From Field to Bottle: Water Footprint Estimation …
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crushing, fermenting and racking; lower strengths are typical during bottling. Table 2
presents reported variability in WWW characteristics for select parameters.
Key parameters of concern include Biochemical Oxygen Demand (BOD) and
Chemical Oxygen Demand (COD) which can result in low DO concentrations in
receiving streams. Na
+ is often found in high concentrations due to sodium-based
cleaning agents used for sanitation, while K
+ is present in high concentrations in
the grape berry pulp [25]. Ions are not removed via typical wastewater treatment
techniques [15], therefore, high Na
+ and K
+ concentrations can reduce effluent reuse
potential (see Sect. 4.4).
Process wastewaters are generally the highest in strength and lowest in pH. The
first flush of tank rinsing water can be very high in COD and other organics, while
subsequent flushes are lower in strength. Cleaning water is generally high in pH as
well as Na
+ or K
+ , depending on the specific cleaning chemicals used [40]. Bottle
washing and disinfection prior to bottling is generally the lowest strength and highest
in pH [13, 16].
Spoiled product, which is of very high strength particularly with respect to
soluble parameter fractions, can also be a source of wastewater requiring treatment and disposal [35]. Lees from racking are also very high strength and, due
to their nature, are high in solids and particulate parameter fractions. These very
high-strength wastewaters can overwhelm on-site treatment systems and, therefore,
it is recommended best practice to keep these separate from other wastewaters, if
possible, for subsequent handling and treatment [16]. For example, in the Niagara
Region of Ontario, Canada, wineries equipped with on-site treatment systems will
often direct very high-strength wastewaters to local municipal Wastewater Treatment
Plants (WWTPs) rather than treating on-site [35].
Despite the wide variability in WWW characteristics, relationships between
various parameters have been successfully developed [14, 36]. Rapid, reliable and
cost-effective methods to characterize WWW can improve performance of WWW
treatment systems and inform decisions with respect to effluent reuse for irrigation
that will not negatively affect soil characteristics [13, 14].
On-site processes typically used to treat the WWW include simple lagoon-based or
constructed wetland systems [22, 35, 43]. These systems can be used to treat WWW
alone, or in combination with sanitary sewage generated on-site. Despite the flexibility of on-site treatment systems, they can be subject to overloading due to the highvolume and high-strength discharges typical during the vintage period. To address
these operational limitations, some wineries will haul some or all of the WWW during
these periods to other locations for treatment, with local municipal WWTPs being
the most common [41]. This can, however, have negative impacts on the performance
of the municipal WWTP and negatively affect effluent quality [8, 9, 35]. In addition,
treating a portion of the WWW offsite results in multiple point-source discharges
of treated WWW that need to be considered when assessing the overall environmental impact of WWW effluents. The on-site wastewater treatment systems may
themselves produce waste streams that also require treatment. Constructed wetland
systems, for example, are often equipped with simple settling tanks at the head of the
113
crushing, fermenting and racking; lower strengths are typical during bottling. Table 2
presents reported variability in WWW characteristics for select parameters.
Key parameters of concern include Biochemical Oxygen Demand (BOD) and
Chemical Oxygen Demand (COD) which can result in low DO concentrations in
receiving streams. Na
+ is often found in high concentrations due to sodium-based
cleaning agents used for sanitation, while K
+ is present in high concentrations in
the grape berry pulp [25]. Ions are not removed via typical wastewater treatment
techniques [15], therefore, high Na
+ and K
+ concentrations can reduce effluent reuse
potential (see Sect. 4.4).
Process wastewaters are generally the highest in strength and lowest in pH. The
first flush of tank rinsing water can be very high in COD and other organics, while
subsequent flushes are lower in strength. Cleaning water is generally high in pH as
well as Na
+ or K
+ , depending on the specific cleaning chemicals used [40]. Bottle
washing and disinfection prior to bottling is generally the lowest strength and highest
in pH [13, 16].
Spoiled product, which is of very high strength particularly with respect to
soluble parameter fractions, can also be a source of wastewater requiring treatment and disposal [35]. Lees from racking are also very high strength and, due
to their nature, are high in solids and particulate parameter fractions. These very
high-strength wastewaters can overwhelm on-site treatment systems and, therefore,
it is recommended best practice to keep these separate from other wastewaters, if
possible, for subsequent handling and treatment [16]. For example, in the Niagara
Region of Ontario, Canada, wineries equipped with on-site treatment systems will
often direct very high-strength wastewaters to local municipal Wastewater Treatment
Plants (WWTPs) rather than treating on-site [35].
Despite the wide variability in WWW characteristics, relationships between
various parameters have been successfully developed [14, 36]. Rapid, reliable and
cost-effective methods to characterize WWW can improve performance of WWW
treatment systems and inform decisions with respect to effluent reuse for irrigation
that will not negatively affect soil characteristics [13, 14].
On-site processes typically used to treat the WWW include simple lagoon-based or
constructed wetland systems [22, 35, 43]. These systems can be used to treat WWW
alone, or in combination with sanitary sewage generated on-site. Despite the flexibility of on-site treatment systems, they can be subject to overloading due to the highvolume and high-strength discharges typical during the vintage period. To address
these operational limitations, some wineries will haul some or all of the WWW during
these periods to other locations for treatment, with local municipal WWTPs being
the most common [41]. This can, however, have negative impacts on the performance
of the municipal WWTP and negatively affect effluent quality [8, 9, 35]. In addition,
treating a portion of the WWW offsite results in multiple point-source discharges
of treated WWW that need to be considered when assessing the overall environmental impact of WWW effluents. The on-site wastewater treatment systems may
themselves produce waste streams that also require treatment. Constructed wetland
systems, for example, are often equipped with simple settling tanks at the head of the