How rabbits use water

Rabbits and other animals use water very sparingly. Rather than have a shower we groom ourselves using our tongues. This saves heaps of water. When we go to the toilet we don’t use any water for flushing. It's not needed. Yes, we do need water for drinking and washing some of our food. But compared to what humans use its not much at all.

Human uses for water

Humans, by comparison are very wasteful with their use of water. Humans take

70% of water from waterways to grow their food.
20% of water to send to businesses and houses in cities.
10% - Only 10% of water remains in waterways for aquatic animals and plants. That doesn’t seem fair.

How can Humans Reduce their Water Use?

There are several ways that humans can reduce their use of water.

Shower for one minute.
Install a very large rainwater tank to collect roof water.
Use grey water from showers to water the garden.
Use a composting toilet and recycle nutrients back to the garden.
Grow food at home (fruit trees, vegetables and keep chickens) using tank water and grey water. 475 litres of water per person per day is used to grow food commercially to feed Melbourne. Growing food at home using roof water will help to reduce this water demand [1]

Showering for One Minute

The shower uses the most amount of water in the house - 49 litres per day Yarra Valley Water report

We can easily shower for one minute, using 7.5 to 9 litres of water, and still be clean.

Just wet yourself, then soap yourself, and give yourself a final rinse.

If you can have a lukewarm shower (25degC) this will be even better because a lot of energy is used to heat water.

There are human health advantages to taking less frequent and cooler showers [2].

Hot Water Heaters

Heating water consumes significant amounts of energy Sustainability Victoria.

For a family of 3:

0.54 tonnes/year for electric heat pumps
0.27 tonnes/year for solar natural gas boosted
0.95 tonnes/year for natural gas storage
0.66 tonnes/year for instant gas hot water

The target needs to be 1/15th of current hot water heating systems (Australians currently produce 15 tonnes GHG/year and we need to reduce emissions to 1 tonne/year).

If we assume that current hot water heater technology generates on 0.5 tonnes/year on average, then the target will need to be 0.03 tonnes/year

None of the options above will reduce the amount of GHG emissions sufficiently to achieve 1 tonne/person/year or the 1.5degC of global temperature rise (67% confidence) Greta Thunberg Climate Delusion

It is not possible to turn down the temperature of these hot water systems and use less energy because of the risk of creating ideal conditions for Legionella bacteria.

Solar Hot Water Showers

Outdoor camping solar showers are a step in the right direction. They hold 20 litres of water or more. However most are made using PVC, which ends up contaminating the water (PVC has a strong recognisable odour)

Building a DIY Solar Hot Water Shower

If you shower at the end of the day you can enjoy a warm shower for free using the sun's rays.

Build yourself a Solar Oven that can hold 4 litres of water. It is easier to use thin dark metal pots. A standard solar oven design should hold two pots, with 2 litres of water in each pot. You can also use glass jars. Each lid on the glass jar needs to have a large hole (make a hole using a nail or 4mm drill) to prevent any pressure build up.

The Solar Oven is made by painting the inside of a cardboard or metal box black using paint. Attach some clear plastic or glass to the top of the oven. This arrangement will help collect and trap the heat from the sun.

Place your dark metal pots filled with water inside the oven. The oven needs to be in a sunny and protected location.

When the water is hot (80 degC), simply decant the hot water into smaller PET bottles half filled with water. Topping up each bottle with the hot water will produce warm water for showering.

The lid of each PET bottle needs to have small holes drilled into them. This way the caps will function similar to a standard shower head. Bottles can be carried up to the shower cubicle using two buckets to balance the load.

To conserve the heat in the water bottles place them in an esky or insulated container until ready for use.

Create a holder in the shower cubicle so that each bottle can be held in place and release water.

Rainwater tanks

Installing a rainwater tank (6-10,000 litres or greater) can reduce the amount of potable water used by 80%.

Rainwater tanks need to be big because most of the water will be used in the garden. Collecting roof water and allowing it to filter into the garden is better for plants and will help reduce the urban heat island effect. Capturing water is also better for waterways because it reduces large flooding events. Removing water from a site using stormwater and sewage pipes is totally unnatural. Water should harvested and used locally.

