July 22 2002
The exhaust stack at Earlwood. Photo: Edwina Pickles
Sydney is a city laced with underground roads. They make motoring sweeter but their exhaust stacks are a battleground between community fears and the engineering mind. Steve Meacham reports.
It's the kind of major project which the NSW Minister for Transport, Carl Scully, loves to announce. A $1 billion, six-kilometre tollway linking the City West Link at Haberfield with the M4 at North Strathfield - an initiative timed exquisitely to make the Sunday papers.
Construction won't begin until 2005, but Scully is confident that traffic gridlock in western Sydney will be substantially eased, thanks to a 3.5km tunnel under the besieged Parramatta Road.
Sydney has become tunnel city. First there was the Harbour Tunnel, then the Eastern Distributor, followed by the M5 East. Two others - the Cross City tunnel, linking Kings Cross and the Anzac Bridge, and the Lane Cove tunnel - are due to open in 2004 and 2006, respectively. Few cities have developed such an extensive tunnel network so quickly.
But, increasingly, questions are being asked about the wisdom of our tunnel-building policy. The debate isn't about the tunnels themselves. All but a few diehards accept that they improve traffic flow and the general environment in the areas they travel through. Instead, the controversy centres on the exhaust stacks that carry concentrated fumes and pollutants into the upper atmosphere. Critics of the Carr Government's tunnel policy, who formed the umbrella group Groups Against Stack Pollution (GASP) in May, accuse Scully and the Roads and Traffic Authority of ignoring or downgrading health concerns in the race to get the politically popular tunnels built. They claim a growing number of Sydneysiders living near tunnels, particularly those close to exhaust stacks, are reporting asthma, heart problems, respiratory diseases and headaches since the stacks were built.
Critics claim the Government built the tunnels "on the cheap", refusing to install state-of-the-art filtration systems. Instead "dirty air" is being pumped out. Worse still, they insist, the stacks have been put in the wrong places - close to housing and in valleys where the pollution cannot be adequately dispersed.
Surely the Government has pollution regulations? Yes, say opponents, but the regulations are used to control air quality across the city and should not be used to measure emissions at stacks where pollution is more harmful. They claim the RTA is measuring the wrong thing in the wrong way. Fiercer critics accuse the RTA of deliberately withholding the truth. Some even insist the RTA is resorting to desperate measures.
When M5 East fans broke recently, fumes wafted out the tunnel. Residents fear this will become the norm, with "limited portal emissions" needed to relieve the poor air quality within the tunnel and improve visibility.
The Government rejects such allegations, accusing its critics of being irresponsible, self-interested and mischievous. But the anti-tunnel-stack lobby is media-savvy, organised, academically distinguished - and unlikely to go away. Mark Curran, until recently a professional officer in Sydney University's school of biological sciences, is a leading member of Residents Against Polluting Stacks (RAPS). He claims the RTA uses the wrong yardstick to decide whether the localised emissions are safe. "The method used to determine the number of particles in the air is PM10, which measures all particles less than 10 microns in diameter. What is really doing the harm are the smaller particles, those which are PM2.5 [2.5 microns or less]. Better diesel engines haven't reduced the number of particles, just made them smaller and more harmful. Weight for weight, diesel is becoming more harmful, though there is less of it.
"Almost all diesel exhausts are PM1 or less. They're the ones which actually go into the lungs, and the finest ones go inside the cells of the lungs. Anything bigger than PM2 gets caught up in the nasal passages."
That's why, he says, "people are getting sick but there's nothing obvious in the monitoring to show why".
As well, the Earlwood stack is in a valley, with its top at the same height as local homes. "Australia's unique contribution to road tunnel design is to place exhaust stacks in valleys," says Curran, pointing out that the stack planned for the Cross City tunnel is also planned to be in a valley, next to the IMAX Theatre in Darling Harbour. So are both the proposed stacks for Lane Cove.
The solution, according to GASP, is to follow the world leaders in tunnel technology, Norway and Japan, which both use various forms of filtration within their tunnels. But the RTA believes filtration is too costly and unnecessary.
