tomaszkiewicz, M.; Abou Najm, M.

Abstract:

Urbanized coastal areas are vulnerable to salt water intrusion into fresh water aquifers due to

increased water demand associated with population growth and exacerbated by potential

climate change and sea level rise resulting in serious socio-economic impacts related to the

deterioration of groundwater resources. Groundwater quality indices (GQIs) that constitute a

reliable management tool in defining coastal aquifer vulnerability to seawater intrusion (SWI)

are relatively limited. This study aims to develop GQIs using water quality from 60 groundwater

wells during vulnerable periods of early and late summer to ensure their representativeness

under worst-case conditions. Generalized and SWI-specific GQIs were developed from various

water quality indicators and spatially analyzed through GIS. The results indicated that

generalized GQI was successful in capturing pollution issues related to wastewater

contamination whereas the SWI-specific GQI was helpful in understanding the extent of saline

water intrusion. Such results contribute to filling a gap in GQI definition, particularly when

accounting for seasonal variability of SWI under urban stress. They form a basis for planning

effective water quality management towards sustainable exploitation of groundwater resources

in coastal urban areas particularly during summer periods when recharge is limited.

Keywords:

Groundwater quality index, sustainable aquifer management, vulnerability mapping.

Proceedings of the Resilient Cities 2013 Congress

Conference organisers: ICLEI – Local Governments for Sustainability

In cooperation with the City of Bonn and the World Mayors Council on Climate Change

ICLEI does not accept any kind of liability for the current accuracy, correctness,

completeness or quality of the information made available in this paper.

http://www.iclei.org/resilient-cities/

1. Introduction

Water resources are increasingly strained due to population growth, development, and

environmental degradation with policy makers and planners often facing serious challenges in

ensuring the long-term sustainability of existing resources and meeting future water demands

for various sectors. This is especially true along coastal zones where population centers tend

to develop resulting in high densities with increased water demands that are invariably

satisfied at the expense of overexploitation and exposure of coastal aquifers to various urban

pollution sources partly due to inadequate infrastructure (Howard, 2002; Appleyard, 2004)

and mostly due to saltwater intrusion (Chang et al. 2011; El-Moujabber et al. 2006; Konikow &

Kendy, 2005). The proposed research is driven by the need to understand the combined

effects of climate change and human impacts on saltwater intrusion. It is predicted that

climate change will aggravate salt water intrusion as 1) a direct consequence of sea level rise,

and 2) an indirect consequence of the changing climate, where a) decreases in precipitation

will affect recharge of the coastal aquifers, and b) increases in temperature will heighten

water demand in addition to affecting recharge of the coastal aquifers through increased

evapotranspiration. Hence, anthropogenic activities such as over-pumping and excess paving

in urbanized areas are currently the major causes of saltwater intrusion, and are expected to

interact with climate change to exacerbate the problem given predictions of population

growth and expected increases in groundwater overexploitation. Increased saltwater

intrusion will carry a significant socio-economic burden (i.e. damage to infrastructure such as

piping, distribution and storage systems, household appliances and supplies, and when

relevant, the cost of averting health threats; salinity damages to soils, impacts on crop yields,

impacts of saline runoff, and consequences for drainage management), which is likely to

touch upon national economies as well as vulnerable and fragile local livelihoods. In this

context, it is essential to quantify the intensity, as well as the spatial and temporal extent, of

saltwater intrusion into freshwater coastal aquifers in order to develop vulnerability maps

and mitigation measures / adaptation strategies that take into consideration socio-economic

impacts and area characteristics. For this purpose, vulnerability mapping is a valuable tool

for environmental planning and decision-making by using index methods coupled with GIS-

based spatial analysis to ascertain aquifer vulnerability (Machiwal et al. 2011). Vulnerability

can be categorized into either intrinsic, based on the sensitivity of aquifers to human and







natural activities (Metni et al. 2004), or specific, based on one or more water contaminants

(Gogu & Dassargues, 2000). Intrinsic vulnerability mapping can be developed using one of

several overlay and index or statistical models, such as DRASTIC (Aller et al. 1987) but has

been widely criticized for its limited ability to predict the aquifer’s reaction to particular

pollutants (Kouli et al. 2008). Specific vulnerability mapping is argued to be a preferable

alternative due to its capability to derive an objective analysis based on the spatiotemporal

variability of monitored water quality parameters that can be translated into a GIS-based

groundwater quality index (GQI).

