Water - for all. An Infographic

Recycling Water Crucial To NT Water Supplies

In the face of global water supply shortages, recycled water has the potential to help us be more climate-independent. And even though it seems novel, reused water is already cycled back into the supply. If you live in a community downstream of another one, chances are, you are reusing its water.

Australians and Americans have embraced “sustainability” in so many aspects of modern life, but not when it comes to water resources.

Recycled or reclaimed water is water that is used more than one time before it passes back into the natural water cycle. Treated wastewater, including sewage and water used for industrial processing, can be cleanly recycled for agricultural and landscape irrigation, industrial processes, toilet flushing, replenishing a groundwater basin and even for drinking water.

Scientifically proven advances in water technology — including reverse osmosis, ultraviolet disinfection, and oxidation — applied to wastewater allow communities to reuse water for many different purposes, treating the water differently depending on the intended use.

And the best part is: there is huge potential for growth in using recycled water. Thirty-two billion gallons of municipal wastewater are produced everyday in the United States but less than 10 percent of that is intentionally reused and the equation is quite similar in the Northern Territory, particularly in the northern areas, as Alice Springs now does have an aquifer recharge program using treated wastewater from the effluent ponds.  

Also, it is known that the NT uses up to four times water per person more than temperate Australia, and much of that extra water is used outside, where non potable water would do.  It is certainly wasteful to treat all water to drinking standards and then use 70% outside as is common in Darwin.

One key reason that water reuse is not a bigger part of the nation’s water supply is that it is still characterized as a waste product in most places. 

In a progressive move, California in the US recently enacted legislation that reclassifies recycled water as a water resource. The state government also recently streamlined the permitting process for using recycled water for irrigation and allocated $200 million in grants to encourage related projects.  While California uses different legislative systems to Australia, the truth is, Australia could do a lot ore with use of appropriately treated wastewater.  AND......such programs would be sensible infrastructure development in a continent as dry as ours.

In other parts of the USA,communities in dry west Texas have used state-of-the-art technology to augment their drinking water supply with reused water; Phoenix in Arizona has had an aquifer recharge program using treated effluent which is subsequently redrawn for use, for about 50 years; the governor of Oklahoma just signed a law to encourage water reuse; and Florida’s most recent water reuse report indicated that 719 million gallons of water is beneficially reused each day in 2013 — the largest amount in the country.  Yet here in north Australia as we discuss developing the north, there is little discussion about reuse of water, in an environment which is totally dry for 6-8 months each year, while in the other few months water flows away freely [ admittedly it is used by the environment!].

The amount of water intentionally reused in both Australia and the USA still quite low and it will stay that way as long as the public regards reuse as an emergency measure. Citizens have embraced “sustainability” in so many aspects of modern life, but not when it comes to water resources.

Conservation cannot meet future water demands alone and other measures that create new sources of water, like desalination, are still more expensive, with some people believing that it is too expensive although newer technologies are encouraging in possibly lower costs.  Desalination has its advocates though, with WA a champion of the technology, with development being driven by the woman who is the Chair of the WA Water Corporation.

In the Top End of the NT the only avenue seemingly being explored for more water is to develop more dams or other above ground storage systems, such as the pumped off river system discussed for an area in hills north of Adelaide River, and the dam above Adelaide River.  Desalination of seawater is also a possible option around Darwin. 

Water reuse is the easiest and most economical fix. It should be included in the water supply portfolio of the Darwin region, and in fact for all  communities.  It at least should be given equal weight in assessing future water resources for the region.

[ partially adapted from an article by Melissa Melker of the US Water Reuse Association in the NY Times 30 June 2014]

UPDATE - http://ecowatch.com/2014/03/20/solar-technology-californias-water/
This is a solar technology to distill irrigation tailwater from agriculture fields using solar technology to heat a oil filled tube and then use the heat to distill the tailwater.  It works and can be scaled up, with a projected cost of about one quarter the cost of desalination of sea water [ many places say a cost for this of $2 per kilolitre].  Search for Water FX online for more details.

Join Room for Debate on Facebook and follow updates on twitter.com/roomfordebate. 

Yes...Sustainable Rum Production

Let's be a little frivolous today.

Nothing like a shot of rum on a cool or cold evening, especially around a campfire.  Think of outback Australia with a campfire blazing or a sea going sailing ship in the roaring forties.  But did you realise that even rum production is going ........well, sustainable!

