25.2 Assessment of operational impacts

During operation, the following potential hazards and risks may be associated with the project:

Accidental releases or improper handling and storage of dangerous goods and hazardous substances in water treatment facilities
Releases of hazardous substances from vehicles transporting dangerous goods and hazardous substances to and from the water treatment facilities in the event of an accident
Releases of hazardous substances from non-project vehicles transporting dangerous goods and hazardous substances in the tunnels
Crashes and incidents in the mainline tunnels or entry and exit ramps
Crashes and incidents on surface roads
Electric and magnetic fields from the project substations
Potential hazards to road users and the general public relating to:

– Electric and magnetic fields – Bushfires – Aviation hazards.

25.2.1 Storage and handling of dangerous goods and hazardous substances

Dangerous goods and hazardous substances stored and used during operation of the project would be limited and may include coagulants, polymers, acid and bases (outlined in Table 25-4). Additional small quantities of other hazardous materials may occasionally be required on site to support maintenance activities.

A comparison of the likely types and quantities of dangerous goods and hazardous substances to be stored on site with applicable thresholds in the SEPP 33 Guidelines indicates that operational inventories would not be potentially hazardous.

25.2.2 Transport of dangerous goods and hazardous substances for the project

Dangerous goods and hazardous substances that would be transported for the project during operation are outlined in Table 25-5. Additional small quantities of other materials may occasionally be required on site to support maintenance activities.

A comparison of the likely types and quantities of dangerous goods and hazardous materials to be transported within the thresholds in the SEPP 33 Guidelines indicates that the transport of operational inventories would not be potentially hazardous. In the event that thresholds are exceeded, transport frequency is likely to be well below the frequency threshold and as such, risks are unlikely to be significant.

Table 25-4 Indicative dangerous goods and hazardous substances stored on site during operation

25.2.3 Transport of dangerous goods and hazardous substances in project tunnels

Dangerous goods and hazardous substances are not allowed to be transported within prohibited areas, in accordance with Road Rules 2014 – Regulation 300-2: NSW rule: carriage of dangerous goods in prohibited areas (Regulation 300-2). Prohibited areas are listed under Regulation 300-2 and include Sydney’s major tunnels.

The project tunnels would be listed as a prohibited area under Regulation 300-2 prior to the commencement of the operation of the project. Signage would be provided near tunnel entry portals advising of applicable restrictions to ensure compliance with Regulation 300-2.

25.2.4 Incidents in the tunnels

Any road project carries an inherent risk of vehicle collision associated with its operation. The potential for incidents and crashes to occur is a function of:

The design of the project
The type and volumes of traffic using the project
Driving conditions, including light conditions and meteorology
Human factors, including compliance with road rules, attention to driving conditions, driver behaviour and fatigue
Vehicle failure and breakdown.

The project has been designed to provide for efficient, free-flowing traffic with physical capacity to accommodate predicted traffic volume. The design has incorporated all feasible and reasonable design measures in relation to geometry, pavement, breakdown bays, lighting and signage. The design is consistent with current Australian Standards, road design guidelines and industry best practice, inherently minimising the likelihood of incidents and crashes.

Tunnel features designed to minimise the disruption caused by incidents and crashes include:

Height detection system prior to the tunnel entry portals
Tunnel barrier gates to prevent access in the event of tunnel closure
Closed-circuit television (CCTV) throughout the tunnel and approaches
Adjustable speed signs
Appropriately spaced breakdown bays and emergency telephones

The project has also been designed to meet appropriate fire and life safety requirements in the event of an incident or accident in the tunnel, as described in Chapter 5 (Project description). Consultation has been undertaken and would be ongoing with Fire and Rescue NSW and other emergency services to ensure the fire and life safety requirements are achieved.

Each project tunnel would be one-directional, reducing the risk of crashes through head-on collisions and simplifying smoke management and egress requirements. The transport of dangerous goods and hazardous substances would be prohibited through the mainline tunnels and entry and exit ramps, reducing the risk of very large fires or the release of toxic materials in the tunnel.

Other fire and life safety aspects that would be incorporated into the project include:

State of the art CCTV and audible systems to detect incidents and manage evacuation processes
Multiple pedestrian cross-passages between the mainline tunnels and longitudinal egress passages along the entry and exit ramps, to allow pedestrians to exit the tunnel and ramps in the event of a major incident (refer to Chapter 5 (Project description)). Cross-passages would cater for egress for people with disabilities; therefore, stairs or ramps with steep grades would be limited, or alternative safe holding zones would be provided where necessary
Automatic fire and smoke detection within the tunnels
Longitudinal ventilation to ‘push’ smoke in the direction of traffic flow away from the fire source towards a ventilation facility or tunnel portal
A water deluge system that could be activated manually or automatically at the fire source
Structures, linings and services that would be fire hardened to protect them from fire damage before the activation of the deluge system, or if the deluge system fails.

