الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Currently SiwaDistrict could be considered one of the most important development areas in Egypt. It is growing rapidly due to high rate of development in agriculture and tourism sectors. A large number of farmers and worker recently immigrate to SiwaDistrict to invest in agriculture sector or to work in tourism sector. Consequently, the population of SiwaDistrict is rapidly increased. The recent estimation of SiwaDistrict population by Siwa Local Counsel is 32186 residences, 20550 from them live in Siwa town and the rest live in the villages. It is expected to be duplicated so soon.
According to the Ministry of Local Development Siwa District consists of Siwa town and 5 main local village units (Maraki, Bahy Eldeen, Aghormy, Abo Shrouf and Qara or Umm Alsagher). with 8 small subvillages villages (Ain Zahra, Qureshet, Badawia1, Badawia2, Haj Ali, Merkeda, Gari, Zaydan,). Siwa town consists of 8 residential settlements (Zegawa, Melol, Badawia, Shabab, Wasat Al-Madena, Ibny Betak, Bo Selman, and Lehrek) and 3 subvillages (Dakrour, wafla, Abu Bakr).
It is clear that Siwa Oasis located in a depression and it depends mainly on ground water. Due to uncontrolled human activities, so assessment for drinking water quality became a must. Most of water quality studies in Siwa District has been carried out for agriculture uses and the current study is considered the first specialized research on quality of drinking water in Siwa District.
Groundwater is the main source of water for drinking and irrigation in SiwaDistrict. The old artisan wells originated from the top (shallow) aquifer are the traditional source of water in SiwaDistrict. The numbers of the old artisan shallow wells are 273. Due to increase in water demand,the number of these artisan wells had been exceeded to 900 wells. Recently, the deep sandstone aquifer has been drilled by 15 deep well with depths ranged from 950 m to 1200 m.
The water supply system consists of several systems due to separate water supply sources and far distances between villages and the town. Every village is provided with separate drinking water supply system(wells) while Siwa town and Aghormy village are supplied with drinking water through three water supply systems connected together through three main pipelines. Although these three systems are connected together, operationally they are separated using control valves to overcome any troubleshooting in the system. This was done according to the strategic planning of national water distribution network and this part of Siwa represents more than 79% of SiwaDistrict population.
SiwaDistrict is formally supplied with drinking water from a total number of 7 deep wells, six of them supplied the distribution system directly and one supplies water treatment plant was aiming to remove iron and manganese water content,thenpumped to the distribution system. Most types of the pipelines of water distribution network in SiwaDistrict are made of PVC followed by PE. However, there are few pipelines made from AC in Siwa town and Aghormy. The distribution systems are tree system with dead ends.
So the aim of this study wasto assess the drinking water quality in Siwa District. through identifying the number and type of wells used as a source of drinking water in Siwa District, describing the drinking water supply system in Siwa District, assessment the drinking water quality from different sources and assessment the efficiency of Iron and Manganese Removal Unit in Siwa District
The assessment study was done through a one year of data collection and analysis on water supply systems in SiwaDistrict. Drinking water samples were collected (from 25 sites to cover the 7 drinking water supply systems) and analyzed physically, chemically and biologically to assess drinking water quality in SiwaDistrict. One water sample from each site was collected monthly for one year started in Autumn 2017 and ended in Summer 2018. The sampling sites were selected to represent the water quality from the wells, mid and end of water distribution system and statistical analyses were carried out.. The same methodology was done for the iron and manganese removal unit and the removal efficiency of the unit was calculated.
The result of the data collection and sampling analyzed were summarized as follow:-
1-interview was done for at least10% of total population of each selected area using pre-designed interview questionnaire sheet which include water source, water supply periods, water pressure, water quality, reasons of water quality changes and how to deal with these problems, water availability, type of internal pipeline material and water related diseases
2-wells assessmentThe wells were observed from many sides like room, door, pumps, doors, floor, cleanness, roof, sampling tap and fence. The most wells were in good conditions.
3-The water quality (physically, chemically and biologically) at wells were almost complying with the Egyptian drinking water quality standards(2007) in terms of the measured parameters except turbidity(2.15 NTU and1.14 NTU)and iron(0.7 ppm and 0.715 ppm) in Abu Shrouf and Haboun, respectively. Also, iron only exceeded(0.74 ppm) in Old Dakrour well..All of the wells were free from total bacterial count.