While the term sustainable has many connotations, in this case it is about improved water use as well as smart, sustainable biomass energy use.

The Caribbean is well known for rum production, as is Bundberg in Australia.  Two of the biggest rum producers in the Caribbean though, have been embracing much more sustainable options in the rum distilling process from sugarcane.

Rum production produces rather nasty wastewater which needs to be disposed of some how. The Serrallés Rum Distillery in Ponce, Puerto Rico produces DonQ, its main brand of rum, which is the most popular rum in Puerto Rico. It is one of the largest rum distilleries in the Caribbean with an annual output capacity of 15 million proof gallons. The company has spent a decade and $16 million on a new filtration system.

Serrallés used to dump its wastewater into nearby fields, but during rainy season the waste would run off and the distillery would have to shut down when flooding starting which cost the company $200,000 a year. There are claims that Serrallés has turned the "$75 million distillery into one of the cleanest in the world."

The filtration system also saves the company money, as Roberto Serrallés, the VP of business development points out. The wastewater produces biogas which the company uses to run its boilers. Serrallés, who is a sixth generation rum maker with a Ph.D in environmental studies from the University of Oregon, said that the system saves them "as much as nearly 50 percent of annual fuel use."

Serrallés is not the only Puerto Rican rum maker to make its operations more sustainable, with itsmain competitor in Puerto Rico, Bacardi Limited also moving that way.  Bacardi released its 2012 CSR report a few months ago which highlights steps it is taking to reduce energy and water use, reduce its greenhouse gas (GHG) emissions, and source more responsible materials. Bacardi Limited is the largest privately held spirits company in the world.

So next time you have a bacardi and coke........you can claim to be drinking sustainably produced rum!!  Will you remember that after a few rums??  Or care?

Fixing Salvinia Issues at Gunn, Palmerston, NT

Salvinia is a nasty, super spreading – even choking – weed.

Over the past few years an infestation has been developing at the lakes at Gunn, in Palmerston, and is now quite significant, covering the lakes [ see lowest lake below]. The lakes are designed as a stormwater buffer, so water levels can rise and fall quite a lot in the wet season.

Late last year Palmerston City Council instigated using their aquatic weed muncher to remove much of the debris across these lakes. Unfortunately, some salvinia remained.

A program which we ran, was used to spray and mop up the balance. That was the theory...... but then it rained and rained, with last wet season being extraordinarily wet, and consistently wet. Too wet for regular satisfactory spraying.

So the salvinia regrew.......and once again dominated the three lakes.

The weed eater is back in action , and the upper lake is now quite clear of salvinia, with the two lower ones likely to be cleaned up this week.

But there is a new activity........the salvinia weevil, a very potent biocontrol agent has today been released into the bottom lake with additional material to be added over the next few weeks in both the lowest and middle lakes, with some destined for the top lake as needed. Biocontrol of salvinia has been very successful at a number of locations around both Australia and in the Northern Territory.

To aid establishment a small amount of salvinia plants will be left behind during the weed munching, to provide a focus for the spread of the biocontrol agent, and these plants will be held in place with a floating boom. Over time, assuming the biocontrol agent establishes successfully, this plant mat will also disappear, and the weevil will spread out onto any remnant salvinia around the lakes.

The biocontrol agent will not necessarily totally eliminate the salvinia, but it will normally, over some time, reduce the salvinia to a small, almost negligible amount.

A monitoring, spray and clean up / collection program will also continue, but concentrating on the smaller scattered fronds that seem to congregate around the edges, readily blown by wind.

This combined program is hopeful of eliminating the salvinia over the next 12 months, and at worse, at least reducing the salvinia to a very minor issue.

The lakes may then bloom again with the stylish water lilies that are quite common, and salvinia will not be very noticeable.

Stormwater Management - Green Roofs Play a Part

The concept of using green roofs has more been around overall city heat mitigation, reduced heat absorption on concrete roofs, more oxygen in the city, even reuse of waste water.

Recent work has indicated that the 'green roof" may be significant in stormwater management, a slightly different outcome than was expected.

While Australia and many other regions do not have a single stormwater and sewer pipe system, some cities do. There the collection of stormwater on green roofs appears to greatly reduce the amount of stormwater entering the sewer system, and thus reduces the potential overflow, quite a problem for these types of systems.

