The Ventilation system of the M5 East has been examined by independent local experts, the Legislative Council GPSC No 5 Inquiry, the Tunnel Ventilation workshop and by the CSIRO (for DUAP). Every one of these investigations raised significant concerns about the safety and appropriateness of the design.

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.

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.

These experts, selected by the RTA represent 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 and the general 'philosophy' of the design:

'Art' Bendelius (USA): "The first reaction I had was why put one stack in a valley… but the system appears that it will work from a standpoint of ventilating the tunnel. .... The real issue is what do you do with the discharge or where do you put it. We've always tried to put them as high as possible, not in a valley."

The experts 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 also 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 M5East, using a simple ventilation system, using 100 kilowatts for normal operation - compared to the 12 megawatts (or 120 times more) for the M5East. The M5E will use 32 Gigawatt hrs, or over $2million of electricity a year, enough for a medium country town! This will produce almost 30,000 tonnes of greenhouse gas per year!

Norwegian and German experts in filtration equipment showed that the dangerous components of vehicle pollution could be economically removed from the M5 East tunnel by using electrostatic precipitators and other new gas treatment systems. This equipment could more than halve the overall cost of ventilation by enabling the use of simpler ventilation systems. Currently electrostatic precipitators are in use in tunnels in Norway, Japan and South Korea and planned for Germany, Vietnam and in the reconstruction of the Mont Blanc tunnel. Their effectiveness was vouched for by all the international experts.

The design was shown to be overly complicated and 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. Swiss based English engineer, John Day noted:.'within our Government we are not allowed to waste energy, and we have to balance resources.'

The CSIRO was asked by DUAP 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:

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!

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.

Although down played by the RTA and Department of Health, evidence about the adverse effects of vehicle emissions is growing, with diesel exhaust being now internationally recognized as a carcinogen. The most recent and largest such study reported in the New York Times in June 2000. shows that adverse health effects of particulate matter were measured at levels below those currently experienced in Sydney.

In June 2000, the NSW State Labor Conference passed a motion calling for the filtration of emissions from the M5 East and future road tunnels, and a similar motion was passed by the November 2000 Local Government Association Annual Conference.

Yet, 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 and the expectation that governments will act in the best interests of all of their citizens.