How much rain water can I collect?

1mm of rain landing on 1m2 of roof will produce 1 litre of water.

As an example, a 10mm rain event, landing on 150m2 of roof will produce 1,500 litres of water.

In Melbourne the average rainfall is between 600-700mm per year. This will change depending on whether we are in a wet year (900mm) or a dry year (400-500mm).

Even if you can't collect all the rainwater in a tank, you can install downpipe diverters and still direct rainwater from downpipes to your garden. Gardens that have lots of plants and mulch on the ground will be able to absorb more rain.

Does it rain during a drought?

Yes, during the Millennium drought in Victoria from 1998 to 2008 rainfall only reduced by 30% on average. There was always rain, just less than normal.

Water utility companies often say that its not worth having a rainwater tank during drought. In fact, during droughts many people install rainwater tanks to help water their garden and conserve drinking water (potable water from taps).

Carbon emissions associated with Water

Polyethylene

One tonne of polyethylene creates 1700 kgs of carbon emissions [3]
A 3500L plastic rainwater tank weighs 115 kg (Cost $1,400) and will therefore have embodied CO2e emissions of 195 kg CO2e (1,700 / 1000 x 115) [4]
Three tanks would have 585 kg CO2e in emissions.
A tank can last 20 years if protected from UV rays and if annualised over 20 years the emissions are 30 kg CO2e/year.

Steel

One tonne of steel creates 1750 kgs of carbon emissions.
A 4000L Modline Aquaplate Steel Water Tank (Cost $2,265) has an embodied emissions of 183 kg CO2e (1750 / 1000 x 105 kg).
A tank will last 20 years.

Ferro Cement Rainwater tank

A Ferro Cement rainwater tank is constructed using chicken wire to create a form for a tank, which is then caked with fresh cement.
The is high embodied energy in both the chicken wire and the cement, however the cement component will have the greatest mass of the two.
Because the tank can be made in situ, it will have a lower overall cost.
25 kg of cement are required per 1000 L of storage
A 4000 L ferro cement tank is estimated to have a 93 kg CO2e of embodied emissions from concrete (25 kg cement x 4 x 0.93) and 70 kg CO2e from steel (1750 / 1000 x 40 kg), giving a total of 163 kg CO2e.

Rain tank water pump

Rain tank water can be pumped using a 12V (6A, 60 Watts) powered pump [5].
The embodied energy in a pump will be less than 100 kg CO2e.
The pump can be powered using a solar PV system with battery storage.
Water can be pumped directly to the garden or pumped to a header tank.

Concrete Stormwater Pipes

One kilogram of concrete releases 0.93 kilograms of carbon dioxide [6].
Stormwater pipes come in different diameters. They are typically 2.44m in length (4 required to cross property).
The mass of a 300mm stormwater pipe is 205 kg so the carbon footprint is 190 kg CO2e (205 kg x 0.93). If four pipes are required for a typical household the embodied emissions are 762 kg CO2e [7]
Stormwater pipes last for 50-100 years.
Annualising carbon emissions over 50 years gives an annual emission of 15 kg CO2e/year per household.
Even if these emissions are low the stormwater makes less of a contribution to the urban environment (e.g. no local food production, no urban cooling, no recharging of groundwater, no watering of trees).

PVC Sewage Pipes and Sewage Treatment

PVC (Plastic) Sewage pipes will have relatively low embodied emissions because their mass is low relative to Concrete pipes.
However, human wastes could easily be treated at home to make a good compost material for gardens.
There are many issues with the production and treatment of sewage using conventional sewage treatment infrastructure.
- Significant amounts of household water used to flush toilets (19% of household water use) [8]
- Treating and recycling waste water is very energy intensive
- Nutrients present in human waste are not reclaimed for agriculture. Phosphorus and Nitrogen are lost.
- Toxic contaminants are often present wastewater.
- Treatment of wastewater with Alum results in the precipitation of heavy metals in sludge.
- Treated wastewater is discharged to waterways. This wastewater still has relatively high levels of nitrogen.

