الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Pollution is defined as any change in the physical, chemical, or biological conditions of the environment, which may harmfully affect the quality of human life including effects upon animals and plants. Environmental pollution represents a major problem in both developed and/ or under developed countries.
The study area lies in the eastern margin of Nile Delta. It is delimited by Latitudes 300 18’ N to 300 41’ N and Longitudes 310 22’ E to 310 57’ E. Offecially it is subdivided into 13 markaz. These are Zagazig, Minia Alkamh, Diarb Nigm, Faqus, Belbeis, Abu Hammad, El Hoseiniya, Kafr Sakr, Hihia, Ibrahimia, Abu Kebir, Mashtol El Souk and Awlad Sakr with population about 5.2 millions. It covers a surface area of about 4191 km2.
Generally, at the eastern part of the Nile Delta, the problem of groundwater quality and quantity intensified during the last few years in response to the increased of human activities and industrial projects. The greatest danger of groundwater pollution is from surface sources such as, sewer, polluted drains (collecting sewage water as Bahr El Bakar, El Aslogy and El Qaluby drains), sewage ponds, septic tanks and refuse disposal sites (landfill and open dump sites, as El Ghar drain location) and human sources. Subsurface pollution is the recharge from the deep aquifer (Miocene & Oilgocene) along fault planes (south of the study area), and the interosion of saltwater from the salty lakes and marshes at El Hoseinia region.
The main objectives of this study are to define and assess the groundwater pollution in some selected areas in Sharkia Governorate and to locate the sources of such pollution, based on the available land use data.
To achieves the goals of this study, the geoelectric resistivity survey will carry out and interpret in the form of apparent resistivity maps, true resistivity maps, 2D images and geoelectric cross sections. In addition:
1-Studying of the geomorphology, surface, subsurface geology and the geologic structures of the studied area.
2-Collecting data of drilled welled wells (after RIGWA Groundwater Research Institute, SHAPWASCO and Arab Drilling Company).
3-Collecting of water samples for chemical analysis from the shallow (private) and deep producing wells. The fieldwork includes the measurement of EC (electrical conductivity), pH (alkalinity) and TDS (total dissolved salts).
4-Hydrogeophysical investigations along the main pollution sources using 1-D Schlumberger sounding measurements to delineate the subsurface layer distributions, the main pollution sources and outline the expected aquifer boundaries.
5-Maping the freshwater and saltwater sectors using 1-D Schlumberger sounding measurements sections and 2-D imaging using Wenner configuration integrated with the bore hole data and hydrogeochemical results, which is represented the main invironmental problem and locating and delineating subsurface freshwater aquifer boundaries valied to drinking and domestic uses.
Topographically: The study area ranges in elevation between 3m (above sea level) at the northern, to about 100 m at the south of the area, with a general slope towards the north. It is dissected by a complex irrigation system, which has a direct influence on both the groundwater recharge and movement of the Quaternary, the elevation of the northern part is less than 15m (above sea level) (Zagazig, Diarb Nigm, Kafr Sakr, Awlad Sakr and El Hoseiniya). Elevation of 15 to 30m is found at Mashtul El Souk, Abu Hammad and El Salhiya region, while the elevation range from 30 to 90m at Belbeis and Tenth of Ramadan. At the southern part the topography range between 90 to 150m and rpresentated by local mountain region of south of Tenth of Ramadan.
The rock units exposed in the area can be mainly classified into Tertiary covers about 1% and exposed in southeast Tenth of Ramadan area formed of sand, clays and limestone with variable amounts of gypsum, and Quaternary deposits covers about 99 % of the studied area, particularly to the north and northeast. It represented by Nile silt, wadi deposits, sabkhas deposits, evaporates, stabilized dunes, neonile deposits alluvial fans and sand dunes.
Structural setting: The Meridian system of folding, of NNW-SSE trend, was initiated by the continental drifting and rotation at south western part of Tenth of Ramadan, which is synchronous with the Caledonian orogeny, and occurred during the Precambrian-Early Paleozoic time interval.
The Syrian arc system of folding and dip-slip faulting, of NE-SW trend at eastern of Abu Hammad, El Salhiya and Tenth of Ramadan, was resulted by the continental separation and plate convergence which is synchronous with the Lower part of the Early Alpine orogeny, and occurred during the Middle-Late Mesozoic time interval.