Given that water resources are continuously facing increasing pressures, research into their

vulnerability can provide useful information for those concerned with environmental policy

and planning. Populations living in vulnerable areas would benefit from better-informed

policy that alleviates the impact of climate change on groundwater quality. As such, in this

study, a groundwater sampling program was implemented and the results were used to map

the vulnerability to a set of indicators and determine corresponding GQIs. Different sources

of contamination were considered in the mapping process (individually and in combination)

and compared to international guidelines used in groundwater quality classification with the

ultimate objective to provide a basis for planning effective water quality management

towards sustainable exploitation of groundwater resources in coastal urban areas

2. Materials and Methods

2.1. Study area characteristics

The study area consisted of a coastal karstic aquifer underlying the city of Tripoli, Lebanon

located along the Eastern Mediterranean (Figure 1). The area is characterized by a semi-arid

climate with mild wet winters (average daily temperatures ranging from 11 to 280C with 636

mm of average annual precipitation from October through March) and moderately hot dry

summers (average daily temperatures ranging from 19 to 270C with 75 mm of precipitation).

With a predominantly residential and commercial land use, the area’s high population density

exceeding 35,000 capita per km2 (Awad & Darwich, 2009), exerts a pressure on existing

water and sanitation infrastructure. The City id one of two pilot areas considered because of

their highest density of urbanization, population growth, and development.







2.2. Field sampling program

Two groundwater sampling campaigns were conducted in early (June) and late summer

(September) to capture conservative seasonal fluctuations when groundwater recharge is

minimal and most vulnerable thus ensuring a representative GQI. During each campaign,

samples were collected from 60 privately owned wells spread throughout the study area

(Figure 1). On site and laboratory analysis included pH; Temperature; Alkalinity; Total

Hardness; Calcium; Magnesium; Sodium; Potassium; Chloride; Fluoride; Nitrate; Nitrite;

Bicarbonate; Sulfate; Phosphate; Fecal Coliform (FC); Total Coliform; and Total Dissolved

Solids (TDS) in accordance with Standard Methods for the Examination of Water and

Wastewater (APHA/AWWA/WEF, 2005).

2.3. Development of GQIs

Decision and policy makers are continuously challenged with varied and complex water

quality problems that require the understanding and monitoring of the spatial variability of

critical water quality indicators. Depending on the complexity of the problem, water quality can

be represented with single-pollutant concentration maps or require the use of sophisticated

generalized or problem-specific GQIs. The use of single-pollutant concentration maps can be

Figure 1. Pilot study area with distribution of groundwater wells and population densities

MEDITERRANEAN SEA







ineffective and misleading for researchers as well as decision and policy makers since water

quality indicators have different and at times conflicting impacts. In such cases, multi-

parameter GQIs become more suitable to translate water quality concentrations into a single

indicator that resolves a pre-defined environmental problem. In the context of saltwater

intrusion, two GQI methods were considered in this study, a generalized GQI (after Babiker et

al. 2007) and a modified, saline intrusion-specific GQI The generalized GQI normalized

results from different water quality concentrations using World Health Organaization (WHO)

threshold-standards and aggregated the results into a single value. Water quality indicators

with potential health impacts were weighted heavier than other indicators in the GQI

calculations. The generalized GQI can be adopted to address a specific environmental

problem through the selection of a range of contributing pollutants. While the generalized GQI

has been successfully used in addressing some environmental problems, it is limited in scope

to applications where related processes follow linear increasing or decreasing trends.

