The effect of agriculture drainage on water quality of the Zaringol in Golestan Province by the water quality index

water, urban, industrial and agricultural centers are usually held near rivers. Surface water sources over other sources of water pollution are more at risk. The goal of this study was to evaluate the quality of the Zaringol River and the impact of agricultural drainage water was designed and implemented. In regard to agricultural activity around the Zaringol river stations studied and the samples from agricultural drainage water and streams in summer and autumn period specified were taken. NSF WQI index parameters including 9 parameter dissolved oxygen, fecal coliform, pH, BOD, temperature, phosphate, nitrate, turbidity, total dissolved solids, which were measured by using standard methods. The results from the study showed that the index based on NSF WQI for all stations were between 54 to 61. Agricultural water drainage WQI index is between 45-37 that according to the index is poor quality. According to the NSF WQI index indicated that water quality in the river is moderate. But agricultural drainage water quality is bad and affects the quality of river water. Due to the relatively high levels of water quality in the middle class of nutrients, especially nitrates, coliform presence of E.coli that drainage water from agricultural and recreational activities in the upstream station is monitored.