Water balance for landfills

A key step in the design of a solid waste disposal facility is the execution of a ‘water balance’ or ‘water budget’ analysis. A water balance is an accounting of the final disposition of precipitation falling on a site. Water balance analysis can be used to estimate the potential leachate production and liner/drain system performance and to compare the relative effectiveness of alternative cover and liner/drain designs. Knowledge of the possible range of leachate production is important for sizing the leachate collection system (e.g., pipes) and in making decisions about how to manage treatment of the leachate. Similarly, prediction of liner leakage and the depth of leachate buildup in a drain layer is important in the selection of liner and drain materials and in the design of collection pipe spacing and liner slope.