- David Gamble, GHD
Waste management is a fundamental part of our daily lives. Just like we have grown to expect clean water to be provided to our houses, schools and businesses, we also rely on the wastes that we produce to disappear without causing us any discomfort, or loss of amenity. Modern waste management systems do just that - for residents, wastes and recyclables are collected weekly or fortnightly, and for businesses, the bins in the office are magically emptied each night, and their contents never seen again.
Obviously there is a downside to this level of convenience - we become disengaged with the fate of the wastes that we produce, and many of us are completely unaware of the environmental impacts of collecting, treating and disposing of the discards of our daily lives. Therefore we go on blissfully increasing consumption, all the time creating even more waste, with no feedback to give us a signal slow us down.
For those who don’t know, most waste materials (that is those that aren’t separately collected as recycled), are disposed of in landfills, operated by local government or the private sector. In Australia, and most western economies, modern landfills are sophisticated tombs for storing waste for long periods, designed by engineers and often operated by engineers. They have liner systems for preventing leachate from affecting groundwater, for collecting gas generated by organic wastes and for preventing stormwater from entering the waste in the first place.
However, not all landfills meet this standard. According to a national survey of landfill sites undertaken by the Waste Management Association of Australia in 2005, only 40 - 50% of landfills receiving more than 200,000 tonnes of waste per year have a gas collection and treatment system (WMAA (2005)). At smaller landfills generally nothing is done to actively treat landfill gas emissions. Landfill gas simply discharges to the atmosphere untreated.
There is no doubt that one of the greatest opportunities associated with reducing the direct impacts of waste activities is to improve this situation by retrofitting small landfills with simple and affordable and simple methane management systems, and to divert more organic waste from landfill. This paper discusses some recent developments in each area, and the impacts of the Federal Governments proposed CPRS (Carbon Pollution Reduction Scheme), which includes the waste sector, a first for any emissions system in the world. The CPRS directly targets landfill gas emissions, so the implications of the CPRS are considerable. If implemented, it has the potential to change the way we deal with waste quite significantly over the next 10-15 years.
BIO:
David Gamble is a Principal Environmental Engineer with GHD, an international engineering consultancy with network of Australian offices, as well as offices in many countries in South East Asia, China, Europe, and the Americas. He has degrees in Mechanical Engineering and Economics, and a Master of Engineering Science in Waste Management.
David is GHD’s Service Line Leader for Waste Management, and has responsibility for coordinating GHD’s waste management business worldwide. He has more than 25 years experience in environmental engineering projects, and special interest and experience in environmental approvals for waste management infrastructure, including landfills, waste transfer stations and alternative waste technology facilities. He has delivered papers at local, national and international waste conferences on topics ranging from waste minimisation, landfill approval processes and developments in alternative waste technologies.