A. Kassem
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I N T R O D U C T I O N
Hydrological and geological studies on the area began in 1924 when a French geological team headed by Deubertret (1933a,b) drew geological maps of Syria and Lebanon at the scale 1/1,000,000. Report of the German mission pay Boeckh E. (1966) and Wolfart R. (1967) identified the essential specification of the general aquifers in western Syria. The most frequent reported sources of pollution of karstic aquifers are urban centers and agriculture. Urban areas cause contamination by sewage systems and when wastes are disposed on surface of the ground or are dis-charged to watercourses, karstic depressions of swallow holes. The studied area is Mediterranean, rainy of average annual precipitation about 1000 mm/year which varies from 800 mm in coastal region to 1,600 mm on mountain peaks in the east. According to their importance and order from oldest to recent(Figure 1) Selkhozprom Export (1979) and Burdon (1961):
• Aquifers of appear cretaceous (Cenomanien-campanien) – Jurassic which join, in general, cracks and fissures consisting of cracked dolomite limestone rocks of large of more than 40 km. in the coastal range as in the range of Lebanon and Anti-Lebanon which form the most important sources of water recharge for cretaceous springs in Syria and Lebanon (Al-Sien, Abou-Koubiss, Al-Fijeh, Jaetah, Al-Tannour):their water is fresh to little salty;
• appear cretaceous limestone marl dolomite basins which feed sources of high salinity;
• Basalt aquifers, age of Cenomanian-Pliocene (Wadi-Al-Aions, Al-Kafroun) south of Tartous and coastal strip has good water, little salty and limited drainage;
• Aquifers of age Paleogene – Neogene and quaternary aquifer of conglomerate, limestone and sand rocks (Fig-ure 1). Karstic groundwater is the most important drinking water resource in Syria and in many other countries of the world.
M E T H O D O L O G Y
Water samples included most important water sources relevant to these formations /springs, wells/ with surface water samples from major permanent and seasonal rivers running in the area.
The physical and chemical characteristics of water were measured. Measurements took place in field /PH, C.E,T/
and in lab./ NH4+, Na+, K+, Ca++, Mg++, Fe+++, Cu++, Li+, Cr6+;F–, Cl–, SO4– –, CO3– –, HCO3–, NO3–, NO2–, PO4– – –/.
For 66 water samples (Figure 2) (54 ground water and 12 surface water) were collected. Analysis was performed at laboratories of Ministry of Housing using the spectrophotometer and another international analysis method.
R E S U LT S A N D D I S C U S S I O N
This study included:
y y
Figure 1. Hydrogeological cross-section along the Syrian coastal range (Deubertret, 1933)
Temperature
The topographic situation and geotectonic condition of the aquifers play a high role in temperature value. The temperature of surface water sample changed frame 8 (at 1,040 m) to 20 in the Jouber polluted river (industrial rejects). But in the groundwater we can notice the effect of the lithology of aquifer and aquiclude with the tec-tonic situation of aquifers or (Kassem,1990; Bilal and Kassem, 1998) with 12.6, 13.2 in the water of Cretaceous basaltic aquifer to 21.1 and 22 C in the water of some wells at north and south of Tartous town, effected by the intrusion of seawater (Table 1).
PH
The degree of PH is changed between 7 and 8 for many water samples, but it is more than in the polluted, hydrothermal and mixing water.
Electrical Conductivity (µs/cm)
It determines the nature of storing surrounding and nature of surface laid or trespassed; they vary from 1,015 µs/cm in the El Marquieh polluted river to more than 59,200 µs/cm in seawater and great than 4,120 µs/cm in some water wells effected by sea water intrusion (Table 1).
Cations ( NH4+, Na+, K+, Ca++, Mg++, Fe+++, Cu++, Li+, Cr6+)
Concentrations such as cations: NH4+, K+, Fe+++, Cu++, Li+and Cr6+(Table 1) increase in the surface and ground water by the effect of swage sludge, industrial and agriculture activities. While the concentration of other cations depend on the natural aquifer rocks as well as the surface water infiltration and sea water intrusion. (Table 1).
