Tasmanian Times

The individual has always had to struggle to keep from being overwhelmed by the tribe. If you try it, you will be lonely often, and sometimes frightened. No price is too high for the privilege of owning yourself. ~ Friedrich Nietzsche

The individual has always had to struggle to keep from being overwhelmed by the tribe. If you try it, you will be lonely often, and sometimes frightened. No price is too high for the privilege of owning yourself. ~ Friedrich Nietzsche


Chlorine dioxide at Mackenzie pulp mill forces evacuation

Mary Frances Hill Vancouver Sun
A chlorine dioxide leak at a Mackenzie pulp mill recently taken over by the provincial government to avoid an environmental disaster forced 35 people out of their homes and workplaces on Sunday. Chlorine dioxide was leaking from a valve in one of three fibreglass tanks at the Worthington mill at the rate of about two gallons per minute, said Pat Bell, MLA for Prince George North. Used to bleach wood-pulp, liquid chlorine dioxide is one of the most dangerous chemicals stored at the pulp mill. When concentrated chlorine dioxide is exposed to air and light, it decomposes into chlorine gas. Read more, Comment here
What Warwick Raverty told Jeremy Ball …
Hi Jeremy,
I don’t know the background to the article in the ‘Vancouver Sun’, but based on what I read, I assume that the company that owns Mackenzie Pulp Mill in British Columbia must have had to file for bankruptcy as a result of the economic recession, leaving the safe shut down of the Mill in doubt. Hence the comment in the article ‘the province [i.e. the Provincial Government of British Columbia] is going to have to run the Mackenzie mill to solve the problem’.

My recollection from Paul Lennon’s statement to the House of Assembly (you will need to check Tasmanian Hansard for Aug – Sept 2007) is that Gunns agreed (reluctantly, following Sweco Pic’s agreement with my earlier advice!) to use the methanol process (one of two approved under the Environment Emission Guidelines) for generation of their chlorine dioxide. Which process is used, the methanol process, or the hydrogen peroxide process (both Accepted Modern Technology) would not change the situation in which Mackenzie Pulp Mill finds itself. Like elemental chlorine, chlorine dioxide is a gas under atmospheric pressures and temperatures, but it is soluble in water and it is this solution that is stored in tanks at Mackenzie Mill and all other ECF kraft pulp mills. This is the reason for the incorrect statement in the article that chlorine dioxide is a liquid. Mill workers, like the Rod Clark quoted, do not have tertiary degrees in chemistry and so often refer to solutions of chlorine dioxide in water as ‘chlorine dioxide’. The difference between elemental chlorine and chlorine dioxide is that, whereas elemental chlorine is stable and can be compressed to a liquid and stored and transported in reinforced metal cylinders, chlorine dioxide is unstable and detonates spontaneously when the concentration of dioxide in air, or water vapour rises above 9% – forming elemental chlorine gas and oxygen. So 99% of all chlorine dioxide made in the world is generated by reducing a solution of sodium chlorate in dilute sulfuric acid (‘chloric acid’) with methanol (or hydrogen peroxide), generating a solution of chlorine dioxide and sodium chloride (sea salt) in dilute sulfuric acid. In order to separate the chlorine dioxide generated in this way, steam is bubbled through the ‘chloric acid’ solution creating a mixture of chlorine dioxide in water vapour that must be kept below 9% concentration and which is then bubbled through water to create the chlorine dioxide ‘bleaching chemical’ that is stored in tanks and eventually mixed with the unbleached kraft pulp after it has been subjected to oxygen delignification. Oxygen is only capable of removing about half of the residual lignin remaining after kraft pulping, hence the need for chlorine dioxide (or the ‘totally chlorine free’ alternative, ozone that is used to make TCF bleached kraft pulp under a slightly more expensive process). Attempts to compress the water vapour-chlorine dioxide mixture into a liquid for transport always result in an explosion – hence the need for it always to be made on the mill site as no mixture of anything in water vapour at 7-8% concentration could ever be transported cost effectively. All AMT chlorine dioxide bleach plants incorporate bursting disks and other ‘relief equipment’ that cater for small detonations (called ‘puffs’ in the pulping industry!) that occur periodically during normal operation because of inadequate mixing of the chlorine dioxide with the air and build up of pockets of chlorine dioxide above the ‘chloric acid’ solution.