However, environmental problems like saltwater intrusion are more complex and involve

processes that causes non-linear trends. For this reason, a saltwater intrusion-specific GQI

was established. This GQISWI accounts for hydrogeochemical processes associated with

saltwater intrusion that are currently explained in common graphical methods like the Piper

diagram (Figure 2). The problem with the latter approach is the inability to georeference them

for use by decision and policy makers. Equations 1 to 4 represent the generalized GQI and 5

to 8 those used to develop the GQISWI of the Piper diagram (Singhal & Gupta, 2010). Thus,

the advantage of the GQISWI lies in its ability to simplify multiple non-linear processes

involving several water quality pollutants into an indicator that can be quantified and spatially

referenced. On the other hand, and in a Piper diagram,water analysis results are presented

on a trilinear plot consisting of cation and anion triangles, which extend to a two-coordinate

diamond diagram. Generally, seawater composition has a uniform chemistry where Cl- and

Na+

make up approximately 84% of the total ionic composition. On the other hand, freshwater

composition varies widely, although Ca2+

and HCO3- commonly dominate (Richter & Kreitler,

1993). As a result, seawater and freshwater appear in distinct areas of the Piper diagram.

Likewise, mixed groundwaters appear in characteristic areas on the diagram representative of

various hydrogeochemical processes associated with saltwater intrusion (Singhal & Gupta,

2010). Points on the two Piper diagram triangles were translated into a gridded value and EC

was normalized against a reference range in groundwater. The three values were then

aggregated into the GQISWI thus allowing the mapping and the visual interpretation of the

spatiotemporal variability of SWI.

CI = (X – Y) / (X + Y) (1)







R = 0.5xCI2 + 4.5xCI + 5 (2)

GQI = 100 – (R1w1 + R2w2 + … + Rnwn) / N (3)

w = mean R for Ca2+

, Mg2+

, Na+, Cl

-, SO4

2-, TDS or mean R + 2 for Fl

-, NO2

-, NO3

-, FC, TC (4)

Where X = Derived water quality parameter concentration at each pixeled grid location (from Kriging analysis); Y = WHO threshold value; CI: Normalized concentration index (ranging from -1 to +1); R = Ranked value (ranging from +1 to +10 , from lowest to highest water quality based on individual parameters); w = weighted rank values for impacting WQ parameters with potential health impacts; and N = number of parameters to develop index.

{( ( ))

( ( )) }

5

{( (

))

( )

} 6

{

}

7

2

GQIGQIGQIGQI ECanioncation

SWI

8

Figure 2. Description of the Piper Diagram (adapter after Piper, 1944)







3. Results and Discussion

A comparison of the results of groundwater quality analyses with WHO threshold standards

revealed generally higher concentrations in late summer, which is typically expected after a

long period of pumping and no recharge. Coupled with subsequent geostatistical analysis,

the primary groundwater pollution sources consist of sewage and saltwater intrusion.

3.1. Sewage contamination indicators

While total coliforms tested positive for most sampled wells in the study area during both late

and early summer, fecal coliform contamination (Figures 3a and 3b) is significantly higher in

the late summer after a prolonged dry period. This can be attributed to sewer network

leakage and the absence of recharge and dilution coupled with increased groundwater

extraction to meet water demand shortages during the summer as well as slightly higher

groundwater temperature, which induces higher biological activity rates (Paul et al. 2004).

Karstic aquifers are highly vulnerable to bacterial pollution, partly due to their large pore

spaces which transmit organisms easily through the aquifer with minimal soil filtration that

usually occurs in non-karstic media (Appleyard, 2004; Kacaroglu, 1999). Total coliforms which

covers all bacteria sources including soil and plant sources, exhibited a smilar trend during

the late summer (Figures 3c and 3d).

Similarly, nitrate levels (Figures 3e and 3f) exceeded the WHO guideline of 50 mg/l in part of

the study area, but with spatiotemporal patterns that are different from bacterial contamination,

thus indicating contribution of different sources. While nitrate pollution often results from

domestic wastewater infiltrating into the groundwater and can be linked with bacterial

contamination particularly in densely populated areas in developing countries, it is equally

linked to agro-chemical and fertilizer usage at nearby agricultural fields (Zhang et al. 2004).







