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A Technical Guide for Wine Producers
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RECENT ARTICLES | WYNBOER HOME
Guidelines For a Winery Wastewater and Solid Waste Management Plan
1. Van Schoor Enviroscientific, 63 Bergstreet, 7140 Gordons Bay, Tel: 082 805 2999, e-mail: enviroscientific@adept.co.za
1. Introduction
The following guidelines should be used to develop a winery wastewater management plan to ensure compliance with environmental legislation as well as the requirements of Integrated Production of Wine (IPW). The purpose of such a plan is to provide the winery with a strategic plan to ensure that their wastewater and solid waste handling is in line with the policies of the Department of Water Affairs and Forestry (DWAF) as well as to form the basis for an application for an Authorization for the disposal of winery wastewater and solid waste to DWAF. The contents of the plan will be regarded as a legal requirement when submitting the plan as part of an application for an authorisation and once the winery, through their management have committed to implementing the plan. Although winery staff can assist in completing such a plan, specialized input with regard to soil studies, vineyard irrigation, environmental risk assessments and legal requirements are needed. Winery management should ensure that only a credible consultant who preferably has the required accreditation with the South African Council for Natural Scientific Professions or the South African Council of Engineering Professions as well as experience in the handling and/or treatment of winery wastewater is appointed. This will ensure that the consultants would be able to provide guidance of an acceptable level and develop a plan, which would be acceptable to DWAF. The consultant should discuss the proposed plan in full with winery management to ensure that all aspects are understood and accepted by the winery. This must also serve as a "training session" before the plan is submitted to DWAF. One cannot use a generic plan for all wineries and winery management should never consider using a plan from another winery. The winery management should also officially approve this plan, as DWAF does not accept any plans from consultants unless it has been clearly approved by winery management, as they have to implement the contents of the plan. Certain aspects are essential to include in an acceptable report and will be discussed in this paper.
2. Current situation
In this section the current practices relating to winery wastewater generation and disposal should be given. Each winery is unique in this regard and the purpose is to identify current problems that can be addressed to minimize wastewater production and improve wastewater quality where possible. The following are examples of information to be provided in this section:
Most wineries do not have a historic record of wastewater volumes. Therefore an estimation of the quantity generated at the winery should be made to ensure that (1) the catchment dam is large enough to contain the wastewater and (2) the wastewater irrigation site is of adequate size to accommodate the wastewater volume to be disposed of or (3) the treatment facilities is of adequate size to treat the effluent etc. It should also take into consideration the percentage of wastewater generated in the peak harvest period (depending on the size of the winery) as well as an estimation of the amount of water that can be re-used during this period.
Worldwide research has shown that wastewater production varies between wineries and can be in the order of 2 to 14 liters of wastewater for every liter of wine produced (this does not take into account evaporation during ageing or "the angels share"). If the winery measures the quantity of the wastewater generated and if storm water (rain water) is separated from the wastewater, the estimation is not difficult and some risk should be incorporated into the calculation for emergency situations such as wine spills. If no monitoring records are available however, the consultant must estimate the quantity generated by the winery and a very good motivation, which indicates that there is already an awareness of water conservation, will result in using the 4 to 5 liter wastewater/liter wine factor and no motivation approximately 6-8 liters wastewater for every liter of wine produced to ensure that the plan is acceptable. This estimation should be done conservatively as this forms the basis of the effluent-handling plan. However, all wineries should take urgent steps to measure at least the volume of water used in the winery and to use this to calculate the volume of wastewater produced.
The volume of the catchment dam and or wastewater holding-dam is dependent on the area, soil, crop and rate of irrigation as well the need to store wastewater during periods when there is no irrigation possible. Aesthetics may also play a role in sizing the dam, as it is possible that the winery prefer the dam being filled throughout the year.
4. Cleaner production strategies for generating minimum quantity and optimum quality of wastewater
The winery should be committed to effective environmental management and must implement cleaner production strategies in the winery to reduce the use of chemicals and water in the winery to the absolute minimum. The consultant must recommend types of chemicals to be used to limit them to environmentally friendly products as far as possible (e.g. K-OH instead of Na-OH and phosphoric acid instead of citric acid) to make it possible to irrigate or re-use the wastewater as an end use. Recommendations on storing and usage requirements must be given according to statutory prescriptions regarding the handling of chemicals. The consultant must also recommend guidelines to limit the water usage in the winery to the absolute minimum and also give the necessary information regarding legal use of borehole or surface water.
