PIPA and the Environment
Plastics Industry Pipe Association of Australia Ltd
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PIPA and the Environment
Plastics Industry Pipe Association of Australia Ltd
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Plastics Pipes Sustainable Practices - Sustainable Outcomes
Plastics pipes are the material of choice for gas, water and sewage reticulation across Australia and indeed the World. The two common plastics materials used in Australia for infrastructure piping are polyvinyl chloride (PVC) and polyethylene (PE). Whilst polybutylene (PB) and polypropylene (PP) materials are also used for pipe applications the focus here will be on the more common PE and PVC materials. Water Conservation Plastics pipes have a unique and invaluable role to play with regard to the more effective and efficient use of one of Australia’s most valuable resources - water. In addition to capping and piping the bores of the Great Artesian Basin, PIPA, through its member companies, is actively involved in enclosing the inefficient and wasteful open channels in rural and regional Australia. These activities return enormous volumes of water back to the environment. Plastics pipes are being extensively used in urban environments to address the leakage issues caused by old and /or ineffective materials. The Industry’s Commitment to Improved Environmental Outcomes The Australian plastics pipe industry is acutely aware of the need to continually improve and implement environmentally sustainable practices. The Australian PVC industry, including PIPA and its member companies has established a Product Stewardship Commitment. This is a voluntary initiative of the Australian PVC industry and reports are published on progress covering a wide range of environmental related issues, including recycling. External analysis In recent years PE and PVC materials generally have come under significant scrutiny by “green groups”. No real issues have emerged for PE products with much of this scrutiny being centred on PVC products. Allegations by “green groups” have been promulgated about the environmental performance of PVC products generally. Much of this relates to questioning the safety of plasticisers in flexible PVC products and heavy metal stabilisers used in a wide range of products (typically lead and cadmium). Australian PVC pipe formulations do not contain plasticisers or cadmium. Lead stabilisers are not used in the manufacture of pressure water pipe in Australia and they are being phased out in other piping applications under the PVC industry's Product Stewardship Program. In any case the impact of lead stabilisers is regarded as insignificant. Small quantities of lead based compounds are used as a thermal stabiliser in some pipe products. The lead stabilisers are held within the PVC matrix and to quote the CSIRO Report from 2001 “the concerns relating to extraction are overstated”. In terms of release of lead from PVC pipe there have been extensive studies both in Australia and Europe on leachate from waste water pipes and landfill situations. In both cases the conclusion is that the amount of lead released is insignificant. Furthermore in 1998 and 2001, the CSIRO extensively reviewed recent scientific literature on PVC and concluded: "the balance of available evidence indicates that PVC in its building and construction applications has no more effect on the environment than its alternatives". In 2004 the US Green Building Council PVC Task Group issued a draft report on PVC related materials. This draft report was based on an analysis of over 2400 scientific papers, submissions from green groups, the building industry and PVC industries. The report concludes “the available evidence does not support a conclusion that PVC is consistently worse than alternative materials on a life cycle environmental and health basis”.
Recyclability PE and PVC are recyclable, contrary to some reports. Both post industrial waste and post consumer waste is recycled. PIPA, in association with Collex, has successfully established a process to recover plastics pipes from construction and demolition waste across Sydney. The process removes practically all plastics pipes from the waste and produces granulated materials suitable for new pipe feedstock. PE and PVC are thermoplastic materials and as such are readily recycled. Being thermoplastics any waste generated in the manufacturing process is recycled. Durability Another significant and positive feature of PE and PVC is that they are particularly durable. The Water Services Association of Australia (the peak industry body representing the major water utilities across Australia) has appraised PVC pressure and non-pressure pipe products as fit for purpose and with a life expectancy in excess of 100 years. Similarly the WSAA Polyethylene Piping Code states “For correctly manufactured and installed systems, the actual life can not be predicted, but can logically be expected to be well in excess of 100 years”. Recent work in Australia by Alan Whittle (Iplex Pipelines) and Jayam Tennakoon (Ipswich Water) further supports the life expectancy of PVC in sewer applications exceeding 100 years (Whittle / Tennakoon Plastics Pipes XII Milan Italy 2004 “Predicting residual life of PVC sewer pipes”). Piping systems are often buried. PE and PVC have shown their suitability as piping products in all natural soils. They have been successfully used in highly aggressive environments such as saline interception schemes for decades. Plastics pipe systems are not subject to corrosion. Furthermore there are no significant environmental impacts associated with buried PE or PVC. For these reasons plastics pipe products dominate in the gas, water and sewer reticulation markets across Australia and the World. Plastics pipes represent the major application for PE and PVC in the construction industry (accounting for around 70% of the PVC products manufactured in Australia). Plastics pipes are manufactured for pressure and non-pressure applications to recognized Australian Standards and often with the additional rigor of compliance to product certification schemes such as StandardsMark. Embodied Energy Embodied energy analysis quantifies the amount of energy used to manufacture a product. This involves the assessment of the overall expenditure of energy required to extract the raw material and manufacture it into a product. In terms of Embodied Energy PE and PVC pipe products perform significantly better than competitive metallic pipe systems (based on independent CSIRO research). This advantage is often more than a factor of 2 in favour of PVC products - particularly the PVC-O pipe products. The advantage of being “light weight” and fit for purpose Plastics pipe is relatively light weight offering advantages in transport, handling and installation costs with flow-on benefits for issues such as occupational health and safety. The common jointing configuration for PVC is a socket and spigot rubber ring joint, although in smaller sizes solvent cement joints are used. In the case of PE, mechanical and welded joints are available and most do not require thrust blocks. These systems offer simple installation, excellent leak tightness for pressure applications and excellent resistance to tree root intrusion in waste water non-pressure applications. Tree root intrusion is one of the major concerns in the operation of sewer systems across Australia. PE and PVC sewer pipe systems offer superior performance in the area of resistance to tree root intrusion through excellent pipe and joint performance. In fact both PE and PVC materials are often employed in the rehabilitation of failing clay and cast iron pipe systems by taking advantage of their versatility as a relining system. Recent advances in manufacturing and pipe design have achieved significant material efficiencies.
Useful References: Australian Standards - Review the Australian product standards for plastics pipes www.standards.com.au Water Services Association of Australia - Review product appraisals, life expectancy rating and their materials selection guide confirming fitness for purpose of plastics pipe - www.wsaa.asn.au SAI Global - Review manufacturers and products certified under StandardsMark product certification schemes - www.standards.com.au CSIRO - Research into Embodied energy, Tree root intrusion performance for sewer pipe joints, Environmental aspects of the use of PVC in building products.www.csiro.gov.au Vinyl Council of Australia - relevant articles on PVC generally - www.vinyl.org.au
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