Issue link: http://read.dmtmag.com/i/764739
w w w. v w m m e d i a . c o m J a n - F e b 2 017 | V I N E YA R D & W I N E RY M A N A G E M E N T 4 5 wineries that treat their wastewater may reuse it for different purposes, such as landscaping and, some- times, vineyard irrigation. The latter definitely became more popular dur- ing the recent drought," she says. Considering California produced more than 638 million gallons of wine and approached nearly half a million wine grape acres in 2015, the potential substitution of recy- cled wastewater in place of fresh- water irrigation could be significant. AERATION LAGOONS OR BIOREACTORS Many wineries already employ aeration lagoons or bioreactors to prepare their wastewater for disposal, using these systems to settle out solids or reduce pH lev- els before discharging to municipal systems or land application. With minor infrastructure adjustments, many could redirect the water to their vineyards. Some producers, like Francis Ford Coppola Winery, have irrigated vineyards for rough- ly 20 years with treated aeration important to work with a qualified engineering team that will build a system to your needs and provide support if you have any issues with the system." After installing the Free Flow s y s t e m , P e r m a n e n c o u n t e r e d numerous painful complications. "We initially weren't doing chemical separation in the clarifier, which led to poor-quality water. The clarifier wasn't sized properly, limiting the GPM we could move through the system and maintain high-quality effluent," he says. "Everyone I talk to who's run a system says it's a lot of work. You need dedicated staff and the infrastructure and capacity to absorb the constant monitoring of a wastewater treatment plant (WWTP)." Perman also cautions that installing a recycling system takes patience to observe perfor- mance nuances and fine-tune its function, which is why he insists on the importance of dedicated staff. "It's definitely not a plug-and-play thing," he says. lagoon water. But an industry-wide stigma lingers, preventing wide- spread acceptance of the practice. "The problem is that most peo- ple doing it don't want to talk about it, and others worry about the long- term effects," says Oberholster. But several recent UC Davis stud- ies help dispel these fears by con- cluding that the most significant issue with wastewater irrigation seems to be its salt content if a winery uses sodium-based clean- ers. "Most wastewater treatments don't remove cation minerals such as potassium or sodium, so if you're using a lot in your winery, they stay in the water," explains Oberholster. Since vines can use potassium much more readily than sodium, that explains why sodium can build up in soils and eventually become toxic if not leached from the soils, while a potassium buildup is less likely. The most recent study, conduct- ed in part by Oberholster, further investigated the effects of potas- sium and sodium concentrations in wastewater on vineyard soils, vine biochemistry, grape phenol- ogy and finished wine quality. In all areas, although there was slight elevation of cation concentrations, actual impacts were negligible. "It appears that using wastewater is pretty safe, but it should fall within certain parameters before you put it on vines, so it should be treated," says Oberholster. "The toxicity lev- els for plants is pretty high and I haven't seen close to those levels [in treated wastewater]." For those still turned off by irri- gating vines with anything other than fresh water, there are other w a y s t o h a r n e s s w a s t e w a t e r. Although Free Flow doesn't have a vineyard to irrigate, it relies on wastewater for cleaning, primarily tanks and floors. "We have three bioreactors totaling 45,000 gallons and a 15,000-gallon tank for treated water," says Perman. He learned a lot from his experience select- ing and installing Free Flow's sys- tem. "At the time, I knew nothing about wastewater treatment, so I relied on the engineer to design and implement the system. It's Anita Oberholster of UC Davis estimates half of California's wineries treat their wastewater onsite. Free Flow Wines' Rob Perman relies on wastewater for cleaning primarily tanks and floors and worked with an engineer to design and implement his treatment system. [Photo by Bob McClenehan]