Wonthaggi Desalination Plant

The Wonthaggi plant is estimated to produce 150 gigalitres of fresh water per year.
The plant is estimated to use about 90 mega watts (MW) of power from the grid, which translates to 2160 MWh per day [9].
This amounts to 0.43 kWh per person per day (2,160,000 kWh per day / 5 million population of Victoria) or 1.03 kWh/household/day (0.43 kwh/p/day x 2.4).
Using the emissions intensity from electricity generation in Australia of around 526.9 grams of CO2e per kilowatt-hour the emissions from the Wonthaggi plant (without abatement) is 0.414 Mega tonnes (0.526 kg/kWh x 2,160,000 kWh per day x 365 / (1,000 x 1,000,000)[10].
This equates to 83 kg CO2e of emissions per person per year.

Emissions from the Water Sector in Victoria

Did you know the Victorian water sector emits more greenhouse gas emissions than any other Victorian government sector? That's more than Victoria’s public hospitals, public schools or train network [11]

Annual total emissions are 876,428 tonnes/year for the sector [12] or 175 kg CO2e/person/year.

All agencies have a target of zero carbon emissions by 2035. Note that this target only refers to scope 1 and 2 emissions.

Local government emissions are not included.

New Renewable energy installations are presented as projects to reduce water sector emissions.

Projects reducing water sector emissions

Melbourne Water is building a 19 Mega Watt solar PV farm for Melbourne's Eastern Treatment Plant that will reduce emissions by 30,000 tonnes per year.
The plant treats around 40 percent of Melbourne's sewage — about 330 megalitres per day — from about 1.5 million people (220 L/p/day), mainly in the eastern and south-eastern suburbs [13].
The farm will house 39,000 solar PV panels [14].
A quick calculation shows that the average size of each panel is 487 Watts (19,000,000 Watts total / 39,000 panels).
However, there are several issues with these claims.
- No battery storage is provided with the solar installation. Power will only be produced during the day.
- The embodied emissions in the panels are estimated to be 615 kgCO2e/kWp of installed capacity (best case) [15]. This installation would still result in 11,685 tonnes CO2e emissions related to embodied emissions which are not counted because they are classified as scope 3 emissions (19,000 kW x 615 kg CO2e/kW).
- The solar PV panels are claimed to save 30,000 tonnes of CO2e emissions per year (or 0.77 tonnes CO2e per 487 Watt panel). However the proposed solar system does not provide any power at night. Additional and more expensive investments in energy storage or other forms of renewable energy will be required to further reduce CO2e emissions. These solutions will have higher embodied energy and if scope 3 emissions are included net zero emissions will not be achievable as claimed.
- The mining of raw material used in the manufacture of solar PV panels and the production of waste have not been disclosed. By excluding these externalities there is no incentive to rethink current water management systems to make the entire system more sustainable. However when renewable energy technology is applied as scale there are significant environmental impacts.
- No behaviour change is required of the 1.5 million residents contributing to the system. Behaviour change will be a critical component in staying within a 1.5 degC world. This project does not address the high usage of potable water used to transport human waste or recover nutrients in the wastewater for re-use in food production. Both of these elements can have significant GHG emission mitigation opportunities.

Large Centralised versus Local Solutions

Local Solution

At the level of the individual household an investment of approximately $10,000 or $1000 per year annualised over 10 years (83 kg CO2e per year per household) could be invested in the following infrastructure:
- $6,000 Rainwater tanks (30kg embodied emissions per year)
- $400 Water pump (20kg embodied emissions per year)
- $300 Composting toilet (negative emissions if nutrients used to grow food locally)
- $3,000 Solar 200 Watt PV system with battery (33 kg embodied emissions per year)

The investment will result in the following outcomes:
- stop all wastewater leaving site.
- reduce household potable water use by 70%.
- reduce most stormwater leaving site
- assist in nutrient recycling and prevention of eutrophication of waterways
- assist with local food production and therefore reduces GHG emissions associated with agriculture sector
- promote urban cooling and irrigation of vegetation
- facilitates low carbon transition for water sector and CO2e mitigation operates 24/7
- requires significant behaviour change from households