Under normal conditions, if the company running a pulp mill became insolvent, there would have to be provision in the Environmental Management Plan modules (the documents that Minister Garrett and his Independent Expert Group are approving for Gunns at present) to have a contingency plan in place (perhaps a sum of money held in trust that enabled the mill to continue running for long enough for the total storage of chlorine dioxide solution in water to be mixed with unbleached pulp and rendered harmless). So, although Gunns propose to store chlorine dioxide solution on site – as is normal practice, if Minister Garrett’s IEG does its job professionally, there should be no risk of exposure to chlorine dioxide in the event that Gunns goes bankrupt at some point during future operation of the mill. It would be well worthwhile Kim Booth writing officially to Minister Garrett, to alert him to what has happened at Mackenzie and to seek assurance that the EMP modules (I unfortunately don’t have time to read them!) prevent the same thing happening in the Tamar Valley. With Gunns’ share price having bottomed at 65 cents fairly recently, the contingencies of insolvency and bankruptcy should certainly be planned for by the Minister in my opinion.

What would happen in the event that a storage tank was breached (by accident, or by deliberate criminal act) is that the solution would be contained in a bund around the tanks and flow into drains to a ‘spill dam’ and covered with a suppressant foam to limit escape of chlorine dioxide – a normal part of any the pollution prevention measures in any modern mill (and part of the Tasmanian-Commonwealth Environmental Emission Guidelines) where it would have to be neutralised by adding a reducing agent (such as kraft pulping chemical (‘white liquor”), methanol or hydrogen peroxide). Nevertheless, emergency services personnel dealing with the spill would have to wear protective clothing and gas masks – a so called HAZOPS plan is a normal part of any EMP for a facility where dangerous goods are stored or handled and a spill of that sort is exactly the sort of event that HAZOPS is intended to deal with.

In the event of a deliberate act of terrorism, where explosives might be used to disperse the contents of the tanks for example, or perhaps in the event of an earthquake (the Tamar Valley is geologically active according to at least one experienced risk assessor and Beaconsfield, site of the mine tragedy that arguably had a strong geological instability component, is less than 10 km from the proposed mill site) the consequences for the local community and animals would be much more serious. If the chlorine dioxide were to be dispersed into the air by explosive force (presumably much of it being converted quickly to chlorine and oxygen) a heavier than air cloud of lethal gas would drift with the breeze similar to the chemical warfare practised in the trenches in France and Russia between 1914-1918 with tragic consequences for people living near the mill (how near would have to be modeled by computer!). Even a rupture of the tank and bund by earthquake would arguably allow many kilolitres of solution to flow down hill on the steeply sloping site, releasing considerable quantities of chlorine dioxide and chlorine into the atmosphere as it travelled. Again, how much would find its way into the Tamar Estuary would have to be subjected to computer modeling.

I trust that you find this information helpful.

Warwick Raverty

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  1. francis

    March 3, 2009 at 12:16 pm

    I do understand Tony. I actually think that site demonstrates beautifully how industry and the other uses of the Tamar Valley can exist together. The photos show the heavy industry in parts of the valley, the powerstation and woodchip mills, then some of the agricultural and tourists uses elsewhere in the valley. There is no reason why the two can’t coexist. The Tamar valley is not a tiny pristine valley, it is a huge expanse which already has been highly impacted by human activities or ALL different sources.

    There are few residences in close proximity to the mill site, certainly only a very small number on the river edge directly opposite the mill site. What is quite disconcerting about all this is that these ‘facts’ touted by so called experts who are incidentially carrying major grudges is that they are passed around and around so much that it is difficult for reasonable people to discern what is truth and what is not.

  2. Tony Saddington

    February 27, 2009 at 11:28 pm

    Francis, I recommend that you go to http://www.tamarpulpmill.info/homesite.html.

    Sure, it is an anti mill site, but the photos displayed are of the Tamar,from Georgetown to Launceston. You will, I hope, understand why we are so passionate about the Tamar valley.

