Passive features for solar gain installed at the centre:
51 square metres of panels are mounted on the north faces of the two dormitory wings of the building. Heated air will be ducted to selected areas of the building using electric fans. Delivering warmth through air grilles effectively pressurises the building so that warm air moves from the grilles throughout the rooms. Outlets for the warmed air have been concentrated in the cool south side of the building. Temperature sensors will be located internally to determine if heat is required and also on each of the three banks of panels to ensure that heat is available.
Night cooling is similar in effect to opening the windows on a hot night. A high capacity, low resistance exhaust fan will ventilate selected areas of the building initiated via an automatic temperature control. It will only function in the summer months. Air will be ducted via a roof mounted cowl.
As part of the planning process the Centre for Sustainable Living has pursued water conservation opportunities. The aim is the reduction in per capita water use and therefore reduction in wastewater generated. This work uses methods in line with the Water Corporation's strategy to reduce water consumption per head from 155 litres/day to 135 litres/day. Water saving appliances have been installed, including water conserving shower roses, waterless urinals, and dry composting toilets. These appliances will be part of an introductory tour and education program for all users of the centre, where the use of water saving behaviour and technologies will be explained, demonstrated and finally used!
Daily Flows:
A total combined flow of 9860 litres/day at 145 litres/person for a population of 68 has been used to design the wastewater systems. Greywater (showers and handbasins) conributes to 60% of the flow (a total of 5916 litres/day) and blackwater 40% of the flow (3944 litres/day). Although the 145 litres/day (standard water reduction figure) has been used this figure is very conservative, because all laundry (linen, clothes etc), apart from that used within the caretaker's cottage (two people maximum), will be processed offsite.
Biolytix aerobic treatment unit
A Biolytix BF-STP (3) system takes the wastewater from the kitchen, male toilets and showers and disabled toilets and showers. The Biolytix incorporates a geotextile filter system and biological treatment organisms such as microbes, worms and compost beetles to break down solids and remove nutrients. This is a innovative system which has been approved by health departments and demonstrated in Queensland, New South Wales , South Australia and Victoria. The BF6 model has received Department of Health approval in Western Australia according to AS/NZS 1547:2001, with the BF2 model approval being processed. The centre will be providing a demonstration system with information collation for Western Australian government departments (for example the Departments of Health and Environment) and educational centres (schools, universities and TAFEs). The biolytix system (BF-STP) designed for the Denmark Sustainability Centre has been rated to cope with loadings of 6,600 litres/day and incorporates a parallel design of three filters. The BF-STP includes a BF2 pre-filtration unit and two BF6 filters, one gravity-fed the other with a pump for irrigation, to maximise effluent treatment. At a maximum loading of 6600 litres/day the system provides effluent to a high secondary standard appropriate for subsurface irrigation in the gardens on site.
Biomax aerobic treatment unit
The Biomax C30 takes wastewater from the women's toilet and shower block, the caretaker unit and the laundry. The Biomax system has been used extensively in Western Australia for decentralised wastewater reuse/disposal. A further modification to the system for this project will include periodic aeration to enhance denitrification. This modification has been requested for the unit to be located at the centre, as a result of research at Murdoch University's Environmental Technology Centre, which found that two hour on-off aeration enhanced denitrification by up to 30%. The Biomax system used for the Denmark Sustainability Centre is a C30 model that treats wastewater to a high secondary standard for subsurface irrigation in the gardens on site.
Composting Toilets:
The Rota-loo 950 and the Clivus Multrum CM10 have been selected to demonstrate two different types of dry composting toilet. Each of these toilets can handle continuous use by up to eight people. Principally the composting toilets will be demonstration technologies for water conservation and human waste reuse techniques.
Demonstration wetland for filtering subsurface drainage:
A 'billabong' will be installed as an additional safeguard to strip any nutrients and sediment from stormwater before entering the Denmark River or groundwater. It will become part of the system with a monitoring program through the centre. The specifications for the managed billabong are currently being developed in consultation with the Department of Environment.
The billabong will enhance a natural flood area so that rainwater runoff is intercepted and slowed to increase sediment deposition and nutrient uptake. The ability for water from intense rainfall to move readily through the system is required. The billabong area will be designed to dry out during the summer period so that mosquito breeding is avoided. The current area has heavy kikuyu and other weed growth which will need significant management and revegetation with riparian reeds, sedges and vegetation. Areas of kikuyu will be maintained as they provide significant nutrient removal and can be mowed to take nutrients away from the site. They can also provide access to the wetland zone. This development will complement local riparian revegetation work undertaken by the neighbouring Denmark High School and Green Skills Inc.
Reducing the waste we produce is the first major step in treading more lightly on the earth! Then we need to be more careful and creative about how we deal with the waste we do produce.
The Centre for Sustainable Living uses cleaning products that do not damage the environment. The basic cleaning ingredients are vinegar, bicarbonate of soda and cleaning fibres that do not require chemical cleaning agents. This is good news for anyone with allergies and chemical sensitivities.
The centre has a policy of purchasing materials which minimise packaging and maximise the ability to be recycled, including sourcing fresh, locally grown foods. The TAFE organic horticulture site is adjacent to the centre and where possible the centre purchases fresh vegetables from this enterprise. Separation of all materials is central to reuse so look out for the appropriate bins.
Feed the worms!
All kitchen wastes and the paper towels from the toilets and showers are good tucker for worms. The centre has established a worm farm on site to turn waste into organic wealth. The compost is used on the gardens at the centre which means that we do not have to rely on purchased fertilizers.