Large Centralised Solution

The OPEX for the 19 MW ground-mounted solar plant is $436,146 per annum [16]
The capital cost of installing solar farms is estimated to be 2.41 per watt on average [17]
The Melbourne Water Eastern Treatment plant is estimated to cost $45 million (19,000,000 x $2.41) or $30 per customer ($45m / 1.5m population)

LOW Carbon Case Study

CO2e emissions associated with household water use
- Heating water
- Waste water treatment
- Desalination
- Food production

Carbon Budget

The table below illustrates the remaining carbon budget to keep global warming at 1.5°C (67% confidence) using budgets starting from 2020.
The remaining global carbon budget was 500 Gt in 2020 and is now 380 Gt in 2023.
Approximately 40 Gt of global emissions are produced every year.
In 2020 this dropped by approximately 7% to 37 Gt due to Covid.
Australians release 15 tonnes CO2e per person per year. At this rate the carbon budget up to 2050 would be fully expended by 2028 or 2032 depending on which confidence level we use.
Carbon budgets are also presented in a wiki [18]

Table - Estimate of Global CO2e Budget consistent with 1.5°C (67% probability).

Chart - Yearly CO2e Budget for Australians from 2018 to 2050 based on 1.5°C (67% probability) with emission reductions based on different start periods for reduction.

Table - Estimate of Global CO2e Budget consistent with 1.5°C (50% probability).

Chart - Yearly CO2e Budget for Australians from 2018 to 2050 based on 1.5°C (50% probability) with emission reductions based on different start periods for reduction.

CO2e emissions associated with Electricity Generation

All forms of renewable energy generate emissions. This may come from all steps of mining, manufacture, transport, maintenance and decomissioning. Currently the estimated emissions from most renewables is estimated to be 50 g/kWh of production throughout the life of the asset. [19].
The range for renewables ranges from 12-50 g/kWh depending on the source of renewable energy [20]

While some sources of renewable energy Tcan produce electricity at emission levels lower than 50 g/kWh the entire grid needs to consider:
- upgrading the electrical power distribution network
- storage of electrical energy. All storage system will create more usable energy but there are energy losses with conversion of energy
- intermittency of renewable energy sources (solar PV and wind)
- embodied energy (scope 3) in the renewable energy asset

The reality is that all renewable energy is associated with CO2e emissions per kWh over their lifetime, albeit, these emissions are significantly lower when compared to coal (1000 g CO2/kWh) and natural gas (475 g CO2/kWh) [21].

Heating Water

Electric Heat Pumps

Heat pumps are able to replace gas hot water heaters.
They are very efficient and consume approximately 0.8 kWatts of power when heating water. To heat water takes between 3 and 4 hours.
Therefore, the total daily electricity requirement is (0.8kW x 3) = 2.4 kWh.
At an emissions level of 50 CO2e g/kWh this equates to (2.4 kWh x 50 g/kWh) = 120 g/day = (120 g/day x 365 days / 2.4 people per house) = 18.25 kg/person/year.

Solar Hot Water Systems

Heating water using the sun only requires a 20 Watt water pump to circulate water from the storage tank to the solar collectors.
The pump operates for 6-8 hours per day.
Total energy use is therefore (20 W x 8 hours) = 0.16 kWh per day
At an emissions level of 50 CO2e g/kWh this equates to (0.16 kWh x 50 g/kWh) = 8 g/day = (8 g/day x 365 days / 2.4 people per house) = 1.22 kg/person/year

Desalination versus Roof water Harvesting

Desalination

The plant can product 150 billion litres of drinking water a year [22]
If the population of Melbourne is 5,151,000 this equates to (150,000,000,000 L / 5,151,000) = 29,120 L/person/year (with is one third of Melbourne's water requirements.
The average person in Melbourne uses 155 L/person/day = (155 L/day x 365 days) = 56,575 L/year.
About 3 to 3.5 kWh/kL for desalination. CO2e emissions would then equate to (3 kWh/kL x 50 g/kWh) = 150 g CO2e/kL [23]
A household using 95,000 L of desalinated water will produce (150 g CO2e/kL x 95 kL) = 14.250 kg CO2e/household/year = (14.24 kg CO2e / 2.4 people) = 5.93 kg CO2e/person/year.