Figure 3. Distribution of sewage contamination pollutant indicators

Greens represent concentrations within desirable limits; reds represent concentrations beyond desirable limits

3.2. Saltwater intrusion indicators

Signs of salinization are manifested through elevated chloride concentrations, ion exchanges,

and characteristic hydro-geochemical ratios. Seawater has a generally uniform chemistry

with an excess of Cl- over alkali ions (Na

+ and K

+) and with Mg

2+ dominating Ca

2+, whereas

fresh groundwater composition can vary greatly although primary cations and anions are Ca2+

,

Mg2+

, Cl-, HCO3

-, and SO4

2- (El Moujabber et al. 2006). In many cases, Ca

2+ is in excess of







Mg2+

in fresh groundwater, particularly in karstic limestone aquifers rich in carbonate rocks,

and typical in the study area.

Elevated chloride concentrations are a primary indicator of salinity, whereby the range of 300-

600 mg/l is considered typical for initial mixing of freshwater and seawater (Oude Essink 2001;

Petalas & Diamantis 1999). The results of groundwater sample analyses indicated that

chloride exhibited similar trends between late and early summer (Figures 4a and 4b), with

increased concentrations along the western coastline. As the dry season progresses,

chloride concentrations are expected to increase due to groundwater pumping with no

recharge. In the absence of chloride monitoring data, total dissolved solids (TDS) can also

serve as an indicator of imminent salinity intrusion. High TDS concentrations (Figures 4c and

4d) in groundwater typically correlate well with elevated chloride concentrations (Park et al.

2005). Initial saltwater intrusion can be identified by TDS concentrations exceeding 640 mg/l,

corresponding to an electrical conductivity (EC) of 1,000 μS/cm (Petalas & Diamantis, 1999;

Pulido-Leboeuf et al. 2003),







3.3. Generalized groundwater quality index, GQI

The GQI developed by Babiker et al (2007) was adopted where a comparative assessment

with reported values in the literature suggests that the GQI can realistically range from 60 to

100, where lower and higher values indicate poor and better water quality values,

respectively. Moreover, the GQI is dependent on the specific parameters selected for

analysis and is best suited for relative rather than absolute assessments (Babiker et al. 2007).

Recent studies characterized groundwater in their respective study areas and categorized the

Figure 4. Distribution of saltwater intrusion pollutant indicators

Greens represent concentrations within desirable limits;

reds represent concentrations beyond desirable limits;

yellows represent initial freshwater-seawater mixing







classification of groundwater as poor, moderate, and good quality based on 10% intervals

between the minimum and maximum GQI although the calculated GQI differed significantly

between studies (Babiker et al. 2007; Machiwal et al. 2011). Therefore, finding a specific

range of GQI to define the acceptability of groundwater is challenging at best. Three

scenarios were considered:

First, a GQI using nine parameters (Ca2+

, Mg2+

, Na+, Cl

-, NO3

-, SO4

-, TDS, TC, FC) was

developed. Classification criteria of the general water quality was based on the assumption

that exceeding maximum WHO guidelines is considered poor while being below half the

maximum threshold is good water quality. For the nine parameters considered, the water

quality is classified according to the GQI score as follows:

GQI < 76: poor groundwater quality,

76<GQI<83: moderate water quality,

GQI > 83: good water quality.

With this definition, the corresponding GQI distribution for the study area is depicted in

Figures 5a and 5b which indicates poor groundwater quality in late summer (mean GQI = 72.5

with the entire area below the 76 threshold) and moderate groundwater quality in early

summer (mean GQI = 78.9 with a few zones exhibiting a GQI > 83 while an appreciable zone

remaining below the 76 threshold).

Second, although bacterial contamination adversely affects water quality due to its potential

health impacts, its contribution to seawater intrusion is debatable. Thus, a comparative

assessment was conducted to define the GQI by eliminating the impact of bacterial

contamination (Figures 5c and 5d). Using the same approach (maximum or half the

maximum threshold imposed by the WHO guidelines), the water quality is classified according

to the GQI score as follows:

GQI < 83: poor water quality,

83< GQI < 88: moderate water quality,

GQI > 88: good water quality.

