Wednesday, December 1, 2010


Dr W. D. Raverty 1st December 2010
Clayton South VIC 3169


I write to give you some of my experiences in dealing with fugitive odour from Australia’s two existing kraft pulp mills over the past 30 years. I am one of very few Australian scientists who is not employed by a pulp and paper company, or an engineering consultancy, and who has direct experience of odour containment systems in kraft pulp mills and knowledge of the chemical properties and toxicology of the chemicals responsible for the odour.
I was intimately involved in commissioning the odour control system at Australia’s larger kraft pulp mill, Maryvale Mill, in the Latrobe Valley in Victoria, and I played a major role in reducing the level of odour at Tumut Kraft Mill in NSW, after the Scandinavian engineers who designed the system failed to make good their promise of ‘no odour beyond the mill boundary’. Significantly for you, as residents of the Tamar Valley, one of those Scandinavian engineers, Mr Sven Lundgren, was employed by Gunns Limited to assist in designing the same section of its proposed kraft mill.
I was selected in early 2004 by the former Executive Director of the Resource Planning and Development Commission, Mr Julian Green, to join the joint Commonwealth-State RPDC advisory panel charged with updating the 1996 Commonwealth Guidelines for Bleached Eucalypt Kraft Pulp Mills and drafting the 2004 ‘Environmental Emission Limit Guidelines for any New Bleached Eucalypt Kraft Pulp Mill in Tasmania’. In conducting that work, the RPDC contracted two eminent international pulp and paper technical consultancies, Beca AMEC of Vancouver, and AF Consulting of Stockholm to provide up to date information on the widest possible range of Accepted Modern Technologies in the kraft pulping industry worldwide.

Long before Gunns’ proposal was known to members of the RPDC advisory panel, in March 2004, one of the first significant pieces of advice the panel received from the odour experts in AF Consulting was:........‘There is no such thing as an odour free kraft mill – never promise such a thing.

That advice is as valid today in 2010 as it was in 2004.
Because the kraft pulping process uses the chemical, sodium sulfide to preserve the strength of the wood fibres during the pulping process, every tonne of pulp produced results in production of 20 – 30 kilograms of an unwanted by-product - a mixture of some of the most offensive and strong smelling organic sulfides known to science, in addition to hydrogen sulfide, or rotten egg gas. In parts per billion concentrations in air, this mixture of gases causes headaches, nausea and exacerbates lung diseases such as asthma. At parts per million the gases are highly toxic and, at parts per hundred in air, the concentration range at which they typically occur in process vessels inside the mill, they are both lethal and explosive. For this reason all modern kraft mills spend many millions of dollars collecting well over 99% of this mixture (known as ‘foul gas’ by mill workers worldwide and as TRS (total reduced sulfur) by pulping technologists) and burning it to produce a mixture of carbon dioxide and sulfur dioxide – both of which have almost no odour at the part per billion level in air.
After the foul gas has been efficiently collected from the many ‘point sources’ in a kraft mill, it must then be conveyed through many kilometres of pipework in order to take it to the furnaces in which it is to be burnt. It is in conveying the gas (and liquids that are saturated with it – called ‘foul condensates’) where problems inevitably arise. All pipework in mills is built from relatively short sections with flanges at each end that are used to bolt the sections together. Gaskets, or seals, made from various rubber, plastic and ceramic compounds are placed between the metal pipe flanges to ensure no gas, or liquid leaks out at the join. Shafts of pumps and other equipment in the mill are sealed using similar materials. While all of these many thousands of gaskets and seals in each mill prevent gross leakage, the foul gas has the unfortunate property of permeating all useful gasket-forming materials. It usually takes around 12 months for these gaskets and seals to become fully saturated with the foul gas and, as this happens, tiny amounts of the gas diffuse into the atmosphere from thousands of pipe joins causing the so-called ‘fugitive odour’ that causes anger, frustration and illness in every community located close to a kraft pulp mill that has been inappropriately situated. Typically a kraft mill will have no fugitive odour for 6 - 12 months and then start smelling worse and worse for decades after construction.

In Victoria, the fugitive odour from Maryvale Mill – a mill that has a three tier odour control system that is arguably more effective than Gunns’ proposal (as it incorporates an emergency flare stack to burn foul gas should the second incinerator ‘flame out’) – the fugitive odour can be detected as far afield as Warragul and Sale (respectively 42 km west and 55 km east of Maryvale) under the worst weather conditions. This wide dispersion of fugitive odour is common in kraft mills worldwide and it was for this reason that the RPDC set the Regional Airshed for the Long Reach site as a an area 55 kilometres in radius centred on the proposed site for the main mill stack – and truncated on the western side, based on advice from the Bureau of Meteorology concerning prevailing wind directions and the blocking effect of the Asbestos Range.
Maryvale Mill produces kraft pulp (and therefore foul gas) at some 30% of the rate of Gunns’ proposal. Maryvale Mill started operation in 1939, but has had many upgrades since and can be considered a modern mill from an environmental standpoint. Significantly in 2008, a senior officer of the Victorian EPA told me that:....... ‘On odour grounds alone Maryvale Mill would be refused EPA approval for construction today in the Latrobe Valley if it were a new greenfield project.’

