Surface cappings and basal liners of landfills have to meet defined technical requirements. The installed quality is monitored by an independent third party.
In order to control the quality of basal or surface liner / capping systems a quality management plan (QMP) has to be established. The QMP includes requirements (according to the German Landfill Ordinance / Quality Standards) for materials and construction as well as for the extent and performance of control. The quality, which is defined in the QMP, has to be monitored by an independent third party control (TPC). Only the authority is authorised to give instructions to the TPC. The costs of TPC have to be paid by the landfill operator.
The TPC and the laboratory have to be accredited pursuant to DIN EN ISO/IEC 17020 and 17025, respectively.
The TPC must have experience in supervision of landfill construction works. Testing polymer and mineral elements requires special accreditations. The TPC may fulfill both requirements of accreditation and monitor the quality of these elements.
The construction company supervises the quality by its own and submits the results to the TPC to be controlled. Besides, the TPC does further, independent quality control of material and construction, including sampling, analysis, and evaluation of results.
The TPC works independently and reports regularly the results of quality control to the authority. The TPC approves the construction works when quality is in line with the QMP. In case the quality is not in line, the TPC is authorised to stop the construction works until quality is achieved.
The cost for the supervision of the quality of surface and basic sealing is about 30,000 Euro per hectare.
Evidence of success
The independent evaluation of quality of material and construction of polymer and mineral sealing elements is an important tool to assure the quality of the protection measures of landfills. Just when quality of the sealing elements is approved, the landfill gets the permission for operation or closure. The independent control by a third party assures quality, since analysis, conducted by the party who construct or owns the landfill, might lead do fraud.
Consultants offering accredited third party control are scarce and highly demanded. This has to be considered and the request for proposal should be at an early stage of planning the construction works.
Potential for learning or transfer
Only by an adequate supervision the quality of the technical sealing and capping elements of the landfill can be guaranteed. This minimized the threat for the environment and human health resulting from the deposition of waste on a landfill.
A defined supervision of the quality of sealing elements should be applied for all type of landfills. It is especially important for hazardous-waste landfills.
It is crucial that the third party control is independent from the construction work company. Only the authority should be allowed to give instructions to the TPC.
Regular reports from the third party control during the construction works to the authority keeps the authorised person in the authority always up to date regarding the quality of applied materials and the construction works and opens the possibility for immediate reaction.
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