The water quality (physically, chemically and biologically) at water distribution system was almost complying with the Egyptian drinking water quality standards in terms of the measured parameters except iron(max 0.79 ppm in Old Dakrour), turbidity(max 11.7 NTU) in Old Dakrour, ammonia(max 0.85 ppm in Qara), total plate count and some in total coliform in all distribution system. With respect to biological analysis the wells and water treatment plant were free fro TPC while in the distribution systems there were some of these distribution systems above the Egyptian standard.
4-with respect to assessment of water treatment plant it was foundthat overall efficiency of the treatment unit for turbidity removal was 45%, iron removal was 89% and manganese removal was 90%. The residual chlorine ranged from 0.2 to 0.59and TPC,TC.FC were not detected
from the mentioned results, it can be conclude that:
• SiwaDistrict has 7 water supply systems due to geographical reasons (long distances between villages and Siwa town).
• The water sources for all water distribution systems in SiwaDistrict are deep overflow artesian wells.
• Considering the Egyptian drinking water standards(2007), the water quality at the wells is almost complying in physical and chemical properties except turbidity and/or high iron and/or high temperature.
• The biological analysis shows that the wells are free completely from any biological hazards according to the Egyptian drinking water quality standards(2007).
• No seasonal variations in drinking water quality were noticed due to confined wells not exposed to seasonal variations.
• No geographical or geological reasons were significant in water quality changes.
• The drinking water treatment unit outlet in Siwa is used only for iron and manganese removal and disinfection.The water quality from it wascompletely complying with Egyptian drinking water standards.
According to assessment of the distribution systems it can be concluded that:-
• Qara village water supply system has a problem of high temperature, ammonia and small bacterial count.
• Old Dakrour distribution system problems were iron, turbidity, high temperature, ammonia and bacterial count.
• Haboun water distribution water supply system problems were iron, turbidity, high temperature, and bacterial count.
• The main problems of a water supply system in Abo Shrouf were iron, turbidity, high temperature, ammonia, and bacterial count
• Maraki distribution system problems were iron, turbidity, high temperature, ammonia and bacterial count.
• Bahy El Deen distribution system problems were iron, turbidity, high temperature, ammonia and bacterial count.
• For the water distribution system of the treatment units, the residual chlorine was less the Egyptian drinking water standards.
• Overall removal percentage of the iron and manganese removal unit was of iron 89%, manganese 90%, and turbidity 45%
sassed on the results of drinking water samples analysis, the following recommendations are suggested:
1- Fixation of sampling taps on water distribution system related to MCWW in several sites for water sampling and installing flow meter and pressure meter for every well to monitor any changes.
2- Chlorination with hypochlorite for safety reasons is recommended for the wells
3- Construction of elevated water tanks at the well sites for disinfection, pressure regulation, temperature reduction and continuous water supply for Bahy Eldeen, Qara, and Maraki.
4- Construction of iron and manganese removal units at Abu Shrouf well for, aeration, sedimentation, filtration, pressure reduction, temperature reduction disinfection and continuous water supply.
5- Avoiding of discontinuity water supply in operation by regulating operation conditions and replace the ACand old pipe line considering pipeline material and diameters.
6- Installing a washing valves and air release valves in the distribution systems and clean it regularly with changing the type of water distribution networks from tree system to circular system.
7- Construction of a sedimentation tank after aeration process and before filtration to reduce the operational load on the filter.
8- Roof construction for coverage both aeration tank and slow sand filter in iron and manganese removal unit. And the sump of clean water has to be closed completely from open air
9- A tank of a storage capacity enough for 45 minutes contact time has to be built before pumps to readjust residual chlorine.
10- Follow up for the residual chlorine in the outlet of treatment plant by applying poster dose to comply with Egyptian drinking water quality requirements.
11- Complete the implementation plan for designed plan in Dakrour iron and manganese removal unit by building new three slow sand filters and one storage tank.
12- Installing a pressure gauge and flow meter after slow sand filter to detect performance of the SSF.
13- Integrated water resources management should be done for all over Egypt to get an ideal model to conserve ground water uses
14- Future research should be done to maximize the use of wells as a source of geothermal energy (renewable energy).
15- Technical monitoring program should be designed, implemented and operated for assessment of quantity and quality all groundwater sources using modeling technique to predict quality of drinking water supplies in Holding Company for Water and Wastewater.