Surface capping and basal liners have to meet defined technical standards. The monitoring of the installed quality is defined in the quality management plan.
The quality management plan (QMP) defines the quality control for all constructed, technical elements in the landfill. The QMP includes quality requirements (according to the German Landfill Ordinance / Quality Standards) as well as the performance and extent of quality control. The QMP has to be introduced before construction works start and is confirmed by the authority.
1) The technical suitability of input materials is evaluated. This is the case for mineral materials, for the polymer ones the quality is guaranteed by a certificate. Chemical, physical, and mechanical characteristics of the mineral material are tested depending on its practical application. Laboratory tests imitate practical conditions. The outcomes approve or deny the material’s quality.
2) The mineral and polymer materials are tested under practical conditions in a test field. The interrelationship between of applied technique, materials, and the achieved quality are examined. When proper quality is reached, the suitability of input materials / applied technique is confirmed and the permit of application is granted by the authority. From the outcomes of the second step main parameter to be tested during the general construction works are derived.
3) The quality during the general construction works are monitored according to the technical requirements and main parameter, derived in the second step. The QMP defines the extent of testing, considering the individual characteristics of each material.
The cost for the supervision of the quality of surface and basic sealing is about 40,000 Euro per hectare.
Evidence of success
The quality control of the materials and the construction works is an important tool to assure the quality of the protection measures of landfill. The three-step approach of quality control guarantees a proper quality of the applied material and technique. Just when quality of the material of the individual sealing elements is approved, the material may be applied for construction works. The quality control in such a manner is also conducted in Andalusia, Cyprus and Malta.
The quality control is quite time consuming, in particular the first two steps (laboratory test, field test). Potential input materials have to be identified at an early stage of the construction works in order to keep in line with the timetable of construction works.
Potential for learning or transfer
Only by an adequate supervision the quality of the technical protection 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 quality of the material is tested in a small scale approach before applying in a large scale in the actual construction. This allows refusing a material in an early stage of the construction works and prevents from retreating sealing elements when bad quality of materials is detected after having constructed the corresponding element.
This good practice describes the German way, but a similar approach is used in Andalusia, Cyprus and Malta and many more regions.
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