www.astesj.com 7 Assessment of Wastewater in Duhok Valley, Kurdistan Region/Iraq Najmaldin E. Hassan * , Musher R. Ahmed Al-barware Department of environment Science, Faculty of science, Zakho University, Zakho Iraq A R T I C L E I N F O A B S T R A C T Article history: Received: 08 August, 2016 Accepted: 22 August, 2016 Online: 25 August, 2016 In order to characterize the waste water in Duhok valley in Duhok governorate, during 25km, seven sites were selected in Duhok valley, to represent their water quality. Monthly samples were collected from the Duhok valley for the period from, April to September, 2015. The qualitative study of Duhok valley water tested, as considered one of the main sources of water pollution for Musol Lake. The physical and chemical test for water samples are taken from different locations in Duhok valley. To know the degree of pollution, and the impact of self-purification processes to improve water quality before arriving to the Mosul Lake, and the indicated results of the study a lack of dissolved oxygen in the water (DO). And high organic load values, (BOD) and most of the bad qualities during water passage within the city of Duhok, while meat a significant improvement in the quality of water downstream before arriving at the dam Lake, is attributed to the effect of operations of self- purification ability of water. In spite of salinity problems and toxicity, the quality of water is suitable for irrigation crops on both sides of the valley .The all samples were tested for conductivity, TDS, pH, total hardness, chloride, alkalinity, sulfate, BOD, and phosphate, according to the standard methods. Keywords: Wastewater Duhok valley Self- purification 1. Introduction Duhok valley considered as main stream for discharge of different liquid waste of Duhok city and its environs, which is transported by long Stream to Mosul Lake on the Tigris River north of the city of Mosul. After expanding population and evolving social, economic and population growth of the city of Dohuk lead to increase the amount of effluent civil, industrial and agricultural to the valley without making any treatment, as well as increasing environmental pollution and the emergence of problems odor problems, and therefore negative impact on water quality in the Mosul Lake. Also considered as a source of irrigation of fruits and vegetable located around the valley, which lead to negative events for the plants and production and soil permeability, as well as be used for watering animals and livestock, especially after passing away from the city of Duhok , as being this valley for a distance more than about 25 km before arriving in Mosul Dam, as the spread of Typha and fragment growth on the sides of the valley, which may play an important role in addition to physical and chemical factors in the incidence of operations demineralization self-water contaminated and improve its quality before it reaches Mosul Dam. Waste disposal of civil, agricultural and industrial liquid, untreated directly into the valley is one of the breaches of environmental water resources and a threat to the lives of people for the possibility of the spread of epidemics and diseases such as cholera, typhoid and dysentery. Water is the most vital element among the natural resources, and is critical for the survival of all living organisms including human, food production, and economic development. Today there are many cities worldwide facing an acute shortage of water and nearly 40 percent of the world’s food supply is grown under irrigation and a wide variety of industrial processes depends on water. The environment, economic growth, and developments are all highly influenced by water-its regional and seasonal availability, and the quality of surface and groundwater. The quality of water is affected by human activities and is declining due to the rise of urbanization, population growth, industrial production, climate change and other factors. The resulting water pollution is a serious threat to the well-being of both the Earth and its population. ASTESJ ISSN: 2415-6698 * Corresponding Author: Najmaldin E. Hassan, Department of environment Science, Faculty of science, Zakho University, Zakho Iraq Email: najmaldin.hassan@uoz.edu.krd Advances in Science, Technology and Engineering Systems Journal Vol. 1, No. 3, 7-13 (2016) www.astesj.com https://dx.doi.org/10.25046/aj010302