A closed landfill with low risk potential in a rural environment was remediated by profiling the landfill body and covering the landfill with a soil layer.
The landfill Klausdorf has an area of 4.5 ha and a volume of 420,000 m³. It was operated from the 60's till 1991. Household and construction waste, scrap, ashes and excavated soil were disposed. The Brandenburg guideline for remediation of landfills with low risk potential was applied to recultivate the site. Following this guideline a landfill with a volume less than 500,000 m³ has to be remediated by installing a surface capping. A risk assessment showed that the level of groundwater pollution was very low. The main aquifer is protected by an aquiclude. There was no landfill gas emergence. The disposed waste mainly consisted of mineral material with low contamination. So the risk potential outgoing from the landfill was not relevant.
In accordance with the guideline the following measures were carried out:
- removing bulky waste from the landfill surface
- profiling the landfill body so that the surface water can run off the landfill
- installation of a drainage trench around the landfill
- covering the surface with a 50 cm soil layer
- establishing grass vegetation.
The evapotranspiration in connection with the water holding capacity of the soil and the surface slope minimises infiltration and groundwater recharge rate. For the profiling of the landfill body 160,000 m³ of inert mineral waste was needed and 25,000 m³ of soil for the capping layer. Further, two groundwater observation wells were installed.
For profiling of the landfill uncontaminated building rubble, excavated soil and road construction waste was used. The producer of waste payed for its disposal on the former landfill although used for the recultivation measure. This resulted in a financial zero- balance for the remediation measure.
Evidence of success
The landfill was remediated by measures which are adjusted to the risk potential of the landfill. The applied measures lead to a reduction of rain water infiltration into the landfill body and elution of contaminants into the groundwater. The landfill body is recultivated and integrated into the landscape.
Considering the Brandenburg guideline a risk assessment was made for the decision – making, that’s why different analyses have been done. As the composition of the deposited waste was not known, a long-term groundwater, soil and air analysis has been carried out, which caused additional costs.
Potential for learning or transfer
This good practice describes an example for remediation of a landfill in a rural environment with a low risk potential. It is replicable for landfills with a small volume (less than 500,000 m3) where waste with low pollution level was disposed. Brandenburg has created a guideline for these landfills.
Many of the existing landfills in the EU member states are small-sized landfills in rural areas; therefor this practice can be widely applicable.
The practice is relevant for cases where the main objective of recultivation is the integration of the landfill into the landscape and the prevention of illegal waste disposals while landfill caused groundwater pollution plays a minor role due to a low pollution level of the disposed waste.
This good practice is currently adopted by an Andalusian COCOON stakeholder for the remediation of a construction and demolition waste landfill in the municipality of Baena.
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