Under these conditions, both late summer (mean GQI = 87.5) and early summer (mean GQI

= 87.7) can be considered to have nearly moderate-to-good water quality with the exception

of the western coastline.







Third, nitrate has a greater impact on the overall GQI but its contribution to seawater intrusion

is also debatable. Thus, a comparative assessment was conducted on the GQI by eliminating

nitrate, effectively leaving only the 6 parameters relevant for saline intrusion (Ca2+

, Mg2+

, Na+,

Cl-, SO4

2-, TDS). A comparison of the resultant GQI vulnerability map (Figures 5e and 5f)

concurs with other saline intrusion indicators, because chloride has the greatest impact on the

spatial pattern of the GQI due to its high mean rank value (w) and high standard deviation. In

this scenario, poor water quality is defined with a GQI < 85, moderate water quality has a GQI

ranging from 85 to 89, and good water quality has a GQI > 89. Although late summer (mean

GQI = 89.3) and early summer (mean GQI = 89.6) are considered to have generally good

water quality in this case, poor water quality remains confined to the western shoreline due to

saline intrusion.







Figure 5. Groundwater quality index (GQI) vulnerability maps

Reds represent poor water quality and blues represent good water quality







3.4. Saline intrusion groundwater quality index, GQISWI

The GQISWI aggregates data from the Piper diagram and EC into a single value ranging from

0, representing seawater, to 100, representing freshwater, which can be used as an index for

spatiotemporal mapping (Figure 6). Nearly 80% of the pilot study area is considered

freshwater in both late (mean GQISWI = 83.5) and early summer (mean GQISWI = 86.5).

However, seawater intrusion is evident along the western coastline, where the GQISWI is

below the threshold value of 75, indicative of mixed groundwater. Moreover, increasing

salinity is more problematic in late summer when groundwater recharge is at a minimum,

including along the ephemeral river bisecting the study area, which potentially allows

seawater to flow inland during the dry season.

Figure 6. GQISWI for (a) late summer and (b) early summer Reds indicate more saline and blues indicate more fresh aquifers







4. Concluding remarks

Climate change is expected to have diverse influences on the availability of water resources

with most predictions indicating that acting alone, climate change will reduce the availability

of water in many areas of the globe and threaten to increase the salinity of water in coastal

aquifers through saltwater intrusion along coastal zones in particular. The vulnerability of

groundwater reserves already strained through high water demand in densely populated

coastal regions, resulting in over-extraction of aquifer water, is known to be an important

driver in increasing aquifer salinity. While it is not clear how much climate change impacts

will augment the existing over-extraction effects on groundwater salinity, or how climate

change, local geology and human activity will interact in different areas under different

conditions to further strain aquifer resources, it is widely believed that this change will only

exacerbate already stressed conditions. In general, those coastal areas occurring in less

developed countries or in localities that are home to underprivileged communities will be

the most vulnerable to changes in water availability and/or quality from the combination of

climate change and increased water demand. Thus, increased saltwater intrusion will carry a

significant socio-economic burden, which is likely to touch upon national economies, and

most importantly, vulnerable and fragile local livelihoods. In this context, using a GIS-based

water quality index is an effective means to aggregate chemical data into a quantifiable value

that can be spatially mapped providing helpful robust visual tool for researchers and policy

makers for defining corrective or adaptive measures and city planning that target areas most

affected/vulnerable and direct potential growth towards areas that have less pressure on

groundwater. Moreover, a GQI can help in performing an objective analysis, but care must

be exercised to standardize which indicators should be considered with a clear definition of

what constitutes poor, moderate, and good water quality to enable policy relevance. Targeted

mitigation efforts can then be based on a specific set of indicators and corresponding ratios

commonly linked to a certain source. While the development of GQIs delineates vulnerable

zones, it constitutes only a step in defining a groundwater management plan for aquifer

exploitation under the stress of population growth exacerbated by climate change impacts.