In the areas with separate storm water and sewer disposal systems, it would seem that the collection of especially higher intensity storm rain, the event that often overloads streets and stormwater disposal designs, would also be enhanced, and less stormwater would flow through the system. And, even if it was partially reduced, it would most likely time shift and reduce the major flows, after the rain had flowed down through the green roof and then out down a drainpipe to the ground. The green roof would also assist with removal of pollutants, often in the rain in cities.

More details of the study here -http://www.enn.com/top_stories/article/42701

Green roofs lend themselves well to regions with some regular rainfall, year round. Has not been much development here in the NT, due to our very strongly seasonal rainfall - wet for half the year, generally totally dry for the other half, so plants require watering then.

There is a good example of a green roof in Singapore, at the Botanical Gardens. It seems to work well.

Less Water Use Reduces Energy Too

Water use and water loss is a major energy cost in many countries.

If just 1% of US homes replaced older, inefficient toilets with dual flush models, the country would save more than 38 million kWh of electricity, the equivalent of 43,000 households’ monthly electrical supply.

While in Australia, dual flush and reduced flush toilets are very common, they are much less common in other countries. As an example, 25 years ago most Australian toilets were single flush, 12L per flush. Best models today are 6L/3L flush with a redesigned efficiently flushed pan, or the more common 9L/4.5L dual flush models. Practically, volumes less than these levels can create congestion problems in sewer lines as the liquids level has diminished so much..........but most countries are nowhere close to the reduced flush volumes now common in Australia.

Big water use reductions are possible, and an important issue, rarely considered is that less water used means much less energy is used. Think electricity for pumping and purifying water as the most obvious point.

Solving leakage is also important in reducing energy use, as a side benefit of reducing water losses. Same issues as above.

Switching to dual flush low volume toilets is a big factor in driving reducing energy use.

More information here -http://www.waterefficiency.net/march-april-2011/detecting-the-unaccountable-1.aspx

Sandalwood Offers a Pathway to Reduced Animal Methane Emissions

Welsh University discovers way to reduce methane from cows and sheep

Research carried out by academics from Aberystwyth University has resulted in a discovery which could lead both to an improvement in milk and meat production and to a significant reduction in methane emissions from cattle and sheep.

The research team, led by Professor Jamie Newbold of Aberystwyth University, found that by adding sandalwood (or a sandalwood analogue) to animal feed the growth of pathogenic bacteria such as E.coli and Listeria in the rumen is reduced. As a consequence, energy which would otherwise be lost through the production of methane is diverted to increased milk and meat production.

At the same time there was a significant reduction in the emission of methane, a greenhouse gas with 23 times the global warming potential of the equivalent amount of carbon dioxide. It is estimated that livestock produce 18% of all global greenhouse gas emissions, more than all forms of transport combined.

Trials in a rumen simulating fermenter (Rusitec) confirmed that Javanol, a sandalwood analogue, reduced methane production by up to 25%. A reduction of 20% in methane emissions was achieved in field trials with sheep when 2ml of Javanol per day was added to their diet.

This is an exciting discovery in two ways," said Dr Ahmed Ali. "Firstly, there would be benefits to the agricultural industry through increased milk and meat production: this increase in productivity would be set against a background of growing pressures on global food supply.
Secondly, there could be a significant reduction in methane emissions."

"Overall, the project is a good example of a University and an SME collaborating on cutting edge research. If this project and projects like this, can be commercialised in global markets, that has to be the way forward for the knowledge economy of Wales."

This might be a plus for Wales, but what about use in Australia, especially those areas of Australia where sandalwood is grown - the NW of Western Australia, SW of WA as well as parts of the Northern Territory. Sandalwood and oil products from the tree are high value materials, strong in demand from perfumery manufacturers.

It is especially important for monsoonal tropical regions, as it is known that methane emissions in livestock increases when animals are on feeds with lower digestibility, a common issue in the dry season when dry feed is most commonly consumed.

Could a small addition of sandalwood or similar materials to metered and medicated water dispensing systems which are increasingly common, offer some options for reducing methane emissions of livestock in north Australia??

Bottled Water - Reverse Marketing

In developed countries, there has been a surge in the use of bottled water over the past decade.

Sure, drinking water is a good idea...........but the bottled water marketing gurus have turned drinking water into an an art form with their "messages". But good ole tap water is kicking back!

