Production of leachate from deposits of solid waste and its attenuation through substrata

Abstract

Open dumping or landfill of refuse is the cheapest disposal system available, but if it is undertaken without careful site selection pollution of surface or underground water can result. Local authority budgets seldom allow for extensive experimental evaluation or computer simulation of the site, so a simplified method of determining potential pollution is required.

Relationships between easily measured paramaters such as rainfall, moisture properties of soil and refuse and the movement of water through refuse and the soil beneath can be derived from the principle of conservation of mass.

Outflow of moisture or chemicals from a unit volume of solid media must equal inflow minus storage or plus the amount released from the media.

Solutions to the equations thus derived were stated and as much information to assist the user in estimating model parameters as possible is included in the text. Qualitative descriptions are given where relationships are too complex to describe quantitatively. The model assumptions were tested using experimental data on leachate attenuation by sand at a site with a shallow water table.

The model equation was found to be relatively easy to use and although predictions were lower than experimental results they were in the same range.