References:

Aller, L., Bennett, T., Lehr, J. H., Petty, R. J., & Hacket, G. (1987). DRASTIC: A standardized

system for evaluating ground water pollution potential using hydrogeologic settings. Ada,

Oklahoma: United States Environmental Protection Agency.

APHA/AWWA/WEF. American Public Health Association (APHA)/American Water Works

Association (AWWA)/ Water Environment Federation (WEF). 2005. Standard Methods for

the Examination of Water and Wastewater, 21st ed. Washington, DC.

Appleyard, S. (2004). Cities overlying karst and karst-like aquifers. In D. N. Lerner (Ed.),

Urban Groundwater Pollution (pp. 181-203). Oxon: Taylor & Francis.

Awad, M. M., & Darwich, T. (2009). Evaluating sea water quality in the coastal zone of North

Lebanon using Telemac-2D. Lebanese Science Journal, 10 (1), 35-43.

Babiker, I. S., Mohamed, M. A., & Hiyama, T. (2007). Assessing groundwater quality using

GIS. Water Resources Management, 21, 699–715.

Chang S.W., Clement T.P., Simpson M.J., and Lee K.K. (2011). Does sea-level rise have an

impact on saltwater intrusion? Advances in Water Resources, 34, 1283-1291.

El Moujabber, M., Bou Samra, B., Darwish, T., & Atallah, T. (2006). Comparison of different

indicators for groundwater contamination by seawater intrusion on the Lebanese coast.

Water Resources Management, 20, 161–180.

Gogu, R. C., & Dassargues, A. (2000). Current trends and future challenges in groundwater

vulnerability assessment using overlay and index methods. Environmental Geology,

39(6), 549-559.

Hanshaw, B. B., & Back, W. (1979). Major geochemical processes in the evolution of

carbonate-aquifer systems. Journal of Hydrology, 43, 287-312.

Howard, K. W. (2002). Urban Groundwater Issues—An Introduction. In K. W. Howard, & R. G.

Israfilov (Eds.), Current Problems of Hydrogeology in Urban Areas, Urban Agglomerates

and Industrial Centres (8, 1-15). Netherlands: Springer.

Kacaroglu, F. (1999). Review of groundwater pollution and protection in karst areas. Water,

Air, and Soil Pollution, 113, 337-356.

Khan, H. H., Khan, A., Ahmed, S., & Perrin, J. (2011). GIS-based impact assessment of land-

use changes on groundwater quality: study from a rapidly urbanizing region of South

India. Environmental Earth Sciences, 63, 1289–1302.

Konikow, L. F., & Kendy, E. (2005). Groundwater depletion: A global problem. Hydrogeology

Journal, 13, 317–320.

Kouli, M., Lydakis-Simantiris, N., & Soupios, P. (2008, 4th Quarter). GIS-based aquifer

modeling and planning using integrated geoenvironmental and chemical approaches.







Groundwater: Modeling, Management, and Contamination. (L. F. König, & J. L. Weiss,

Eds.) USA: Nova Publishers.

Machiwal, D., Jha, M. K., & Mal, B. C. (2011). GIS-based assessment and characterization of

groundwater quality in a hard-rock hilly terrain of Western India. Environmental Monitoring

and Assessment, 174, 645–663.

Metni, M., El-Fadel, M., Sadek, S., Kayal, R., & Lichaa El Khoury, D. (2004, December).

Groundwater resources in Lebanon: A vulnerability assessment. International Journal of

Water Resources Development, 20(4), 475-491.

Oude Essink, G. H. (2001). Improving fresh groundwater supply - problems and solutions.

Ocean & Coastal Management, 44, 429–449.

Ozler, H. M. (2003). Hydrochemistry and salt-water intrusion in the Van aquifer, east Turkey.

Environmental Geology, 43, 759-775.

Park, S.-C., Yun, S.-T., Chae, G.-T., Yoo, I.-S., Shin, K.-S., Heo, C.-H., & Lee, S.-K. (2005).

Regional hydrochemical study on salinization of coastal aquifers, western coastal area of

South Korea. Journal of Hydrology, 313, 182–194.

