Rabbit hate taking baths
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. 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]
- 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.
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
- 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.
- Excess 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 farm will house 39,000 solar PV panels [13].
- 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 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) [14]. 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.
Large Centralised versus Local Solutions
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 [15]
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 [16].
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 [17].
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.