Case Study: 002
Reed Beds
The Task
To create two lined reed beds with an over-liner geotextile protection
layer and sealed pipe penetrations for treatment of landfill leachate.
The Solution
In this case our customer required tow lagoons, each 2,500m2 in area,
to be lined with 2mm HDPE covered with a protection geotextile. The
gravel fill and collection pipe work contained within the lagoons is
part of the filtration and gravity flow system. The HDPE liner was
chosen for its chemical resistance and recognised long-term
durability. The protection geotextile placed over the HDPE liner was
designed to offer it protection from the overlying drainage gravel.
The HDPE geomembrane was installed using standard heated wedge and
extrusion welding equipment.
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Geomembrane Lined Reed Bed
Containing Gravel Filter
Planted Reed Bed |
General
Reed bed treatment systems are self-contained, artificially
engineered, wetland ecosystems. They are designed to optimise the
microbiological, chemical and physical processes naturally occurring
in the wetland. Wetland plants, such as reeds, transfer atmospheric
oxygen down through their roots in order to survive in waterlogged
conditions. This creates both aerobic and anaerobic soil conditions,
allowing extraordinary microbial species diversity to flourish. These
bacteria and fungi can use organic pollutants as a food source,
breaking down a wide range of organic chemical products. So, chemicals
are not simply stored in the reed bed; they are actually degraded into
harmless components.
Customer
Argyll & Bute Council
Earthworks Contractor
I & H Brown
Consultant
Halcrow
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