The lifecycle of a landfill begins with siting studies for the first phase landfill permitting and ends with the completion of post closure monitoring. This paper will present the various duties of a geologist in all of the aspects of the landfill's lifecycle including: permitting, monitoring, groundwater remediation and post closure monitoring. In the initial stages of landfill development owners have to demonstrate that the landfill meets all of the siting requirements. Demonstrating conformance with siting requirements is usually the first and most important phase of the permitting process. During siting investigations the geologist performs several field data collection activities including: drilling boreholes, preparing geologic logs, constructing piezometers, measuring water levels and collecting soil samples for geotechnical testing. These data are assimilated by the geologist into a comprehensive hydrogeological report of the site including conclusions regarding the site acceptability. Once a landfill has received a permit, geologists also perform routine groundwater monitoring activities that include; installation of monitoring wells, groundwater sampling, statistical analysis of groundwater analytical data, preparing potentiometric maps and reporting.

Groundwater remediation may be required at some landfills where the geologist performs additional site investigations, assessment of remedial options and finally remediation of contaminant plumes. Once a landfill closes the geologist can perform post closure monitoring until the closure requirements have been satisfied.