Conveying

From making to filling holes

Boral is traditionally known for making holes, not filling them.  However, in 1999, Boral Waste Solutions (BWS) began to fill the disused void of Boral?s Deer Park Quarry in Melbourne?s west, by accepting waste at the new Boral Western Landfill. The site is one of Australia?s largest landfills, with an estimated life span in excess of 50 years. To date, Boral Western Landfill has received more than 3.5 million tonnes of waste, mainly commercial and industrial waste (C&I) and municipal solid waste (MSW).

Boral?s Quarry End Use (QEU) business unit was established when Boral recognized the need to create greater value from its land assets, particularly its quarry and former quarry properties. Boral Waste Solutions was formed in 1996 as part of the QEU business, with the objective of capitalising on the conversion of Boral quarry voids into landfills for the purposes of waste disposal.  Initial business planning was in respect to Boral?s Deer Park quarry in Melbourne?s west.  The idea was to reclaim and rehabilitate the quarry void on a staged basis in conjunction with a still active quarry development plan.

A series of extensive site investigations clearly demonstrated the site?s excellent potential for landfill use. These site investigations confirmed that much of the floor of the quarry consisted of clay, an ideal natural environment for siting of a series of landfill cells. In addition, the quarry floor was located above the natural water table and there were no major surface water courses in the vicinity.  The relative isolation of the site also lent support to a landfill proposal.

A works approval application for the development of the landfill was submitted to the Environmental Protection Agency (EPA) and a planning application was submitted to the Shire of Melton, both of which were granted in 1998.  Boral Western Landfill completed construction of its first landfill cell and obtained a licence to accept waste late in 1998. It opened for acceptance of waste on 12 January, 1999.

The Boral Western Landfill now receives more than half a million tonnes of waste each year, the majority being C&I and MSW. The landfill also receives smaller quantities of construction and demolition (C&D) waste as well as some prescribed wastes including Category C soil and asbestos. Boral also works with Pinegro Products Pty Ltd for the recycling and composting of green waste received from local councils.

ENGAGEMENT WITH THE COMMUNITY
Any new quarry or landfill development requires comprehensive consultation with relevant stakeholders and the local community. Boral Waste Solutions established a community advisory committee in February 1997, prior to the preparation of the relevant works approval and planning applications. This process enabled BWS to engage with community and other stakeholders. This improved communication and helped minimise the possibility of misconceptions arising.

BIOGAS TO ENERGY
Landfills which accept organic or putrescible wastes produce biogas (alternatively known as landfill gas) as the waste decays and stabilises. Biogas is generally about 45 to 60 per cent methane and is considered a significant greenhouse gas (over 21 times the greenhouse warming potential of carbon dioxide). Unless properly managed, the methane component of biogas is a threat to the environment and is also a health risk due to its combustible nature. The amount of methane produced is dependent on several factors including the amount and type of organic matter in the waste, moisture content and ambient temperature. As waste decays over several decades, biogas can continue being produced for 40 or even 50 years after the waste is placed.

Landfills, including Boral Western Landfill, are required to manage any biogas emissions as part of EPA licence conditions. Commonly this is done by collecting the gas through wells drilled into the landfill mass or placed during waste placement. To date, more than 90 vertical biogas collection wells have been drilled into the waste at the Boral Western Landfill site. The captured gas is collected through these wells and then piped up to 700 metres to the biogas to energy facility. Here it is combusted to make it safer and to reduce its greenhouse gas potential. The resultant products are carbon dioxide, heat and water. Combustion can be done in a flare or in a combustion engine to generate electricity. As the engines generate ?green?, renewable energy, it can be used to reduce society?s reliance on electricity generated from fossil fuel sources, such as coal and natural gas.

Boral?s first biogas to energy module was commissioned in February 2006, the second in February 2008 and the third in April 2009. Each 1.1 megawatt biogas to energy module produces enough electricity to power around 1000 homes.

Boral have considered using the electricity from the biogas to energy modules to power their quarry operations that share the Boral
Western Landfill site. To date, this has not been economical as Boral sells the electricity into the national grid while also generating revenue
from Renewable Energy Certificates (RECs) and NSW Greenhouse Gas Abatement Certificates (NGACs).

Boral will continue to invest in its biogas to energy infrastructure.  This will become of even greater importance if Australia introduces its Carbon Pollution Reduction Scheme (CPRS). This scheme will provide a strong financial incentive for landfills to further reduce their methane and carbon dioxide emissions.

THE FUTURE
Changing attitudes to waste in recent years have posed a significant challenge to the profitability and long term viability of landfills, not only Boral?s. In response, the business made a strategic decision to explore other waste management options, including the development of the Boral Resource Recovery Facility (BRRF). The BRRF will be a resource recovery facility or ?waste recycling factory? that will utilise automated sorting and screening technologies to process waste and recover valuable commodities.  This project is currently in the detailed feasibility phase.

Boral Waste Solutions will continue the expansion of the biogas to energy plant through the installation of more modules. As well as managing the landfill gas, this will be important in managing Boral?s potential liabilities under the Government?s proposed CPRS.

Boral Waste Solutions are always on the lookout for other quarries around the country that have the potential to be turned into landfills. A number of other quarries have been assessed for conversion to landfill, but as yet none have proven to be commercially viable due to factors such as:
? The layout of the quarry not being conducive to safe and efficient cohabitation of both quarry and landfill operations.
? The layout and material of the quarry not being suitable to meet landfill environmental requirements (and modification has excessive costs).
? Location and market conditions.
? The site possibly having a higher value for an alternative use (eg property development).
The business is continuing to explore expansion opportunities.

Boral Waste Solutions has grown significantly in the last five years. Although not its traditional industry segment, Boral?s move into waste has provided some stability. The business has provided strong profit growth and continues to do so, even in these challenging global economic times.

Brian Fox-Lane is the national manager of Boral Waste Solutions.

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