In landfills geosynthetic materials are used to contain potential pollutants
and prevent precipitation from entering the landfill body. Since May
2001 several geosynthetic installations were carried out in the landfill
Meia Serra, Portugal. The Portuguese Naue Fasertechnik partner BBF from
Coimbra won the project and installed this project with several Naue
geosynthetics.
The project was divided into two installation
phases with one domestic waste cell and one ash cell. The base liner
consisting of a geosynthetic
clay liner Bentofix® and a 2 mm thick Carbofol® polyethylene
(HDPE) geomembrane structured on both sides (KN/MK) was installed for
the 27.000 m2 large domestic waste section. A Secutex® nonwoven acted
as the protection geotextile under the mineral leachate collection layer.
In the steep slope areas, a geosynthetic drainage mat Secudrän® was
used. The cross-section of the 5.500 m2 large ash cell where the sediments
of waste incineration were deposited was identical to the domestic waste
section. In addition, the contractor and the authority decided to install
two geomembranes encapsulating a drainage net to protect the groundwater
against escaping leachate in this section, due to the consideration that
possible escaping leachate would cause the most environmental damage.
In September 2002, the second installation phase
started which was recently completed. The same material as described
above was used for lining the
21.000 m2 domestic waste cell and the 10.000 m2 large ash cell. In November
2002, the installation of a cover liner started on the 46.000 m2 large
first landfill section. The capping system consists of a HDPE Carbofol® 1,5
KN/MK geomembrane, a drainage mat Secudrän®, Secutex® protection
nonwovens and a geogrid Secugrid® ensuring stability in steeper slope
areas.
The high requirements for the Meia Serra landfill design due to narrow
spacing and the morphology of the island were perfectly met by the use
of a geosynthetic combination of geosynthetic clay liners, drainage mats,
protection and reinforcement elements.
|