RELIABILITY OF GUELPH PERMEAMETER FOR DETERMINING THE LINERS HYDRAULIC CONDUCTIVITY

The aim of this study is to evaluate whether the Guelph permeameter can be effectively used as a quick and reliable instrument to measure the hydraulic conductivity of compacted mineral liners. The investigation was carried out on two distinct areas of the final capping of a municipal solid waste landfill in Italy. On the first test site, hydraulic conductivity tests were performed using the Guelph permeameter, assessing reliability and repeatability of test results. On the second one, many undisturbed soil samples were taken and tested in the laboratory using a modified oedometric apparatus as a falling-head permeameter. Further hydraulic conductivity tests with Guelph permeameter were also performed in the holes made by soil sampling. The campaign was integrated with in situ density tests using the calibrated sand method, to check the uniformity of the compaction degree of liners. A final comparison between hydraulic conductivity obtained in situ and in the laboratory was proposed and critically analysed. The experiments performed on the two test sites with the Guelph permeameter and their statistical processing demonstrate that the instrument is not only economical and easy to use, but also reliable if used with appropriate precautions.