What is causing the smoke in Yolo County?

A fire in a compost facility in Zamora sent thick smoke billowing over Yolo County on Monday.

The Yolo-Solano Air Quality Management District put out a warning Monday for Zamora, Woodland, Esparto, Davis and Winters. Heavy winds from the north/northwest sent the smoke through Yolo County, the smoke alert said. It advised people with sensitive lungs to avoid going outside.

The volunteer Zamora Fire Protection District got the call at 10:30 p.m. Sunday for a grass fire outside the facility, Chief Richard Covington said. The fire started inside the Northern Recycling Compost Facility before spreading to the grass outside, he said.

Two task forces, or approximately 60 people, worked to put out the grass fire until 2 a.m., he said. Personnel stayed on-site to watch for hot spots or flare-ups in the grass around the perimeter of the facility.

Northern Compost, whose website lists its corporate headquarters as Napa, has its own staff and equipment to handle the fire inside, he said. He thinks the flames started in the windrows, which are long piles of organic material that are periodically turned for large-scale composting.

Windrows burn “kind of like a haystack,” Covington said. It takes a lot of water and heavy equipment to put out that kind of fire, which the volunteer fire district does not have, he said.

The Northern Recycling Compost Facility could not be immediately reached for comment.

This story was originally published October 2, 2017 at 10:51 AM with the headline "What is causing the smoke in Yolo County?."