Issue 22: Waste Water Accreditation Scheme

Issue 22
May/June – 1995
Story Title: Waste Water Accreditation Scheme
Author: Roger Fox

The Nursery Industry Accreditation Scheme of Australia (NIASA) was set up to establish safe water disposal practices for the nursery industry, Australia wide. As one of the chief architects of the plan explains in this article, proving you are a clean and responsible industry can have many benefits.

The threat of restrictive water run-off legislation is a dark cloud on the horizon for many nurserymen and hydroponic growers in Australia. It is already a reality in parts of Europe, notably Holland, where nil run-off requirements are set to take effect by the year 2000.

While few would question the need to safeguard our environment, the fear of having one’s livelihood curtailed by a set of impossible-to-achieve rules, introduced by an unsympathetic authority, and taking effect immediately, hangs heavily in the minds of many growers as a possible ‘worst case’ scenario.

It was this concern over what ‘could’ happen, that first prompted nurseryman Peter Albery to become involved in the area of water accreditation schemes for Australian nurseries. Many years experience as a nursery grower and consultant, both here and in the US, had convinced him that safe water practices could be realistically achieved and in the long term could actually offer benefits to the grower. But most importantly, Peter could see that it was essential that the first move come from within the industry and not from an outside environmental body. In NSW, the Clean Waters Act already indicated minimum standards for horticultural producers to follow.

“I could see by reading material from overseas,” Peter explains, “that nil run-off will be required at some time in the future and that very serious problems will arise when nurserymen come to sell their land to a new owner.

“In some overseas countries for example, you have to have an environmental assay done when selling land, and the new owner has to accept responsibility, or the old owner clean it up if there’s a problem.”

While individual states had already begun moves towards introducing nursery run-off standards, there was no cohesive national scheme in existence when Peter first became involved in 1990. Victoria was probably the first State to introduce some form of run-off scheme, followed by Western Australia, where regulations were actually imposed as a law, in an attempt to prevent the spread of phytophthora into bushland areas. It was when NSW and Queensland decided to follow suit with schemes of their own, that a national scheme was proposed and Peter was asked to lend his support in getting the NIASA off the ground.

“A number of us have worked very hard to develop the National Scheme,” Peter says. “You can understand that with the political nature of each State and their associations, it was a remarkable achievement to make it Australia wide.

“As a result of this, the WA government have decided that if they like the total scheme, they will remove their compulsory scheme. This is a good achievement, because it gives all growers a bit of breathing space to have a look at the requirements, what they’re there for and slowly bring them into position as they can afford them. We can’t do it overnight, we can only do it piece by piece,” he says.

Many believe that the price of water is ready to skyrocket . . .

Australia’s comparatively dry climate makes irrigation essential for all forms of plant production, whether it be broad acre cropping, nurseries, market gardens or hydroponics. This, combined with a plentiful and cheap supply of water, has, many argue, made us rather casual in our habits of using and dumping irrigation water.

But over the last decade or so, much attention has focused on the problem of pollution of our waterways, such as the Hawkesbury and Nepean rivers near Sydney, or the Murray-Darling river basin in southern Australia, and the tide has started to turn. Many believe that the price of water is ready to skyrocket, to provide the funds needed for effluent treatment improvements, to help save our rivers. From this will follow the policing of growers to ensure no pollutants are dumped from their properties.

Peter Albery’s research, combined with visits to meetings of the Nurserymen’s Association and the Water Pricing Tribunal, confirmed that there was a need to act quickly. At the same time though, he could see that such action would have numerous trade-off benefits for the nurserymen themselves.

“I could see that we really needed a national accreditation scheme that would stand us in good stead all the way through these increased environmental requirements, while also bringing about an awareness that we are responsible,” Peter explains.

“We as an industry that are promoting goods that are supposed to be for the environment, should make sure that our methods of production are also environmentally sound.

“The minute you start cleaning your act up, you have a better image, particularly if it’s a national scheme and it can be used as an advertising point. In the same way hydroponic growers, if they had accreditation, could use it as an advertising point.”

The issue of industry image is one that is often raised in discussions of hydroponic produce marketing. Developing a positive environmental image can translate into higher sales, since these days consumers are more environmentally aware and ‘chemical conscious’ than at any time in the past. While there have inevitably been some critics among nurserymen about an accreditation scheme, most see it as a positive move for their industry reputation.

So what are the mechanics of the scheme? In terms of reducing water run-off, the basic tennets are collection, treatment and ultimately, re-use. Effective collection of water demands an impervious ground layer such as black poly plastic, concrete, asphalt or bitumen. Gravel and weed-mat do not fit the criteria, since they are not impervious and so water and pesticides can still leach through them.

In order to contain and treat the nutrient-rich water that runs from the plant pots, a holding dam is required. This must be of a capacity to cope with the highest run-off levels of the nursery during times of heavy irrigation, and should be as impervious as possible and fitted with sediment traps. A secondary dam a short distance away, connected by further sediment traps, is also desirable. This enables the water to be filtered from one dam to the other without the use of expensive filtration equipment. The sediment traps themselves are essentially biological filters, which use rocks, gravel and plants to remove as many nutrients and pollutants from the water as possible.