The Mediterranean Sea system of oblique-slip faulting and folding at Abu Kabir and El Salhiya, of E-W trends, was brought about by the plate divergence and sea-floor spreading, which is often synchronous with the Middle Alpine orogeny, and occurred during the Late Tertiary time.
The Quaternary aquifer represents the main source of groundwater in the studied area. It is underlained by the Pliocene plastic clay that acts as an aquiclude, especially in the area of flood plain around Belbeis, Zagazig and Abu Hammad cities. The Tertiary aquifer represented by Miocene aquifer occupies the most southern part.
Quaternary Aquifer (Nile Delta aquifer): A number of distinguishable horizons. Each of these horizons has its own characters such as porosity, hydraulic conductivity, ability for retaining and yielding water, and mode of water occurrence rather than water quality. These horizons are:
a) Nile silt, sandy clay and clayey sand (Holocene),
b) Fine and medium sands with related sediments
c) Coarse sands and gravels.
Tertiary aquifer: Represented by Miocene sediments, which is the main aquifer occupies the most southern part (southwestern Tenth of Ramadan), where the Quaternary not extended due to the presence of number of normal faults. The Miocene aquifer lies under the semi-permeable silty clay layer and groundwater exists under partially confined conditions.
For studying the lateral and vertical lithological variation and structure elements affecting on the different aquifers in the study area, eight hydrogeological cross sections were constructed covering the whole area. They are marked as Lo-Lo’, L1-L1’, L2-L2’, Vo-Vo’, V1-V1’, V2-V2’, V3-V3’ and V4-V4’.
The aquifer is recharged mainly by five main sources:
i-The seepage from the Nile Delta aquifer, which is the most important source.
ii- Seepage from fresh water Ismailia canal, surface irrigation canals and drains and seepage from agricultural water uses and its fertilizers.
iii-Rainfall from desert wadis and from surface run off falling on shed area to the south.
iv- Subsurface recharge from the deep aquifer (Miocene) along fault plains at the southern part of the study area.
v-The seepage from Manzala Lake and Suez Canal.
The direction passing of groundwater flow is from the southwest towards the north, northeast and east with gentle gradient. The seepage is from the canal to the surrounding lands, mainly at the central part, where the canal cutting through a good pervious layer of Pleistocene old deltaic deposits. The saline water from the Miocene aquifer is up warding leakage through the fault planes and was seepage laterally. As a result, the salinity of Quaternary aquifer is increased. Also it increased with the seepage from the Nile Delta aquifer, which is the most important source; surface irrigation canals and drains and seepage from agricultural water uses.
In the area of study, the occurrence of groundwater is highly controlled by the surface water. It is bounded by fresh water Demietta Nile branch and dissected by a number of fresh water irrigation canals and bounded to the east by salt water. Also, it is dissected by brackish water drains, in addition to Manzala Lake in the northern part. The relationship between groundwater and surface water is strongly influenced by the following factors:
i- Canal or lake depth.
ii- Height of the water table relative to the surface and surface water levels.
iii-Type of sediments forming the bottom and banks of surface water courses.
iv- Rate of horizontal and vertical hydraulic boundary conditions of the groundwater system.
v- Hydraulic conductivity of the aquifer.
Many ecological changes that occur in water result from human activities includes agricultural, industrial and municipal wastes), the liquid wastes and sewage are sometimes discharged into the river Nile canals and other water resources
There are many sources of water pollution from the human activities and natural resources. Generally, pollution expected from the following four sources;
i-The seepage from the saltwater Manzala Lake and Suez Canal.
ii-Seepage from surface polluted irrigation canals, seepage from agricultural water using fertilizers, refuses disposal sites, sewer, polluted drains, sewage ponds, septic tanks (landfill and open dumpsites) and human sources.
iii-Rainfall on the area of study from salt rock wadis and from surface run off falling on shed area to the south.
iv-Subsurface recharge from the salt deep aquifer (Miocene) along fault planes (south of the study area).
The direction passing with of groundwater salinity increasing is from the south (Belbeis BB-5) towards the north (Diarb Nigm DB-30) with gentle gradient. The water salinity with depth reflect that the seepage is from the lower salt aquifer through a good pervious layer of Pleistocene old deltaic deposits.
