Carbon and Sulfur Isotope Methods for Tracing Groundwater Contamination: A Review of Sustainable Utilization in Reclaimed Municipal Landfill Areas

Reclaimed landfill areas are excluded from various development options including construction, while contaminated zones around such places have no such restrictions. The successful reclamation of landfills means that the old landfill visually fits in well with its surroundings, but soil and water contamination problems remain valid. Former landfills were built without properly preparing the land, which resulted in the migration of contaminants in groundwater for a long period after these landfills were closed, further resulting in the limited use of such areas, at least for some purposes. Due to the development of cities, landfills formerly located in suburbs are becoming a part of these cities. In order to optimally and safely use these spaces, knowledge regarding the quality of the soil and water environment is necessary. This article presents methodological considerations regarding the use of carbon and sulfur isotope methods to assess groundwater contamination around former municipal waste landfills, especially reclaimed municipal landfills. It has been shown that natural groundwater is characterized by low values of both δ 13 C DIC and δ 34 S (δ 13 C DIC from −20 to −10‰ and δ 34 S at approximately −5‰), whereas leachate-contaminated groundwater is characterized by high values of both parameters (δ 13 C DIC from −10 to + 5‰ and δ 34 S from +5 to +20‰). The aim of this article is to demonstrate that carbon and sulfur isotope methods extended via SWOT analysis are universal and reliable methods for assessing the migration of pollutants, thus facilitating decisions regarding management.