Hydrologic Evaluation of Landfill Performance: HELP 4.0 User Manual
Citation:
Tolaymat, T. AND M. Krause. Hydrologic Evaluation of Landfill Performance: HELP 4.0 User Manual. U.S. Environmental Protection Agency, Washington, DC, EPA/600/B-20/219, 2020.
Impact/Purpose:
In this effort, we have translated the HELP model code from FROTRAN 77 to an Excel based VBA code to allow the software to be used on any platform as long as Excel is present. To ensure that the model calculations were not impacted identical simulations were carried out using HELP 3.7 and HELP 4.0. The simulation results were compared to ensure that differences were minimal as outlined in the ORD approved QAPP.
Description:
The Hydrologic Evaluation of Landfill Performance (HELP) model was developed by EPA’s Office of Research and Development in the 1990’s. The software is used by landfill designers and permit writers to calculate the head on the liner and to estimates water balances for landfills and other land disposal systems as required under the Resource Conservation and Recovery Act (RCRA). The HELP models rainfall, runoff, infiltration, and other water pathways to estimate how much water builds up above each landfill liner. Prior to publication the software underwent internal and external EPA review as well as field verification. Last time the HELP model was updated was in 1994 using FORTRAN 77. Since the software does not run on 64bit machines it requires users to download 16 bit DOS operating system emulators to run properly. Thus, there was a clear need for ORD to update the model to run on 64bit computers. In this effort, we have translated the HELP model code from FROTRAN 77 to an Excel based VBA code to allow the software to be used on any platform as long as Excel is present. To ensure that the model calculations were not impacted identical simulations were carried out using HELP 3.7 and HELP 4.0. The simulation results were compared to ensure that differences were minimal as outlined in the ORD approved QAPP. Included in this clearance package is the new version of the HELP model (HELP 4.0), the software manual, the results of our beta testing and responses to the beta testers and finally the results of the 3rd party evaluation between the HELP 3.7 and 4.0 modeled. If approved for publication all these documents will become available for the HELP users to read and download.