Groundwater hydrochemistry of the area of study is based on the chemical analyses of water samples collected from 57 bore holes distributed at the study area.The chemical analysis includes the measurement of pH (alkalinity), TDS (total dissolved salts), EC (electrical conductivity), total major cations (Na+, Mg++ and Ca++) and total major anions (Cl-, HCO3- and SO4--).
The pH values ranges between 6.5 (At well Belbeis) and 11.7 (El Rest). Its distribution map shows that, the alkalinity increases toward northern and eastern parts (Rest and Bahr El Bakar) reflecting shallow saline groundwater (lagoonal deposits) and decreases from the direction passing with north towards the southwest with gradient. The water PH lines around Ismailia Canal and Bahr El Bakar drain are irregular and concave in shape which reflect that the seepage is from the canal to the surrounding lands through a good pervious layer of Pleistocene old deltaic deposits the central region of Zagazig, Belbeis and El Abbasa, where the groundwater is more deep and fresh water.
The TDS contour map illustrates that low salinity samples occupied the central and western parts, while the high salinity are concentrated in the northern and the eastern parts. Total dissolved solids (TDS) ranges between 220 ppm (At El Abbasa and Abu Hammad with freshwater old deltaic deposits) and 18356 ppm (At sample 57 El Rest with lagoonal deposits). The salinity shows gradually increase with depth and reaching about 1700 ppm at depth 125. The used evaluation methods show that the water is generally suitable for drinking, irrigation and industrial usage whereas some samples have concentrations more than the permission by oxidation (weathering) precipitation and infiltration before usage.
The maximum EC. (9.1 mmhos / cm) is attained in sample No.57 (El Rest), while the minimum is obtained in sample No. 30 (At El Abbasa. 0.45 mmhos /cm). These values reflect the relation between the EC. and TDS, where as the electric conductivity of water increase.
The constituents of major cations (Ca++, Mg++ and Na) and major anions (Cl- and HCO3-) beside the TDS and some other parameters goven the chemical properties of groundwater.
The distribution of calcium allover the area shows two relatively high concentration areas. The first is located to the southeastern part (76.8 ppm) at south Tenth of Ramadn and the other is located to the northern part at El Rest (5212 ppm) reflecting shallow saline groundwater (lagoonal deposits). The other parts show relatively low values at El Hawaber (28 ppm) and Tenth of Ramadan (20 ppm) with freshwater old deltaic deposits. It decreases from the direction passing from north towards the southwest with gradient.
The common source of magnesium is dolomite and sea water. The concentration of Mg++ ion in the studied area varies from 4.8 to 766 ppm.
Sodium concentration ranges between 20 and 1189 ppm. The lower value is recorded at sample No. 44 beside Ismailia canal, while the highest value is recorded at sample No. 57 in the eastern part (El Rest).
Chloride concentration varies between 50 ppm (well No. AH-1) and 5212 (well No. S-A-102). The inspection of the contour pattern of chloride ions distribution (Fig. 28) is highly conformable with the distribution of sodium ions and the total dissolved salts all over the area, i.e. Cl- increases proportionally with Na+ and TDS.
Sulphate ion varies between 21.1 ppm (well No. AH-1) and 560 ppm (well No. S-A 102). The distribution of this anion (Fig. 29) is nearly conformable with the TDS and Na+.
The concentration of carbonate anions is, however, controlled by the pH value of the water. It is well known that the carbonate are mainly derived from calcium carbonate rocks and also the biochemical activities in soils release a considerable amount of CO2 at a partial pressure of about 0.01 atmospheres which adds more bicarbonate anions to the groundwater. The distribution map of CO3-- plus HCO3- reveals that, they are varying from 36 (at sample No. 46) to 4196 ppm (at sample No. 56). The higher concentrations are detected along eastern northern and most southern part, where the saltwater introsion, limestones, marches and fertilizers are common.
