Errors Involved in the Estimation of Leachate Pollution Index

An environmental index known as the leachate pollution index (LPI) to quantify and compare the leachate contamination potential of municipal landfills in a given geographical area was developed and reported elsewhere. The LPI integrates complex analytical data and generates a single number expressing the potential of a landfill to pollute the leachate-receiving environment. This index is based on the concentration of 18 pollutants of the leachate and their corresponding significance. That means, for calculating the LPI of a landfill, concentration of these 18 parameters are to be known. However, sometimes the data for all the 18 pollutants included in the LPI may not be available to calculate the LPI. In this paper, the errors involved in calculating the LPI due to the nonavailability of data are reported. The leachate characteristic data of a municipal landfill in New Delhi, India have been used to estimate these errors. Based on this study, it can be concluded that the errors may be high if the data for the pollutants having significantly high or low concentration are not available. However, LPI can be reported with a marginal error if the concentrations of the nonavailable pollutants are not completely biased.