Water budgets as a tool for landfill owners and decision makers

According to the outcome of a United Nations conference in Johannesburg, 2002, manycountries of the world are facing large water management challenges that requiregroundwater and surface water resources to be protected. Leachate from landfills and citydumps is a significant source of groundwater and surface water contamination. LocalEnvironmental Protection Authorities have, during recent years, increased theirrequirements on the municipalities, the waste management companies and the industriesthat are running solid waste landfills. These requirements include having a goodknowledge of and control over the water budget and the geohydrological position of thelandfill area and its surroundings. In the case of new landfills, the demands are higher.According to the Waste Council Directive 1999/31 /EC on landfilling of waste, theMember States should set up a national strategy for pollution reduction, water control andleachate management at landfill areas. A meteorological station should be located on site.In order to ensure a proper and optimized design of the facilities, it is of the highestimportance to know the seasonal and short-time variations of the different terms of thewater balance, from both a quantitative and a qualitative point of view. Water budgets foran entire area can give a picture of water conservation, water allocation priorities,groundwater and stream flow, pollution tracking and ecosystem requirements in thewhole region around the landfill. These budgets can easily be made as hand calculations.In order to ensure adequate designs that are practical and economical, it is essential tohave reliable and accurate design tools and models available to estimate the waterbalance components and to predict liquid movement into, through, and out of landfills ofvarious designs. There are a number of models, such as HELP, PREFLO, MOBYDECand FILL, available. However, this paper presents water budget calculations on varioustime bases that can easily be carried out by hand and by the landfill owner.