Hilmar Dairy Farm Experimenting With Worms Cleaning Wastewater

HILMAR (CBS13) — A dairy farm in Hilmar is the first commercial farm in the country to experiment with worms cleaning wastewater.

Fanelli's Dairy is known for its Jersey cows. But two months ago, it received a new creature on the farm. One whose population averages 10,000 per square meter.

There are now more worms than cows on Vic Fanelli's farm. He doesn't mind.

"We're always looking for something new in the dairy business," he said.

The worms are actually a government science experiment. Conservation groups approached him to get a federal grant to use a large worm box to help clean his farm's wastewater.

"They're basically just eating the organic matter that is in the wastewater," said Joe Choperena with Sustainable Conservation.

The farm's wastewater lagoon gets pumped, and sand and other solids are removed.

"From there, the water gets pumped to the worm box where it gets sprayed through the sprinklers," Choperena said.

Worms eat the nitrogen and the remaining water is now filtered down.

Scientist Sina Pram tests the water once a week and checks on the worms.

"They like to live in a pH of between 5 and 8, so that's within their living condition," he said.

Healthy worms, he says, can remove 80 to 90 percent of the nitrogen from the water.

"You never want too much nitrogen on a crop, you will burn it. It doesn't need it. We only supply our crops with as much nitrogen as it needs," Fanelli said.

Now he can regulate the nitrogen sprayed on the crops, and less nitrogen pollution could seem into the groundwater.

"Imagine it as an underground aquifer," Pram said. "We're creating nature, adding worms, and it percolates down through."

The whole worm experiment lasts for a year, and a second project is planned for a Napa winery in the fall.

Nurseries and wineries will pay top dollar for the high-quality compost and worm droppings left behind.