Sustainability Indicators
Aim: The following Sustainability Indicators aim to demonstrate how we provide reliable sewerage services that match our customer’s needs and minimise our impact on the environment.
Sewer spills contained within five hours of being reported
Where we would like to be:
In our Water Plan we committed to containing 100% of sewer spills within five hours of being reported. From 1 July 2005 this measure is also a Guaranteed Service Level, meaning that we will pay the customer reporting the fault $25 when we do not contain a sewer spill within five hours of it being reported.
Where we are:
| % of sewer spills contained within 5 hours | 2002-03 | 2003-04 | 2004-05 | 2005-06 |
|---|---|---|---|---|
| Actual | 100% | 100% | 100% | 100% |
| Target | 100% | 100% | 100% | 100% |
| Total GSL payments | n/a | n/a | n/a | $0 |
Results:
This year we contained 100% of our sewage spills within five hours, meeting the service standards outlined in our Customer Charter.
Where we are headed:
We aim to maintain our focus on spill management by continuing to train personnel and also by escalating events to ensure impact to our customers and the environment is minimised.
Sewer spills due to pumping station failure
Where we would like to be:
To have zero sewer spills due to pumping station failure.
Where we are:
| Sewer spills due to pumping station failure | 2002-03 | 2003-04 | 2004-05 | 2005-06 |
|---|---|---|---|---|
| Actual | 0 | 0 | 0 | 0 |
| Target | 0 | 0 | 0 | 0 |
Results:
The continued emphasis on maintaining our pumping stations has again achieved our target.
Where we are headed:
A power outage contingency review will occur next year. This review will examine whether current infrastructure and response capability is suitable to maintain services in the event of a widespread power outage.
Sewage spills, wet weather
Where we would like to be:
In our 2003-06 Environment Improvement Plan we committed to satisfying the requirement of the State Environment Protection Policy to upgrade our network to meet the 1-in-5-year Average Reoccurrence Interval (ARI) containment standard.
Wet weather spills (not including spills caused by pumping station failure and extreme wet weather*) are those that result from inflow into the sewer network during rainfall.
*extreme wet weather is defined as an event which has an ARI of greater than 1-in-5 years at a particular location.
Where we are:
| Wet weather spills | 2002-03 | 2003-04 | 2004-05 | 2005-06 |
|---|---|---|---|---|
| Actual | 0 | 3 | 7 | 1 |
| Target | 0 | 0 | 0 | 0 |
Results:
There was one non-compliant wet weather spill during the 2005-06 financial year and as part of City West Water‘s hydraulic improvement program, flow monitoring and closed circuit television inspections were undertaken in the affected sewerage catchment. Hydraulic analysis of the cause of this spill will be completed during 2006. This analysis will determine the nature and extent of any hydraulic improvement works required to alleviate non-compliant wet weather spills in this catchment.
Where we are headed:
We will continue to work on improving the hydraulic capacity of the sewerage system through the construction of new infrastructure. We will also reduce the potential for spills by continuing to maintain our assets and reduce the average water consumption of customers.
Sewage spills, dry weather
Where we would like to be:
To continue to minimise dry weather spills through monitoring and targeting particular assets for improvement works.
Dry weather spills are defined as spills that result from a combination of factors including: pipeline blockages due to tree roots, fatty substances or objects, pipeline structural failure and infiltration into the sewer network during non-extreme wet weather.
Where we are:
| Dry weather sewer spills | 2002-03 | 2003-04 | 2004-05 | 2005-06 |
|---|---|---|---|---|
| Actual | 710 | 830 | 739 | 638 |
Note: There is currently no target for this Sustainability Indicator.
Results:
The results this year indicate that our tree root removal program and cleaning program in the sewer system were successful. The low number this year was also influenced by extensive work conducted toward the end of 2004-05.
Where we are headed:
We aim to continue our emphasis on tree root removal and cleaning to reduce the chance of blockages occurring in the sewer system.
Customers receiving more than three sewer interruptions/blockages
Where we would like to be:
In our Water Plan we committed to providing a service standard of no customers experiencing more than three sewer blockages in a 12-month period. From 1 July 2005 this measure is also a Guaranteed Service Level, meaning that we will pay affected customers $25 each time they experience more than three sewerage service interruptions in a 12-month period.
Where we are:
| Customers receiving more than 3 unplanned sewerage interruptions | 30 June 2003 | 30 June 2004 | 30 June 2005 | 30 June 2006 |
|---|---|---|---|---|
| Actual | 4 | 0 | 0 | 0 |
| Target | 0 | 0 | 0 | 0 |
| Total GSL payments $ | n/a | n/a | n/a | $0 |
Result:
A continued emphasis on preventing sewerage interruptions has again resulted in City West Water meeting its target.
Where we are headed:
We will continue to focus on achieving this target of no customers receiving more than 3 unplanned sewerage interruptions by replacing poor performing assets, monitoring customer issues and quickly responding to faults.
Average time to rectify a sewer blockage
Where we would like to be:
In our Water Plan we committed to rectifying sewer blockages within 141 minutes. From 1 July 2005, this measure is also a Guaranteed Service Level, meaning that we will pay affected customers $25 any time we take longer than five hours (300 minutes) to restore an interruption to their sewerage services.
Where we are:
| Average time to rectify sewer blockages (minutes) | 2002-03 | 2003-04 | 2004-05 | 2005-06 |
|---|---|---|---|---|
| Actual | 162 | 141 | 129 | 115 |
| Target | n/a | n/a | 142 | 141 |
| Total GSL payments | n/a | n/a | n/a | $2,325 |
Result:
During 2005-06, 93 customers experienced a sewer blockage over five hours (300 minutes) in duration.
An ongoing emphasis on maintaining services to our customers has led to continued reductions in the average time to rectify sewer blockages.
Where we are headed:
We intend to continue to improve our services to customers through a focus on reducing the response and rectification times for sewer blockages.
Altona Treatment Plant licence compliance
Where we would like to be:
To comply with the licence conditions set by the EPA Victoria for operating our sewage treatment plant at Altona.
Where we are now:
| ATP operating licence compliance | 30 June 2003 | 30 June 2004 | 30 June 2005 | 30 June 2006 |
|---|---|---|---|---|
| Actual | 100% | 94% | 94% | 59% |
| Target | 100% | 100% | 100% | 100% |
Results:
The EPA Victoria required that City West Water comply with the conditions for the new treatment plant from 14 October 2005. Unfortunately, as shown in the results above, the existing treatment plant failed to comply with all the new licence conditions, which demonstrates the importance of building the new treatment plant.
Where we are headed:
The new treatment plant is to be commissioned in August 2006. We anticipate that the new treatment plant will be producing high quality treated wastewater by the end of 2006, with the objective of meeting all the EPA Victoria licence requirements.