Anions ( F–, Cl–, SO4– –, CO3– –, HCO3–, NO3–, NO2–, PO4– – –)
Anions concentration such as: F–, NO3–, NO2–, PO4– – – (Table 1) increase in some surface and ground water samples by the effect of the housing swage, industrial and agriculture activities (fertilizer, factories air pollution etc.). The most frequent reported sources of pollution of karstic aquifers are urban centers and agriculture. Urban areas cause contamination, particularly when they lack adequate sewage systems and when wastes are disposed on surface of the ground or are discharged to watercourses, karstic depressions of swallow holes.
While the concentration of Cl–, SO4– – and HCO3– (Table 1) depend on the kind of surface soil and aquifer litholo-gy. The groundwater of karstic and no polluted aquifers have a little concentration in Cl–and SO4– – with a high quantity of HCO3–witch is due to the time of the water reserved in the aquifer. We can see the same situation for Chloride, Sodium and potassium concentration. In the surface water the content of these ions change by the housing rejects pollution that exist in chalky marl aquifer and mixing with sea water in some locations.
Spring water is the most likely water source to be developed for this region (El-Sien spring 12 m3/s). The problem is continuity of discharge and potential pollution. To use the permanent Dams water as the domestic water supply, or to management of aquifer recharge (MAR),water treatment is needed. In this area there are more chance for storm water to infiltrate and recharge into the groundwater body at the zones A and B (Fig. 2).
Managements of bank filtration schemes should be incorporated in order to limit potentially polluting activities in the groundwater recharge area and also to balance rivers and dams infiltration losses with ecological needs of the water in this area. 6 and 13 chemical types were identified successfully in surface and groundwater, it shows the change in surface and groundwater quality watch resulting from contamination or mixing with polluted surface water or by the seawater intrusion. The evaluation of the hydrochemistry data, presented by the diagram of Piper, show an increase in the quantity of some ions (Na+, Mg++, Cl–, SO4– –, NO3–,..), in the groundwater relating from the intrusion of seawater or by the existence of the marl and gray sandstones formations which are rich in these ele-ments, or by the infiltrations of the urban and industrial sewages (Fig. 2).
T O P I C 2 Geochemistr y dur ing inf iltration and flow 293
( )
Table 1. Chemical and physical characteristics of the surface and groundwater at the Coastal Basin
Note: 1,2,…54 = Groundwater and 1*,2*,…12* = Surface and sea water.
T O P I C 2 Geochemistr y dur ing inf iltration and flow 295
Figure 2. Samples water sites (with chemical types and water quality) of the study’s area
i ( ) l i ( i h h i l d li ) f h d
C O N C L U S I O N A N D R E C O M M E N DAT I O N S
There are an assay to use of Management of Aquifer recharge (MAR) by injected the surface or ground water in the wells. But in these area we have a project to store the water of the El-Sien spring in the El-sekabeh Dam at 1 km NE of Banias city (Figs. 1, 2).The water of this dam with anthers dam and wills, will be transfered after treatment for drinking suply to Damascus city.
This study gave us a good idea about the quantity and the quality of surface and ground water that will be utilizing in several water use or in future artificial recharge in some dams or well at basaltic or unconfined karstic rocks at the southern of Tartous city (Figure 2).
In coastal studied area there are about 900 Mm3 /year, from ground water, discharge in sea, and there are about the same quantity of surface water loss in the Mediterranean sea. For that reasons this water need good management projects to use it in natural or artificial recharge in these region or at the arid and semi-arid area of the Orontes basin at East of the studied area (Figure 2).
As a result of this work several recommendations are advised:
• Developing sustainable system for enhancing and protecting groundwater resources.
• Range of methods including bank filtration, aquifer storage and recovery and soil aquifer treatment.
• Using the aquifer to improve the quality and security of drinking water and agricultural water supplies.
• Reducing the toxic load of each contaminant by adsorption and biodegradation as water passé through the soil.
• After considering the environmental damages caused by natural and anthropogenic pollutants, it is necessary to find out whether artificial recharge will be profitable to attenuate these natural processes and artificial pollutants.
• Treatment of the municipal and housing sewages before it’s mixing with the surface water.
• Decreasing the utilization of fertilizers or pesticides quantity in the agricultural activity.
• Determination of the pollution causes, chemical types and quality of surface and groundwater for the different aquifers, dams and rivers in these region and the anthers of Syria.
AC K N O W LE D G E M E N T S
The author is thankful to Prof. I. Othman general director of AECS for his encouragement and his support.
