Evaluation of effective parameters for the construction cost of compacted clay liner in municipal solid waste landfills

Lining is one of the most important components of waste landfills, whose main function is to limit the penetration of leachate from waste from the landfill base. Since the cost of a lining system is a significant part of a landfill’s total cost, therefore, it is necessary to design the compacted clay lining with environmental and economic considerations equally in mind, which requires identification of factors affecting the construction cost of clay lining. For this purpose, using a performance-based approach, the factors affecting the technical design and hydraulic performance of clay linings in preventing leachate leakage, four variables include of trench height, trench lifespan, land price and distance from the soil loan, have been identified as the variables affecting the cost of clay lining construction. Using the HYDRUS one-dimensional model, the appropriate lining thickness was determined in the scenarios of 30, 60,180,360,720 and 1080 days for the trench lifespan. Then, by defining design scenarios based on the effective variables, the cost of different parts is estimated. Investigating the cost variations shows that increasing the height of the trench in different parts leads to lower costs of construction. While changes in the cost of lining construction over the lifespan of the trench initially had a downward trend, it then showed an incremental pattern. The variation in total cost is affected by land cost variations and indicates the importance of land prices in assessing the overall costs of constructing the lining. Also, an increase in the distance from the loan increases the cost of lining construction significantly and, if suitable soil for lining can only be located more than 100 km from the site, then the use of a Geosynthetic clay lining is more cost-effective. The trench lifetime can be considered as a variable with less design constraints, depending on the cost of other parts. Investigating the costs in different parts of compacted clay lining construction shows the necessity for economic modelling and creation of cost functions for the optimal design of compacted clay linings in every area.