A critical analysis of non invasive approaches for the identification of leakage from landfills: a case study from Lecce (Italy)

Landfill waste can produce contaminated fluids like leachate and greenhouse gasses which can harm the environment and public health. If there is poor maintenance or unsatisfactorily engineered landfill facilities, humans can be directly impacted and therefore study of these areas can be really important. In this thesis, a critical analysis of non-invasive approaches for the identification of landfill leakage is demonstrated. The investigated landfill is located in Lecce, south Italy. Its solid urban waste is confined by High-Density Polyethylene. There is an assessment that there could be potential zones that are contaminated. Therefore, the need to identify those areas is extremely important. Non-invasive techniques, like geophysics, have become an indispensable parts of a large number of engineering projects because they reduce potential problems in terms of damaging objects, the information can be obtained faster and cheaper. Since leachate is characterized by high conductive properties, the electrical method can be the right strategy to locate potential leakages. Electrical resistivity tomography and mise-à-la-masse techniques application have a lot of benefits in this environment. Three-dimensional and two-dimensional electrical resistivity models as well as resistance distribution obtained by mise-à-la-masse techniques provided important information regarding potential landfill leakages. The results are marked by a conductive anomaly in the middle of the landfill bottom labeled as a leakage area and two smaller conductive bodies arguably presenting water leakage. A non-invasive geophysical survey was successful and it provides a good base for further, more detailed investigations.