Roof water Harvesting

By comparison, a DC water pump will consume [24] 62.4 Watts pumping at 11 litres per minute. The energy cost per kL is (1000 L / 11 L/min = 90 minutes = 1.5 hours x 62.4 Watts = 0.09 kWh/kL. This is very efficient if a header tank is used to create water pressure of the household.

CO2e emissions are calculated to be (0.09 kWh/kL x 50 g/kWh) = 4.5 g/kL. This figure can be verified using a solar PV system with battery storage.
A 5000 L tank attached to a house receiving 400 mm of rain per year will harvest 95,000 L of water per year. This equates to (95,000 / 2.4) = 40,000 L/person/year.
A household using 95,000 L would have carbon emissions of (95 kL x 4.5 g/kL) = 0.427 kg CO2e/household/year = (0.427 kg CO2e/ 2.4 people) = 0.178 kg CO2e/person/year.

Commercial versus Local Food production

Commercial Food Production

It takes over 475L of water per capita per day to feed Melbourne, around double the city’s household usage 16.3 million hectares of land is required to feed Melbourne each year, an area equivalent to 72% of the state of Victoria [25]
Feeding Melbourne generates over 907,537 tonnes of edible food waste, which represents a waste of 3.6 million hectares of land and 180 GL of water
Around 4.1 million tonnes of CO2e emissions (4.1 / 5.151 Melb population = 795 kg/person) are emitted in producing the city’s food, and a further 2.5 million tonnes from food waste.
The carbon footprint of beef, lamb (57.8%) and dairy (20.9%) is very high.
A switch to a more vegetarian based diet would reduce GHG emissions significantly.
- 2.8% - cereal grains
- 0.7% - legumes
- 0.4% - nuts
- 2.3% - oil crops
- 5.2% - fruit
- 3.5% - vegetables
- 0.5% - eggs
- 1.0% - fish

There is no clear strategy for reducing CO2 emissions in the food sector.
Data from the USA show that emissions related to the production of food come from a range of sources.

Different types of food require different amounts of water.
For example, 18% of the average Melbournian’s diet is fruit, but only 0.5% of the water used to grow their food needs to be used to grow fruit.
Beef and lamb use 26.3% of the water used to feed Melbourne and Dairy uses 53.1%.
By comparison, vegetable crops use significantly less water and this water could come from households.
- 0.1% (475 L/p/day x 0.1% = 0.48 L/p/d) - cereal crops
- 7.7% (475 L/p/day x 7.7% = 36.5 L/p/day) - nuts
- 0.5% (475 L/p/day x 0.5% = 2.37 L/p/day) - fruit
- 8.2% (475 L/p/day x 8.2% = 38.95 L/p/day) = vegetable crops

Local Food Production

Food can be produced locally at home using fruit and nut trees and vegetable plots.
Water comes from rainwater tanks, natural precipitation and grey water.
Nutrients to support local food production can come from food waste, humanure (waterless toilets) and nitrogen fixing crops.
Importing manure and synthetic fertilisers will be expensive and also contribute to GHG emissions.
Local food production will have zero or negative carbon emissions because almost all the high carbon emitting components related to food production will be eliminated (e.g. synthetic fertilisers, transport, packaging, retail sale).
Local food production may be able to produce 20% of the household food requirements.
Local food production will significantly change water use behaviours for a household.
- use of waterless toilets
- large rainwater tanks for harvesting roof water
- greywater reuse
- greater conservation of internal household use of water (e.g. 1 minute showers)
The CO2e emissions associated with local food production are associated with the pumping of irrigation water.
A 5000 L tank attached to a house receiving 400 mm of rain per year will harvest 95,000 L of water per year.
CO2e emissions to operate the irrigation pump are calculated to be (0.09 kWh/kL x 50 g/kWh) = 4.5 g/kL.
Total irrigation emissions to pump all the roof water collected in tanks are calculated to be (95 kL x 4.5 g/kL) = 0.427 kg/year per household or 0.178 kg/person/year

