Rosedale Wastewater Treatment Plant Upgrade, Auckland, New Zealand
Key Data:
Volume of wastewater treated
19.7 million m³/y
Activated sludge tank capacity
7,000m³ each
Secondary clarifiers
4 x 48m diameter
Secondary treatment BOD removal
75% to 80%
Secondary effluent BOD load
0.5t/d
Polishing lakes detention period
Up to 35 days
New faecal Coliform standard
1,000cfu per 100ml (median value)
Final UV treatment system (after expansion)
Six-channel system (1,296 lamps)
UV treatment full peak flow
3m³/s to 4m³/s
UV treatment system cost
NZ$2.26 million
Total estimated cost (Stage 4)
NZ$31 million
Estimated cost of the new outfall
NZ$60 million
Project Timeline:
Resource consent approval
April 2001
Stage 4 upgrade duration
3 years (2002-05)
New faecal Coliform standard effective from
1 January 2004
Foreshore sewer upgrade Phase I completed
November 2003
Foreshore sewer upgrade Phase II commenced
May 2004
Deadline for reuse/composting of biosolids
2007
New sea outfall completion required by
1 July 2008
Key Players:
Project sponsor / finance
North Shore City Council
Regulatory body
Auckland Regional Council
Consulting engineers
Sinclair Knight Merz
Environmental planning consultants
Simpson Grierson
Nutrient removal system design
URS
UV system
Wedeco
Maintenance contractor
Techscape
