The book deals with the study of correlation relationship of factors affecting leachate quality to predict pollutant from landfill which are determined by temperature, precipitation and waste age. Results of the study revealed that there is a good correlation of pollutants leaching from landfill to the factors of temperature, precipitation and waste age. Higher pollutant concentration is found in average age landfill than mature age landfill site mainly due to transition from acetogenic phase to methanogenic phase of pollutant decomposition. Using multiple regression Aaalysis method, mathemetic model known as Pollutant Prediction Model is developed to correlate relationship of pollutant to factor affecting leachate quality in the landfill site in term of temperature, precipitation and waste age.