ABSTRACT
Water sources available for drinking and other purposes must possess high degree of purity, free from chemical contamination and microorganisms. Groundwater is a vital natural resource for the economic and secure provision of potable water supply in both urban and rural environments, and plays a fundamental role in human well-being, as well as that of many aquatic ecosystems. The rapid growth of urban areas has further affected the groundwater quality due to over exploitation of resources and improper waste disposal practices. The sources of groundwater contamination are many and varied because, in addition to natural processes, practically every type of facility or structure installed by man and each and every human physical activity may eventually cause groundwater quality problems. The groundwater contamination is widely regarded as a major environmental problem now and in the future. Therefore, The vulnerability of groundwater, especially of groundwater supplies, to existing or potential sources of contamination underscores the need for a systematic process by which these potential threats can be recorded, identified and evaluated also an inventory of groundwater contamination sources can be provided. As the Mashhad Plain located in Iran is a great pollution sources and a serious threat for the health of groundwater supplies resources, many engineers and planners have proposed various policies and programs for controlling groundwater contamination until now. This paper discusses about identifying the major sources of groundwater pollutant and estimates their contamination potential in Mashhad Plain. The results measure the importance of different pollutants of Mashhad Plain and indicate the potential benefits of groundwater contamination abatement.
