In ‘Greywater’ Category
Composting toilet buyers guide
Tired of flushing water? With care and maintenance, a composting toilet can be a good alternative to the water-loo, writes Anton Vikstrom.
Who has ever pondered what happens when you flush the loo? Apart from thoughts of how much water is chasing your deposit, what about the process downstream? There are alternatives for people to take care of their business on site. While composting toilets have been popular on rural and ‘off pipe’ locations such as national parks for years, increasingly people are interested in composting their sewage on site.
READ MORE »So, what is a composting toilet? How does it work? And how can I get one? This article provides an introduction to composting toilets as well as important information about maintenance.
Sewage treatment today
While the modern sewerage system is an integrated engineered marvel, it is also a marvel of wasteful design. In a standard home in a developed city, all black (toilet) and grey (shower and sink) water is combined, usually in the house slab, before leaving site. From that point it is a long downhill trip to our modern wastewater plants. In Melbourne alone, 330,000 million litres of wastewater are processed each year, including trade waste from industry.
Our centralised sewerage system is a case of out of sight out of mind. Waste is processed at primary level—sieved, screened and mashed up. It passes through a series of ponds where oxygen is circulated to aid microbial digestion of the solids. Water from the system is discharged into oceans or streams after being treated with chlorine. As they say, ‘with pollution dilution is the solution.’ However, releasing this water can cause nutrification, blue-green algae, heavy metal concentration, let alone the negative effect large amounts of chlorine has on ecosystems. Just think how 330,000 million litres of water could be used otherwise.
The other system that operates in ‘off pipe’ conditions is the ubiquitous septic tank (septic being from the Greek ‘septikos’ meaning ‘to make putrid’.) After flushing, all solids settle in the bottom of a large concrete tank and are later pumped out by Mr Wiffy. The excess fluid is disposed of in a sub-surface disposal/leach field. These systems are anaerobic and produce a classic stinky sewage smell. There is no separation of cured waste and fresh waste, allowing direct transfer of any pathogens to the leachate field. While very common in Australia, septic systems are increasingly linked to a number of water pollution issues resulting from a high density of the systems in close proximity to water catchments.
Composting toilets operate on completely different principles from conventional wet systems and offer a proven alternative.
Read the full article in ReNew 104
Greywater system buyers guide
Water restrictions require creative solutions to keep gardens alive. Adam Maxey looks at the pros and cons of greywater recycling.
The advantage of greywater is that we produce it on a daily basis. In most cases it can be intercepted and diverted to the garden with minimal effort and cost in a number of different ways. However, whether you intend to buy a commercial greywater system or set-up your own DIY system there are a number of things you need to consider. This guide highlights the main issues associated with greywater reuse. There are many choices available and there is no single solution for all circumstances. Therefore, the more research you do, the more suitable your system will be for your particular situation.
READ MORE »Greywater sources
Greywater is any wastewater generated from your laundry, bathroom and kitchen, before it has come into contact with the sewer. This includes bathroom (bath, shower and basin), laundry, kitchen and appliance discharge. It does not include toilet wastewater, which is classed as blackwater.
However, while kitchen and dishwasher water is technically greywater, unless you are treating kitchen greywater it is recommended that this source of water not be used. Kitchen water only makes up around five percent of total water consumed in the average home, yet it is considered the most contaminated. This is largely due to high sodium levels from dishwashing detergents, particularly from dishwashers, as well as fats, grease and oils from cooking and cleaning, which can all damage soil structure if allowed to build up.
Cleaning products
Choosing the right cleaning products is perhaps one of the most important elements in reducing the risks associated with greywater reuse. The chemical and physical quality of greywater varies enormously, as greywater is essentially made up of the elements that you put into it.
Generally speaking pathogen and bacteria content is low in most greywater sources (unless you are washing contaminated items such as nappies, soiled clothes etc) and as long as you take all the right steps to minimise potential contact, such as delivering greywater subsurface, it is of minimal concern.
Equally, phosphorus and nitrogen are nutrients necessary for plant growth. If phosphorus and nitrogen are kept to an optimum level by choosing cleaning products with low phosphorus and nitrogen, they can replace the need for fertilisers for gardens and lawns, and the nutrients can actually be utilised by plants and soils.
