Although the M5 East, Cross City and Lane Cove Tunnels as proposed by the RTA have individual design specifications, all three tunnel proposals apply the same ventilation system design. Thus although each tunnel project has its own figures on impacts and costs involved the concept is the same across all three: ventilation through a single unfiltered stack. This page will outline some of the major criticisms of the ventilation arrangements proposed by the RTA. It will look at alternatives recommended by RAPS that are in use in tunnels overseas. It will also address, with reference to the Cross City Tunnel, the alternative of not constructing the tunnel in the first place, thus eliminating the problems associated with a stack, as recommended by Greenways and the Total Environment Centre.
As the M5 East was the first of the three tunnels to have this system proposed, acting as a blueprint for the other two, the majority of studies on the impacts of this design have been focused on this specific motorway.
The RTA solution for ventilation of the proposed tunnels involves sucking in air at tunnel portals, then pumping the air using large axial fans through the tunnel and out through a single ventilation stack. According to the RTA, this ventilation design will meet current air quality goals, and that air filtration and treatment systems will not be required to meet health goals.
According to RAPS however, potential health risks are continually trivialised by dependence on 'compliance' with the NEPM air quality goals when it has long been clear that these goals are unsuitable for use in regard to point sources. Furthermore, these goals do not take sufficient account of long term cumulative impacts. At no stage have the RTA acknowledged the fundamental issue, that at current levels, where the NEPM goals are rarely exceeded, between 400 and 500 people die prematurely each year in Sydney from the effects of air pollution. The only responsible position which can be adopted is to aim to reduce levels of air pollution to the lowest levels possible using the best available technology.
The RTA's ventialtion design has been examined with regard to the M5 East by independent local experts, the Legislative Council GPSC No 5 Inquiry, the International Tunnel Ventilation workshop and by the CSIRO (for the Department of Urban Affairs and Planning). As RAPS point out, every one of these investigations raised significant concerns about the safety and appropriateness of the design.
The Child Report (for Canterbury Council, April 1999)
The single stack ventilation scenario, as currently proposed, involves a very high and unacceptable level of risk that the levels of air pollutants in the area will exceed established regulatory goals. Such an outcome has clear and unacceptable community health implications, and to date no provision has been established to deal with such an eventuality.
To read the Executive Summary of the Child Report, click here.
The Parliamentary Inquiry (Dec 1999)
The Committee believes that the impact of the stack on the surrounding community has not been properly assessed. The operation of the stack in the Wolli Creek Valley will result in an increase in the air pollution levels in the locality, and this will occur no matter how high the stack is constructed.
The Committee’s key, unanimous recommendation was for expressions of interest to be immediately sought for the installation of filtration systems. Instead, the RTA held a workshop.
International RTA Workshop on Tunnel Ventilation (June 2000)
These experts, selected by the RTA representing the very best in road tunnel design around the world, found that the proposed design did not represent the 'world's best practice' claimed by the RTA, but was highly unusual, even idiosyncratic. "The complex, remotely located M5 East single stack tunnel ventilation design can be distinguished from any other tunnel ventilation scheme in the world". (Dix report August 2000, p 43)
All the experts were critical of the location of the M5 East stack, being in a valley, as well as the general 'philosophy' of the design. They felt the current design would meet the ventilation requirements inside the tunnel, but were less confident it would meet the environmental conditions outside the tunnel. They were concerned about the excessively complicated design of the whole system due to the the exhaust stack being 800m away from the tunnel in a valley and also the total prohibition on any emissions escaping from the tunnel ends.
Swiss expert, John Day, had just designed a comparable tunnel to the M5 East, using a simple ventilation system, using 100 kilowatts for normal operation - compared to the 12 megawatts (or 120 times more) for the M5 East. The M5E will use 32 Gigawatt hrs, or over $2 million of electricity a year, enough for a medium country town! This will produce almost 30,000 tonnes of greenhouse gas per year!
The design was shown to be highly wasteful in terms of its capital and running energy costs and its ability to respond to changed conditions. While the cost of ventilating tunnels overseas is decreasing with improvements in vehicle emissions, this could not be expected to happen in the M5 East. The real cost involves the 'life time cost' of running and maintenance as well as capital costs.
