Questions from community sessions

 Please find below answers to some questions asked by residents at the Summer Hill substation project community sessions, as well as for other similar projects.


Project need

1. Why does Ausgrid need to do this work? 
The Dulwich Hill zone substation has been operating since 1966 and the equipment needs to be replaced so we can maintain a safe and reliable electricity supply. Additionally, due to the noise levels generated by the current transformers, Ausgrid is planning to replace the current transformers with newer, quieter transformers. The project would involve construction of a new switch room, control room, transformer driveway and three transformer bays with potential space for a fourth transformer bay if needed in the future. The existing substation needs to remain in service during the replacement.   

2. Why can’t you just replace the equipment in the existing building?
The existing substation building was built in the early 60s and is reaching the end of its serviceable life. The equipment in the existing substation supplies the local area with electricity and needs to continue this function until the new substation is built. When the new substation is on line and supplying power to the community we can then switch off the old substation and decommission the building. The site for the new substation was selected because it is adjacent to the existing facility, allowing the new substation to be constructed in an area where there has traditionally been one operating. The proximity of the new substation to the existing one would make it easier to construct and would have less impact on the community overall. Ausgrid is taking the opportunity to construct a new architecturally designed building that caters for the community's future electricity needs and fits in with the character of the surrounding neighbourhood. 

3. I haven’t heard any noise from the transformers, do they really need to be replaced? 
The existing transformers need to be replaced to meet environmental requirements. 

4. Does this proposal cater for future demand?
While this project is driven by the need to replace equipment that was installed in the 1960s, the new substation could allow for future expansion, if needed, with the provision of space for an additional spare transformer bay and associated equipment. This is being considered as part of the planning process. 

Concept designs

1. Is there a height difference between the design concept options?
No, all of the proposed concept designs are the same height.

2. Are the glass bricks (shown in the design concepts) windows?
No they are not windows but a visual treatment designed to break up the building’s height and bulk.

3. Would the new building be set back from the street?
Ausgrid is looking to set the building back from the street as this has been indicated as a preference by several community members. The project team is working on the extent of the setback by first determining the exact location of existing underground services, planning the location of the new underground cables and considering the location of other electrical equipment that would be required for the new substation.

4. Will the building look the same all the way around?
No, as there are requirements for the site that need to be considered such as the location of the transformers, the driveway, existing services etc. that would affect the design and location and to an extent the appearance of the building. However, Ausgrid is considering all view points and applying architectural design to each of the substation's facades.

5. Why do the concepts designs only show one view?
The concept design, showing the view from the Old Canterbury Road side, was prepared to give an indication of potential architectural styles that could be used for the substation design. The community's feedback will help determine a preferred concept that will be the basis of more detailed designs for further community input. These more detailed designs will include a range of views from around the proposed substation.

6. Can Ausgrid make the new building look like the double storey Victorian building located across the road?
Characteristics of Victorian and Federation houses in the area have been picked up as elements in the design options prepared by the architects Brewster Murray. Brewster Murray advised in answer to this question that directly copying a building’s architectural style is often not as effective as designing a building with architectural elements to fit into the surroundings as it is hard to get the proportion and other details right.

7. What does Ausgrid mean by security considerations in relation to the design options?
This relates to measures to prevent unauthorised people from entering the substation building such as fencing types and heights, wall heights and surfacing, as well as landscaping.

8. What is a CLC building and what would it look like?
Customer Load Control (CLC) is the technical name for the system that controls off peak hot water in homes and businesses. In the existing substation it is located in a small dedicated building. For the proposed new substation the project team is working on the best location for this equipment such as within the main structure or in a small separate building. Further planning has to be completed before the location can be confirmed but the location will be shown in the detailed designs developed for the community's feedback.


1. Will Ausgrid need to remove the large tree located on the land proposed for the substation?
Yes, this tree will need to be removed to allow the substation to be constructed. New native landscaping is being planned as part of the substation proposal.

2. Does landscaping around a new substation have to be a certain height and a certain species?
Ausgrid generally selects lower native shrubs and other plants as landscaping around substations. This is to avoid the risk of people using larger vegetation as climb points to gain unauthorised access and to avoid large vegetation dropping into a substation and causing damage. By using local native plants, these are suited to the area and more likely to thrive. As part of the early design process, a variety of plants including shrubs and small trees have been proposed and these can be viewed online as part of the concept design package (link at right or by going to the community information and presentations section within this project page).

3. Could Ausgrid plant hedges in front of the substation that faces Old Canterbury Road?
 Ausgrid will consider this as feedback for consideration as detailed designs are developed.

