Environment industries archive
Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.
Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.
Berri Estates is using the wastewater from its winery to grow a plantation of Murray River Redgums. Their success has solved problems posed by large volumes of smelly waste water that cannot be easily treated when disposed of by traditional lagooning systems. The trees are a resource for the future, are aesthetically pleasing and are ensuring that Berri’s wastewater doesn’t add to the serious salinity problem facing the region as a result of past land clearing. Berri Estates’ future depends on the sustainability of the Riverland region, and the plantation is an investment that both supports the environment and may become a new industry for the region.
The company is pointing the way for cleaner production in one of Australia’s fastest growing industries - the production of wine.
The Riverland region is part of the Murray-Darling basin, Australia’s foodbowl. The region faces serious problems of environmental degradation, and concerted action by all producers in the region is needed for a sustainable future. To play its part, Berri Estates needed to change its wastewater management procedures. The specific guidelines Berri had to meet in managing its wastewater, as laid down by the Minister for Water Resources, were:
The Berri Estates winery is located on the Sturt Highway at Glossop in South Australia's Riverland. The winery crushes about 110,000 tonnes of grapes per year (based on 2001) to produce grape juice, a range of table and fortified wines, brandy and fortifying spirit. During the four-month vintage (grape harvest) running from February until April, the winery operates on three shifts, seven days per week. For the remainder of the year, two shifts operate. Processing includes crushing of the grapes, draining and pressing, fermentation, centrifugation, distillation, maturation, storage and bottling of the product.
Wineries generate large quantities of low-solids wastewater from washing down of plant equipment, such as tanks, presses, and the bottling plant. This effluent includes skins, pips and pulp wash. The wastewater contains a medium- to high-content of biochemical oxygen demand (BOD). Still wash from distillation has the highest BOD level. The load factors are not hazardous, but the sheer volume of wastewater can cause problems. The wastewater does not biodegrade easily and quickly generates offensive odours if left to stand in ponds.
The wastewaters fall into two categories of low-level (winery) and medium-level (distillery) wastewaters. Zero level wastewaters are negligible because of recirculation of cooling water and the use of refrigerative rather than evaporative cooling of tanks. Storm water is not collected in separate drains. It is mixed with the winery wastewater being produced at the time.
Berri Estates’ winery produces around 200 megalitres (ML) per annum of low-level wastewater with a BOD of about 2,500 mg/L. The distillery wastewater is around 10 ML per annum at about 15,000 mg/L. The monthly volumes of the two streams of wastewater are set out in Table 1 at the end of this report, along with their BOD, organic load, pH and salinity. Production is highly seasonal with the highest flow during the warmer weather of the vintage.
Berri Estates had been using evaporative lagoons, the traditional approach of the winemaking industry in managing wastewater. Wastewater was collected in drains which discharged into a common sump and then into three storage and evaporation lagoons at the rear of the winery. The three lagoons operated in series and the last lagoon was pumped into a drain flowing to the Berri Evaporation Basin (Winkie Lagoon). Odours were generated in both the lagoons behind the winery and at Winkie. During high rains, wastewater from the Winkie lagoon overflowed into the Murray River.
To meet the new standards, Berri Estates considered numerous options for disposal of the wastewater, using consultants as necessary. A summary of these various wastewater disposal methods is set out in Figure 1.
Figure 1. Outline of options for waste disposal
The option that best met the company’s cost and environmental objectives was to establish a plantation of Eucalyptus camaldulensis, using the wastewater from the winery waste for flood irrigation. The wastewaters from the winery would be screened and settled, and then pumped around 5 km to the plantation, located on the river plains.
The required land area was deduced from the volume and characteristics of the winery effluent, climatic data and evaporation rates at different times of the year. Further land was required for driveways, borders, etc., leading to the selection of a total area of around 30 hectares. Flood irrigation demanded that the land be level. Spray irrigation would have been unsuitable for young trees during their establishment stage.
For aesthetic reasons and potential commercial value of the trees, River Red Gums, for example, Eucalyptus camaldulensis (Lake Albacutya Provenance), were selected. The trees were to be planted at a rate of approximately 2,222 per hectare on a 3 x 1.5 m grid, then irrigated with one metre of wastewater per annum. No process data was available for the rates of evapo-transpiration for such a system, but some data suggested that evapo-transpiration would be around double that of evaporation without the trees. In the Riverland, this would indicate that the trees could utilise four metres of water per annum.
The final design criteria were as follows:
After selecting and acquiring a 30 ha-site, planting of 40,000 seedlings of Eucalyptus camaldulensis commenced. Planting was completed in the final quarter of 1986. (An additional 20,000 seedlings were planted in 1999). During the early stages of the plantation, irrigation was carried out with river water to ensure that the seedlings became well established. From the 1988 vintage onwards, only winery wastewater was used.
While the plantation proper was being planted and established, winery wastewater screening, settling and pumping ponds were constructed.
The three excisting winery wastewater lines were fed together by gravity through a Surescreen parabolic 2 mm-gap wedge wire, self cleaning static sieve, before running into one of the two settling ponds. A little experience showed that at times of high wastewater generation, the Surescreen sieve was unable to handle the grape skin solids and so a wiped slotted screen was installed between the Surescreen sieve and the settling ponds, to remove gross solids.
