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A Technical Guide for Wine Producers
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A formula for quantification and prioritisation of negative environmental impacts in the wine industry
The key element in, and first step towards an effective EMS is the identification of key environmental risk factors. Once identified, these factors can be used to ascribe priorities for rectification and effective management. Various formulas have been compiled for this purpose, but most are specific to particular industries, having environmental risk factors that are unrelated to the activities of the wine industry (ISO/TR 14061, 1998). In the wine industry the majority of environmental risk factors differ slightly from one winery to another, although the severity with which some factors impact on the environment may vary.
A formula to calculate the significance of individual environment risk factors was therefore developed by the author specifically for the South African wine industry. In addition to environmental risk factors, this formula includes environmental factors of a social and aesthetic nature, as well as requirements for the integrated production of wine (IPW). The formula ascribes significance values varying between 0 (lowest significance) and 100 (highest significance), and is expressed in the following terms:
S = [(fd + int + sev + ext + loc) x (leg + ipw + pol +ia + str) x P]
Numerical Criteria
The following numerical criteria for the above-mentioned parameters should be used in the formula. It can also be adjusted for specific on-site differences:
Example
This example concerns an imaginary winery situated in the Stellenbosch residential area, a few kilometres from a natural wetland. Production-related activities such as bottling continue throughout the year. The water table in this area remains almost permanently below a depth of two meters. Groundwater is used for drinking and irrigation in the vicinity of the winery. The winery generates more than 20 ML of wastewater annually. This wastewater is stored in a concrete pond, then pumped through overhead sprinklers onto a grass-covered area of sandy to loamy soil. The rate at which the wastewater is applied exceeds 550 m3 per day during the peak harvest period. This peak period, during which wastewater disposal is a daily event, extends over a period of at least eight weeks. Monitoring of water quality is carried out at four-week intervals, as required by legislation. Chemical oxygen demand (COD) exceeds the legal limit of 400 mg/l throughout the year, with a lowest observed value of 11 210 mg/l. The sodium adsorption ratio (SAR) of the wastewater is highest during January. This January SAR value (13.7) greatly exceeds the legal limit of 5.0 and stems from the use of caustic soda in the water, which is used to rinse equipment. In contrast, the electrical conductivity (EC) values are always lower than the legal limit of 200 mS/m. Values for pH vary from month to month and range from 4.0 to 9.0, and do not always fall within the legally accepted range of pH 6.0 to pH 9.0. The winery does not have an environmental policy, environmental strategy or an environmental management system in place.
By substituting this information in the formula it is easy to determine the priorities that are associated with the various environmental impact factors as shown below.
Significance of winery wastewater
In this example, the potential impact of winery wastewater was calculated to establish the importance (priority) of the individual factors. The winery wastewater applications occur daily for at least two months and therefore score 3.0: high for both frequency and duration. The intensity of the impact depends on the concentration of the chemicals in the wastewater, as well as on the quantity of the wastewater. The high COD and SAR values and the low pH values signify that the pollutant concentration is high. The latter, combined with the fact that a large quantity of water is being disposed of on a daily basis (>550 m3 on any day), give a score of 3.0. Generally, disposal of 10 m3 wastewater can be regarded as a small quantity and 50 m3 as a medium quantity. When water or groundwater pollution occurs, the impact is irreversible. The score for severity will therefore be 3.0. Since groundwater contamination will inevitably occur as a result of leaching through the sandy to loamy soil into the underlying groundwater, the extent of the impact will be regional (outside the boundaries of the winery), giving a score of 2.0 for ext. In view of the proximity of the wetland, a score of 3.0 must be awarded for the sensitivity of the locality. The water quality does not comply with the guidelines as set out in the National Water Act, and would therefore score 1 for non-compliance. The South African system for integrated production of wine requires responsible management of effluent water and a non-conformance with this requirement will result in a score of 1.0. Because no environmental policy exists at this winery, both pol and str will score 1. Odour problems resulting from the high COD concentration will definitely have an effect on the neighbouring areas, resulting in a score of 3.0 for ia. Since there is no environmental management system in place to monitor and control wastewater disposal, or to seek alternative methods of disposal, it is certain that the activity will continue to take place, scoring 0.95 for P. Substitution of these scores in the significance formula, gives an impact significance value of 93.1, as indicated below:
S = [(3 + 3 + 3 + 2 + 3) x (1 + 1 + 1 + 1 + 3) x 0.95] = 93.1
If an environmental policy were implemented and management decided to investigate strategies to reduce the impact of winery wastewater on the environment, the significance of the impact could be considerably reduced. Citric acid, along with grape solids, lees, grape juice, wine and tartrate increase the COD of wastewater. If winery management decided to use an alternative acid, such as phosphoric acid, for neutralising caustics during washing, this option alone would reduce the total significance value, since the intensity (int) of the impact would be reduced to a value of 2.0 because of the reduced COD concentration of the wastewater (high quantity, medium concentration). Because an environmental policy was implemented to attend to environmental risks, pol scored 0 and because a strategy was put in place to partly address the wastewater issue (using an alternative option), str scored 0.5. Odour problems resulting from the high COD concentrations might also have been reduced, giving a score for ia of 1. When adjusting these scores in the significance formula, it will add up to:
S = [(2 + 3 + 3 + 2 + 3) x (1 + 1 + 0 + 0.5 + 1) x 0.95] = 43.2
Apart from reducing the impact on the environment, cost will also be reduced because phosphoric acid is cheaper than citric acid. By using alternative methods in cellar processes, one can therefore save money and lessen the potential risks on the environment and neighbours.
Conclusions
By using this significance formula, winery management could list and prioritise negative environmental impacts. This is the first step towards an effective EMS (e g ISO 14001) and it may also reduce costs in and around the cellar and vineyard. Any possible impact on the environment and on neighbours can be rated using this formula.
For further information, contact Lourens van Schoor at tel 021-809 3158, or e-mail lourens@nietvoor.agric.za.
References
ISO/TR 14601, 1998. Information to assist forestry organisations in the use of environmental management system standards ISO 14001 and ISO 14001. ISO, Switzerland.
VAN SCHOOR, L H, 2000: Management options to minimise negative environmental impacts at wine cellars. Wineland, July 2000.
VAN SCHOOR, L H, 2001: Environmental legislation in viticulture and the wine industry. Wineland, January 2001.
VAN SCHOOR, L H & VISSER, G A, 2000: ISO 14001 Environmental management systems: Background, elements and benefits. Wineland, September 2000.
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Wine production in South Africa has increased over the past decade. This phenomenon is associated with increased pressure on environmental resources such as water, soil and vegetation (Van Schoor, 2000). National legislation and foreign markets stipulate that all factors that have potential environmental impacts, such as wastewater, solid waste disposal from cellars and the use of agro-chemicals in vineyards, must be responsibly managed by means of an effective environmental management system (EMS), for example ISO 14001 (Van Schoor & Visser 2000; Van Schoor 2001). 
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