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Treated Timber Source: Lockwood.co.nz

New Zealand’s forestry industry contributes 12% of the country’s annual export earnings, making it New Zealand’s third largest industry. Within this powerful industry, there is the manufacturing of CCA treated timber. In 2005 4,215, 000 cubic metres of rough sawn timber was produced within New Zealand. We found a great report on Extended Producer Responsibility within the Timber Industry by Simon Love (2007) which is a great resource for information on Treated Timber and finding a solution and states that estimates for 2006 show that the amount of treated timber within that timber production total is 830,250 cubic metres.

Data from the Ministry for the Environment from their waste composition analysis from 2008 statistics states that for the whole country Timber makes up 11% of the total waste to landfill. An estimated 3.156 million tonnes of waste went to landfill in 2006 so that’s 347,160 tonnes of timber waste. More here.

A certain percentage of this timber to landfill is CCA Treated Timber which is an issue for all landfills and the surrounding environment.

Radiata pine is one of the world’s most widely planted plantation species and has the ability to grow to a large diameter faster than almost any other tree species. In New Zealand, both the ideal climatic and soil conditions exist for advanced radiata pine plantations, making pine New Zealand’s number one commercially grown tree species and is used for external building structures, including fences, decks, landscaping, pole houses, playground structures, marinas and walkways. However, due to a natural susceptibility to fungal decay, radiata pine must be extensively chemically treated in order for it to withstand the outdoor exposures.

Internationally, CCA treated timber has been banned or had restrictions placed on it due to the growing concern over its possible health implications for humans, and the environmental implications that can result from the chemicals leaching during landfill.

In 1997, The Department of Conservation commissioned a report on CCA treated timber within New Zealand. Written by Dr. Michael Hedley, the report explored the possible future disposal of treated timber, including controlled incineration and fully encapsulated landfill disposal. Dr. Hedley stated in the report that  ‘Though these may be possibilities…while there has been little significant evidence produced within New Zealand on the effects of CCA timber landfill disposal, municipal landfills, will continue to be the most viable option for CCA timber disposal.’ Download the report.

Here are some facts on what exactly CCA treated timber is, and why internationally, jurisdictions have been placed on its use.

What is CCA treated timber?The most commonly treated timber is CCA treated, or Chromate Copper Arsenate. The chemical mixture is injected into the wood under pressure, ensuring that the wood is saturated with the chemicals.

What are the possible health effects from exposure to it? According to the United States’ EPA’s Incident Data System, exposure to treated timber can result in ‘itching, burning, rashes, neurological symptoms, and breathing problems after handling lumber; damage to nerves in feet and legs from CCA sawdust and fumes from construction; chronic rash; eye swelling from dust; headache, nausea, shakiness, and thirst from cutting timber; rashes on arms from dust; nausea and headache from drilling timber’. These side effects are linked to the exposure to high arsenic levels. Internationally, the concern for the health implications has led to the United States, Canada and the European Union banning the use of CCA-treated wood in residential and recreational settings.

Why is their concern for the environment? Currently in New Zealand, the most common disposal for CCA treated timber is straight to landfill. The concern for the environment comes from the issues of chemicals leaching from landfill into the soil. For Christchurch, CCA treated timber is to be placed in kerbside red wheelie bins – for  landfill dumping.

With such prolific use of treated radiata pine within New Zealand, and landfill being the most common disposal of treated timber within New Zealand, it seems worth taking a look at international responses and the reasoning for so many countries placing jurisdictions on the use of treated timber and also to find a solution to the large amount of treated timber that goes to our landfills and affects our ecosytems and human health.

Is there a solution out there that could remove the CCA from the timber so it can be reused or a solution for recycling the timber in some way? Would the Extended Producer Responsibility programme describe in Simon Love’s research work for New Zealand. What could we do? What do we need to do to solve this waste stream issue?

We would love to know. Treated Timber is one of SIFT’s key waste streams to be solved. As such we are inviting expressions of interest to help solve this problem from anyone who thinks the have an idea, the solution, or could help set up a Producer Responsibility Program.