Project Name: Vissershok Cell 4A

Client: Vissershok Waste Management Facility (Pty) Ltd

Project Description: The Contract comprised the design, site supervision, quality assurance and contract administration of a new cell (Cell 4A) at the Vissershok H:H Waste Management Facility. The Site is situated next to the N7 approximately 30km north of Cape Town CBD.

The layer works for Cell 4A comprised of the following (from top to bottom):

  • 300mm thick stone drainage layer of 38mm crushed stone
  • Kaytech Rock GX 130/30 reinforcing grid between the stone layer and geotextile protection layer on longer slopes to reduce tensile stresses in the underlying protection geotextile
  • 200mm thick sand protection layer on floor and 1000g/m² non-woven geotextile as geomembrane protection layer on the side slopes.
  • 2mm HDPE geomembrane (32 500m²)
  • 4 x 150mm thick compacted clay layers
  • A4 non-woven geotextile separation layer
  • 150mm thick sand layer as a leachate leakage detection layer
  • Rip and Re-compact 150mm thick in-situ clayey material

Perforated HDPE leachate drainage pipes were installed within the stone drainage layer. These pipes connect to solid wall HDPE drainage pipes at the cell’s low point from where it gravitates into the pump sump. The leachate is then pumped to the leachate storage area. The leachate storage area consists of steel “Botanks” that are lined with 2mm HDPE geomembrane. The storage area has 2 of these tanks and each has a capacity of 222kℓ.

The sand leakage detection layer underneath the layer works is connected to a leakage detection sump which is linked to a detection monitoring pipe next to the pump sump for easy monitoring.

Location: South 33 46 18  East 18 32 06

Contract Data (Cell 4 Construction)

Contractor: Martin and East (Civil), Engineered Linings (Geosynthetic lining work)

Commencement date: 25 September 2008

Completion date: 9 June 2009