The CSIRO Report
The CSIRO was asked by the Department of Urban Affairs and Planning to report on aspects of the ventilation system design and on the air quality modeling produced to 'validate' the stack height, rather than review the adequacy of the whole system. The report found:
- In our view, it is quite possible that actual PM10 emissions could be a factor of two or more higher than the PIARC estimates at full engine load as the majority of the emission will in fact, come from high power operation. If PM10 emissions were a factor of two or so higher, there would be exceedences.
- Although GDI (Gasoline Direct Injection, an emerging engine technology, soon to be used in Australia) gives a 20% improvement in fuel economy, it will lead to an increase of particle emissions of three to four times as great as present conditions (SAEA, 2000).
- Although the modelling (by Hyder) shows that PM10 Standards are not exceeded, it is possible that at other times this may not be the case
- We also believe the possibility of plume strike on tall buildings needs to be taken as a serious possibility and that building height restrictions be imposed in the region following modelling studies.
- We also believe the reliance on the wind tunnel results to support a claim that the numerical modelling is conservative, has not been justified.
- The obvious differences between day-by-day levels of NO2 and PM10 for 1995 and 1998 support a conclusion that we wish to make strongly: We do not agree with the approach followed in the Hyder Reports. There is far too much variation in the real atmosphere for the Tier 3 methodology to be considered conservative.
Yet, the Department of Urban Affairs and Planning approved the project, with a number of new conditions applied to the system, such as increasing the stack height to a minimum of 35m, more comprehensive monitoring, and provision for buying back wood heaters as a way of improving air quality!
To read the CSIRO Report, click here.
Community Response
Local residents have long objected to the stack design because of its health, environmental and visual impacts. They have already suffered significant drops in the value of their homes as a result of this development, but they have been refused any form of compensation.
Despite four years of community protest, a court case, a Parliamentary Inquiry, a critical Tunnel Workshop and over 17,000 petitions and letters, there has been no change in any significant aspect of the system in response to well founded concerns. It is clear that the current design proposals for the M5 East and other city tunnels, such as the Eastern Distributor, Cross City and Lane Cove tunnels are environmental and economic disasters in the making. They are unhealthy, uneconomical to run and represent a careless attitude to public health and safety.
There are clear alternatives to the health and environment threatening use of a single unfiltered stack as the ventilation solution to the road tunnel projects. Possible sollutions currently in use overseas include filtration in a stack, or progressive filtration at tunnel ends with dispersal through vertical dispersal units (mini stacks) as well as, or alternatively, portal emission.
The alternative recommended by RAPS is for the application of the system used in Norway involving in-tunnel air cleaning for the 4 km long M5 East tunnel that will make the stack unnecessary as the air emitted from the tunnel will be able to comply with air quality goals. The installation consists of two sets of air cleaning equipment made up of electrostatic precipitators and catalytic nitrogen dioxide removal filters, placed close to the exits of each traffic tube.
Fresh air enters the tube under the influence of traffic flow assisted by ceiling mounted jet fans and travels along the tube towards the exit. As the air moves along the tube it becomes more and more laden with exhaust gases, the actual concentration of which is determined by the traffic load and the amount of air entering the tube, as is the case in the harbour and other tunnels. Just before it exits the tube it is diverted into a side tunnel where it passes through firstly, an electrostatic precipitator which removes up to 95% of the particulate matter and then into the nitrogen dioxide bed where over 90% of the nitrogen dioxide is catalytically converted to oxygen and nitrogen and sulphur dioxide and VOC's are also removed. At the concentrations involved, the carbon monoxide and nitrogen oxide in the exhaust present no health risk.
The tunnel air is then vented to the outside, either through the tunnel portals or through an above ground structure designed to jet the air directly upwards. Although the Norwegian solution has been to install the filtration equipment underground, there is no reason why it could not be housed above ground, above or close to the tunnel portal.
The electrostatic precipitators require cleaning after about 200 hours of use. The process requires about 2 hours and the solid waste produced at each cycle will amount to about 0.5 cubic meters in volume. The water used in the process is cleaned and recycled and the solid waste presents no particular hazard. The nitrogen dioxide catalyst will require no maintenance other than cleaning about every 3 years.
