Leachate pollution index (LPI) value can be used as a tool to assess the leachate pollution potential of landfill sites particularly at places where there is a high risk of leachate migration and pollution of groundwater and thus can help to take necessary decisions as deem fit. In this paper, leachate treatment efficiency was evaluated on the basis of LPI value of leachate before and after treatment by passing through permeable reactive barrier (multibarrier) in a laboratory scale study. Permeable reactive barrier (multibarrier) consisted of low cost locally available waste materials, which is an innovative in-situ remediation technology to treat landfill leachate contamination. Leachate sample of Jamalpur landfill site of Ludhiana City, Punjab (India) was collected and analyzed for 5 significant leachate pollutant variables viz pH, TDS, BOD5, COD and Chloride (Cl−) to estimate its pollution potential. The concentration of all the studied leachate pollutant variables exceeded the permissible limits. Jamalpur landfill site has neither any base liner nor leachate collection and treatment system. Therefore, all the leachate generated finds its path into the surrounding environment. LPI is an increasing scale index, where a higher value indicates poor environmental condition based on the Delphi technique; which is an opinion research technique to extract information from a group of panel lists. The formulation process involved selecting variables, deriving weights for the selected pollutant variables, formulating their sub indices curves and finally aggregating the pollutant variables to arrive at the LPI. The LPI value of the standards given under Municipal Solid Waste (Management and Handling) Rules, 2000, Government of India for the disposal of leachate to inland surface water is 7.378. In the present study, LPI value of leachate before and after treatment is 26.45 and 7.03, thus LPI value after treatment is under permissible limits.