Cromwell Geobag Removal and Pond Desludging

Details

RFx ID :	34819845
Tender Name :	Cromwell Geobag Removal and Pond Desludging
Reference # :
Open Date :	Monday, 31 August 2026 3:00 PM (Pacific/Auckland UTC+12:00)
Close Date  :	Wednesday, 23 September 2026 2:00 PM (Pacific/Auckland UTC+12:00)
Department/Business Unit :	Central Otago District Council
Tender Type :	Request for Proposals (RFP)
Tender Coverage :	Sole Agency  [?]
Categories :	47100000 - Water and wastewater treatment supply and disposal 83101500 - Water and sewer utilities
Regions:	Otago
Exemption Reason :	None
Required Pre-qualifications :	None
Contact :	Laura McLellan tba
Alternate Physical Delivery Address  :
Alternate Physical Fax Number  :

The Central Otago District Council is inviting proposals from experienced and qualified contractors for
desludging two oxidation ponds at the Cromwell Wastewater Treatment Plant (WWTP).
The scope of work covers:
• Removal of the existing sludge stored in Geotextile bags (Optional Separable Portion)
• Design of a sludge removal methodology, dewatering basin and monitoring programme
• Desludging of the two oxidation ponds
• Dewatering of the dredged sludge using suitable technology
This procurement specifically covers the desludging and dewatering components. Disposal of the
dewatered sludge and the new geotextile bag are excluded from the contract works.
Desludging is a routine but infrequent maintenance activity essential for maintaining the treatment. The
Cromwell ponds have been desludged previously in 2017. Further sludge surveys were conducted in
2026 and confirmed the need for intervention.
For more info, see RFP document