The observations of different major constituents of the groundwater are conformable with the geologic and hydrogeologic situations of the central southern part of east Nile Delta. It is noticed that increase of salinity to the northeastern part may be attributed to the fluviomarine and evaporate sediments occupying this part. The brackish water at the southeastern part may be attributed to the upward leakage from the deep salinity water of the fluviomarine deposits of Miocene age and/or due to the dominance of fertilizers. Along the eastern side (or boundary of the studied area) the increase of salinity may be due to the diffusion of saline water from the greater Manzala lake and Suez canal. Besides, the low salinity at the central (around Ismailia canal) and western (Minya Al-Qamh and around Zagazig cities) parts may be attributed to the seepage of fresh water from Ismailia canal, Demietta branch and Nile Delta aquifer.
According to Chebotarev (1955) and Todd (1980) classifications, it is found that 77.2 % of the total samples are fresh water and the remaining 22.8 % belong to the brackish water.
The classification of the Quaternary groundwater aquifer in the studied area show that the total dissolved solids for the analyzed water samples vary from > 500 ppm and 24.6% of the total number of the groundwater samples belong to good potable water but fresh water from 8500->700 ppm is 28.1%, fairly fresh 700->1500 ppm 26.3%, slightly brackish 1500->2500 ppm 8.8%, brackish 2500->3200 0%, definitely brackish 3200->4000 is 5.3% and saltwater more than 4000 is 8.8% of the total samples. Consequently, groundwater samples can be classified depending on its suitability for livestock and poultry as follows:
(1)Excellent water for all classes of livestock and poultry (TDS > 1000 mg/l). where fourty water points lie in this class is about 70.2 %.
(2)Very satisfactory for all classes of livestock and poultry (TDS ≈ 1000 to 2999 mg/l). where nine water samples is about 15.79 %.
(3)Satisfactory for all classes of livestock but, poor for poultry (TDS ≈3000 to 4999 mg/l): where only five smples is about 8.77 %.
(4)Satisfactory for all classes of livestock but, poor for poultry (more than 5000 mg/l): includes only three smples is of about 5.26 %.
Good quality water may be expected at the depth more than 36 m (south and medium parts of governorate). Polluted water may be expected at the depth less than 16 m (south and medium parts of Governorate) high salinity hazards occur to the east ( El Hoseiniea ) and north ( Kafr Sakr and Awlad Sakr), in the study area. Also, at middle and south, most of water samples are acceptable to permissible for drinking and domestic uses, except three wells (5, 12 and 18) located to the northeastern and southeastern parts, where their TDS exceed the permissible limits (<1500 ppm).
Different electrical resistivity surveys were applied. These include 1-D Schlumberger resistivity sounding and 2-D resistivity imaging surveys. The resistivity measurements were carried out using SAS 300C system manufactured by ABEM Co., The measuring current is selected manually with a maximum of 20 mA without booster, and the instrument adjusts the output voltage to reach the selected current.
A total number of 97 points of 1-D resistivity sounding were excuted all over the area. The measurements were carried out along some selected drains, canals and other pollution sources at some selected sites. These sounding were carried out to reflect a regional picture about the subsurface geologic succession and to have an idea about the water bearing Formations in the area. The locations of the measured points was marked using GPs positioning. The electrical sounding were carried out using Schlumberger configurations with maximum current electrode (AB) spacing of 400 m to 800m to explore shallow subsurface conditions using SAS-300C resistivitymeter during sounding measurements.
Interpretation of the sounding measurements was performed using qualitative and quantitative techneques. The qualitative interpretation carried out by merely looking at the shapes of the field curves and the ranges of the apparent resistivity values. The shape and type of the field curves may represent the specific geologic or hydrogeological conditions. The sounding curves were interpreted quantitatively to obtain the true resistivities and thicknesses of the subsurface layers using two different techniques. The automatic interpretation technique of zohdy (1989) was used as a first step, where a multi-layer model is automatically obtained from multi-layer model from zohdy technique was used as preliminary 1-D forward modelling and treats the data for IPI2WIN program. It based on linear filtering as 1-D forward modeling and treats the data for a profile as a unity representing the geological structure of the survey area as a whole, rather than a set of the independent objects dealt separately.
The most severe limitation of the resistivity sounding method is the ambiguity of interpretation due to the principle of equivalence, which means that many different layered models may produce practically the same resistivity curve.
