There are common misconceptions about winery wastewater that run in both directions. Some winery and vineyard owners are concerned that the wastewater is unsafe to reuse, even after processing in an open-air pond. On the other end of the scale, some owners and managers believe that waste water is automatically safe to use in any amount. The truth is somewhere between the two extremes. Wastewater is often safe for direct reuse during certain parts of the year and in need of processing during other months. Some facilities may have highly diluted water that won’t leave salt deposits in the soil even after years of use, while others must watch salination carefully due to both wastewater parameters and soil conditions. Explore some of the most valuable ways to reuse winery wastewater and the processing that is usually necessary.
Irrigation is the most popular form of reuse, for wineries, because vineyards need thousands of gallons of water per week during the driest parts of the growing season. Without a steady supply of water at crucial times, wine grapes develop unpleasant flavors or fail entirely. However, growers were long concerned about the potential for soil and plant damage from reusing winery wastewater in this way. Both microbes fed by the high sugar levels, and the salts left behind by cleaning products, were particular concerns for growers. Considering the cost of establishing and nursing grape vines through years of growth before harvestable grapes appear, it’s not surprising vineyard managers are sensitive to anything that could damage the plants.
Thankfully, there’s been recent research that establishes the safety of winery wastewater once it has been treated on site, in open ponds, with aeration. A study completed in 2015 and published in the American Journal of Enology and Viticulture, found that wineries with on-site treatment were generating irrigation water well within soil safety parameters for most sites. Even heavy clay soils, which are prone to salinity accumulation, weren’t impacted negatively by the use of treated wastewater. Of course, every soil and wastewater mixture is different. Work with a local environmental agency, or agricultural extension office, to determine parameters for safe wastewater in irrigation application. Routine testing is a basic process to ensure wineries irrigation practices won’t risk damage to their vines.
Direct Reuse for Washing
Most wastewater from wine making is too dirty and difficult to clean to consider reusing it for further cleaning or washing. Yet, for wineries where fresh water is extremely expensive or difficult to find, treating the water to this stage of cleanliness may be worth the effort. It is possible to sanitize and filter water to a level that is safe to use for washing tanks. Just keep in mind that energy costs and time frames for this kind of treatment are far higher, and longer, than for any other use. However, it might be a good option for cleaner wastewater that needs less extensive treatment.
Selling Off Pomace and Wine Solids
The solid materials suspended in the wastewater generated by a winery is known as pomace. Wastewater is especially high in solids at the peak of crushing season from late summer to early fall in North America. Whether it’s captured by filters and screens or dredged out of the bottom of a pond, this thick material is valuable in its own right as a fertilizer or animal feed additive. It’s rich in nitrogen and many trace minerals that can enrich the soil, but it must be added with care, and in specific amounts, because potassium and sodium can also build up in it. Make a plan for drying, storing, and transporting pomace if you plan to reclaim them for yet another source of secondary winery income.
Natural Habitat Development
Creating artificial wetlands can support the restoration of an area’s ecosystems. Constructed wetlands don’t just help process wastewater through microbial life, they also provide homes for migratory birds, endangered amphibians, and even dragonflies. Constructed wetlands double as waste treatment centers and wildlife attractions. If establishing the winery, and its fields, disturbed natural habitats, building a wetland is a great way to help compensate for those changes. It’s also another marketing tool to use, especially if the wetland features attractive flowering plants. Be sure it is properly placed in an area that visitors can enjoy the view, without allowing close access where off-putting odors may become problematic.
Irrigation, with winery wastewater doesn’t always have to involve direct application to the vineyard. If cows, sheep, or other livestock live in fields nearby, consider piping the water out to irrigate their fields instead. The widespread application of this wastewater can stimulate growth in hay grasses without any risk of excessive salination in most soils. Highly treated wastewater may be safe to directly dispense to animals for drinking, but irrigation over grazing fields is a much easier goal to accomplish. In addition to livestock, consider nearby golf courses or any other attractions with acres of turf that need a constant supply of water during drought periods.
Building large ponds on agricultural properties is not solely for storing irrigation or wastewater purposes. They also serve as on-site, fire prevention and control measures. Large, narrow, ponds and canals create fire breaks so that routine wildfires can’t jump the water and reach grape vines and other flammable materials. With pumping and spraying equipment on hand, it’s possible to fight nearby fires on your own while waiting for the firefighters to respond. Since the highest concentrations of wineries in North America also happen to be located in areas where wildfires occur each year, fire prevention and control is a major concern that adds value to any storage pond.
Each winery will have a different combination of potential uses for their wastewater. Building open ponds gives you the most opportunities to experiment with different uses for the water in the future. Adding pumps and other equipment is easier with a pond than with other types of wastewater storage. If you’re storing your wastewater for a valuable use like irrigation, you won’t want to lose essential gallons to seepage through the ground. Start each pond with an impermeable and flexible liner from us here at BTL Liners.