Each settling tank is around 120 kL capacity, being 20 m x 6 m x average depth of 1 m and allows a minimum residence time of approximately one hour at peak flow rates. The main solids settling in the ponds are diatomaceous earth from the filtration processes, and when one pond is full, the flow is diverted to the second while the first one dries out and the solids are removed. When originally installed, the solids were removed by front end loader, but are now pumped out as a slurry into a small area of land fill.
Because of the high variability of winery wastewater generation rates during and outside the vintage period, two centrifugal pumps were installed in the pumping pond, each of different capacity. Self-priming centrifugal pumps were used, of 12 L/sec and 24 L/sec capacity. Level float switches in the pumping ponds controlled the pumps.
Screened and settled winery wastewater is transferred from the pumping ponds to the plantation through a 150 mm-PVC pipe equipped with relief valves and scouring outlets. Part of this pipe had previously existed to transfer winery wastewater to the Winkie basin, but an extra length was added to take the total pipeline distance to around 5 km.
The general layout of the plantation into irrigation bays was based on a total of 320 bays, each 200 m long and 3 m wide with a gradient of 1 in 2000. To achieve this gradient, the whole area was laser-leveled, with some terracing where required. The 320 bays are grouped in 20 sections of 16 bays per section.
The general mode of operation and intermittent irrigation of the plantation is based on each section of bays receiving 50,000 L of winery wastewater in any one watering. The flow of water through the settling ponds and into the pumping pond dictates whether the smaller or larger capacity pump operates. At the completion of each batch of 50,000 L, a computer controlled radio link at the pumping station relays the information 5 km to the plantation receiving station which opens the valves on the next section of bays and closes the valves on the previous section of bays. This new section of bays then receives 50,000 L of water and the cycle goes on. There are various protective controls to prevent over-pressure building up in the line. The whole day-to-day operation of the pumping and irrigation system is automatic.
The water authority, the Engineering and Water Supply Department (EW&S), had expressed major concern about the effect of wastewater irrigation on the water table and ground water salinity level. It required the company to implement extensive wastewater test well sampling and monitoring, and to submit these data each month to the Department. An example of these data during 1991 is shown in Table 2.
Another major concern was the likely effect on the soil pH of the continued application of lowish pH winery wastewater to the area. Data collected since 1987 is shown in Table 3. Current advice is that the scheme should be treated with horticultural lime should the pH fall below 6.5. As the data demonstrates, the reduction in soil pH has been negligible so far.
Since 1988, a range of leaf analyses has been carried out from representative areas in the plantation. The data is shown in Table 4. The relatively low nutrient levels in the winery wastewater shows in the declining, but not worrying, levels of nitrogen, phosphorus and potassium. Some nutrient addition may be necessary during the life of the plantation.
The plantation requires annual weed clearance to keep the bays free, and general maintenance of the area. Some diatomaceous earth solids also enter the pipeline during vintage and annual flushing and/or pigging is needed to avoid blockages.
The growth and health of the trees indicate their capacity to absorb all the winery wastewater. The advantages include:
Plantation maintenance has involved pruning and thinning to maintain the trees in the growth phase for as long as possible. Approximately every third tree is removed at the base to reduce root obstruction. The remaining trees are trimmed to the 2 m level. There is little experience in the future development of the plantation, but major crowning may be required at 10-years. This will be followed by a second 10-year growth period before replanting. With terracing required for flood irrigation and the different residual depths of top soil remaining, some areas of the plantation are flourishing more vigorously than others. This has resulted in some natural staggering of the development of different areas of the plantation, which is proving a boon, in that redevelopment phases occur progressively throughout the plantation rather than all together.
Winemaking is one of the fastest growing industries in Australia, already having established itself as a quality product in export markets around the world. Winemaking is one way Australia can capture greater advantage from its highly competitive agriculture. Berri Estates is pointing the way for cleaner production with this Australian success story.
Berri Estates’ future is invested in the health of the Riverland environment. That environment is under stress and so the company, like all land users in the region, has to find sustainable production techniques. The solution it has found is economic, environmentally benign, and may even yield an economic source of timber in the future, creating a new industry for the region.
The lack of process data on evapo-transpiration, nutrient uptake, effect on soil pH and the general lack of experience with red gum plantations meant that planning and management have had to be flexible. Nevertheless, data obtained during this and other projects, and recent research into species selection and propagation will ensure that the efficiency of wastewater usage and the speed of tree growth will improve all the time. These will also improve the economics of treatment in the second planting.
BRL Hardy continue to reap the benefits of the plantation for the management of their wastewater, however it has been highlighted by the SA EPA that drainage from the plantation may be displacing saline groundwater underlying the plantation into the Murray River. In order to ascertain whether this is in fact occurring, Sentec soil moisture probes were installed throughout the plantation in early 2001 in order to quantify any drainage occurring through a mass balance approach. Should the irrigation of the plantation be found to result in unexpected drainage then diversion of the wastewater from the Berri Estates Winery to an alternate location will be required.