General project questions

1. Will Ausgrid talk to other government bodies about this project?
At the first community session, residents raised concerns about existing storm water issues in the area in relation to our plans and whether we would be addressing these issues with other government bodies. Ausgrid meets regularly with other government bodies as part of our planning and any community concerns will be raised as part of this process.

2. Is there a technical reason that determines where the new transformers would be located?
Yes, there are technical reasons but also construction feasibility, community and environmental considerations that are factored into the planning of the transformer locations and the rest of the site layout. The preferred layout is the one that best meets all of these factors.

3. What are the plans for rest of the site?
Following the process of putting a new substation into service and decommissioning the existing facility, it is expected that Ausgrid would then consider the sale of the surplus land.

4. Would the new substation be noisy?
The new substation would cause minimal noise emissions as a result of the modern low noise equipment we propose to install in the substation. Ausgrid will complete a study on the expected noise from the operating substation to ensure that it meets all relevant guidelines and standards. This report will form part of the environmental assessment of the project.

5. Will the 11,000 volt cables that currently run from the Ausgrid site to Herbert Street be relocated as part of this project?
 No, there are no plans for these cables to be relocated at this stage.

6. Can buildings be constructed over cables?
No, Ausgrid generally has easements over cables and under power lines to prevent buildings being constructed under or over our network. Cables and power lines need to be able to be accessed for maintenance or emergency work and to be protected from damage.  

Construction related questions

1. What will the work site look like?
A typical work site would encompass a number of vehicles including excavators, trucks to bring concrete and remove spoil and other trucks containing equipment and material. On-site personnel includes the civil contractor completing the building work for Ausgrid, specialist contractors and Ausgrid staff.  Traffic control staff are also be present as required for any works such as special deliveries that may have a short term impact on traffic or parking.

2. What hours does Ausgrid work? Would there be work at night?
Ausgrid generally works the standard construction hours for these types of projects  – 7am to 6pm Monday to Friday and 8am to 1pm on Saturdays. However, there may be times when we need to work out of hours, for example, to receive over size deliveries or to run tests overnight. We would advise nearby resident in advance of any out of hours work or activities that would have a greater impact than usual.  

3. How long will it take to complete the work?
A civil builder would be engaged to construct the new substation buildings over approximately 12 months, with Ausgrid technicians then to complete the electrical fit out. It is anticipated that civil construction of the proposed new substation would be completed by end of 2017 and connected to the electricity network by 2018.

Construction impacts will be similar to any building construction site, with the more significant disruption occurring during the first three to six months while excavation and concreting is carried out. Once the building construction stage is finished, there will be minimal disruption while Ausgrid staff complete electrical work in the building. Once the new substation is in service, Ausgrid staff would then attend the site periodically for maintenance and the facility would not be permanently staffed.

Electric and magnetic fields

1. What are the predicted EMF levels for this project?
Modelling of the magnetic fields from the proposed substation would be completed independently of Ausgrid by consultants as part of the environmental assessment of the project. Modelling reflects Ausgrid’s annual 20 year electricity network forecast and the measures to minimise magnetic fields. Modelling is conducted based on predicted forecast operation of the substation and associated cables up to 20 years in the future, which factor in load growth over this time. This means that the magnetic field levels indicated in the report will likely be higher than those actually experienced for the majority of the time. As the proposal is to replace the existing substation with a new one with no extra capacity, it is expected that magnetic fields would remain largely the same for the area. Ausgrid has taken some measurements of the existing area which can viewed in the link to the infographic at top right.

2. Will the levels of electric and magnetic fields (EMF) from the proposed cables be safe and comply with relevant Australian health guidelines?
Safety is Ausgrid’s highest priority. The proposed substation has been planned on the basis that the new substation can be operated safely in the community and this is Ausgrid’s first and most important consideration. The proposal would operate well within Australian and international health guidelines, with very little, if any change to existing magnetic fields in nearby properties.

3. What is Ausgrid’s approach to EMF?
While there remains a lack of scientific consensus about whether electric and magnetic fields (EMF) can cause any adverse health effects, Ausgrid understands that there is concern in the community about EMF. We take seriously our responsibility to help address these concerns by providing balanced and accurate information about EMF, by taking reasonable steps to limit exposure and by operating all our electrical installations prudently within Australian health guidelines. We also regularly monitor research and policy into EMF and health. As there is a lot of research and studies regarding health and EMF, Ausgrid is guided by Australian Government agency ARPANSA, which takes a whole of science approach in relation to electricity and health. This includes implementing prudent avoidance measures where practical and feasible, as we will do for this project. Ausgrid's position includes complying with all relevant national and international guidelines.