Variations of chemical quality for drinking water sources in zarand plain
The ultimate source of most dissolved ions in water is the mineral assemblage that occurs in rocks near land surfaces. The solids that dissolve into groundwater from this point, form part of the geochemical. Rock composition, purity, crystal size of its minerals, rock texture and porosity, regional structure, degree of fissuring and length of previous exposure time also influence the composition of water passing over and through rocks. The natural chemical content of groundwater is consequently influenced by type, depth of soils, and subsurface geologic formations through which groundwater passes (Pye et al., 1983). Contamination of ground water/subsurface systems (GWSS) by leachate from sanitary landfills and human wastes (septic tanks, land application of sewage sludge, and municipal waste water) and industrial effluents, have become an issue of major concern and public attention in the last decade (Ventullo and larson, 1993). One particular issue has been the question of whether the entry of anthropogenic “human made” organic materials into subsurface soil or groundwater represents a permanent contamination problem or whether removal processes are available that prevent the accumulation of such material (Chakraborti et al., 1998). Human health is remarkably dependant upon safe and clean drinking water. Preserving the water resources and hindering them from being polluted is preferred to the treatment of polluted water and rendering it suitable for consumption. Due to the variety and plurality of the contamination sources, the experts have been persuaded to endeavor assiduously to spot the ways through which the pollutants enter the water resources.