In early 2005, following the acceptance of the Environmental Emission Guidelines by both the Commonwealth and State Governments and the winding up of the RPDC advisory panel, I was selected by the RPDC to be a member of the assessment panel for Gunns proposal.
Initially I was optimistic that Gunns would select the Hampshire site for their detailed Impact Assessment, as it was the sort of remote site for which the Environmental Emission Limit Guidelines had been framed. When Gunns selected the much more environmentally challenging Long Reach site, all members of the panel were at pains to ensure that the people of the Tamar Valley were not adversely affected by the inevitable fugitive emissions from the chosen site.
To this end, Gunns was sent a letter by Julian Green in mid-2005 asking them to provide detailed information on how much odour they expected from fugitive sources and what measures they planned to minimise emissions in the Valley. No satisfactory reply was ever received during my time on the panel. This despite the fact that estimates should have been readily available based on experience at the Jinhai Kraft Mill on Hainan Island in China that started operations in 2004. Gunns staff had made a number of public statements about their proposal being very similar in size and process to the Jinhai Mill and had made frequent visits to the mill. Some weeks after that letter was sent to John Gay, Gunns Project Manager, Mr Les Baker sought a meeting with the panel to outline Gunns’ plans for background air monitoring. At that meeting, the panel made the eminently reasonable suggestion that trials of odour diffusion be conducted in the Tamar Valley under the supervision of DPIWE. Mr Baker flatly rejected the suggestion and claimed that, ‘The mill will not smell’. When asked by the panel to provide a written guarantee to that effect, Mr Baker refused and became angry. As far as I am aware, to this day Gunns has never made any meaningful estimate of the likely impact of odours coming from anywhere other than their proposed main stack.
Gunns stubbornly refuse to accept that these odours exist despite the fact that CSIRO, in their review of Gunns’ air monitoring, stated quite categorically:.........‘As pointed out in CSIRO’s Review of Air Quality A spects of Gunns Ltd “Bell Bay Pulp Mill Draft Integrated Impact Statement, July 2006 ( .au/__data/assets/pdf_file/70703/14 CSIRO Assessment of Tamar Background Air Quality CSIRO_ReviewOfGunnsDraftIIS_Final4Oct.pdf), a full assessment of potential TRS impacts should also include the possibility of fugitive emissions from the proposed mill.

Visy Pulp and Paper published data in 2004 that showed that of the total odour output from Tumut Mill, LESS THAN 5% CAME FROM THE MAIN STACK – the other 95%, that caused over 60 complaints per month from residents living up to 8 km from the mill (in a valley that is sparsely populated by Tamar standards), was from fugitive sources close to ground level. Tumut Mill at the time was one sixth the capacity of Gunns’ proposal.
Increasingly throughout my period serving on the RPDC assessment panel I became concerned that Gunns staff did not have sufficient skills to manage a project of the size and complexity of their proposal. Important questions regarding other potential problems with the mill were also blatantly ignored, as were requests to put information forward in a form that could be easily assimilated and cross referenced by the RPDC and interested members of the public. Indeed it seemed to me that Gunns had formed a view that they need only provide the RPDC with the information that they, Gunns, elected to divulge, rather than the information that the RPDC legitimately requested. It therefore came as no surprise to me in February 2007, (following the resignation of Julian Green and myself on the recommendation of the Solicitor General) that Julian’s successor, Justice Christopher Wright, judged Gunns’ information to be ‘critically deficient in a number of important areas’.
Some advocates for Gunns’ proposal have claimed that French vineyards operate in harmony close to kraft pulp mills. Like much of the information put out by advocates for the mill, these claims are complete misrepresentations of the truth. The closest kraft mill to the Bordeaux region is 30 km away and is the subject of ongoing protests from local residents about pollution of local beaches. In the Rhone Valley, the Tarascon Kraft Pulp Mill had its odour problems upgraded to ‘code red’ in 2009 by the local authorities following the failure of the mill owners to reduce the odour emissions from the mill.

In summary, fugitive odour is the single worst impact experienced by MOST PEOPLE LIVING OR WORKING CLOSE TO A KRAFT PULP MILL. In my opinion, the topography and climate of the Tamar Valley make it one of the worst possible places to site a large kraft pulp mill. Gunns is arguably the least experienced pulping company in the world. I urge you all to voice your concerns to your elected representatives and ask them to ensure that present and future generations of the people of the Tamar Valley do not have to spend the next hundred years enveloped in nauseating and irritating kraft odours.

Yours faithfully,

(Dr) Warwick Raverty


  1. If its also on Tasmanian Times how could it be 'exclusive'?

  2. There there pettle.
    Perhaps i should have just said something like
    "yooz saw it ere first".
    What was your excuse for not showing up to the meeting to hear Dr.Raverty guv'na? or should i say "councillor"?

  3. Perhaps being absent was one way of avoiding some well known fruit loops, I didn't realize attendance was compulsory

    Gunns would like to thank the organisers for providing a platform to show the mill proponents in a good light it worked well if you measure it by column inches in the Examiner. well done!

  4. The Tailrace meeting was held within the West Tamar Municipality. Therefore if I were a West Tamar Councillor elected on a large anti-pulp mill vote, yes, I would regard it as compulsory to attend the meeting. Not to be sitting at home blogging on my favourite website instead of being out in support of the people who voted for me on the issue they voted me in on.