When planning to build, aim to use materials that have low embodied energy. Embodied energy is a measurement of the amount of pollution produced when manufacturing and distributing a certain material. For instance Aluminium sheets have a higher level of embodied energy than timber – the following table gives a general indication of embodied energy for various materials.

             
                  Source: CSIRO MMT Brochures - Technologies Embodied Energy

Please note: this table should be used as a general indication only. A number of factors, including the distance required for the material to travel to reach the building site will alter the amount of pollution produced.

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Hazardous waste

Everyday we buy, use, and throw away many products which contain small amounts of hazardous chemicals that can be a risk to you, your family and pets, waste collectors and the environment.  Hazardous waste can be corrosive, toxic, flammable or reactive.

Everyday we buy, use, and throw away many products which contain small amounts of hazardous chemicals that can be a risk to you, your family and pets, waste collectors and the environment.  Hazardous waste can be corrosive, toxic, flammable or reactive.

When we dump these materials see simply put the danger elsewhere, usually a landfill where they can seep out as gases and liquids, posing health and environmental risks.  If we pour them down the drain, they pollute our waterways.

Some common products that produce hazardous waste are batteries, gas cylinders, fluorescent light fittings, oil, grease, solvents, paints and paint strippers, swimming pool chemicals, some air fresheners, hair dyes, fabric cleaners, pesticides, herbicides and some of the packaging that these products come in.

A recent study showed that nearly 86 per cent of households put these materials into their usual kerbside waste.  Instead, why not contact your local council for the best way to dispose of hazardous products?

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And some useful tips for the garden

What is compost?

Composting is a natural process by which organic materials such as leaves, grass and vegetable scraps are broken down by micro-organisms to form a rich soil-like substance.  It’s produced in the natural environment from decaying leaves and litter on the forest floor.

Over time, further decomposition of compost produces humus, an essential component of all soil that normally takes ages to form.  Adequate levels of this organic matter - compost or humus - are essential for good soil.

We can achieve the end result much more quickly in the home garden by building a compost heap.  Essentially, this process been used in crop production for over 4000 years.

Why compost?

Composting is a natural process that breaks down food, vegetable and garden waste into rich organic material and soil conditioners.  So it’s a great way to reduce the amount of waste we need to put in the wheelie bin.

We pay a high price in both monetary and environmental terms for the disposal of household garbage, about half of which is food and garden refuse that can be turned into compost.  We can all play a part in land care by composting the organic parts of household garbage.

Some of the benefits are that composting:

• Reduces waste to landfill (about half of our home garbage is organic waste);
• Reduces water use and urban run-off (by increasing the absorbency of soil);
• Increases the nutrient value of the soil and improves its productivity;
• saves money by reducing the need for artificial fertilisers and pesticides (because
      it increases the ability of plants to resist disease); and
• It’s an environmentally responsible way to help your garden grow well.

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Getting started

While it’s not essential that compost piles be enclosed, many people use a bin or similar enclosure which can be bought from hardware and garden shops; or you can easily construct one with common materials such as chicken wire, old fencing timbers or used pallets.

Choose an easily accessible warm spot on a grass or soil base.  Place some coarse sticks and twigs on the bottom to help with drainage and aeration.  Then just add your organic scraps.  The finer you can shred the materials the better (a mower for small jobs or shredder for larger ones is often useful).

Moisten the pile as you go and give it a turn with your garden fork to get air into the pile.  Then turn the compost pile every few weeks so that the outside layers are exchanged with matter at the centre of the pile.  Cover it so it doesn’t dry out or get soggy with rain (you can put a lid on it with wet newspaper, old carpet, tin or roofing materials, anything that slows water loss and still allows some air-flow).

Composting can begin at any time of the year, but many people start in the autumn when leaves are abundant.

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The process

If the pile is large enough, and the conditions allow the micro-organisms to flourish, the composting process will be rapid.  The temperature at the centre will rise to about 60 degrees C as the waste materials begin to breakdown.  As the decay process continues the compost heap will gradually shrink to about one third of its original size.

Finally, the temperature cools and earthworms invade the heap.  The compost is ready when there are no recognisable bits of the original material.  It will be fine to crumbly in structure, almost black in colour and will have a good earthy smell.

Not all compost heaps are quick to decompose and they don't all generate a lot of heat.  Efficient composting is performed by micro-organisms that thrive on oxygen. If your compost is cool and smells like the tip it is probably because the organisms at work like saturated, airless conditions.  So remember to turn your compost regularly to let the air get into it.

Essentials

A good organic mix is three parts ‘browns’ (such as dead leaves that are high in carbon) and one part ‘greens (fresh grass clippings and prunings that are high in nitrogen).

