The winery that ships in bulk juice may not need irrigation water, but it still needs a steady supply of fresh water for sanitizing and cleaning every part of the fermentation system. The cellar rooms themselves need regular and thorough cleaning, along with the bulk fermentation tanks and the individual barrels used for aging. All the rinse water left over from these routine chores results in thousands to millions of gallons of process water in need of storage. Since this water is mixed with wine, sediment, fruit pulp, and cleaning chemicals, it’s not safe to simply release it into the soil or water. Find out what processes all contribute to the total amount of produced water coming out of a winery to ensure you’re addressing all of the sources with your plans.
Produced and Process Water Definitions
The term produced water comes from the mining and drilling industry. It’s been widely used to describe all of the wastewater generated by mineral extraction and oil mining, but now it’s most commonly applied to the water produced by hydraulic fracturing. Winery wastewater can also be broadly described as produced water since it’s the residue of a manufacturing process. It’s easy to forget that food and drink production is still manufacturing, but these industries create wastewater that requires the same special handling as any other produced water. That’s why process water is a common synonym that is often more commonly used in industries like food and wine. Whether you’re calling it produced, process, or wastewater, the resulting need for containment and treatment is the same. With the right treatment, it’s often possible to turn produced water into reusable, clean water that’s valuable in the vineyard and beyond.
Crushing Grapes and Creating Juice
The crushing season produces a particularly high amount of wastewater because of the constant need to rinse the crush pad off between batches of fruit. Allowing seeds, pulp, and skin to build up on the pad only results in metallic or mineral flavors in the wine as well as excessive sediment that interferes with proper fermentation. Cleaning and sanitizing the crushing equipment ensures that the wine has a high quality and no off flavors that could decrease its value. The pulp and skins are separated from the wine during crushing in some large-scale wineries, but boutique wineries tend to keep this must mixed in for the first stages of fermentation. This gives the wine more color and flavor than if it’s separated during the first pressing. Pressing the must later, adds additional equipment in need of thorough cleaning, increasing the total amount of wastewater produced by the facility. After all the crushing and sorting is done, the grape harvesting bins also need cleaning before storage for the next year or prior to returning them to the vineyard.
Fermentation Vessels and Finishing Barrels
The large stainless-steel tanks used for primary fermentation require thorough rinsing before use and then generate plenty of wastewater during cleaning and sanitizing after a batch. While these stainless-steel containers are designed with easy cleaning in mind, they still generate plenty of produced water due to the extensive rinsing required to ensure there are no cleaning chemicals left behind. The wood barrels used for the final fermentation and aging of the wine also need regular cleaning. Since it’s hard to penetrate the wood’s surface to kill off bacteria and other pathogens deep in the material, cleaning methods for these barrels typically use more water than those for metal tanks.
Sanitation Methods
Cleaning is one part of the process, but it doesn’t substitute for sanitizing. Removing physical dirt and debris like seeds and grape skins qualifies as cleaning, yet invisible issues like bacteria and chemical residues linger until more extensive methods are used. Sanitization often requires water-intensive methods like steam generation or multiple rinses to remove chlorine residues. Every part of the wine making system necessitates routine and repetitive sanitizing. With the need to sanitize the majority of a facility and not just the equipment and utensils, it’s no wonder that wastewater production can remain high throughout all the stages of wine making. Both hot and cool water rinses are required. Tartrates removal requires a warm water rinse and sugars are cleaned with cold. While many chemicals and products applied to tanks and equipment are designed for cleaning, only a few offer sanitizing effects as well. Modern wineries have turned to everything, from UV lights to high powered steam machines, to reduce the amount of wastewater produced by sanitation methods.
Secondary Cleanup
Crush season is the period that produces the most wastewater in the winery industry, but it’s followed by the secondary cleanup period after bottling is completed. Even if a winery only processes wine seasonally and therefore has a single crush and cleanup event per year, secondary cleanup eventually follows when the wine is completed. This can take months to years depending on the winery’s particular methods and schedules. Since a seasonal winery often lets tanks, barrels, and equipment stand empty for a few months before the start of the next cycle, skipping the cleanup process before this break could result in widespread mold and bacterial overgrowth.
Bottling
Brand new, glass, wine bottles may look clean and ready to use, but they’re not sterile after being packed for shipping and handled for delivery. Sterilization of bottles is usually accomplished by steam, boiling water units, or the use of chemicals like bleach or sulphites. Many wineries use more than one bottle preparation method to prevent yeasts and bacteria from settling on the glass during the filling process. Keeping the room and bottle equipment sterile is just as important as treating the bottles themselves. All of these cleaning and sterilizing techniques release a lot of produced water, filling ponds and tanks designed for storage.
Pumping and Transfer Station Cleaning
Wineries don’t use as many transfer and pumping stations as other industries, but some large-scale facilities truck in bulk grape juice and need this kind of equipment. Spills at transfer stations can cause just as many problems as accidental releases from any other wastewater storage tank or pond. Even raw grape juice is very acidic and can trigger soil and water health changes due to high sugar and protein content. If wine being pumped into trucks for bulk distribution or bottling elsewhere, the problem of spills remains the same. Setting up secondary containment with impermeable liners can protect a transfer station or pumping area just as well as it does for storage ponds and tanks.
Visitor and Worker Wastewater
Many wineries make a large part of their annual profits from conducting tours and encouraging visitors to spend time on the property. In fact, some facilities are almost entirely funded by tourism and drinking on-site rather than from sales of the finished wine by the bottle. These businesses produce far more wastewater in the bathrooms and other guest facilities than those that only have workers. Yet even a small workforce is enough to produce a few thousand gallons of sewage and gray water a year. Since this wastewater is different in composition from the produced water from wine making, it’s generally handled in a separate system like a septic tank. Gray water may be able to blend in with the wine making waste, but sewage is generally handled separately regardless of the volume.
