Influence of Urbanization on Water Quality Deterioration of Northern Wadi Shu ′ eib Catchment Area Springs , Jordan

Jordan is known to be one of the most water scarce countries in the world. More than 80% of the country is desert and about 90% of the annual rainfall is lost to evaporation with a share of 64% for agricultural purposes as irrigation water (MWI, 2004). The growing demand for water supply is a result of the fast socio-economic development of Jordan and high population growth. Therefore, efforts were spurred to protect the quality of this limited water resource. NWSCA is mainly dependent on groundwater resources where water quality is at risk by groundwater hazards. It is experiencing rapid expansion with unsewered development and using septic tanks, thereby discharging to the unsaturated zone reaches groundwater where it affects water quality. Approximate times for septic effluent to pass the vadose zone to reach groundwater depend on the volume of effluent and the distance to water table. A septic plume in groundwater moves at a rate similar to the groundwater velocity (Robertson et al.,1991). The karst aquifer properties allow wastewater to recharge the springs very quickly and without any purification (Al-Kharabsheh and Ta’any, 2003). Therefore, the groundwater of the Upper Cretaceous Karst (carbonate) aquifer, which is prominent in the study area, is highly vulnerable. The inherent characteristics of the aquifer, namely, highly flow velocities, short residence time and fast hydraulic reactions accelerate groundwater pollution levels (Bender, 1974). Werz (2006) found that highest risk intensity at Wadi Shu′eib area occurs in urban areas. The urban areas in the study area, often situated in karstified limestone's are not covered by auxiliary sediment or soil cover. This leads to a high vulnerable groundwater. Furthermore, the main contaminants are point source hazards caused by missing or leaking sewer systems, factor farms, manure heaps septic tanks and car service stations without unpaved floors and illegal waste dump. McQuillan (2006) studied groundwater contamination by septic tanks effluents. He observed several health hazards from the contaminants, blue babies, neurotoxin and other specific outbreaks of disease. Furthermore, he suggested alternatives to conventional septic systems including advanced wastewater treatment units, which are like mini sewage treatment plants. Foster (2001) investigated the interdependence of groundwater and urbanization in rapidly developing cities. He found that there are rather widespread indications of degradation of the groundwater resource-base caused by excessive exploitation and/or inadequate pollution control. Minnesota Pollution Control Agency (1999) conducted a study to determine the effects of septic systems on groundwater quality in residential areas of Baxter, Minnesota. The agency reported that septic waste discharged to coarsetextured soils proceeds vertically through the unsaturated zone and into groundwater, through developing septic plume, which move with groundwater flow. It also found that median nitrate concentrations were significantly higher in areas with individual sewage treatment systems than in areas served by municipal sewers. Moreover, bacteria and Volatile Organic Compounds (VOCs) were found in septic effluent at all investigated sites. The main objectives of this study are to determine the recent annual level of pollution fluctuations on these springs throughout the year, and classify the spring's′ water quality according to the biological and chemical properties. Furthermore, the interrelationships were pointed out between the results of the springs′ water analyses and recent pollution levels of these springs with the increased numbers of populations nearby of the springs′ catchment areas. Moreover, the urban expansion leads to increasing non-point source pollution with high effects on spring's′ water quality.