A residual product is left after the incineration process, which is disposed of to landfills. A residual product (bottom ash, fly ash and air pollution control residues) is left after the incineration process, and it is disposed of to landfills as well. The incineration process also involves a flue gas cleaning process, which may give rise to externalities in the form of wastewater. For landfill disposal, the main emissions are the greenhouse gases CO2 and CH4. Moreover, leachate is emitted from the.
landfill to the surrounding soil and water. Generally, most of the available information is on air emissions and less information exists on the emissions to soil and water. For both disposal options there is in addition disamenity connected to the facility. By recovering heat and/or electricity emissions from other energy sources can be avoided. This is an example of a positive externality.
There is substantial literature and research on the quantification and valuation of the impacts of conventional air emissions and their resulting damage. The dispersion and impact patterns are relatively uniform once pollutants are emitted. Therefore, it is relatively easy to generalize the damage estimates and to apply such estimates widely. It can thus be concluded that valuation results in this field - covering both the external costs and the external benefits -can be considered to be quite comprehensive and fairly robust although they are of course still subject to uncertainties. These uncertainties are reflected in relatively wide ranges of estimates. Other air emissions such as heavy metals and dioxins are, however, quantified relatively rarely. .
However, very few attempts have been made to quantify and quantify soil and.
water externalities from landfills. Pollution pathways of emissions to soil and water are very site specific and difficult to measure. They depend largely on the quality of the soil, and on the specific location of the landfill with respect to for example groundwater reservoirs and receiving waters.