To draw a regional picture about the subsurface layer distributions, the interpretation results of the 1-D soundings were correlated with the available surface and subsurface geological information obtained from the drilled boreholes and previous investigations. The interpreted layer parameters in the form of true resistivities and thickness of the subsurface layer are used to construct 35 geoelectric cross-sections displaying the distribution of the subsurface layers. In addition, resistivity and thickness maps are constructed for the deduced layers.
from the constructed cross-sections and maps of the deduced subsurface geoelectric layers, it can be concluded that the investigated area contains three sectors layers.
Resistivity spectrum and lithology of the obtained layers in sector 1:
Belqas Formation of Holocene deposits is the Surface layer (Agricultural layer) with resistivity range 2.01- 28 Ώm, thickness range 0.2-1.5 m and clayey facies with resistivity range 1.69- 9.82 Ώm, thickness range 0.9–38m.
Mit Ghamr Formation of Pleistocene deposits is the Clayey to Sandy facies (Cape rock) with resistivity range 5.09-72.8 Ώm, thickness range 1.33-57m and Sand with gravel with resistivity range 31.4- 383 Ώm.
Resistivity spectrum and lithology of the obtained layers in sector 2:
Belqas Formation of Holocene deposits is the dry surface layer with resistivity range 59.5-383 Ώm, clayey facies with resistivity range 2.1- 124 Ώm, flood plain mud resistivity range 1.22- 59.9 Ώm, Lagoonal mud resistivity range 0.35-35 Ώm and peat resistivity range 0.623-2 Ώm.
Mit Ghamr Formation of Pleistocene deposits is the Sand associated with mud layer has resistivity range 0.892-62.1 Ώm, marine transgressive sand resistivity range 1.1-10.2 Ώm and fluvial sand resistivity range 1.3-18.3 Ώm.
Resistivity spectrum and lithology of the obtained layers in sector 3: Holocene deposits is Surface layer with resistivity range 99-122Ώm, thickness range 0.9 – 4.4m and Clayey facies with resistivity range 6 - 8Ώm.
Mit Ghamr Formation of Pleistocene deposits is the Clayey to Sandy facies with resistivity range 83.7 – 127Ώm, thickness range 58 - 140m and Sand with gravel with resistivity range 8.88 – 49.33Ώm.
2-D Resistivity Survey: The measured resistivity pseudosections are 4 profiles at 4 sites. It were inverted using RES2INV inversion software, version 3.4. The inversion procedures used by this program are based on the smoothness-constrained least-squares inversion algorithm. To construct an image of the obtained true subsurface resistivity distribution and map the water type in four selected sites. 2-D resistivity imaging survey was executed using Wenner configurations to confirm both lateral and vertical variation.
Sector1 centeral and southwest fresh water aquifer: The aquifer represented by Mit Ghamr Formation . The deduced layer parameters were used to construct 28 geoelectric cross- sections at different locations and direction passing withs. It is the greatest sector of the freshwater aquifer and, more or less, govern the amount of flow-outflow, as well as water quality. It coveres middle and western parts of the investigated area (markaz Zagazig, Minia Alkamh, Diarb Nigm, Faqus, Belbeis, Abu Hammad, estern of markaz Kafr Sakr, Hihia, Ibrahimia, Abu Kebir, middle and north of Tenth of Ramadan and Mashtol El Souk). The aquifer is recharged mainly by three sources:
i-The seepage from the Nile Delta aquifer. Which is the most important source.
ii-Seepage from fresh water Ismailia canal, surface irrigation canals and drains and seepage from agricultural water uses and its fertilizers.
iii-Rainfall on the area of study from desert wadis and from surface run off falling on shed area to the south.
It dissected by a number of water irrigation canals as Ismailia, Bahr Faqus, El Saidiya, El Salhiya, Kafr Sakr, and Mweiss. Also, it is dissected by drains of brackish water such as Bahr El Baqar, Bahr Saft, Ibrahimia, and El wadi drain. Depth to water level range from 1.8 m. (Fa-4 elevation 6 m) to 5.59m (8 elevation 12m).
Polluted water may be expected from sources such as surface irrigation canals, seepage from agricultural water uses and its fertilizers, sewer, polluted drains, sewage ponds, septic tanks and refuses disposal sites (landfill and open dumpsites) and human sources.
The correlation between 1-D models 79 V. E. Ses and 22 boreholes shows resistivity spectrum of the subsurface litho- hydrogeological units in the middle and western of the studied area characterized by fresh water aquiufer area.
