We all want to live well and enjoy life
Ordinary domestic life wastes finite resources, worsens climate change and pollution and can make enjoying life that bit harder.
Our desire to do what we have ended up doing in Brisbane originated in England during the “Oil Shocks” of the 1970’s. For most Australians the British experience of an oil-dependent economy without enough oil is quite literally unthinkable.
But… World oil production has peaked and prices are not going anywhere but up, yet demand for fossil fuels keeps growing.
Food security, sustainable energy and resource use, affordable housing, pollution control and climate change will not go away. Australia will become a conserver society soon enough. How will we make the change – in an ordered way by choice or chaotically when there is no choice left?
‘Bellis’ has been adapted to reduce our impact on the natural world: saving domestic water use, reducing sewage and stormwater pollution, reducing peak demand for energy and reducing greenhouse gas production.
The back garden grows fruit, vegetables, herbs and spices. The decorative front garden grows plants suited to natural rainfall and long-lived stock has been selected to cope with predicted climate change for Brisbane to 2050. Both are grown organically.
We aimed to spend about the same as a new family 4 wheel drive car on the sustainability items. The only subsidy has been one rebate from the federal government for installing solar panels.
Michael Mobbs of Sustainable Projects has been the sustainable design coach, liaising with Brisbane City Council, arranging site inspections, diagrammes for the sewage system, etc.
Rain Water Harvesting
We installed a 21,000 litre, in-ground concrete rainwater tank. When full, this provides a four week supply of water for house and garden. Excavating the tank pit generated 37 cubic metres of soil. Aware of the problems of rapidly filling landfill sites we conditioned it for cultivation on site.
Leaf and mosquito excluding rain heads have been fitted, one atop each downpipe to prevent any leaf litter entering the tank. Each downpipe is fitted with a first flush device. The rainwater tank is gravity filled.
The tank is connected to mains water. A float valve prevents the water level falling below our output pipe. Our capacity to collect rainwater is hardly affected but we need not worry about running out of water. A soakaway trench will capture any overflow during very wet weather and it connects to the soakaway pit.
A sediment and activated carbon filter on the mains supply to the tank remove chemical (chlorine) and biological pollutants . A ceramic and carbon filter are fitted to the drinking water fountain.
All waste water feeds this system which digests solid waste. Water passes through a sand and gravel filter, enters a holding tank and then passes through an ultraviolet filter for chemical free disinfection and is ready to flush the toilet and water the garden.
Once the garden layout is complete, excess water will be recycled via trickle irrigation to water the fruit trees and hedge. Independent water quality testing will, hopefully, document that no contaminants, including chloramines, remain in the recycled water.
The photovoltaic system comprises six solar panels which supplies 220 to 240 volt, 50 Hertz power, the Australian Standard, and plugs into the power grid. During the day power is directed into the grid, power is drawn from the grid when needed, effectively using the grid as a battery.
A standard agreement with Energex means that we only pay for the excess power we draw from the grid. Our peak power output will normally coincide with Brisbane’s peak demand, when everone’s air-conditioning is working its hardest.
We replaced the electric cooker with gas and the electric water heater with an efficient instantaneous gas water heater since there wasn’t enough room on our roof for a solar hot water system and photovoltaic panels.
The washing machine is water and energy efficient. The ‘energy star’ and water efficiency ‘A’ ratings are helpful in making the most approriate choice, but the water ratings are not absolute. They compare like with like. For example a four ‘A’ top loader is not nearly as good a water saver as a four ‘A’ front-loader.
We use compact fluorescent light globes or dimmer switches in rooms like the bathroom and bedroom where compact fluorescents are less energy efficient.
Originally we wanted the rainwater tank under or alongside the house, Brisbane City Council would not permit it within ten metres of the sewage system – a hang over from the bad old days of leaky septics. The resultant extra plumbing work cost twice as much as the tank itself.
Energex took three months to connect the solar panels to the grid, so we were unable to generate electricity during summer.
It’s critical to use quality gravel for the recycled water filtration tank. Our gravel was full of iron. This dissolves out and the resulting brown water stains the toilet bowl and impedes efficient decontamination by the UV filter. The gravel was replaced
Nick Walford-Smith, an award-winning Gold Coast-based landscape designer, worked with us to improve our initial garden design and drew a plan to scale to work from.
Green Survival, Brisbane-based landscape contractors, installed land drainage, the stormwater soakaway and front garden path.
Soil conditioning was based on thorough laboratory testing and specialist advice. A test crop has been grown and laboratory tested for the presence of heavy metals (lead, cadmium, etc) that might prevent bioaccumulating crops from being eaten. The soil has proved safe for cropping.
Find out more about the changes faced by Brisbane gardeners in Sister Cities
Jerry Coleby-Williams & Jeff Poole