Landfill Performance Assessment at a Semiarid Site: Modeling and Validation

Abstract
The HELP model (Version 2.05) was applied to simulate the long‐term percolation from a proposed landfill in southern New Mexico. The model predicted percolation would be about 0.0012 in/yr (10‐10 cm/s). This result compared very favorably with independent estimates of recharge at the site which used the chloride mass balance method and hydrogeologic properties. The recharge estimates at this site are also quite similar to values obtained at other sites in New Mexico and west Texas. The long‐term percolation through a closed landfill at this site is very small and would be nearly 1000‐fold smaller than the saturated hydraulic conductivity of a typical clay liner.