Sector2 North and eastern (shallow saltwater aquifer1): The aquifer of sector 2 represented by Belqas and Mit Ghamr Formation. This group generly represents high salinity hazards occur to the east of markaz El Hoseiniya and surrounding (north Kafr Sakr and Awlad Sakr). It refers to the enclosed groundwater salinity,
Fifteen sounding were excuted all over the sector. The interpreted layer parameters in the form resistivity spectrum and lithology of the obtained layers is listed in table (13). Depth to water level range is 0.7m El Rest to 4.92m at ves 39.
The quantitative interpretation based on the results of 15 soundings, 7 boreholes information and five geoelectrical cross-sections, covering the selected area was constructed. It can be seen how much the ionic content of the enclosed saltwater of groundwater.
Lagoonal facies characturized all V.E.Ses indicating lagoonal mud, peat Flood plain mud and sand associated with lagoonal mud.
Sector3 Souththern (shallow saltwater aquifer2): The groundwater aquifer is located at south of Tenth of Ramadan (south of the study area). It represented by Quaternary and Tertiary aquifers which a hydraulic interconnection between the Quaternary and Miocene aquifers. Depth to water level is 76 m (E-5 elevation 86m).
The geoelectric resistivity using vertical sounding carried out to explore shallow subsurface conditions and zone of pollution. Three vertical electrical sounding (V.E.S.’es) using Schlumberger configurations with maximum current electrode (AB) spacing of 400m to 800m has been carried out and one cross-section. The study represents the sector characurized by the salt groundwater. The aquifer is recharged mainly by three sources:
1-The recharge from the subsurface recharge from the deep aquifer (Miocene saltwater & Oilgocene) along fault planes.
2-Seepage from fresh water Ismailia canal, surface irrigation canals and drains and seepage from agricultural water uses and its fertilizers.
3-Rainfall on the area of study from desert wadis and surface run off falling on shed area to the south.
Polluted water may be expected from the subsurface recharge from the deep aquifer (Miocene saltwater & Oilgocene) along fault plains aquifer, surface irrigation canals and drains and seepage from agricultural water uses and its fertilizers.
Contour maps: True resistivity maps are prepared by contouring the values of interpreted true resistivities for different geoelectrical layers, in order to study the lateral and vertical variations of the resistivities with depth. from the tabulated resistivity values, six geoelectrical layers are mapped. Consideration of these maps shows that: Depth 1m. is represented by high resistivity values at layer 1 of dry sand and presence of drains or sabkha , which is shifted toward the west. This anomaly is decreased at depth 3m and 5m as the effect of seapage water and firtilizers. This anomaly is graded to medium values at 10m of saturated gravelly sands. The developed low resistivity anomaly may be due to decreasing in the percent of gravels in this local part of buried chanels. Groundwater resistivity characterized depth 36m and 46m which low grade variation in values. The anomaly graded to medium values towards north and east is will agreement with TDS contour map.
Groundwater resistivity of cape rock characterized by low grade variation in values. The anomaly graded to medium values towards north and east.
2-D imaging: Four 2-D inverted sections were obtained along the selected locations using Wenner array.
Site 1, located eastern side of El Qaliuby drain at Teheimer village sector 1. Along the profile, a well defined low resistivity zone 0.865 to1.91 ohm.m can be noticed at depth of 6.38 m and corresponds to the fresh and brackish water as indicated by the drilled bore hole. The lower aquifer boundary defined by a layer contining less saline water, the depth to fresh water and saline water boundary is increased in the western part (drain direction passing with) to reach maximum of 12.4 m at spacing of 28 m to reflect more thickness of polluted water at that place. It should be noticed that the dry zone near drain of increasing resistivity is in agreement with 1-D sounding 16.
The results of the study indicates that; very high conductive anomalies in the top 4-12 m of the subsurface. Improper land waste disposal within the drains has negative impacts on the quality of the groundwater at the studied area. The study suggests that landfill sites should have secured lines so that the groundwater resources left in a potable condition, recommendations is the principal for prospecting.
Recommendations; The save fresh water is locating at depth more than 36m, far from pollution sources lateraly at least 38m and locating at sector 1 Fig. (53). Fresh water is increased toword the western part of the studied area.