investigating the chemical quality of ground water in the vicinity of the sanitary landfill of yazd in 2008

background: groundwater is the most important source of water supply in industries and agricultures; therefore the need to protect this valuable resource against pollution is felt more than ever. in this study, the possible impact of yazd municipal solid waste landfill was investigated on the chemical quality of the area’s groundwater. methods: groundwater samples were collected from three wells around the landfill, one located at the upstream and two located at the downstream. the following parameters were measured: ph, electrical conductivity (ec), chloride (cl - ), nitrate (no 3 - ), total hardness, alkalinity and heavy metals including lead (pb), cadmium (cd), copper (cu) and zinc (zn). the data statistical analysis was performed by spss t-test and microsoft excel was used to draw the curves. findings: the groundwater’s ph in downstream was significantly lower than the ph in upstream (p = 0.038). also the values of ec, cl - , no 3 - , total hardness and alkalinity were significantly higher in downstream (p < 0.05). however no increase was observed in heavy metal obtained from downstream groundwater of the landfill. conclusion: the study findings indicated that the chemical quality of groundwater improves by increasing the distance from the landfill. therefore it is better to avoid utilizing the groundwater closed to the landfill. however, the best practice is insulating the landfill’s floor to control the movement of the current contaminations into the groundwater.