R E F E R E N C E S
Abdulrahmen Kassem A. (1990). La géochimie « Qualité » de l`eau et en particulier sa pollution fluorée et sulfaté dans une région aride et semi-aride (Palmyre-Homs-Hama)en Syrie, Thèse Sci.Université de Nancy I, 244 pp.
Bilal A.; Kassem A. (1998). Conditions hydrogéologiques de l’acquisition du chimisme des eaux souterraines de l’Al-Badia (Syrie), Hydrogéologie,N° 3, pp. 27–34.
Boeckh E.; Bender H.; Wagener W. & Hanerstein G. (1966). German geological Survey of the Republic of Germany:
German Geological Mission in Syria, April 1966 – June 1967. Report I. Hydrogeological Results, II. Documen-tation,1970 (unpublished); Texts 1. Géologie et hydrogéologie,Enquêtes relatives à l’exploitation des eaux souter-raines en Syrie Occidentale, 1963 (unpublished), Ministry of habitation, Damascus-Syria.
Burdon D.J. (1961). Groundwater devlopment an conservation in Syria / F.A.O.Report, 80 pp., Rome.
Dubertret L. (1933a). La carte géologique au millionième de la Syrie et du Liban, Revue de géographie physique et de géologie dynamique, Bull. Jub. Géog. phys. Fac. Sci. Paris Vol. VI, Facs. 4. pp. 269–318.
Dubertret L. (1933b). L’ hydrologie et aperçu sur l ’ hydrographie de la Syrie et du Liban dans leur relations avec la géologie dynamique., Loc.cit., pp. 347–452.
Abstract
The aim of the study was to calculate mixing proportions of treated wastewater in the surface water and production wells during bank filtration as well as the travel times to observation and abstraction wells. For this purpose, a variety of tracers such as the stable isotopes deuterium (D) and 18O and several wastewater indicators like chloride, EDTA (ethylenediaminetetraacetic acid), boron and the rare earth element (REE) gadolinium (Gd) are used and compared to each other. Time series measurements in the surface water could be traced back in bank filtrates and raw water. Gd-DTPA was found to be a useful sewage indicator, even though it is biodegradable at favourable conditions at very slow rates. The travel times of the bank filtrates were obtained by the analysis of the peak shift in time-series of the tracer. Most tracers were found to be applicable but best results were obtained with the stable isotopes.
Keywords
Bank filtration, wastewater, tracer, stable isotopes, gadolinium.
I N T R O D U C T I O N
The drinking water production in the Berlin metropolitan is carried out by bank filtration and artificial groundwater recharge. The production well galleries are located near the main rivers and, induced by the pumping of the wells, the surface water infiltrates into the ground. The raw water in the production wells then consist of a mixture of natural groundwater from the landside and bank filtrate of around 70% (Pekdeger and Sommer-von Jarmerstedt, 1998).
The Berlin drinking water production can be characterized as a semi-closed cycle. Drinking water is produced in 9 waterworks (Fig. 1) of the Berlin Water Company (e. g. 215 Mio m³ in 2003). After use, the wastewater is distri-buted to the 6 Berlin wastewater treatment plants (WWTPs) and after treatment it is released into the surface waters. Despite of the biological treatment stages several substances are not eliminated completely and the waste-water discharge increases the concentrations of boron and EDTA (detergents), chloride and dissolved organic com-pounds in the receiving surface water. These wastewater indicators can then be used to calculate the proportions of wastewater in the surface water and in the drinking water that is produced by bank filtration as well as the travel time of the surface water to the production wells.
Within a well gallery the proportions of bank filtrate considerably differ because of (a) the heterogenic aquifer con-ditions in this region and (b) the number and location (depth) of the well screen. Depending on the degradation and sorption capacity of the aquifer material, the wastewater indicators reach the production wells by bank fil-tration and artificial groundwater recharge, generally in reduced concenfil-trations. The dilution with natural ground-water further decreases the concentrations of these indicators. In some cases the wells are screened in depths were the intrusion of salt water of geogenic origin occurs. Hence, the Cl–and B concentrations in the natural ground-water can exceed the concentrations of the surface ground-water and can therefore locally not be used to determine the proportion of bank filtrate. Temporal and spatial variations of the surface water quality additionally complicate