Both sections of the equipment are modular and their capacity can be increased if necessary. In some overseas tunnels the electrostatic precipitator equipment now deals with air flows 50% over its original design capacity. The equipment cost for the complete treatment of air at the currently proposed ventilation rate of 600 cubic meters per second is less than $19 million and the other costs involved less than $7 million. This is to be compared with the estimated cost of the RTA's suggested stack and air inlets of over $36 million.
ALTERNATIVES TO THE CROSS CITY TUNNEL
Another sure way of eliminating the threat posed by unfiltered stacks is by not building the road tunnel which (supposedly) requires their use in the first place. The estimated cost of constructing the M5 East Freeway is $750 million and of the Cross City Tunnel, $400 million. These are huge sums of money, and so one would want to be sure they are worth the expenditure. In the case of the Cross City Tunnel, Greenways and the Total Environment Centre argue that it is not.
In response to the Environmental Impact Statement (EIS) on the Cross City Tunnel, Greenways and the Total Environment Centre have written a submission outlining significant flaws in the tunnel design and suggesting a number of public transport alternatives which are less expensive, more environmentally sound and a better solution in the long run. For a full copy of this submission click here.
Problems with the Cross City Tunnel (CCT) design
- the CCT encourages motor vehicle use in the CBD. The EIS states both roads and rail are nearing capacity, thus which ever mode is expanded will be the mode people travel by
- expressways like the CCT have been identified as inducers of traffic by the NSW EPA 1997 State of the Environment Report. This jeopardises the Government's air quality objectives which require a 43% reduction in the growth of vechile kilometres travelled
- the design does not pay due attention to surrounding suburbs where the CCT would greatly increase traffic congestion, thus in the long run expanding the area where traffic congestion is a major problem
- the EIS fails to make an adequate assessment of traffic demand management options, claiming insufficent data available (the onus must be on the RTA to aquire that data before wasting $400 million on 2km of road!)
- the EIS fails to consider workable public transport alternatives
- the cost of the public transport option is distorted in the EIS to be significantly larger through the inclusion of an unnecessary and expensive bus tunnel
- from the EIS, no confident conclusions on the environmental impacts of the tunnel can be determined, and thus it should be rewritten to a higher standard, addressing all environmental concerns
- the ventilation system of the CCT suffers the same flaws as that suggested for the M5E, through the use large fans to pump air through the tunnel requiring massive amounts of electricity, and therefore producing tonnes of greenhouse gases, and the use of a 39m unfiltered stack at Darling Harbour. This ventilation is unecessarily expensive and harmful.
The Alternatives suggested by Greenways and the Total Environment Centre
Trams
City Trams
Construction of the city tram loop to Circular Quay should begin as soon as possible. The current government policy to delay construction until the completion of the tunnel is a peculiar twist of logic. The government's logic indicates that major problems need to be created by cars before public transport options are developed. A sounder logic would be to develop public transport to prevent cars from creating chaos.
Inner West Trams
Extension of the existing tram line to Ashfield, Dulwich Hill or Five Dock should proceed in the near future.
Bay Light Express
A new proposal has recently been released by EcoTransit for a tram system in Southern Sydney on both sides of Botany Bay. This proposed tram system would link into the existing Inner West Tram Line and would act as a major East West transport link.
Eastern Suburbs Tram Line (Coogee Tram Line)
There has been a strong call for a reopening of the Eastern Suburbs Tram Line along ANZAC Parade to Coogee.
Buses
Cross City Bus Services should be established to provide public transport for East West commuters
Bicycles
There are no bicycle routes through the CBD. There is a need for a continuous bicycle route from ANZAC Parade through the CBD then linking up with the existing bicycle routes over Darling Harbour and onto the Glebe Island Bridge.
Many Councils support public transport. Marrickville Council recently announced they will undertake a feasibility study of extending the Inner West Tram Line to Dulwich Hill. Leichhardt Council supports the construction of New Tram Lines instead of the Cross City Road Tunnel.
Thus there needs to be serious consideration taken as to whether it is worthwhile spending $400 million on a tunnel only 2 km long, which will cause chaos on the roads in the CBD during the 3 year construction period, when there is evidence that it will increase traffic congestion rather than aleviate it. If alternatively a budget of $400 million were geared toward public transport, which was proven to be a winner during the 2000 Olympic games, the benefits would be significant and be felt across greater Sydney, not just the CBD.