The sustainable use of geosynthetics : landfill drainage case study

Geosynthetics are commonly employed in landfill applications; to serve a variety of functions. One specific example is the use of geosynthetics as under-drainage placed on the base of a landfill cell, underneath the engineered geological barrier. This paper presents a case study that compares the CO2 emissions produced from three different solutions for under drainage, all employing geosynthetics but using varying products and quantities. The project used for the case study employed a geocomposite drain solution, however, other alternative solutions could have been included such as a continuous gravel layer or the use of gravel trenches. The Life Cycle Analysis boundaries set for this case study were of cradle to end of construction. The calculation process required embodied carbon data, as well as transport and construction details. These calculations provided a carbon footprint for each solution and showed the geocomposite drain solution to be more sustainable than the continuous gravel blanket. The results suggested that there was little difference in CO2 emissions between the gravel trenches and geocomposite solution. However, in this project the Environment Agency (England and Wales) (EA) insisted on a continuous drainage layer, hence the gravel trenches were not an allowable option.