The likelihood of a fire during operation of the project cannot be entirely removed. Uncontrollable human factors inherently lead to a residual risk of incidents and crashes, although the likelihood of such events would be low.

In the event of an incident, approaching traffic would be prevented from entering the mainline tunnels. Vehicle occupants at the location of the fire and upstream of the fire source would be instructed to stop their vehicles, and exit in the opposite direction through the section of carriageway that would be protected by the smoke management system, or through an exit door to a cross-passage leading to the other (‘non-incident’) mainline tunnel.

Occupants downstream of the fire source would be encouraged to continue driving out of the tunnel. If this is not possible and they are forced to evacuate on foot, egress would be provided via an exit door to a cross-passage leading to the non-incident mainline tunnel. Emergency services would be able to reach the fire source via the non-incident tunnel (by vehicle or foot), or from the upstream direction in the affected tunnel (by foot).

25.2.5 Probability of tunnel fires

A summary of available tunnel fire incident data for Australia is provided in Table 25-6. A historical tunnel fire frequency based on a vehicle-kilometre basis for two of the tunnels listed in Table 25-6 has been calculated:

For the Lane Cove Tunnel, historical fire frequency has been around 0.5 fires per 100 million vehicle kilometres (all vehicles)
For the CityLink Tunnels (in Victoria), historical fire frequency has been around 0.8 fires per 100 million vehicle kilometres (all vehicles).

Based on traffic forecasts, the mainline tunnels are anticipated to experience around 20 million vehicle kilometres in 2023 and around 40 million vehicle kilometres in 2033. Applying similar tunnel fire frequencies to forecast traffic volumes for the project indicates:

An expected annual tunnel fire frequency of 0.10 to 0.15 is expected in 2021 (equivalent to about one fire incident every 6.6 to 10 years)
An expected annual tunnel fire frequency of 0.20 to 0.30 is expected in 2031 (equivalent to one fire incident every 3.3 to five years).

These values are comparable to observed annual tunnel fire incident rates for other Australian tunnels presented in Table 25-6, which range from around 0.16 to 0.76 per year, or around 0.5 to 0.8 100 million vehicle kilometres. Details regarding traffic volumes with and without the project are provided in Chapter 8 (Traffic and transport).

25.2.6 Incidents on surface roads

As discussed previously, the design of the project has been developed to inherently minimise the likelihood of incidents and crashes. Surface roads and infrastructure have been designed to provide an efficient and safe road network.

WestConnex provides an underground motorway connection for motorists travelling longer distances. In some cases, this results in fewer vehicles on major surface arterial roads across and in the vicinity of the project footprint. The M4-M5 Link would result in reduced traffic on sections of Parramatta Road, City West Link, and Victoria Road between Iron Cove Bridge (eastern abutment) and City West Link, and would also provide some relief for key northsouth corridors such as Southern Cross Drive.

A detailed discussion of the impact of the project on traffic volumes is provided in Chapter 8 (Traffic and transport).

The traffic reductions would result in the following traffic related benefits:

Improved traffic flow and intersection performance
Reduced crash rates
Improved road safety for pedestrians, cyclists and motorists
Improved travel times for bus services and motorists.

These traffic-related benefits are expected to result in an improved road safety environment.

Further details of the expected changes in traffic volumes on existing and new road infrastructure and improvements to road safety are provided in Chapter 8 (Traffic and transport). Impacts and improvements to air quality, noise and human health risks are discussed in Chapter 9 (Air quality), Chapter 10 (Noise and vibration) and Chapter 11 (Human health risk), respectively.

25.2.7 Road user and general hazards

Electric and magnetic fields

The Draft Radiation Standard – Exposure Limits for Magnetic Fields (Australian Radiation Protection and Nuclear Safety Agency December 2006) is based on a large body of scientific research since 1989. It proposes a series of exposure standards to replace the Interim Guidelines on Limits of Exposure to 50/60 Hz Electric and Magnetic Fields (National Health and Medical Research Council 1989).

