User manual for the Hydrologic Evaluation of Landfill Performance (HELP) model 4.0

HELP is a quasi-two-dimensional hydrologic model of water movement across, into, through and out of landfills. The model accepts weather, soil, and design data. It uses solution techniques that account for key factors affecting water movement in a landfill, including: surface storage; snowmelt; runoff; infiltration; evapotranspiration; vegetative growth; soil moisture storage; lateral subsurface drainage; leachate recirculation; unsaturated vertical drainage; and leakage through soil, geomembrane, and composite liners. Landfill systems including various combinations of vegetation, cover soils, waste cells, lateral drain layers, low permeability barrier soils, and synthetic geomembrane liners may be modeled. The model was developed to conduct water balance analysis of landfills, cover systems, and solid waste disposal and containment facilities.

• HELP Model 4.0 User Manual (PDF)(53 pp, 3 MB, January 2020 , EPA/600/ B-20/219)
  Manual for using HELP Model 4.0