Laura Díaz Muñoz, winemaker and general manager at Ehlers Estate in Napa Valley, is passionate about worms. They factor deeply into the notable focus on sustainability at Ehlers, a 130-year-old, certified-organic, family-owned property. It all begins with water.
“We’re installing a new water treatment system that uses worms to process the wastewater, and I’m really excited about it,” Díaz Muñoz says. “It will allow us to treat all the wastewater we use in our facility without chemicals and produce water that’s clean enough to irrigate the vineyards and the landscaping.”
Indeed, Diaz Munoz is one of many winemakers and growers in California and throughout the West who are discovering that worms make a surprisingly effective ally in the quest to buttress winery operations against climate change.
At Ehlers, the unusual process comes courtesy of Chilean environmental engineering startup Biofiltro, a pioneer of vermifiltration—aka worm-based biofiltration—in the form of the company’s patented Biodynamic Aerobic System (BIDA). Harnessing the digestive power of millions or even billions of earthworms together with beneficial microbes, the system removes up to 99% of contaminants without the need for chemicals, Biofiltro claims.
Feeding on the grape skins, seeds, sugars and other organic compounds in winery gray water, the worms generate nutrient-dense worm castings, a rich source of fertilizer. Best of all, the worms work their magic in a matter of hours with little energy required, unlike the most common rival system, aerobic filtration ponds, which typically draw power from the electric grid to pump and circulate the water.
The Down Low on Vermifiltration
BioFiltro’s process isn’t unique. Vermifiltration has been around since the early 1990s, when researchers in Chile began studying and promoting it as a low-cost, low-tech method to treat agricultural wastewater and sewage. However, the method only began to gain traction internationally in recent years, and while a few small companies provide similar systems in New Zealand, India and elsewhere, BioFiltro is currently the only company with offices and projects in the U.S.—and certainly the only one with a specialization in the wine industry. (Biofiltro also has more than 190 installations up and running around the globe, at dairies, waste haulers and facilities for processing meat, milk and other foods.)
“My company was contracted to do an analysis of the technology as an independent third party and I was impressed,” says wastewater specialist Ron Crites, the chief engineer for the environmentally-focused Brown & Caldwell Engineers. “They do a good job, and they’re very efficient and sustainable.”