Victory Gardens

During World War II households in England, Europe, USA and Australia were all encouraged to plant Victory Gardens.
Households were encouraged to plant vegetables and keep animals such as chicken, pigs and goats for meat, milk and eggs.
Not all food products can be produced at home and not all food crops are suitable (e.g. cereal crops are better in large fields).
Home food production may have met 20% of food needs (based on food costs).
The production of vegetable-based crops requires 80 L/p/day on average with most of the water use during the irrigation seasons in Spring, Summer and Autumn.
The collection of 95,000 L in roof water could provide up to 260 L/household/day or 108 L/p/day (260L/h/day / 2.4 people) which would be enough to produce fruit, vegetables and nuts for the average household.
The carbon footprint for the irrigation component would be (95 kL x 4.5 g/kL) = 0.427 kg/year per household or 0.178 kg/person/year

Wastewater Treatment

Large Centralised treatment of wastewater

In Melbourne the annual emissions from treating wastewater between 2011 and 2016 are [26]:
Emissions come from bacteria releasing CO2 and CH4 when digesting the waste and from emissions from electricity generation.
- 408,860 tonnes CO2e/year - Melbourne Water
- 32,004 tonnes CO2e/year - Yarra Valley Water
- 41.774 tonnes CO2e/year - South East Water
- 40,307 tonnes CO2e/year - Greater Western Water
- 522,945 tonnes CO2e/year Total
This equates to (522,945 tonnes CO2e/year / 5,151,000 pop Melb) = 100 kg CO2e/person/year
State-of-the-art facilities consume 20-45 kWh/person/year [27][28]
If electricity is sourced from renewable energy (50 g CO2e/kWh) then emissions from the treatment of wastewater could reduce to 1-2.25 kg CO2e/person/year

Currently these emissions are divided up in to three scopes:
- Scope 1 - GHG emissions released as a direct result of the processes controlled by the water corporation (e.g. bacteria digesting wastewater).
- Scope 2 - GHG emissions released from indirect consumption of energy by the water corporation (e.g. motors and pumps)
- Scope 3 - GHG emissions released during the production or manufacture of assets used in the water sector (e.g. concrete pipes)
Currently only Scope 1 and 2 emissions are considered in GHG emission calculations.
Projects aimed at reducing GHG emissions focus on the production of renewable energy (solar and wind renewable energy projects) and the conversion of food waste to biogas to produce electrical energy[29].

Waterless Toilets

The Victorian EPA has approved several waterless toilets (also called dry or compostable toilets) [30]
Their energy and infrastructure requirements are significantly less than for conventional toilets connected to the sewage system.
Waterless toilets are powered with [31]
- 310 Watt Heater (optional)
- 45 Watt motor to mix and aerate the holding chamber
- 25 Watt ventilation fan
Based on a power consumption of 35 Watts and 24 hours of running the CO2 emissions are (35 Watts x 24 hours = 0.84 kWh/day x 365 x 50 g/kWh = 15.3 kg/year for one household or approx (15.3 kg/year / 2.4 people in house) = 6.4 kg/person/year.
The theory and operation of waterless toilets are better understood today [32][33]
The DIY Humanure Waterless toilet uses no heater or fan. In temperature environments such as Melbourne no heater is required and the toilet is tightly sealed so that ventilation is not required.

Grey water helps to water the Garden

Most excess water can be sent to the garden.

It can keep your plants watered during the summer. Plants will die without water.
Plants that are well watered also help to reduce the Urban Heat Island Effect, keeping our cities cooler.
Greywater can be used to water fruit trees and other food producing plants
Bugs in the soil (microorganisms) will help to reduce organic pollutants in grey water (e.g. skin and hair)
Watering the soil will help recharge our groundwater systems. Groundwater eventually makes its way to waterways to keep rivers flowing even during dry times.

Remember that if we have shorter showers we won't be sending the same amount of water to the garden as before (only 9 litres per person per day). Healthy plants and trees will be able to use this water even in winter.

If we are to send grey water to the garden then we need to be more responsible with our use of soaps and detergents. These all need to be biodegradable so that they don't harm the soil.

You can order bars of soap and soap flakes from The Australian Natural Soap Company [34]

Washing by Hand

Many people who live off grid or in camper vans use small hand operated washing machines or you can just wash clothes by hand in a bucket.

Our clothes really don't get that dirty. Reserve your really dirty clothes for the garden and keep them separate from your good clean clothes.

