Wastewater & Cell Construction

Himatangi Wastewater Treatment Facility

Bulk earthworks for construction of a new wastewater treatment plant.

Earthworks

  • Site clearance
  • 28,000m2 topsoil strip
  • 10,000m3 cut to fill
  • Form and maintain access track
  • Form pond embankments, compact & trim ready for placement of the liner.

Other

  • Installation of Gas collector and ventilation pipework
  • Installation of pond anchor posts
  • 7 wire farm fence and deer fencing and associated gates etc.
  • Upgrade of existing access road
  • Assistance with laying of plastic liner

 

 

 

Palmerston North Wastewater Treatment Plant 2007

Bulk earthworks for the construction of a new wastewater treatment plant, preparation of building platforms and placement of geotextile fabric and geogrid reinforcement

Earthworks

  • Remove unsuitable from site 4,500m3
  • Bulk excavate, stockpile and place 7,200m3 fill
  • Bulk excavate and cart away 2,600m3
  • Place 18,500m3 imported fill
  • Place hard fill for clarifier

General Comments

  • Shape had to be to exact and to very fine tolerances as concrete was poured directly to ground.
  • Geotextile fabric and geogrid reinforcement was laid for access roads

    

Levin Landfill 2007

Clearing, stockpiling topsoil, cut to fill, cut to waste, and preparing the landfill for placement of liner.

Earthworks

  • 30,400m2 topsoil strip, stockpile and respread
  • 48,000m3 cut to fill
  • 6,100m3 cut to waste
  • Landfill cell cut and slopes
  • Hydroseeding

Erosion & Sediment Control

  • Work was in sand and the only method required was silt fences

General Comments

  • Work involved preparation for liner to fine tolerances and exact shapes

Shell Landfarm 2010

Land farming to treat contaminated soils at the Shell site in Seaview.  Work involved demolition, excavations, and backfill.

Earthworks

  • Excavation of 750m3 overburden material
  • Filling and compaction of 1800m3 of processed materials
  • Excavation of 350m3 contaminated soils to landfarm
  • Landfarming involved regular turning of soil to aerate it. It also involved covering it with large covers to contain the contamination.  Work had to be systematic and controlled.

Erosion & Sediment Control

  • Erosion and sediment control consisted of silt fencing

Drainage

  • Installation of ducts
  • Capped off lines
  • Replaced stormwater line

Concrete Work

  • Replacement of concrete slab
  • Reinstate test pits with concrete

Demolition

  • large footings (up to 1mx1.5mx2.5m), kerbs, bunds and nibs
  • Removal of metal poles
  • Removal of concrete bridge slab panels
  • Decommissioning of existing drainage system
  • Demolition of deep concrete oil interceptor – difficult demolition
  • All demolition concrete was crushed on site for reuse

General Comments

  • Landfarming involved regular monitoring of gas to ensure it was safe to work
  • Dewatering was required when working in the oil interceptor