In an unlikely area............New York City. They have a program to kick the bottle so to speak, and use conventional ready to go tap water. There are many, many dubious claims made by users and bottlers within the bottled water industry. They play on fear and paranoia - mostly, as there is little evidence that bottled water delivers anything but extra cost to users, and it is disease free.

Can this be a welcome change and be a campaign that could be developed in Australia too with various partners?

see: http://www.nyc.gov/html/dep/html/news/outreach.shtml


The New York campaign uses the following slogans:

NYC Water doesn't just taste great:

• It’s Healthy: NYC Water helps you maintain a healthy weight because water contains zero calories, zero sugar and zero fat. A typical 12-ounce can of soda contains about 150 calo­ries and the equivalent of 10 tea­spoons of sugar. Sports drinks, which are marketed as healthy alternatives, have as many calories as sugary beverages and usually contain high levels of sodium.

• It’s Affordable: NYC Water is a great deal. At approximately one penny per gallon, it is about 1,000 times less expensive than bottled water.
  


• It’s Green: Plastic water bottles produced for the U.S. use 1.5 million barrels of oil a year—enough to power 250,000 homes or 100,000 cars all year. And it takes more than 3 liters of water to produce each bottled liter of water.
  


• It’s Convenient: NYC tap water is available right from your tap. DEP’s Water-On-the-Go fountains will make tap water easy to get in public places in each of the five boroughs all summer.

All are true..........absolutely!!

It could be a marketers dream.

[ top image x BBC; lower cartoon x Greenberg, Ventura Star]

Recycled Effluent Safe - Public Health Study Finds

Recycling of water is now a major effort in Australia, a very dry continent.

Serious drought over about 10 years has driven urban water users and the various urban water authorities to invest in a range of water recycling schemes. Some are very sophisticated, others less so.

The Ministerial Council on the Environment has promulgated new Guidelines to Using Recycled Water and many jurisdictions have started to use these guidelines to develop recycled water schemes too.

The following is a media release that reports on a public health examination of recycled water use and abuse in a major scheme NW of Sydney, Australia.

It is generally good news..........treated recycled effluent was ok, even with some misuse and abuse of the water.
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As purple taps become an increasingly common sight in new Australian suburbs, a study has found no corresponding jump in gastro cases linked to the recycled water they deliver.

Researchers checked two years' worth of patient records from GPs located in Australia's largest residential recycled water scheme, in Sydney's northwest, and they found nothing out of the ordinary.

More than 18,000 homes are in the Rouse Hill Recycled Water Scheme and residents are told the extra water they have on tap, coming from a nearby waste-water plant, is not for drinking.
Similar schemes have been rolled out in new suburbs across the country, but the Monash University study was the first to check for any related impact on public health.

"They have recommendations on how the water should be used but (authorities) obviously can't police that," says Associate Professor Karin Leder, of the university's School of Public Health and Preventative Medicine.

"But what we can say ... in practice, we were unable to identify any observable health risks."
Dr Leder says the recycled water was "very heavily treated" and "any health risk would be very unlikely" but there was still a chance, in the event of a treatment failure, that it could contain pathogens or bacteria capable of making people sick.

The study did uncover some well-meaning households which used recycled water to top up their swimming pool, against advice.

"Even if people are using the water exactly as recommended there is the potential for ingestion - drinking very small amounts of water - during activities like car washing," Dr Leder says.

Researchers reviewed 36,000 patient visits across 11 doctors' clinics to check for any spike in acute gastroenteritis, acute skin complaints or acute respiratory conditions. Rates of illness were no different to surrounding suburbs with no access to recycled water and, Dr Leder says, this was a positive sign for the water-saving scheme. "Australia should continue to pioneer ... these kinds of recycled water schemes," she says. "When properly managed, they are a safe option that can be considered among the many options that might be available for recycling water."

Oestrogen in the Water

Several years ago we were involved in an environmental report on effluent reuse for Alice Springs in Central Australia. One of the issues highlighted by us was the potential for oestrogens to move through the effluent system and ultimately into the environment - and water - as the effluent was discharged. This issue was not recognised by many then as a significant issue, yet it is becoming much more of a problem.

