Worms get a pretty bad rap. Probably because the only times you read about them are when they’re getting extracted from various body parts or when people are forced to eat them on reality shows. But worms, it turns out, are pretty miraculous creatures that can help farms and wineries treat wastewater in an energy-efficient way without harsh chemicals.
That’s the pitch from BioFiltro, which uses a combination of wood shavings, river rock and millions of worms to remove between 90 and 99 percent of contaminants from wastewater.
As Mai Ann Healy, Country Manager for BioFiltro explained it to me, BioFiltro builds large tanks on a site that are four and a half feet tall. Inside these tanks is a foot of river rock on the bottom, topped with three and a half feet of wood shavings. Wriggling amongst the wood shavings are worms. Lots and lots of worms.
According to Healy, the average wild cubic yard of healthy soil contains between 600 and 800 worms. There are 12,000 worms per cubic yard in a BioFiltro tank, doing three things:
- The worms eat up the grease, sugars and other contaminants trapped in the wood shavings.
- As they burrow, the worms create an aeration network that introduces oxygen, which is a key element of wastewater treatment, into the system.
- The worms poop out microbes and bacteria, which form a biofilm layer across the wood shavings and the rocks to filter out microscopic solids.
BioFiltro says its wormy approach to wastewater treatment is beneficial to farmers and other agricultural sites in a number of ways. Sites that send wastewater to local treatment plants typically pay more for dirtier water. Sending cleaner water to the treatment facility reduces those costs. For sites that discharge wastewater over their own land, cleaned up water means it can be spread over a smaller amount of land to comply with nutrient regulations, freeing up land space for other productive uses.
Additionally, because BioFiltro doesn’t require high-end machinery, there is not as much upkeep or specialized technical training required for staff, and there aren’t chemicals to store and handle. And as a final bonus, the solids the worms create can be reapplied as fertilizer elsewhere on the farm or vineyard.
BioFiltro customers can choose to either pay upfront to install the system or pay a price per gallon fee. Each installation is custom to its particular use case, with even the type of worm used tailored to the specific treatment needs. The installation is large, however, and does require a lot of space.
BioFiltro’s origins date back to 1990, when the idea for using earthworms and bacteria in wastewater treatment started as a research project at the University of Chile. In 2011, the company won the Global Cleantech Open in Silicon Valley, and in 2015, BioFiltro opened its first commercial scale plant. The company is friends- and family-funded, has roughly 40 people working in offices in the U.S., New Zealand and Chile, and is installed in more than 140 plants across eight different countries.
So don’t get grossed out next time you read about worms. Remember all the work worms and can do, and show them a little respect.