MODFLOW/MT3DMS Based Modeling Leachate Pollution Transfer in Solid Waste Disposal of Bahar Plain Deep Aquifer

Abstract Background and purpose: This paper presents a case study in simulation of process governing leachate occurrence and subsequent transport, and investigates its migration away from the landfill to control environmental adverse effects on a deep aquifer. Materials and Methods: The landfill examined in this study was an area of 240 ha and received 500 ton/day of solid waste generated from Hamedan and its surrounding including Bahar, and Jurghan. Based on the finite difference technique, leachate transport and penetration into the Hamedan plain aquifer was simulated exerting MODFLOW and MT3DMS codes in GMS Software. Results: It was concluded that landfill geological structure had the greatest influence on the transfer of urban solid waste leachate in traditional disposal sites. A low permeable conglomerate layer prohibited leachate migration to the main semi-confined aquifer. The results also indicated that urban solid waste leachate was only excited to migrate toward recharging waterways of aquifer by surface flows flooding as well as severe rainfalls. Conclusion: Geological structure of the landfill area had the greatest influence on the development of leachate pollution of municipal solid waste in traditional disposal sites. The spread of pollution to the deep aquifer near the waste disposal site was practically inhibited by an impermeable conglomerate layer in the municipal waste disposal.