While this system did not involve effluent reuse for potable water, at least in the short term, there was strong evidence of this problem as a potential issue to be considered. More compelling evidence is now accumulating of a worrisome trend in the western world of increasing amounts of oestrogen accumulating and causing detriment, not only to the environment and animals, but to mankind itself.

When the following article and similar starts to appear in the mainstream press, then it is time to really take note. It is reproduced in its entirety, and was in the Weekend Australian in Australia, January 10, 2009.

It is seriously worth noting.
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It's wise to be wary of the pill

Angela Shanahan January 10, 2009
Article from: The Australian

THIS week news of an important report was published in L'Osservatore Romano which, if you will excuse the painful pun, should have been a godsend to eager environmentalists. After all these people are great doomsayers and the contents of the report was the stuff of science fiction horror stories.

According to the International Federation of Catholic Medical Associations, an alarming rise in male infertility in developed nations is possibly caused by the quantities of synthetic female hormones, particularly estrogen, in the food chain and water. These quantities are directly attributable to increased use of the contraceptive pill and hormone replacement therapy.

The original report published in German has been widely publicised but mysteriously, the only response to this terrible scenario, which seems to be with us just as surely as global warming, were a couple of letters in this publication and in The Sydney Morning Herald that could have come straight from a 19th-century Old Bigot's handbook of insults. They hysterically decried the whole thing as a Vatican misogynistic plot. Never mind that it didn't come from the Vatican. But apparently, in some people's minds, any taint of Catholicism is enough to justify screaming "ignorant, stupid, unscientific" and of course predictably "misogyny".

Strange then that in 1998 women's groups and environmentalists formed an alliance in Japan against the legalisation of the contraceptive pill. Apparently some Japanese women and environmentalists, including the Women's Network for Ecology, were worried enough about the effect of introducing synthetic hormones in a country that relies on very intensive agriculture and aquaculture to campaign against its legalisation. That is aside from widespread suspicion among Japanese women that there is a definite link between the use of the pill and breast cancer in their Western sisters.

The evidence that synthetic hormones can have grotesque environmental effects has actually been around for a long time and it is mounting. As long ago as the 1980s, studies were done in the US which showed the effects of estrogen pollution on wildlife, famously alligators in Florida with deformed genitals. But more recently, in February 2008, the University of Cardiff published a study that claimed a link between sexual deformities in birds around sewerage outlets of large British cities and the increased amount of estrogen finding its way into rivers and estuaries.

Recently during research for a story on the viability of using recycled water in Canberra, I came across several papers that pointed to the problem of estrogen in recycled water. Indeed, according to Canberra Hospital professor Peter Collignon, an opponent of recycling sewage water into the potable supply, estrogen can be more of a problem in recycled water than microbes because it cannot be filtered out and we simply do not know how well it breaks down. Just as the Romans drinking from lead cups unwittingly caused infertility in themselves, perhaps we are seeing after 30 years of contraceptive pill use the long-term effects of introducing artificial estrogen into our wider environment. So you see this is not just a preoccupation of the misogynistic old Vatican.

But how can it be misogynistic to point out that artificial hormones can have a bad effect on men as well as women? And who exactly are the misogynists? Is it the people warning of the possible dangers of long-term exposure to artificial estrogen for both sexes, or the hysterical letter writers and doctors who seem to be saying, "There dear, just go ahead and take your pill and everything will be all right?"

As a woman I think Australian women ought to think again about this great biochemical boon to the human race, or perhaps I should say to men. Australian women have one of the highest rates of contraceptive pill use in the world. Most women feel obliged to use it as soon as they become sexually active and the average time women stay on the pill is 10 years. That is 10 years of suppressing one's normal hormonal cycle and replacing it with artificial hormones with all the physical and psychological ramifications, including the decline of libido.

However, even though we have the highest rate of breast cancer in the world, and there is a lot of research pointing to the pill as at least a partially causative factor, many doctors (even some of my own acquaintance) have no compunction in prescribing it to girls who have just reached puberty. In fact one doctor I know told me she feels legally obliged to give it to any sexually active girl, no matter what age. Furthermore, not only is long-term pill use implicated in infertility and sexually transmitted disease, what is worse is it has not prevented our abortion rate from being one of the world's highest.

There are so many reasons for being wary of the contraceptive pill. Why are we not questioning its prevalence?

