RICHARDS EQUATION APPROACH TO THE DESIGN OF EVAPOTRANSPIRATION BEDS

Evapotranspiration (ET) bed design commonly uses a simple mass balance (SMB) approach to determine adequate depth and area for on-site waste water treatment systems. The SMB approaches tend to oversimplify inter actions among water, soil, and plants. This article proposes an altern ative approach to ET bed design that utilizes the Richards equation si mulation model and a well-known groundwater modeling computer program. Results indicate that this approach more accurately represents an act ual system because it includes consideration of the dynamics of the so il-water-plant system.