Although the Draft Radiation Standard has never been finalised and published, the exposure limits presented are typically applied when considering electric and magnetic fields from new development. The project would include the provision of five aboveground substations, located at the Darley Road motorway operations complex (MOC1), Rozelle West motorway operations complex (MOC2), Rozelle East motorway operations complex (MOC3), Iron Cove Link motorway operations complex (MOC4)
and Campbell Road motorway operations complex (MOC5). As identified in Appendix F (Utilities Management Strategy), the project would also require the provision of new high voltage (132kV) utility infrastructure and the relocation, treatment and/or protection of existing high voltage utility infrastructure, within and outside of the project footprint.

The detailed design of project substations and high voltage utility infrastructure would ensure that the exposure limits for the general public in the Draft Radiation Standard – Exposure Limits for Magnetic Fields (Australian Radiation Protection and Nuclear Safety Agency December 2006) would not be exceeded at the boundary of the substation sites or for high voltage utility infrastructure.

Bushfire risks

As outlined in Chapter 18 (Biodiversity), vegetation in the project footprint comprises ‘urban exotic’ and ‘native cover’ (NSW Office of Environment and Heritage 2013a). No ‘bushland’ as defined in clause 4 of State Environmental Planning Policy No. 19 – Bushland in Urban Areas (SEPP 19) is considered to be present. Therefore, bushfires would not occur within the project footprint.

Notwithstanding, the operational infrastructure of the project is largely invulnerable to direct bushfire attack due to its incombustible nature (road surface materials, retaining walls, road barriers) and thefact that a lot of the infrastructure is in tunnels underground. Indirect bushfire risks to the project, including risks related to damage to communications networks or power supply are discussed in Chapter 24 (Climate change risk and adaption). The project would not increase the extent of bushfireprone
land.

Aviation risks

The operational design of the project has considered airspace protection and associated risks and hazards. As discussed in Chapter 2 (Assessment process) and section 25.1.4, under the Airports Act, a ‘controlled activity’ in relation to a prescribed airspace must not be carried out or caused to be carried out without the approval of the Secretary of DIRD or otherwise exempt under the Airspace Regulations.

CASA stipulates requirements for the construction and operation of new infrastructure that has the potential to influence aviation safety. CASA may determine that a plume, as exhausted from a ventilation outlet, is a hazardous object if the vertical velocity of the exhaust exceeds 4.3 metres per second. The Rozelle interchange and associated local road upgrades, the motorway operations complex at the St Peters interchange, and other ancillary infrastructure for the project would be located near flight paths used for Sydney Airport.

No buildings and structures that form part of the project are designed to intrude into prescribed airspace. The proposed ventilation outlets at the Rozelle interchange (at the Rozelle Rail Yards), Victoria Road (near the eastern abutment of Iron Cove Bridge) and at the St Peters interchange, are designed to be below prescribed airspace heights.

The project would include the construction and operation of ventilation facilities at:

Haberfield, at the corner of Parramatta Road and Walker Avenue (this ventilation facility is being built as part of the M4 East project. The M4-M5 Link project would undertake the electrical and mechanical fitout of the ventilation outlet for the project)
Rozelle, within the Rozelle Rail Yards
Victoria Road, Rozelle, near the Iron Cove Link portals at Terry Street
St Peters, within the St Peters interchange site near Campbell Road.

The exhaust plumes from all of the ventilation facilities have the potential to penetrate either or both the OLS or PANS-OPS levels. The project has been designed to satisfy requirements set by the DIRD in relation to erected structures (such as ventilation outlets), equipment manoeuvring and lighting. To determine whether plume rise resulting from the operation of these ventilation facilities would be a controlled activity as defined in section 183 of the Airports Act, a plume rise assessment would be carried out in accordance with the CASA Advisory Circular Plume Rise Assessments AC 139-5(1)
November 2012 prior to the operation of the project.

Aviation hazard lighting may be required on ventilation outlets at Haberfield, Rozelle, Iron Cove and St Peters. Surface road lighting would include an ‘aeroscreen’ type lens to minimise upward light spill. Aviation hazard lighting and surface road lighting would be in accordance with the requirements of CASA and Sydney Airport.

25.3 Environmental management measures

The implementation of environmental management measures for the project would avoid, to the greatest extent possible, risk to public safety and achieve the desired performance outcomes in relation to the hazards identified in Table 25-1. Environmental management measures relating to hazards and risk are outlined in Table 25-7.

