Waimakariri District Council

Contract 25/107 - Kaiapoi Oxidation Pond Desludging – Advertising Notice

Tenders are invited from suitably qualified contractors for the above contract.

This Contract is for the Kaiapoi WWTP Pond 2A and Kaiapoi WWTP Infiltration Basin Western Side de-sludging.

The contract comprises two separable portions:
• Separable Portion A – Kaiapoi WWTP – Pond 2A
• Provisional Separable Portion B – Kaiapoi WWTP – Infiltration Basin Western Side

The contract works include, but are not limited to the following:
• Sludge survey for Pond 2A and Infiltration Basin Western Side to confirm sludge levels and quantities.
• Preparation of the existing lay down area, including inspection of the existing liner and leachate pump station for suitable operation.
• Provision of suitable pumps to pump leachate from the new geobags back to an oxidation pond.
• The preparation will include levelling of the existing geobag area so a suitable platform is made to accommodate additional geobags from this contract (these will be placed on top of the existing)..
• De-sludging the Kaiapoi WWTP Pond 2A by suction head mounted on a suitable vehicle.
• De-sludging the Kaiapoi WWTP Infiltration Basin Western Side by a suction head mounted on a suitable vehicle. This is a provisional item and is dependent on costs associated with desludging Pond 2A
• De-watering and storing the sludge in geobags on site.
• Leachate from the geotextile bags to be returned to pond systems via pumping station.
• Transfer of all sludge and leachate will be via enclosed pipeline transfer system.
• A flocculants will be injected into the transfer pipeline to affect the separation of solids from the sludge prior to placement in geotextile bags. It will be up to the successful contractor to determine the correct type and concentration of flocculants to use.
• De-sludging may occur from 0730 until 1800, Monday to Saturday subject to minimal noise levels as assessed by the Engineer and dependant on the successful contractors’ time frames.

The objective of the works is to restore the Kaiapoi 2A and Infiltration Basin to their original design (Sludge free) volume

Tender documents are available for download from vendorpanel.nz/waimakariri/tenders.

If you have not registered for VendorPanel, you may do so using this link: http://www.vendorpanel.nz/marketplace

The VendorPanel Reference Number for this tender is: VP2298

Tenders for this contract close at 4pm on Wednesday 14 January 2026, with tender submissions via VendorPanel.