Composting Toilets

Humans are using excessive amounts of nitrogen and phosphorus to grow food and other agricultural products.

We have exceeded the Planetary Boundary related Nitrogen and Phosphorus The Nine Planetary Boundaries

Excess nitrogen and phosphorus enter waterways leading to the formation of algal blooms which kill aquatic animals because oxygen levels can drop to dangerously low levels (so called black kill events).

We ingest Nitrogen and Phosphorus in the foods we eat, and we throw these nutrients away (single use) when we go to the toilet.

An easy way to recycle these nutrients for local food production is to use a composting toilet at home.

A composting toilet accepts all our human eliminated waste and then gently composts it over 12 months. The end residue (humanure), which has the texture of healthy soil, can then be added to the garden. Holding humanure for 12 months renders it safe from potential human pathogens.

Nitrogen is most concentrated in our urine (80% of the nitrogen we excrete is in urine). You can use a pee bucket or pee directly in the garden under fruit trees to give them a free boost of fertilizer.

Most of the manure we buy from garden stores comes from animals reared in captivity, making the manure easy to collect. The animals are not free to wander in open fields and green pastures.

How to Build a Composting Toilet

Waterless toilets can be built using timber and uses food grade plastic to hold humanure.
Waterless toilets require composting facilities to treat the humanure.
After 12 months of storage the humanure material can be used in the garden without any safety issues (not to be used directly in vegetable gardens).
The addition of nutrients from humanure can provide fertiliser inputs for local food production. The local application of nutrients and water will directly reduce GHG emissions associated with the food and agriculture sector.

Composting toilets are available commercially and are approved by the Victorian EPA [35].

There are instructions available on how to build a simple composting toilet. The The Humanure Handbook by Joel Jenkins provides excellent information on waterless toilets and is available via the Internet Archive Humanure Handbook pdf.

Dry composting toilet construction instructions have also been published [36].

How to make Humanure

Growing Food at Home

The easiest way to start growing food at home is to plant fruit trees and grow some vegetables that you like to eat.

It takes patience and dedication to grow food, so find someone with experience or do a course to help you on this journey. The Urban Farming Course at CERES is highly recommended. Find yourself a local Community Garden. Helping out at the garden and meeting like minded people will give you access to an excellent support network.

It takes a 5-10 years to grow trees and become experienced in the garden.

Growing food at home requires lots of water. The bigger your rainwater tank at home the better. Aim for 6-10,000+ litres of storage. You can also store excess water in the ground so that it will be available to trees. Trees are very good at drawing up water from the soil.

Avoid using commercially available manure products. They come from animals reared in captivity and feed lots. Do not use commercial fertilizers. Nitrogen fertiliser is made using large amounts of fossil fuels and phosphorus is a limited resource that is being mined excessively.

Nitrogen is naturally produced from the legume family and have a symbiotic relationship with bacteria in their roots which fix atmospheric nitrogen. Even large trees such as the Acacia family can fix nitrogen, and can be placed adjacent to fruit trees.

Phosphorus in a limited, non-renewable resource. Bird dropping are rich in phosphorus. All animals (including humans) eliminate phosphorus in their poop, so its always best to compost this material on site to recycled the precious phosphorus.

All garden and good waste should be composted at home and reused on the garden. There is no need to send any organic waste material offsite.

Composting

Composting bays are used to compost all organic wastes on site.

To make a good compost you need to mix two types of material together

high nitrogen material - food scraps, grass clippings, leaves, fresh cuttings
high carbon material - dried straw, sawdust, wood chips

Mix the two together and add enough water so that all materials are moist.

It is best to create cages using open wire mesh. This will help to aerate the compost heap.

Worms and other bugs will migrate in and out of the compost heap. The heaps may also start to generate steam as the interior warms up.

Placing food waste in buckets of water for 2 weeks to ferment will make your compost heaps less attractive to mice and rats. However sometimes you may need to catch and kill rodents. Use stainless steel traps and inspect the traps daily. Keep the traps in a sheltered spot just in case you accidentally catch a lizard.

Larger branches can be kept and dried. They can use used on special occasions for BBQs and to cook tomato sauces such as passata.

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