Evaluation the Effect of Landfill Leachate on the Surface Water Quality: A Case Study in Tonekabon Landfill

Introduction: Leachate is a liquid coming out of accumulated wet wastes which contains several chemical and dangerous elements. Furthermore, it causes the aquatic ecosystem contamination. The purpose of this study is to give an indication of the effects of Tonekabon landfill on the surface water, so evaluating the amount of leachate polluting in surface waters was investigated. Materials and Methods: In the current study, after 4 sampling periods at 4 stations, parameters of pollutants including BOD5, COD, TSS, TDS, pH, and EC at different stations and in different seasons were investigated and analyzed. Results: The results revealed that there was no significant difference between 4 stations in pH mean values, while values of other parameters were significantly different in various stations. Based on Duncan's test, the station of 3 and 4 were significantly different in the same group, and the stations of 1 and 2 were each in separate groups. On the other hand, an examination of the difference in data mean based on sampling season shows that there is a significant difference between the mean values of pH between summer and spring, while in other parameters there is no significant difference. Conclusion: This landfill is important due to its location in the forest area near the rural and agricultural centers. The results showed that leachate could be transported to farther places in order to prevent soil and aquatic ecosystem contamination.