The reason is, of course, that it is the sacred cow of the sexual revolution. One imaginative letter writer claimed the Catholic view of the pill was that it was "the great Satan", and actually that is not a bad description. It was marketed as an instrument of sexual freedom, and it has provided that, particularly for men. But one might ask if for women it has been the means of sexual liberation or just a way of turning us into empty vessels for sex? Is it like the sexual revolution itself: a pretty and alluring package that turns out to be - for both sexes - like a series of empty boxes, one inside the other. At the end, there is nothing but an empty box.

The environmental effects of the pill on men may in fact gradually reveal the extent of the damage to our whole society, something that Francis Fukuyama points out in his essay, The Great Disruption: that we can't just introduce something such as this for 30 years and not expect unforeseen consequences, moral, social and, of course, physical. But tragically it will be young men and boys who suffer before women will also free themselves of this burden.

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There are not many clear references, but the message is quite clear, unambiguous and getting even more so......is mankind killing itself off?

KISSS for Green Roof Applications

There is a new product by the KISSS group that is well suited to green roof applications. It is called Ebb and Flow mat

The KISSS Ebb and Flow Mat represents a giant leap forward in green roof technology. The mat is an integrated extensive green roof system that provides not only irrigation, but drainage and root protection. The Ebb and Flow Mat has several advantages over other systems, Most importantly, it is an "active" drainage system that intelligently manages the moisture level of your green roof soils. Additionally, this system is the most cost effective system on the market today.

The KISSS Ebb and Flow System is simple to install and saves a tremendous amount of labour. Additionally, it is easy to work with in the event that a roof leak should occur.
Simply roll out the Ebb and Flow mat onto the roof and overlap the mats as shown below. Finally, install your drainage system. Then you have an active drainage system, irrigation system, and root barrier all in the one system.

The KISSS Ebb and Flow Advantage
The perfect solution for an extensive green roof on structures that are sensitive to water loading. This system provides an active drainage layer while elimination water holding on structure.
Integrated design and roll out installation reduces labour and eliminates the need for many of the standard components within other green roof systems, making it the lightest and most economical system in the market today.
The system can be manufactured to be compatible with conventional green roof systems and add supplementary drainage, as well as effective irrigation.

An ideal system for green building initiatives like LEED.

Light weight, flexibility, and low cost make it a prefect fit for any retro-fit with a restrictive weight allowance or budget.

Green Roof Frequently Asked Questions

How does it work?
The KISSS Green Roof product irrigates the soil media above it, and assists in the drainage of the soil to keep it at optimum moisture content. It does this without the soil being saturated, as saturated soil forces out air. Air in the soil media is just as important as water to plants, and especially on a roof where the minimum amount of soil media should be used to minimize the loading on the roof, and maximize the run-off in heavy rainfall. The difference between the KISSS system and other green roof irrigation systems is that it can drain the soil media at a gentle rate, and if the media is drier than the irrigation system, the system will provide more water to the media via capillary action. This keeps the top few centimetres reasonably dry which reduces evaporation and weeds germinating, but keeps the lower layers moist which encourages deeper root growth.

What soil/media can be used?
Plants of any kind can be grown on a green roof and the only limiting factors are enough soil media for support, moisture, air and nutrients. We suggest a light weight media product and there are a few in the market eg CocoEarth media mixed with sands of a particular grade to give stability and hold water and nutrients that are required. These can be provided by the installer.

How durable is the material?
The materials in the KISSS product are not biodegradable. They are synthetics that are made from polyester and polyethylene and do not break down in soil and do not compress easily. The materials are made in such a manner so that the water and nutrients runs along the fibres but do not fill the fibres and only the pore spaces in between the fibres hold the water, soil and nutrients.

What about roots damaging the materials?

Roots can invade the materials and run between the fibres, but will not penetrate the fibres themselves therefore the fibres still maintain their functions. The drip line that is in the system to supply the water to the geotextiles is encased in the geotextile for protection and also to make sure the water flows uninhibited across the fibres. The system is made to encourage the roots to invade the system to provide a source of water and nutrients and not to just rely on the soil above the system.

Can the system provide nutrients to the soil/media?

Liquid injection can be used with the KISSS system to add nutrients at any time. The benefit of the KISSS system is that the roots are in direct contact with the fibres in the system so that if nutrients are supplied through the water then the roots get access to these in solution immediately, thereby reducing the amount of fertiliser required. Controlled release fertilisers can be used on top of the plant material or soil media and the rainfall and moisture in the atmosphere will make these available over time, but 30% less fertiliser will be required than the rate for potted plants.

