128
M. B. Johnson and M. Mehrvar
6 Case Studies
The WF concept is still fairly novel, with the first definitive guidance document
published in 2011 [28]. As such, the application of this process to assess the impact
of wine-making on freshwater resources is still in its infancy. Despite this, a number of
assessments have been completed over the past decade that aim to quantify the impact
on freshwater resources from a holistic perspective to a process-specific focus. Table 5
presents summaries of recent WF studies of wine-making processes. Enhancements
to the original WF assessment protocol as proposed by Hoekstra et al. [28] that are
specific to wine-making have been successfully developed and applied [27, 39]. In all
cases, the system boundary was clearly defined, although the breadth of the factors
included (viticultural and vinification stages, direct and indirect WF) varied. Typical
functional units were a 750 mL bottle of wine and L of wine produced, although
some studies also reported values in terms of WF per glass of wine [10, 21].
Using the consumptive approach, the green WF was found to be the largest contributor to the WF of the viticultural stage [39] and, where a LCA was used, the green WF
represented the largest contributor to the overall WF [10, 11, 21]. The water-balance
approach, by contrast, resulted in negligible values for the green WF and negative
values for blue WF, indicating net groundwater recharge within the vineyards of New
Zealand [27]. Direct comparison of the consumptive green and blue WFs to those
developed using the water-balance approach is not possible.
The impact of drift, runoff and leaching was typically considered during the
estimate of grey WF during the viticultural stage, although sometimes only a subset
of these factors was considered [39]. Nitrogen was the critical parameter used to
assess the impact of leaching on groundwater sources, while pesticides and nutrients
in drift and runoff were typically considered. During vinification, simplifications
were generally made in the assessment of the grey WF. Lamastra et al. [39] and
Bonamente et al. [11] did not consider the impact of WWW on the grey WF, while
other assessments assumed a grey WF of, at most, the volume of WWW discharged
[10, 21, 27]. A regional assessment of the impact WWW co-treated at municipal
WWTPs in Niagara Region, Canada, suggests that the discharge of WWW treated
to levels that exceed regulatory requirements can still exert a significant grey WF of
as much as 960 times the volume of treated WWW effluents discharged [34].
7 Conclusions
Combined agricultural practices (viticultural stage) and physical and chemical
processes (vinification stage) associated with wine-making exert significant water
demands and complex impacts on local freshwater resources. Local climatic conditions affect surface and groundwater demands for irrigation, while vineyard configuration and operation affect the need for fertilizer application, runoff volumes and
potential for drift. Water is used in large volumes during vinification for cleaning
M. B. Johnson and M. Mehrvar
6 Case Studies
The WF concept is still fairly novel, with the first definitive guidance document
published in 2011 [28]. As such, the application of this process to assess the impact
of wine-making on freshwater resources is still in its infancy. Despite this, a number of
assessments have been completed over the past decade that aim to quantify the impact
on freshwater resources from a holistic perspective to a process-specific focus. Table 5
presents summaries of recent WF studies of wine-making processes. Enhancements
to the original WF assessment protocol as proposed by Hoekstra et al. [28] that are
specific to wine-making have been successfully developed and applied [27, 39]. In all
cases, the system boundary was clearly defined, although the breadth of the factors
included (viticultural and vinification stages, direct and indirect WF) varied. Typical
functional units were a 750 mL bottle of wine and L of wine produced, although
some studies also reported values in terms of WF per glass of wine [10, 21].
Using the consumptive approach, the green WF was found to be the largest contributor to the WF of the viticultural stage [39] and, where a LCA was used, the green WF
represented the largest contributor to the overall WF [10, 11, 21]. The water-balance
approach, by contrast, resulted in negligible values for the green WF and negative
values for blue WF, indicating net groundwater recharge within the vineyards of New
Zealand [27]. Direct comparison of the consumptive green and blue WFs to those
developed using the water-balance approach is not possible.
The impact of drift, runoff and leaching was typically considered during the
estimate of grey WF during the viticultural stage, although sometimes only a subset
of these factors was considered [39]. Nitrogen was the critical parameter used to
assess the impact of leaching on groundwater sources, while pesticides and nutrients
in drift and runoff were typically considered. During vinification, simplifications
were generally made in the assessment of the grey WF. Lamastra et al. [39] and
Bonamente et al. [11] did not consider the impact of WWW on the grey WF, while
other assessments assumed a grey WF of, at most, the volume of WWW discharged
[10, 21, 27]. A regional assessment of the impact WWW co-treated at municipal
WWTPs in Niagara Region, Canada, suggests that the discharge of WWW treated
to levels that exceed regulatory requirements can still exert a significant grey WF of
as much as 960 times the volume of treated WWW effluents discharged [34].
7 Conclusions
Combined agricultural practices (viticultural stage) and physical and chemical
processes (vinification stage) associated with wine-making exert significant water
demands and complex impacts on local freshwater resources. Local climatic conditions affect surface and groundwater demands for irrigation, while vineyard configuration and operation affect the need for fertilizer application, runoff volumes and
potential for drift. Water is used in large volumes during vinification for cleaning