    The photos will give you a better idea of what things are like. Far better than Google Earth.

  3. Horse Badorties

    February 27, 2009 at 10:51 am

    Woodworker, post 8 above: you say “Everyone is encouraging a thorough and proper evaluation of the Bell Bay proposal…..” Who is the ‘everyone’ you are referring to?

    Your post shows a real lack of understanding of the issues involved and is the typical knee-jerk response of an industry lickspittle.

    Here are a few factoids to enlighten you:

    1. The Tamar mill is proposed for Longreach, not Bell Bay – Bell Bay is some six or seven kms north of the proposed site which is a reserved buffer zone. Please stop calling it the Bell Bay mill – it is not. That’s like calling the Zinc Works the Salamanca Place Zinc Works (for all you Hobart-centric readers).

    2. The body entrusted to do the ‘thorough and proper evaluation” (RPDC) was dimissed on what has proven subsequently to be a pack of lies from Gunns. The mill was then fast-tracked WITHOUT ‘thorough and proper’ evaluation.

    3. In the words of the pulp mill experts on that RPDC panel, the Gunns proposal was found to be “critically non-compliant” for the Tamar valley. The guidelines drawn up by that panel were for a mill in a remote location, not a heavily populated valley subject to an Autumn and Winter inversion problem. I don’t know about you, but ‘critically non-compliant’ (the real reason for Gunns withdrawal from the RPDC) is a little frightening. It makes me uneasy to think of a ‘critically non-compliant’ piece of giant infrastructure being built anywhere along the Tamar.

    4. If you read Gunns IIS, you will find that the only assessments that have been done are ‘benefits only’ (to Gunns) assessments – there has been nothing LIKE a proper risk assessment of any kind done. Proferred risk assessments from other expert groups and individuals have been dismissed out of hand.

    5. How dare you call people who have been following this issue and amassing a large body of knowledge about it ‘the whacko brigade’ and be accusing them of having a ‘little bit of knowledge’ I know that a number of the anti-mill ‘whacko’s’ are more on top of the figures than Gunns own pulp person, Calton Frame – he has been caught out a number of times with scant or incorrect knowledge of stuff he SHOULD know.

    6. Why don’t you ask Dr Warwick Raverty – a pulp mill expert – what he thinks. And don’t dismiss the answer, because he knows what he is talking about. He also thinks that a pulp mill for Tasmania would be a good idea, (or he used to – I believe he now thinks that no pulp mill anywhere should be entrusted to a company of Gunns calibre) but it must be the right mill in the right location. This man KNOWS that the Tamar is the absolute wrong place for just about the biggest pulp mill in the world.

    7. What pulp mill?

    Have a Dorky Day,

  4. Tony Saddington

    February 26, 2009 at 9:41 am

    The thing is that we who live here in the Tamar have no options if there is a containment leak and given the lifespan of 70 years, (or more), the odds of an accident is likely.
    This is further compounded by the proponent, with its history of cost cutting and gross inexperience in pulp mills.

    Throw in the unknown, that some nutter will deliberately sabotage the plant – a likely scenario.

    Francis, you need to visit the mill site, 6 kms South of Bell Bay. It was a nature reserve, a buffer from industry to the North. It is still covered in native growth.
    The only nearby industry is the wood chip mill. The rest is farmland, orchards and homes spread along the river and up the bank.

  5. Steve

    February 25, 2009 at 10:31 pm

    What a load of crap francis. You are obviously very familiar with that stretch of river. Yes, there is a fish farm opposite, try looking around the corner..? Heard of a little place called Rowella? No? Perhaps Kayeena? Go the other way, Beauty Point?
    Oh dear, you are demanding. How about Georgetown, Launceston, all within range? Still, nothing should reach TCA in Hobart, you’ll be right

