Field Verification of HELP Model for Landfills

Abstract

Long‐term simulations of 17 landfill cells from six sites are performed using the Hydrologic Evaluation of Landfill Performance (HELP) computer model. Results are compared with field data from a variety of landfills to verify the model and to identify shortcomings. The sites are located in California, Kentucky, and Wisconsin. Since site data are not available for some of the model input parameters, default values are used in many instances. It is found that model predictions are generally bracketed by field measurements. Good agreement between the predictions and measurements is obtained by calibrating the hydraulic conductivity of the cover materials while staying within the range of hydraulic conductivity values reported in the literature for these materials. The results indicate that the HELP model can be a very useful tool for designing and evaluating landfills. Additional data are required to rigorously test many of the model assumptions and mechanisms.