NorthConnex Tunnel

Photo of NorthConnex Construction team
24 October 2018

Mr ALISTER HENSKENS (Ku-ring-gai) (20:35:34): Areas of public policy that involve technical matters are ripe for scare campaigns, as the environmental consequences of the NorthConnex tunnel have demonstrated. In early 2015, an approval was granted for the tunnel after an environmental impact statement [EIS] process with community consultation, and well before I became the endorsed Liberal candidate for the seat of Ku-ring-gai. When the scare campaign about pollution from the tunnel started in 2014, the Government asked the independent NSW Chief Scientist and Engineer to appoint international experts to assess whether the NorthConnex EIS predictions about air quality were correct. In 2014, the Chief Scientist appointed Professor Peter Sturm, from Graz University of Technology in Austria, and Dr Ian Longley, from the National Institute of Atmospheric Research in New Zealand, to review the NorthConnex EIS conclusions.

In the second of their two comprehensive reports dated 2 December 2014, which were released to the public, Professor Sturm and Dr Longley concluded that :

In the areas where additional pollution can be expected - particularly along M1 North of the tunnel portal [i.e. Wahroonga and Waitara] ... the change in air quality is likely to be very small ...

Air pollution in Wahroonga and Waitara in particular and in Sydney in general is very low by international standards. For example, data presented by the NSW Office of Environment and Heritage shows that fine particulate matter—that is, PM 2.5—in Sydney is well below and only a fraction of the levels of international cities like Rome, Berlin, Madrid, Amsterdam, New York, London and Paris. The overall addition to the pollution of Wahroonga and Waitara from the tunnel ventilation outlet will be minimal. As shown in volume 1 of the EIS, outlet emissions will contribute only about 1 per cent of the PM 2.5 in Wahroonga and Waitara. The 1 per cent addition is so small that it is within the calibration error of the measuring equipment.

I am advised by scientists that the NorthConnex ventilation outlet is not a chimney or stack, and that it will push air out of the tunnel at speeds of up to 50 kilometres an hour through a 20-metre-high ventilation outlet. The air will go high up into the atmosphere, rapidly disperse and not concentrate in any one place. That is better for our children's health than the exhaust pipes of trucks and cars presently passing at chest height near our local schools. To ensure the predictions within the EIS verified by the international experts are made out, the infrastructure approval for the tunnel has some of the most stringent conditions in Australia.

First, there will be 12 months of air monitoring at various sites, including near Waitara Public School, before the tunnel is operational. This air monitoring will start shortly. Secondly, air-quality monitoring will continue to take place for at least two years after the tunnel is operational. Thirdly, the air quality to be measured includes the small particulate matter, or PM 2.5. Fourthly, the results of the air monitoring will be fully transparent and will be published on a website in near real time. Fifthly, if the air quality is not within the specification of the approval, the tunnel can be shut down. Rectification works necessary to re-open the tunnel are at the full cost of the operator and not the Government.

The ventilation outlets have been designed taking into account local weather conditions. A sophisticated computer model was used to generate a full year—or 8,760 hours—of location-specific meteorological data at more than 14,000 locations around NorthConnex. The model modifies measured official meteorological data from Lindfield, Terrey Hills, Richmond RAAF Base, Prospect and Sydney airport to account for the influence of local terrain. The model includes still-weather conditions and temperature inversions. Some opponents of the tunnel have called for filtration of the ventilation outlets. However, based on the review of the Advisory Committee on Tunnel Air Quality, appointed by the NSW Chief Scientist, I am advised by scientists that the filtration of the NorthConnex ventilation outlet at Wahroonga would have an impact on total PM 2.5 levels of only one-quarter of 1 per cent, but would consume the equivalent of the energy used every day by 5,000 homes.

Recently it has been wrongly suggested that the NorthConnex in-tunnel air quality will be similar to smoking 20 cigarettes at once. The scientists point to the fact that these critics have wrongly taken a 24-hour average and applied it to the six minutes that people will be in the tunnel, grossly overstating their air quality conclusions. If trucks are diverted off the Pacific Highway from North Sydney into the Lane Cove Tunnel, M2 and NorthConnex, they will avoid 31 traffic lights. The tunnel will allow traffic along Pennant Hills Road to avoid 24 traffic lights. Each will substantially reduce air pollution as a consequence. The NorthConnex tunnel will provide substantial public benefits. It will permit traffic to proceed from North Sydney to Newcastle with only one traffic light or from Newcastle to Canberra without a traffic light. The NorthConnex project is a great example of this Government providing essential infrastructure for our State's people and its economy.