One of the results of random system of buildings in the third world is the problem of water pollution. Underground septic tanks are used to collect domestic wastewater. Groundwater pollution is a consequence of wastewater discharging into permeable underground septic tanks. In this study, groundwater (from a well used for irrigation and drinking) samples were taken at the pumping level. A series of chemical analysis was carried out for water samples at different periods of time. Harmful effects of wastewater on the chemical compositions of groundwater were detected. In addition to that, toxicity and chemistry of heavy metals are increased in groundwater.