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:
to reduce, if not totally eliminate, the odour problem from the lagoons behind the winery and from the Winkie basin;
not to contribute to river salinity or the rise of the water table in the area;
to enhance the environment, and certainly not to decrease its aesthetics; and
to be economically feasible.
The Berri Estates winery is located on the Sturt Highway at Glossop in South Australia's Riverland. The winery crushes about 50,000 tonnes of grapes per year 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.