  6. George Harris aka woodworker

    February 25, 2009 at 2:08 pm

    Here we go. A little bit of knowledge is dangerous, and an even smaller amount of encouragement to the ‘whacko’ brigade, and other members of the protest industry, and we get comments like the first five above. (francis, you’re a gem!)
    I am told the circumstances of the mill in B. C., Canada, which is in shutdown mode, is made worse by the local climate, where winter temperatures drop to up to 20 below, and pipes and contents of tanks, etc, can freeze and expand. Volume change and thawing is going to cause problems, especially in circumstances where workers on care and maintenance are threatening to turn off the boilers to address payment of wages issues, and significant environmental problems are a real risk. There are important diffenences in concept, in circumstances, in regulatory framework, and in detail between an aging mill in Canada, and that proposed for Bell Bay. Everyone is encouraging a thorough and proper evaluation of the Bell Bay proposal, and you can’t say these types of risks aren’t being evaluated.
    As for tremors and seismic activity in the Beaconsfield mine, I am told it was all a direct result of the blasting activity that was part of the mining operation.

  7. Pete Godfrey

    February 25, 2009 at 1:59 pm

    Resistance to earthquakes is a novel idea.
    I guess that one would build in resistance to Nuclear Submarines to prevent them from colliding in a large ocean. Or measures to stop chemical plants from having valve failures ( look up Seveso Italy 1978) or to stop Nuclear power plants from melting down ( Chernobyl )
    Unfortunately anything that people create is capable of going wrong. Nothing is fool proof or even nature proof. Any good planning takes into account the worst possible scenario.
    Burst Pipelines, Fires, blown and leaky valves and the possibility of sabotage should all be factored into a very large proposal such as a pulp mill.
    As should the possibility that there won’t be enough water to run the thing. Or the ethical question of whether so much clean water should be allowed to be polluted and wasted. Or whether our catchments should be allowed to be degraded by plantation establishment and clearfell forestry.
    Google Mathinna and see what I mean

  8. francis

    February 25, 2009 at 12:23 pm

    AND the Earth could also be struck by a large meteor ending all life!

    What “many” homes on the river edge, directly opposite the mill site? Google Earth shows a couple of buildings, seemingly associated with the salmon farm. Don’t you think that resistance from potential earth quakes would be built into any chemical storage facility? At any rate how often are there earthquakes in Launceston? How far below ground were the miners when trapped by an earth tremor? How often do large industrial facilities catch fire? A terrorist attack on such a facility in Tasmania is highly unlikely, what would that achieve? Be realistic, rather than simply scare-mongering. I would be very worried about your home Scott if a rupture at the river crossing was going to flood it!

  9. don davey

    February 25, 2009 at 1:26 am

    Not too sure about that Pete, we cant forget the George Town residents ! then again one is tempted to ponder ,just how far are wind borne contaminants likely to travel ?


  10. Pete Godfrey

    February 24, 2009 at 10:34 pm

    Well isn’t that great what have we to look forward to. A company that is struggling to survive like the proponents of the mill, will cut corners at every opportunity. ( like they do in the bush).
    So a chlorine dioxide leak is bad, but there is worse!!!!!
    If there happens to be a fire in the Chlorine plant say goodbye to everyone downwind.
    Burning Chlorine produces DIOXIN.
    Pray the wind is blowing towards Bass Strait if the mill catches fire

  11. Scott

    February 24, 2009 at 5:54 pm

    In a similar vein, there was a news item over Christmas documenting the destruction caused by a burst 66″ (1.67m) water main in the U.S.


    I found the photo gallery alarming, given that I live approximately 200m from the proposed pulp mill water supply pipeline. The diameter of the proposed pipe for the pulp mill is just over 1m from Reatta Rd to Mt Direction (IIS Vol 3 p2-16). In the event of a “catastrophic rupture” at its lowest point (river crossing), 31ML of water would be released “over a period of a few days” (IIS V16_56, 4.12 / p59).

  12. Tony Saddington

    February 24, 2009 at 8:48 am

    The last paragraph is the most frightening. The Beaconsfield mine collapse was caused through earth tremors and the mine is a stones throw from the mill site.
    Human intervention or accidental rupture or leakage is a possibility.
    There are many homes on the river edge, directly opposite the mill site.

    Hampshire was the site of choice for this very reason. Major industrial spills and fugitive emissions were less likely to affect human populations in remote areas.

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