It is mandatory in each state that if water is to be re-used, it must be disinfested first to kill pathogens and other organisms. The most common way of doing this is with chlorine, though ozone treatment and ultraviolet sterilization are newer techniques. In Queensland at present, research is being done into using a combination of chlorination and sodium bromide to disinfest spent water.

According to Peter, one of the problems with UV is that the water needs to be reasonably clean in order for it to work. Because a light beam is being put through the water, organisms and sediment can interfere, thereby reducing its effectiveness. It will work however, in situations where water is caught off a concrete surface and recycled, without going into a dam.

Some trials have been conducted where chlorine is injected into the line and pumped around the nursery, but this according to Peter, is not foolproof. A holding tank or dam is preferable because of the greater contact time. After chlorine has been used, the Accreditation Scheme calls for a residual level of no greater than 2 parts per million.

Using clean media is integral to achieving clean water run-off.
In drafting the broad scope of the Nursery Accreditation Scheme, water disposal was the prime, but not the only issue. Other areas covered by the scheme are media storage to avoid contaminants, pot storage, secure pesticide storage and the effective disinfestation of old media. Clearly, using clean media is integral to achieving clean water run-off. Accordingly, the Scheme recommends that after sterilisation, old media can be re-used as 10% of a new mix.

“Fundamentally, the aims of the Accreditation Scheme are to produce better plants, cleaner plants, while using less pesticides through proper nursery hygiene and management, and controlling our water run-off,” Peter says. “In this way, we can prevent the pollution of our rivers and streams.

To gain accreditation, nurseries apply to the scheme, whereupon samples of plant, soil and water are taken and analysed to ensure there are no serious problems. Two inspections are required per year for a nursery to remain accredited under the scheme.

Over the four years that Peter has been involved in establishing the scheme, he has visited many nurseries and made contact via newsletter with regional nurserymen’s associations across the country. It is all part of a gradual process of convincing industry members of the need for these initiatives. For the past 18 months, Peter has written a regular column in NSW Nursery News, to address many of the issues and objections that have arisen.

Hydroponics – Implications
For hydroponic growers, the need to conform to guidelines on water disposal is seen by many as being not too far away. But Peter believes that hydroponic growers on the whole will have an advantage over their nursery counterparts, simply because they usually have more land. This will enable many of them to re- use water, after treatment, to irrigate a side-line crop grown in soil. A hydroponic lettuce farm for instance, could incorporate a crop of cabbages in soil and this would in effect turn a problem to advantage.

Already, recirculating hydroponic systems have a significant advantage over nurseries in environmental terms, because the water is not leaving the system. The problem arises when the whole lot is eventually dumped, because the nutrients have got too far out of balance, or sodium and chloride ions have reached unacceptable levels. The solution here is storage, analysis and further treatment, and research in Europe is already providing the best methods for this.

Peter’s main advice to hydroponic growers is not to build themselves into a corner, but to leave space if possible for an additional line of cropping, as well as improvements such as dams or holding tanks. In the worst case, a hydroponic grower could be left with a large quantity of highly saline spent water, which he could not legally remove from his place.

Hydroponic growers and nurserymen are not alone in the problems they confront in meeting present or future guidelines. All irrigators are implicated, a notable example being the cotton farmers of northern NSW. They too are exploring methods of treating and re-using the enormous amounts of water required to grow their crops.

“If a user-pays system comes in, it will teach the user very quickly to make full use of that water . . .”

But from the grower’s point of view, the need to safeguard our environment is not the only argument in favour of limiting water use. Just as compelling is the threat of large water price increases, which many believe are imminent. Even if there were no pollution problems, this alone would prompt irrigators to drastically change their patterns of use. The Accreditation Scheme therefore, by encouraging early reforms in nursery practices, will also help ensure the industry’s financial viability under a user-pays system of water charges.

“If a user-pays system comes in, it will teach the user very quickly to make full use of that water to reduce their expenses,” Peter says.

“Just imagine if collectively there was a 100% increase in water charges to nurseries, how much it would cost to produce a plant. So the recycling of the water will become realistic and will benefit growers financially.

“I believe ultimately we’ll have even better nurseries, because they’ll start managing the water better, which in turn will give better nutrient management. In fact we’ll be more professional.”

Water Boards around the country are yet to implement the envisaged price increases, but one suggestion which is being considered is to provide cheaper water to nurseries that recycle their water. It is an idea that hydroponic producers could also benefit from.

Environmental watchdogs, such as the Environment Protection Authority (EPA) in NSW, have been made aware of the Accreditation Scheme and Peter believes that they will look upon it as a sound industry initiative by the nursery people in general, to show that they are doing something about their own industry. It’s a question of acting first, rather than waiting until legislation is enforced.

“If we have our own regulatory scheme,” Peter explains, “and it’s accepted by the Departments of Agriculture, who in fact have read it all through and are on side with it, and if the EPA sees it and is supportive, then the industry will have more time to bring the aspects of it into being, on a voluntary basis, without it being enforced.