Annual Report 2010 - Christchurch City Council

p108. Annual Report
Christchurch Otautahi
2010
Council activities and
services
Wastewater collection
and treatment
Council activities and services
Wastewater collection and treatment
Trend
Watewater collection is provided in a safe, convenient and efficient
manner: response time for blockages
100%
98%
96%
98%
94%
91%
94.1% 97% 99% 100%
Target: ≥99%
Metrowater: 97%*
94%
92%
Target: ≥90%
90%
88%
Main blockages and non-consented overflows
responded to within 1 hour
86%
Blockages responded to within urban areas: 1 hour
84%
Blockages responded to within rural areas: 2 hours
82%
80%
2006/07 2007/08 2008/09 2009/10
Blockages responded to within urban areas: 2 hours
Blockages responded to within rural areas: 4 hours
* Auckland City water and wastewater utility benchmark
Where are we heading?
The biosolids drying facility will be fully commissioned in 2010.
This removes water from the waste matter, significantly reducing
the cost of transportation to disposal or re-use sites.
Construction on the Western Interceptor and Fendalton Duplicator
will commence during the 2010/11 year, as will upgrade works
at Pump Station 22. These projects are required to meet resource
consent conditions that require a reduction in the frequency of
wastewater overflows in wet weather into the Avon and Heathcote
rivers. The Western Interceptor also provides for city growth in the
South West.
Planning and consenting work will continue to ensure future
discharge of the small wastewater treatment plant aligns with the
2009-19 LTCCP construction programmes. Many of the Lyttelton
and Akaroa wastewater treatment plants obtained only short term
consents under Banks Peninsula District Council to discharge
waste into the harbours. Upgrades and new consents are required
to enable continuance of the wastewater services for these
communities.
Strengthening of the Christchurch Wastewater Treatment Plant
electrical network will continue in 2010/11 to reduce the risk of
disruption of the plant’s operation.
Wastewater catchments modelling will commence in the city. This
work is needed to optimise networks and identify any areas of high
inflow and infiltration. This provides better information on how
the sewer network operates in wet weather events, so that the most
cost effective programme of works can be implemented to reduce
overflow frequencies.
Automation upgrades to rural pump stations and wastewater
treatment plants (to increase reliability) will continue in 2010/11.
Asset renewal works will progress in line with asset management
plans. The asset management plans identify rates of replacement
that will ensure a continuation of appropriate levels of service.
Design work will be completed for a new co-generation engine for
the Christchurch Wastewater Treatment Plant and construction
will commence late in the 2010/11 year. This is to replace equipment
used to generate electricity from gas made at the plant, which is
reaching the end of it’s useful life. The new equipment will be more
efficient.
Design and consenting work associated with water and wastewater
reticulation systems in Charteris Bay will be completed in 2010/11.
Construction will follow in 2011/12. The Charteris Bay community
currently has no water supply or wastewater service. Originally a
weekend batch community, it is increasingly becoming a place of
permanent homes. Many failing septic tanks and an expectation
that the same services should be applied to all significant Lyttelton
Harbour communities has led to the inclusion of these works in the
programme.