Kuruvilla Mathew

Solar energy has a major role in moving towards carbon neutral settlements. Three different Australian settlement types are included in this research: urban villages, remote indigenous settlements and isolated mine site camps. This study contributes to a broader ARC research program by Curtin University and Murdoch University on Decarbonising Cities and Regions. A six-element model for carbon neutral human settlements was developed. This was subsequently upgraded to include food as a separate element. The process to achieve a carbon neutral settlement via an emissions reduction plan, following a life cycle analysis, was proposed in six steps. It was found that this planning method can enable new urban developments to achieve a ‘zero energy development’ but achieving a carbon neutral status would require additional measures that address the complete lifecycle of the development. Monitoring and data collection systems were installed in a minesite camp and the data used in a new modelling tool to evaluate different renewable energy systems to offset total lifecycle emissions. These systems were found to only reduce emissions below that of the existing gas-fired power generation somewhere between 2013 and 2018 when costs are expected to drop significantly. In the case of remote indigenous settlements the elements of this planning model were used to identify opportunities for sustainable livelihoods linked to renewable energy in the new carbon economy.

This paper presents a model for carbon neutral land development as a mechanism to help drive innovation and emission reduction within the built environment sector. The carbon content model is comprised of the following: • The greenhouse gas (GHG) embodied in the materials of the buildings and the infrastructure; • The GHG emitted during the construction process with different approaches; • The electrical power and natural gas used in the buildings for different building types; • The transport fuels used in the construction and the on-going use by residents; • The GHG produced in the full water cycle • The GHG from the solid waste. Understanding the interactions between the six elements of the model allows better decarbonisaton options to be developed. Two remote settlement cases are analysed. Firstly for a mine site camp, we introduce the “Smart Camp” digital control and monitoring concept . This includes sustainable village design, heating and cooling reduction, renewable energy, water use and reuse, and landscaping. Secondly, for the remote Aboriginal settlement, we address the need for sustainable livelihoods, including local food production and rangelands forestry and management.

The process to achieve a carbon neutral settlement via an emissions reduction plan, following a life cycle analysis, is in five steps: 1) Understanding energy use, 2) Behaviour change programs, 3) Energy efficiency improvements, 4) Monitoring and control, 5) Renewable energy technologies, and 6) Biosequestration as a sink for the balance of past, current and ongoing emissions. Three cases typical of Australia are analysed with this six-step reduction model: the urban village, the remote minesite camp and the remote Aboriginal settlement. Following extensive research a carbon reduction plan has been developed for each case.

Vermifiltration systems rely on the biodegradation of organic matter in household wastewater to produce a humus filter. The humus filter in an appropriate design is capable of treating wastewater to a high secondary standard suitable for non-contact reuse purposes e.g. irrigation. The variable nature of household wastewater production and constitution may cause toxicity from particular wastewater constituents to the species that biodegrade the organic matter in vermifiltration systems. Due to this, this study was undertaken to assess the toxicity of one particular constituent, hypochlorite, to key species within the vermifiltration process. Hypochlorite and its by-products are present in many household products, especially disinfectants and household cleaners.

During the study, the key vermifiltration species, the worm Eisenia fetida, was subjected to a series of hypochlorite toxicity tests in solid phase mesocosms. The tests showed that the adult worms were relatively tolerant to hypochlorite toxicity, but the reproduction by the worms was impaired at a very low hypochlorite concentration. The overall risk assessment showed that hypochlorite and its main by-products total organic halogens and sodium chloride are unlikely to cause toxicity to E fetida from accumulation in a vermifiltration system, during normal household use.

Earthworms due to their peculiar feeding habits and habitats are commercially utilised in waste management, fish food and fish baits. They also have been proved to be versatile tools for the environmental monitoring and ecotoxicology. The garden earthworms are known to improve the soil quality and crop production, while certain species are ideal for commercial applications for waste management. Maintaining the system within the tolerance level of each commercial species is important for the successful operation of the vermicomposting or vermiculture systems. Domestic vermicomposting toilets can be used in National Parks (campsites), isolated roadhouses, farmhouses, and on peri-urban or semi-rural blocks under current legislation in Australia. Their use is ideal in places where disposal of effluent is difficult due to low soil infiltration, lack of availability of land, limited water resources, or in ecologically-sensitive areas. A greywater recycling system may still be needed where wet facilities are required. The mature vermicompost product is free of pathogens, ideal for the garden and results in a cycling of the nutrients. The domestic vermifiltration system can replace septic tank systems. This system avoids the need for periodic pumping of sludge as well as the need for two separate systems. Again vermicompost is produced for the garden and the treated effluent can be recycled on the garden by subsurface irrigation. Any system that requires disposal of effluent from septic tanks can use the vermifiltration method.The Vermitech sludge stabilisation process uses the same vermicomposting principles and can process successfully sewage sludge from municipal sewerage facilities as well as a range of other organic wastes. A design procedure for loading of organic matter has been developed and varfied with the present pracice of loading in the vermocompost treatment plant in Redland, Queensland Australia. If the loading is full of organic matter it is possible to load a maximum of 2 to 4 cm per day. Any thing more shall create an aerobic condition and the process will be difficult. It may be possible to take an average of 10 to 20cms per week.