Study on the Adequacy of Landfill Cover at Muassim Landfill, Makkah, Saudi Arabia

摘要

This study examined the adequacy of an existing sandy landfill cover-1.0 m to 23 rn in thickness and 0.9 km~2 in area-in protecting the waste against rainfall infiltration by testing equivalent cover material at a location away from the site. The landfill is located in Muassim, Makkah-Mecca, in English-Saudi Arabia, while laboratory tests were carried out in Malaysia using simulated sand of equal gradation properties as material of the site. Samples of thicknesses between 0.1 m and 0.9 m were tested in a transparent column, 0.194 m in internal diameter, and applied to the top of the column was 3.31 L of water, the equivalence of 1 year rainfall in Muassim. A container was placed at the bottom of the column to collect water in case of a "breakthrough". Each experiment was allowed to run for 24 h and measurements were made for "breakthrough" time, volume of water collected over time, and depth of wetted front over time. The veracity of the measurements was verified by carrying out similar tests at site, in the Saudi Arabian landfill, using real cover material. The study suggests that under ideal circumstances, the existing sandy landfill cover probably is capable of protecting the waste body against infiltration. The study also demonstrates the appropriateness of carrying out tests on simulated geotechnical material in a situation when the actual material is not readily available.