Paul, M., Wolf, L., Fund, K., Held, I., Winter, J., Eiswirth, M. & Hötzl, H. (2004).

Microbiological condition of urban groundwater in the vicinity of leaky sewer systems.

Acta hydrochimica et hydrobiologica, 32(4-5), 351−360.

Perry, E., Velazquez-Oliman, G., & Marin, L. (2002). The Hydrogeochemistry of the Karst

Aquifer System of the Northern Yucatan Peninsula, Mexico. International Geology

Review, 44(3), 191-221.

Petalas, C. P., & Diamantis, I. B. (1999). Origin and distribution of saline groundwaters in the

upper Miocene aquifer system, coastal Rhodope area, northeastern Greece.

Hydrogeology Journal, 7, 305-316.

Piper, A. M. (1944). A graphic procedure in the geochemical interpretation of water-analyses.

American Geophysical Union Transactions, 25, 914-923.

Pulido-Leboeuf, P., Pulido-Bosch, A., Calvache, M. L., Vallejos, Á., & Andreu, J. M. (2003).

Strontium, SO42−

/Cl− and Mg

2+/Ca

2+ ratios as tracers for the evolution of seawater into

coastal aquifers: the example of Castell de Ferro aquifer (SE Spain). C. R. Geoscience,

335, 1039–1048.

Richter, B. C., & Kreitler, C. W. (1993). Geochemical Techniques for Indentifying Sources of

Ground-Water Salinization. Boca Raton: CRC Press, Inc.

Singhal, B. B., & Gupta, R. P. (2010). Groundwater Quality. In Applied Hydrogeology of

Fractured Rocks (Second Edition ed.). the Netherlands: Springer.

Vengosh, A., & Rosenthal, E. (1994). Saline groundwater in Israel: its bearing on the water

crisis in the country. Journal of Hydrology, 156, 389 430.







WHO (World Health Organization). (2011). Guidelines for drinking-water quality - 4th ed.

Geneva, Switzerland: World Health Organization.

Zhang, S., Howard, K., Otto, C., Ritchie, V., Sililo, O. T., & Appleyard, S. (2004). Sources,

types, chacteristics, and investigation of groundwater pollutants. In D. N. Lerner (Ed.),

Urban Groundwater Pollution (pp. 53-107). London and New York: Taylor & Francis.

Acknowledgements:

This study is part of a program on climate change and saltwater intrusion along the Eastern

Mediterranean funded by the International Development Research Center (IDRC) of Canada

at the American University of Beirut. Special thanks are extended to Mr. Mark Redwood and

Dr. Carrie Mitchel at IDRC for their support in implementing this program.







The author(s):

Mutasem El-Fadel

Professor and Chairperson

Department of Civil & Enviromental Eng.

American University of Beirut

Email: [email protected]

Marlene Tomaszkiewicz

PhD Student




Majdi Abou Najm

Assistant Professor




Bios:

Mutasem El-Fadel got his BE in Civil Engineering from the American University of Beirut,

Lebanon, MS in Environmental Engineering, MS in Water Resources Engineering, and PhD

in Environmental Engineering, all from Stanford University. He is currently Professor and

Chairperson of the Department of Civil and Environmental Engineering, Faculty of

Engineering and Architecture, American University of Beirut, Lebanon where he also holds

the Dar Al-Handsah (Shair & Partners) Chair in Engineering.

Marlene Tomaszkiewicz got her BS in Civil Engineering from Illinois Institute of Technology,

and her MS in Civil Engineering from Louisiana State University. She is currently a PhD

student at the Department of Civil and Environmental Engineering, Faculty of Engineering

and Architecture, American University of Beirut, Lebanon.

Majdi Abou Najm got his BE in Civil Engineering and ME in Environmental and Water

Resources Engineering from the American University of Beirut, and his PhD from Purdue

University. He is currently an Assistant Professor at the Department of Civil and

Environmental Engineering, Faculty of Engineering and Architecture, American University of

Beirut, Lebanon.

mailto:[email protected]

mailto:[email protected]

sustainable coastal aquifer management in urban areas

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