Quality assessment of Tehran's Firoozabad Channel surface runoff for irrigation uses

Concerning the importance and limitations of water resources in particularly arid and semi-arid areas such as Iran, it seems that the use of surface runoff may be considered as a fundamental step to compensate a part of water scarcity. This study was aimed to assess the quality of surface runoff in Tehran’s Firoozabad Channel for irrigation uses.
Throughout this experimental-laboratory study, sampling was done from the channel’s downstream in the south of Tehran during the spring and summer seasons in 2015. Arrangements were made well in advance with related organizations in order to sampling as well as to make use of required data. Water samples were analyzed for physic-chemical and biological parameters such as BOD5, COD, TSS, pH, SAR, Na%, TP, TKN, calcium, magnesium, sodium, electrical conductivity, boron, chloride, heavy metals, as well as intestinal nematodes, Total coliforms and Fecal coliforms.
The mean concentrations of BOD5, COD and heavy metals except for nickel as well as pH were in compliance with the standards set by Iranian Environmental Protection Agency for irrigation uses of effluents. Electrical conductivity, total dissolved solids, SAR, chloride, and boron were in the range of low to moderate. Furthermore, Na% was considered as permissible for irrigation uses. The average of turbidity, TSS and numbers of Coliforms and Thermotoerant Coliforms exceeded the desirable limits recommended for agricultural irrigation.
The significance of results obtained simply emphasizes that although some measured parameters was found within national and international standards, there is a need for runoff treatment and notably disinfection for particular studied parameters. Additionally, continuous monitoring of such a surface runoff to determine its compliance with promulgated standards is recommended.