In addition to these measures, a Work Health and Safety Plan would be implemented during construction of the project. This would support the management measures and procedures included in the CEMP for the project and would be supplemented by site and activity specific Safe Work Method Statements.
Table 25-7 Environmental management measures  hazards and risks

Spills and leaks from the storage and transport of dangerous goods and
hazardous substances

HR1 Storage of dangerous goods and hazardous materials will occur in accordance with suppliers’ instructions and relevant Australian Standards and legislation including the:

Work Health and Safety Act 2011 (NSW) Storage and Handling of Dangerous Goods Code of Practice (WorkCover NSW 2005)
Environment Protection Manual for Authorised Officers: Bunding and Spill Management, technical bulletin (NSW EPA 1997).

Storage methods may include bulk storage tanks, chemical storage cabinets/containers or impervious bunds.
Construction

HR2 Secure, bunded areas will be provided around storage areas for oils, fuels and other hazardous liquids. Impervious bunds will be of sufficient capacity to contain at least 110 per cent of the volume of the largest stored container.
Construction

HR3 Management measures to reduce the potential for spills, reduce potential spill volumes and prevent any contamination will be developed and implemented for
activities such as vehicle refuelling, servicing, maintenance, washdown, where there is a potential for spills and contamination.
Construction

HR4 Safety Data Sheets for dangerous goods and hazardous substances will be stored on site prior to their arrival.
Construction

HR5 Transport of dangerous goods and hazardous substances will be conducted in accordance with relevant legislation and codes, including the Dangerous Goods (Road and Rail Transport) Regulation 2014 (NSW) and the Australian Code for the Transport of
Dangerous Goods by Road and Rail (National Transport Commission 2008).
Construction

HR6 The project will be constructed in accordance with the design requirements of CASA and the Sydney Airport Master Plan 2033, with respect to lighting used during
construction.
Construction

Potential impacts from fire and safety incidents

OpHR1 The fire and safety systems and measures adopted for the project will be equivalent to or exceed the fire safety measures recommended by National Fire Protection Association 502 (American), Permanent International Association of Road Congresses (European), AS4825 (Australian) and Roads and Maritime standards.
Construction Impact No. Environmental management measure Timing

OpHR2 Ongoing consultation will be undertaken with emergency services regarding fire and safety systems and measures adopted for the project.
Operation

OpHR3 The transport of dangerous goods and hazardous substances will be prohibited through the mainline tunnels and entry and exit ramps.
Operation

OpHR4 An Incident Response Plan will be developed as part of the Emergency Response Plan for the project and implemented in the event of an accident or incident.
Operation

OpHR5 The response to incidents within the motorway will be managed in accordance with the memorandum of understanding between Roads and Maritime and the NSW Police Service, NSW Rural Fire Service, NSW Fire Brigade and other emergency services.
Operation

Spills and leaks from the storage and transport of dangerous goods and hazardous substances

OpHR6 Storage of dangerous goods and hazardous materials will occur in accordance with suppliers’ instructions and relevant Australian Standards and legislation including
the:

Work Health and Safety Act 2011 (NSW)
Storage and Handling of Dangerous Goods Code of Practice (WorkCover NSW 2005)
Environment Protection Manual for Authorised Officers: Bunding and Spill Management, technical bulletin (NSW EPA 1997).

Storage methods may include bulk storage tanks, chemical storage cabinets/containers or impervious bunds.
Operation

OpHR7 Secure, bunded areas will be provided around storage areas for oils, fuels and other hazardous liquids. Impervious bunds will be of sufficient capacity to contain at least 110 per cent of the volume of the largest stored container.
Operation

OpHR8 Management measures to reduce the potential for spills, reduce potential spill volumes and prevent any contamination will be developed and implemented for activities such as vehicle refuelling, servicing, maintenance or washdown, where there is a potential for spills and contamination.
Operation

OpHR9 Material Safety Data Sheets for dangerous goods and hazardous substances will be stored on site prior to their arrival.
Operation

Exposure to electric and magnetic fields

OpHR10 The detailed design of the project substations will ensure that the exposure limits for the general public suggested by the Draft Radiation Standard (Australian Radiation Protection and Nuclear Safety Agency 2006) will not be exceeded at the boundary of the substation sites.
Construction

Impacts from air emissions

OpHR11 Should the exhaust plumes at any of the M4-M5 Link ventilation outlets be assessed as a ‘controlled activity’ under the Airports Act and the Airspace Regulations,
then the project will be operated in accordance with any Construction and operation
Impact No. Environmental management measure Timing conditions of approval from the Secretary of DIRD.

OpHR12 Aviation hazard lighting (if required), building lighting and surface road lighting will be designed and operated in accordance with the requirements of CASA and the Sydney Airport Master Plan 2033.
Construction and operation