Remediation of a landfill by a surface sealing system with an electronic leak control system

The landfill Senzig was in operation from 1968 until 2002. About 1,670,000 m3 of municipal, construction, commercial, and industrial waste was deposited on an area of 11.7 ha. A geological barrier and a base liner do not exist; the groundwater level is high. Thus, after closure, remediation measures were obligatory. As the volume of the landfill body exceeds 500,000 m3 the remediation had to be executed following the requirements for the landfill class II of the German landfill ordinance. Accordingly, the landfill had to be covered by a sealing system with two sealing elements. However, in the case of Senzig the authority approved the substitution of the second sealing element by an electronic leakage control system (LCS).
The LCS detects leaks > 5mm and the polymer liner can be repaired locally. The LCS consists of a grid of voltage sources installed above and electrode-sensors installed on both sides of the polymer liner. The voltages sources feature a grid of approx. 30 m, the sensors a grid of 10 m. The polymer liner acts as an insulator as electricity is not well conducted. In case of a leak the conductivity increases as the water percolating through the leak promotes conductivity. The electric potential changes, the differences in the potential provoked by a leak in the liner can be measured by the installed sensors. Overall, the LCS reduces the risk of hazards.
Twenty-five percent of the installation of the sealing system was financed by ERDF funding.