• Moisture - Materials should feel moist but not soggy to encourage the micro-     organisms.  It should feel damp rather than wet.  Check this each time the heap     is turned.
• Temperature - It should feel warm to the touch except in the cold winter months.
• Air - Turn the material regularly to ensure air reaches the centre of the pile and     to prevent any unpleasant odours that can occur when materials decompose     without oxygen (oxygen is essential in the composting process).  Remember:     lots of air = lots of organisms = rapid decay.
• Micro-organisms - These are the naturally occurring compost activators -     bacteria, fungi, worms, millipedes.  To be sure of a healthy population scatter a     spade full of soil through the raw materials or add some old compost to the new     heap.
• Time – The decay process may take as little as 8 to 10 weeks depending on the     composition of the compost.

The following materials are suitable for composting:

• Uncooked vegetable trimmings, peelings and tea bags from the kitchen;
• Soft hedge clippings, dead leaves, lawn clippings;
• Shredded paper (not shiny magazine-type paper) cotton and wool fabrics;
• annual weeds.

Materials not suitable for composting are:

• Meat, bones, fish, oils and fats (they attract vermin);
• dog, cat and human waste (may contain harmful bacteria or intestinal worm   larvae);
• Fruit fly infested fruit;
• Soil pests and diseased plant material;
• Large volumes of salty water (salt is not good for soil);
• Fruit and seed from invasive weeds (like privet and lantana);
• Synthetic fabrics;
• Large woody material like prunings (which need to be put through a shredder    first);
• And try not to compose your compost of too much of the same material – variety   is best.

Worms

Earthworms are the intestines of the earth' said the philosopher Aristotle. This is because worms create pure humus.  So worm farms are great for recycling food scraps and organic matter and for composting if you are short of space.

A worm farm operates on a rotating cycle with a tray/box containing food scraps sitting at the top or side which attracts the worms until the food is eaten.  Scraps are then put into the other tray/box bringing the worms back but leaving their castings, ready for the garden.  This cycle is endless: feeding, migrating, and feeding again.

Worm castings are a smorgasbord of nutrients: a handful of castings stirred into a 10 litre bucket of water and applied during the growing season will produce outstanding results.

As well as saving money on artificial products, you won't burn your plants by over-fertilising.

Rainwater Tanks

Home rainwater tanks have long been a necessity in rural Australia and now they are catching on among urban homeowners.  High water usage, population growth through urban sprawl, and the worst drought in generations are encouraging this trend, often with Government rebates.

Rainwater tanks are an effective way to take the pressure off our limited water resources and to help manage stormwater run-off.  By storing run-off from your roof, a tank can provide a valuable water source for flushing toilets, washing machines, watering gardens and washing cars.

By installing a tank you can:

• Reduce mains water consumption (and therefore reduce water supply   infrastructure costs and requirements for new or bigger dams);
• Improve water security of supply;
• Improve your own asset protection (eg your tank water can be used at any time   for lawns, gardens and motor vehicles); and
• Improve stormwater quality (and reduce stormwater volume and peak   stormwater discharges).

You can also make a big difference to your water bill by using rainwater appropriately in conjunction with devices like dual flush toilets, AAA-rating showerheads, taps and tap aerators.

Government action

• In Sydney and NSW new building regulations call for a 40% reduction in mains water usage.  Sydney Water has a rebate program offering customers up to $650 to install a rainwater tank.  To qualify for the rebate, it must be a new tank with a capacity of at least 2,000 litres and be purchased on or after 20 October 2002.  The rebate is based on the size of the tank and whether the rainwater is 'plumbed' into your toilet or washing machine.
• In Canberra in the ACT, new developments must include a water tank and in Victoria new homes have to be 5-star standard and must install either a solar hot water system or a rainwater tank.

While the NSW Department of Health doesn't advise using rainwater for drinking when there's an alternative mains water supply available, it believes that people in NSW could save millions of litres a year by using rainwater for toilets, in washing machines, and for garden and outdoor use.

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How it works

Rainwater tanks store run-off directed from your gutters and downpipes from your roof catchment. This means you may need to make alterations to your guttering and you will need to install appropriate screens to stop debris and insects entering the tank.

If you are connecting your tank to the toilet or washing machine you will need to maintain a minimum level of water in the tank and will therefore need a top-up system to deliver water through a pipe from the mains supply.  An air-gap is required between this pipe and the rainwater tank to ensure no backflow from the tank can go into the drinking water supply.

If the flow rate is too high, it can affect the water pressure supplied to you and your neighbours.  A plumber can advise of the requirements of the top-up system for your property, including determining the air-gap required and flow rate restriction required.

New shapes

Manufacturers have a wide range of tanks on the market made from metal, plastic (or PE / polyethylene) or concrete (not often used in urban areas).  The tanks are long-life with variety of shapes and colours.
The days of the old round corrugated iron tank on its timber stand have long gone. The new tanks come in a range of capacities and can be oval-shaped to run along an exterior wall or rectangular with rounded-off corners to minimize the encroachment on your garden area.

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