Wastewater Goes Green
With many architects and project managers under increasing pressure to design the most efficient and eco-friendly buildings possible, product choice is now more important than ever in the search for the revered Green Star points.
One company with environmentalism firmly on its mind is wastewater specialist Halgan. The team was recently involved in the huge 1 Bligh Street project in Sydney, which attained a 6 Star Green Star rating, signifying ‘World Leadership in environmentally sustainable design and/or construction’.
Halgan national commercial manager Stephen Morgan says that this was made possible due to the material polyethylene, which is used to produce Halgan’s range of wastewater products.
“Polyethylene is especially good because it meets much of Green Star’s required criteria, especially in categories including materials, energy, transport, water, emissions, land use and ongoing cost savings in maintenance,” he says.
“Also, our products are 100% recyclable, so any offcuts that we have from manufacturing can be reused again.
“After grinding down offcuts, the material can then be reused in products that don’t require food grade or virgin polyethylene such as wheelie bins and pallets.”
THE MATERIAL
Polyethylene is a product of polymerisation, whereby small molecules are combined to form larger substances. It is formed using the ethylene by-product of natural gas production, however in the future, sugarcane bio-ethanol may be used to produce bio-plastics and renewable polyethylene for a ‘greener’ alternative.
The result is a product so safe that more than a third of the world’s toys are made from the material.
Halgan tanks are made from low density polyethylene (LDPE). Unlike more traditional materials, such as concrete, the energy used in manufacturing polyethylene is relatively low, requiring temperatures of 200°C, a small amount of oxygen as an initiator and 2000 atmospheres pressure.
On the other hand, the cement in concrete is manufactured by a process of hydration, where the raw materials undergo complex chemical and physical changes in a kiln, reacting together in a process that becomes progressively hotter up to about 1480ºC.
This process makes cement production one of the most energy-intensive of all industrial manufacturing processes. If you include direct fuel use for mining and transporting raw materials, cement production takes around 7 million megajoules for every tonne of cement produced.
Additionally, due to the cement industry’s heavy reliance on coal, high levels of carbon dioxide, nitrous oxide and sulphur are emitted. So much so that for every ton of concrete, three quarters of a ton of carbon dioxide is emitted.
Unlike the tanks, Halgan’s grease arrestors are made from high density polyethylene (HDPE). Due to the lightweight build of HDPE, transport costs are significantly reduced; a 3000L concrete grease trap weighs 6100kg, whereas Halgan’s 3000L Modular Grease Trap is less than 5% that weight at just 280kg.
Stephen adds that Halgan’s grease arrestors are manufactured to achieve computer-controlled product quality, which provides a projected product life of over 50 years.
“Testing using Finite Element Analysis (FEA) shows that product strength is 200% higher than the Australian Standard for Buckle Load Factors (BLF), making the product well suited to inground use,” he says.
A GREEN OUTLOOK
Halgan has been operating since 1996, however, Stephen says that Green Star has been a priority focus for the company in the last 18 months.
“Green Star is still a bit of a buzz term at the moment. There is a big demand for buildings with a high rating and we want to make sure we meet that demand,” Stephen says.
“Our products are increasingly being specified on projects by hydraulic engineers and architects as they realise how efficient they are.”
Although wastewater is only one piece of the Green Star puzzle, Stephen says that it is an essential focus as there is a fine line between the final ratings.
“One or two points can be the difference between achieving World Leadership and not, so it really is important,” he says.
“This can make a massive difference to the property owner when they are renting out the space.”
However, Stephen adds that Green Star aside, product choice is also imperative on a more widespread scale.
“There are ‘unhealthy’ buildings out there, which don’t use the proper ventilation, lighting or materials,” Stephen explains.
“Architects and hydraulic engineers are increasingly looking to alternative materials in every facet of a building to make buildings more eco-friendly and give them a longer lifespan.”
He adds that the current climate of the market makes engineers and architects compete to be more efficient, which is for the greater good of the environment.
“People in general are more environmentally-focused these days, which is great. Our role as a company is to educate and inform them on products which can help,” he says.
“Hopefully this trend will continue down the track.”
Contact:
Halgan
www.halgan.com.au