Herbicide and Fungicide Mixing and Cleanup
For wineries with integrated vineyards, herbicides and fungicides are often an unfortunate requirement for healthy plant growth. Humid environments, in particular, encourage sooty mold, powdery mildew, and other fungal diseases that often strike right when the fruit is about to ripen. Herbicides are necessary to control vigorous weed infestations that can suck up all the water and nutrients needed by the grape vines. Water used for mixing and rinsing these blends will need special handling to keep it from affecting local water or soil health. The same is true for any fertilizer, especially those mixed with water to create sludges or sprays for easy application.
Methods for Reducing Wastewater Production
Improving the entire wine making and cleaning process may sound like a tall order, but it’s easy enough with just a few adjustments. Start by tackling whichever part of the wine making process is the most wasteful; which varies between facilities depending on the exact wine being produced. The following methods have all been proven to reduce wastewater production during wine making.
High Pressure Spray Nozzles
High pressure sprays are used to speed up cleaning while simultaneously reducing water use. By pressurizing a smaller volume of water, the sprayers move larger amounts of solid debris and loosen scale and sugar build-up. These sprayers work well for tanks, floors, walls, and even barrels, but they can’t replace other sterilization methods. It may be possible to sterilize bottles, equipment, and tanks with sprayers that dispense the right chemicals, but most barrels will need a different sterilization method to penetrate the wood.
Steam Cleaning
Steam has long been used for both cleaning and sterilizing stainless steel tanks, but not all steam methods are water efficient. Some methods call for producing such large amounts of steam that both water and heating costs run high. Efficient steam sanitizing equipment will employ pressure to boost the microbe killing effects while using less heat and water. This is especially true for equipment designed to work on wood barrels where the extra pressure is required to sanitize deep inside each stave of wood.
Ozone and UV for Sanitizing
Treating large areas, like entire fermentation rooms and large-scale bulk vats, can require thousands of gallons of water per cleaning and sanitizing cycle. Turning to a replacement for the chemicals involved can cut down on both wash and rinse water without leaving residues behind. UV light is one option for sterilizing most non-porous surfaces when exposure is long enough. It’s ideal for reducing rinsing, instead of large steel tanks. For entire rooms, where the walls and floors need thorough sanitizing, ozone generators are a great choice. They require very little water and produce a concentrated ozone mist that kills off microbes within seconds, speeding up large scale sterilization chores. Some systems are also available for using ozone alone or combined with UV on tanks and barrels as well.
Storage for Produced Water at Wineries
No matter the source of the produced water, it requires some kind of storage before it can be discharged or reused in some way. Even short-term storage, of only a few weeks, requires carefully planned ponds, tanks, underground cisterns, or a combination of all three. Add in treatment, to bring the water quality up for reuse or discharge, and you have a complex system that needs as much attention as the rest of the winery.
Reuse of Process Water
Most process water generated by a winery is safe for direct reuse as irrigation water, according to multiple studies conducted on Mediterranean and Californian vineyards. The one main concern, common to all produced water from wineries, is high sodium levels. Salt quickly builds up in the soil because it doesn’t wash out or evaporate easily, and almost all plants find it hard to grow in soil with high salinity. Dumping even a few loads of water full of sodium-based cleaning products can have a long-term impact on soil and vineyard health. Most wineries find it easy enough to avoid this problem by switching to potassium-based cleaning products or methods like UV and ozone sterilization. If other water quality issues like acidity or high levels of dissolved solids are a concern, on-site treatment ponds double as storage space to bring the water within certain parameters for reuse.
Discharge Options
If there’s no way to reuse the water on-site or nearby, discharge is the primary method for getting rid of the unnecessary wastewater. However, produced water from wineries often requires even more treatment and processing to reach a stage safe for discharge than it would for reuse. Don’t choose a discharge method based on the idea that it will reduce the treatment necessary to improve water quality. Open water discharge, in particular, requires high water quality to prevent environmental damage, but even sewer and septic tank discharge may require pre-processing.
Land Discharge
Similar to reusing the wastewater as an irrigation supply, land discharge allows for the release of the wastewater over open ground. This allows bacteria in the soil to quickly break down dissolved and sunken solids, so they don’t generate odor issues. However, the produced water will need to fall within specific parameter or require extra treatment; especially if it has a high sodium level.
Open Water Discharge
Releasing the produced water from a winery into a nearby river or lake may seem like a convenient way to get rid of it, but it also tends to be the most expensive due to high fees for this kind of arrangement. You’ll also need to bring the wastewater back to the highest level of purity possible to keep acidity or chemical compounds from affecting the health of the body of water. In most cases, any other kind of discharge or reuse is easier and more affordable for wineries than open water discharge.
Sewer Discharge
Connecting to a nearby sewer system may seem like the perfect way to deal with produced water. While it will work fine for sewage and graywater generated in the bathrooms, many municipal systems can’t handle large volumes of the process water coming from wine making chambers. The high level of dissolved and suspended solids are particularly challenging for municipal systems not designed to accommodate them. In these cases, you may find that a solid removal program and a septic system is a better choice than a public sewer connection.
With so many individual sources within a winery or vineyard, it’s easy to see why each facility is capable of creating thousands to millions of gallons of produced water a year. Storing this process water in a securely lined pond is the best way to make full use of it, whether that’s for irrigation or through careful discharge to refill local wetlands. Don’t let produced water become a hazard when it can be a productive and valuable resource instead. BTL Liners can help by providing the flexible liners you need to keep the water from seeping or leaking away while it’s being processed.