Associate Professor Ray Kearney, chairman of the Lane Cove Tunnel Action Group, is an expert on immunobiology. He believes there is a fundamental problem with the way tunnels are planned. They are designed by the RTA, based on transport criteria, with no input in the design stage from the Department of Health until it is forced to become involved, at the end of the construction stage, by community complaints.
"I have been approached by an employee of the RTA on behalf of toll booth collectors. He provided me with the documentation of occupational health and safety [OHS] standards which allow workers to be exposed to levels of pollution which are 100 times higher - for example with benzene - than is currently accepted in the UK. Where is the duty of care here by the Department of Health?" says Kearney.
"This person is a traffic surveyor. When he puts his boot down in the tunnel, it is soon covered in soot. He approached the RTA, concerned about the health of the toll booth operators. The RTA relented and appointed an independent consultant who applied, not the UK standards, but the OHS guidelines. The RTA report that came back inferred that everything is OK."
Kearney gave evidence to three parliamentary inquiries concerning exhaust stacks, and is appalled by
"the tainted culture and mindset of the bureaucrats who run the RTA and the Department of Health, where it seems patronage is their lifeblood".
The potential health problems associated with the emissions from the tunnel stacks "warrants a full, independent investigation", he insists, alleging both government arms use their financial might to stifle criticism, with some health professionals dependent on government funds for their consultancies and research projects.
"There's a system which effectively silences experts."
He predicts residents in Darling Harbour will suffer the same problems as their counterparts in Earlwood and Woolloomooloo if the proposed Cross City Tunnel stack is built in Darling Harbour. "What an absurd place to put a stack. At 39 metres high, it's lower than many of the buildings around it."
According to Paul Forward, the RTA's chief executive, "filters remain extremely expensive yet unproven technology".
An RTA delegation to Norway found the filters in Norwegian tunnels "are mostly not turned on", while in Japan "there is no operational evidence that demonstrates improvement of external air quality". In any case, he says, Japanese vehicles are not subject to the same stringent vehicle emission standards as Australian vehicles.
"Filtration, in any case, is intended to deal only with particulates. It does nothing to address carbon monoxide and nitrogen dioxide emissions," Forward says.
"It has been suggested by some residents that the M5 East could operate without a stack and instead use a combination of portal emissions and filtration. This system would not meet the air quality goals set by PlanningNSW for the M5 East. A stack is a far more effective means of dispersing emissions."
The RTA "has not ruled out filtration" for Sydney's tunnels.
But Forward says that while he is sympathetic to residents' concerns about air quality, "standards for the M5 East were set under the planning approval process by PlanningNSW and the Environment Protection Authority [EPA] as the professional experts and regulators. The RTA does not determine these standards; it is simply required to meet them.
"To date, these air quality standards for the surrounding area have been met. The levels of particles, carbon monoxide and nitrogen dioxide are generally well below the levels set by PlanningNSW. The sole exception occurred during the bushfires last Christmas when all of Sydney was affected by air pollution."
On the air quality within the M5 East, he admits there have been "teething problems", but said there had been only four times when "in-tunnel monitors showed readings of carbon monoxide levels marginally above the standard for short periods. On one occasion, traffic had built up in the tunnel after an accident".
Potential risk to motorists in the tunnel "would have been minimal", but says Forward, "we are working closely with the tunnel operators, Bhegis, to review operational procedures for the ventilation system and traffic management".
As to the claim that the RTA should be monitoring smaller particles, PM2.5 and under, he says: "The monitoring of the external air quality is prescribed in the conditions of approval set by the Minister for Planning. These conditions required monitoring of PM10 to ensure compliance with the air quality set by the EPA ... Any policy and actions in relation to them are determined by the National Environment Protection Council, the EPA and NSW Health."
Asked if the RTA believed the regulations which govern the emission levels of existing and future tunnels are adequate to ensure there are no health risks, he says: "The RTA is not the expert body on environmental health and does not set the standards for air quality for Sydney's tunnels.
"They are set by PlanningNSW in consultation with expert bodies such as the EPA.
"The RTA is expected under the conditions of the planning approval to meet those regulations and to date it has. We do, however, have a concern obviously that some residents have said they are experiencing ill effects, which is why we invited NSW Health to investigate their complaints."
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