What can I grow on the green roof?

You can grow just about anything from lawn to shrubs to small trees to cactus to ferns to veggies for the family and it all depends on what you want and the aspect and climate of your roof. The simplest solution is to just turf your roof and have a veggie patch or flower garden. Small areas can be grown with a simple UV stabilised corflute structure that can be laid out on the mat and filled with media and planted out with whatever you desire.

What if I don’t want a green roof but want to grow my veggies or herbs?

KISSS has an answer with the combination of their ebb and flow mat and the veggie box on the mat. This can be planted out with flowers, herbs or veggies. The unit is 4.5m long by 1.2m wide and 200mm high. It can produce a wide range of veggies and herbs for all the family and can sit in the backyard on the ground and be connected to the tap and only requires two irrigation cycles of one hour each per week in summer and once a week in winter. It uses drip technology inside the ebb and flow mat to spread the water to the soil. The Cocoearth media is optional and can also be sent in the mail and you will require 12 blocks for a 4.5m long unit costing $80 plus postage and handling. Nutrients can be added by liquid form or organic fertiliser mixed in by shovel or chemical fertiliser as slow release. The corflute box is UV stabilised and light weight, and the system will last for 7 years under normal sunlight if the materials are not damaged by mechanical means or animals.
For more details see - http://www.kisss.com.au/kisss_ebb_flow_mat/green_roof_applications

Arsenic Bioremediation Cure Might be Near

A recent serendipitious breakthrough by the Australian CRC for Contamination Assessment and Remediation of the Environment might just be the start of a seriously useful method for curing arsenic contamination.

They have isolated a microbe that can use arsenite - a common and the most poisonous form of arsenic and transform it to arsenate, a chemical form that can be fixed in soil into immobile forms.

More details are available here: http://www.crccare.com/view/index.aspx?id=14980

Arsenic presents in the enviroment in sites used for animal dipping, leather tanning, old mine workings, timber treatment and similar areas as well as in many shallow drinking water wells in Asia, particularly in Bangladesh. Old mine workings are often especially arsenic contaminated, and this often poisons down stream water sources, in conjunction with acid mine drainage. Arsenic, as an element of the periodic table can not be made to "go away" in the conventional sense but there are many forms of the element that are highly insoluble, resistant to leaching and could be contained within the existing sites in a relatively non toxic low solubility form, including forms that are relatively resistant even to acid leaching. Getting it into that chemical format has always been tricky.

In warmer regions, use of plants such as vetiver grass have been used to grow on contaminated soils, slowly accumulating arsenic and other heavy metals into the plant roots, and tolerating the poor soil environment, and actually growing moderately well on the site, a place where many other plants could not grow. But a multi faceted approach combining microbial remediation with use of these plants offers long term solutions in many places, as even getting a soil cover was difficult and this cover will ease issues of erosion of further arsenic from the soil into the environment too, with the organic cover from the plants assisting.

This new microbial solution seems to offer a real option, assuming that formulations of the microbes can be produced on a scale required for industrial use. Bioremediation on actual sites is a bit more difficult than a simple lab trial, and adequate microbes will be required to "saturate" the site environment, grow and proliferate and do the business of conversion.

BUT.........it is VERY promising.

New Duckweed Water Treatment System Installed at Wickham

A new duckweed barrier water treatment system was installed for WA Water Corporation at Wickham in the Pilbara in mid June 2007, with the duckweed itself to be placed on site in July.

This is part of a serious evaluation of the concept for use in warmer areas of Australia where duckweed thrives year round.

The barriers provide the ideal still water conditions for duckweed growth in sewerage lagoons where there is adequate nutrients, plus plenty of sun, for growth. The duckweed aids in the elimination of the algal growth in the effluent which currently impacts effective reuse of the effluent for irrigation.

Currently the TSS level in the pond is very high [mainly algae], and it is expected that this will fall dramatically as duckweed growth accelerates and covers the pond. Reduction in bacterial levels are also expected, along with small reductions in nutrient levels [ which are still of benefit in most agricultural water reuse situations].

The photos are of before and after installation of the barriers. These systems significantly "quiet the water" , even with very windy conditions and allow for adequate growth of duckweed. Wind at the time of these photos was around 30km/hr.