Sustainable Development: Water Quality Assessment of Tajan River

Tajan river is one of the biggest and the most important river in Iran. It emerges from Alborz mountain and north of Semnan provice and after 180 km continuing to Caspian sea. So, protection of this river from industrial and agricultural pollution is quite crucial. On the other hand the knowledge of water quality is one of the essential management tools in integrated water management control. The aim of this study was awareness of changing in water quality in different seasons. The samples were collected from different stations along the river during different seasons of 2000.The samples were analyzed for BOD5, COD, TDS, pH, EC, DO, NO2, NO3, NH4, PO4, and total and fecal coliform. The results of this study showed that the minimum and maximum of BOD are 18 and 25 times higher than standard limit respectively. The results also showed that the average of total coliform bacteria is up to 60 times higher than standard limit.