5. Water quality: vineyard irrigation
If the winery is committed to implementing cleaner production strategies, it could be possible to irrigate vines with its wastewater. International norms are available for vineyard irrigation with winery wastewater. If the wastewater continuously comply with all the parameters as provided by the specialist, it may then be used to irrigate vines (subject to an authorisation by DWAF), but irrigation scheduling must be a direct function of the water requirements of the specific vineyard and soil. In this manner the wastewater will be utilized as a resource and not affect the soil and groundwater negatively.
6. Irrigation of crops other than vines
If the water quality does not comply continuously with all the parameters for vineyard irrigation, the winery may consider irrigating grass and or, gardens in the vicinity of the winery (subject to an authorisation by DWAF). The same principles however, have to be followed to ensure that no over-irrigation occurs. The winery must ensure that a thorough soil study is conducted prior to any irrigation of these crops. Irrigation may then only occur if a soil scientist indicated that it would be a viable practice. If the soil conditions are not favorable for wastewater irrigation, other alternatives will be considered in collaboration with the DWAF and other specialists.
7. Alternative disposal methods
South Africa is a water scarce country, which necessitates that all water resources must be used efficiently, sustainably and beneficially. The National Water Act, 1998 (Act 36 of 1998) stipulates that all wastewater must be treated and discharged into a water resource to sustain the environment or to be available for a potential downstream user. The management plan must therefore also address the future required treatment systems such as constructed wetlands and/or bioreactors, in consultation with specialists and the DWAF. These treatment systems are normally fairly expensive and the planning surrounding the construction of such facilities are very important. It is import for winery management to note that the treatment systems do not guarantee an end use. However, the wastewater must be treated to allow its re-use (1) in the winery, (2) for agricultural crop irrigation or (3) discharge to a water resource. Wineries that treat their waste water to the required legal standard to allow its discharge into a water resource, is still very limited in South Africa and the beneficial agricultural crop irrigation is possibly still the best use of the treated waste water.
8. Sampling prior to irrigation
South African legislation requires cellars to follow a wastewater audit procedure. Since most wineries do not have historic records of wastewater volumes or quality, an intensive monitoring programme should be followed during the first two years. The monitoring programme should calculate, on an annual basis, the volume of wastewater, the normal variation in volume between peak periods of wastewater production, the normal variation in chemical composition between peak periods of wastewater production, as well as the potential environmental and social impacts of the recycling or disposal activities. Once a winery has followed the initial intensive monitoring programme for two years, a routine monitoring programme should be followed to confirm the variation in wastewater volume and chemical composition. Furthermore, the winery should monitor the impact of wastewater on soil, water resources, vegetation and health. A successful monitoring programme goes hand in hand with a thorough and representative soil sampling programme and the consultant should provide a procedure to conform to the above-mentioned aspects.
9. Cleaning of catchment dams and general solid waste disposal
The consultant must provide guidelines in the plan regarding the cleaning procedure of the wastewater dam to ensure that a suitable time frame is included and that sludge is disposed of effectively. The disposal of skins, stems, pips, lees, diatomatious earth and bentonite clay must be in line with legal requirements. The consultant should also include legislative requirements (information) for composting if applicable.
10. Emergency preparedness and rehabilitation
It is important that emergency preparedness procedures form an integral part of the plan and that soil and watermonitoring results will serve as indicators for rehabilitation actions prior to environmental damage.
11. Quantification of potential environmental impact of wastewater and solid waste practices
Any client or any Government Department needs to know whether the implementation of the winery wastewater and solid waste plan is effective or not. It is therefore important that an independent environmental risk assessment is conducted comparing the current environmental situation with the situation after implementation of the plan. During May 2001, Van Schoor's formula for prioritizing and quantifying of potential environmental impacts in the wine industry was published and can be used by the consultant to evaluate the proposed plan.
12. References
Van Schoor, L.H., 2001: A formula for the quantification and prioritisation of negative environmental impacts in the wine industry. Wineland, May 2001.
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