Read the full article in ReNew 102
Stay smart with the grey stuff
As we head into summer water is worth saving more than ever. Anjali Brown surveyed Alternative Technology Association members about their own domestic greywater systems. Here’s what you need to know.
The average house produces around 83,000 litres of greywater a year. Some Australian households have found ways to reuse this otherwise wasted resource, either with DIY nous or commercially available greywater systems. With commercial systems growing in popularity, the time was right for the Alternative Technology Association (ATA) to survey its members about their own experience with these systems.
READ MORE »ATA members who had purchased a manufactured, commercially available greywater system were invited to complete the survey in May.
Of those surveyed, 80% had bought diversion systems most of which came with some form of filtration device (to remove particles such as hair and lint), a mains diverter, a surge tank and in some cases a pump. These elements differentiate these diversion systems from a simple hose out the laundry window or a good old-fashioned bucket. While untreated greywater from these diversion systems can be used to flush toilets, it is most commonly used for garden irrigation.
The remaining 20% of respondents had purchased treatment systems which involve a high level treatment of greywater via biological or chemical processes (sometimes both). The treated greywater can be stored for more than 24 hours without becoming a health hazard and it can be used for non-potable indoor water needs as well as on the garden.
Read the full article in ReNew 109.
Soaps, shampoos and soil
Hard soap is out and bodywash is in when it comes to greywater in the garden. A report about the impact of bathroom products on soil shows why.
Greywater use has become so widespread in many parts of Australia that it is now more a case of who isn’t using greywater to keep their gardens alive. This is great news for water conservation efforts. Greywater use is not an exact science, though, and successful greywater irrigation depends on a number of factors including soil type, plant type and ultimately which chemicals and elements make up your greywater.
READ MORE »Typically, laundry and bathroom water are the most common and safest waste waters to use depending on which products you are using. Thanks to Robert Patterson of Lanfax Laboratories (www.lanfaxlabs.com.au) and his independent study of laundry detergents we have a better idea of which laundry products are safe for greywater irrigation (see report in ReNew 98). This data has been a valuable resource over the years for people using laundry water to irrigate their gardens, yet there has been a need for similar studies for bathroom products.
With this in mind, the Alternative Technology Association, in conjunction with Associate Professor Barry Meehan and RMIT University’s Environmental Science Department, set about filling this information gap. The plan was to analyse typical ingredients in a number of bathroom products and assess the potential impact on soils.
The Alternative Technology Association (ATA) conducted a member survey last year about the types of bathroom products used in households.
The survey identified the most popular products in four categories: shampoos, conditioners, solid soaps and bodywashes. Within these categories a further distinction was made according to whether the product was mainstream, generic or ‘eco friendly’.
All of the 44 products tested in this study were brands identified by ATA members who were watering their gardens with bathroom greywater. Product samples used in this study were provided by the ATA.
Read the full article in ReNew 107.
Staying green with greywater
Jacinta Cleary visits one experienced green thumb who keeps her garden thriving with greywater.
On a rainy Melbourne day a visit to Karen Sutherland’s edible garden is a bit like a trip to the tropics, with feijoa, mango and avocado trees all surviving well. Admittedly, the mango tree is far from fruiting, but maybe one day if the weather continues to warm.
READ MORE »It’s a combination of rainwater, greywater and a little bit of mains water than keeps this suburban garden absolutely thriving. Keeping a garden alive in dry periods is one thing, but taking it to the next step and growing healthy produce with minimal water requires some planning.
Household greywater is used every day in this garden and has made a big difference. Karen specialises in designing and installing edible gardens and importantly, helping people learn how to grow and maintain their own veggies, fruit and herbs. Her philosophy on gardening is very much tied in with sustainability and the fact that sourcing food locally can help the planet by reducing transport emissions. Through years of experimentation she can judge just how much water is needed for an abundant crop of fruit and veg.
Karen and partner John had enough hands-on expertise to design and construct their own greywater system. Greywater can’t be stored longer than 24 hours, so the system is only big enough to hold a day’s worth of water. The header tank holds between 180 and 200 litres, with an overflow going to the sewerage system. Karen keeps track of how much water has gone into the header tank each day to ensure a minimum of wastage from overflow.
Read the full article in ReNew 110.