(PD) - A Napa County vintner looking for additional production space is laying plans for a large-scale winery and distillery on a pastoral stretch of Highway 12 between Santa Rosa and Sebastopol.

The facility, which would be capable of producing up to 500,000 cases of wine and 250,000 gallons of distilled spirits a year, would be constructed on the site of an old family dairy on the south edge of the highway, about 100 yards east of Llano Road.

Current property owner and winemaker Joe Wagner already uses fruit from 40 acres of pinot noir vineyards planted on the 68-acre site in some of the premium wines produced in Napa Valley under his Belle Glos label.

A member of the winemaking family behind Caymus Vineyards and several other brands, Wagner wants to make wines at the so-called Dairyman site from grapes harvested there, in the Russian River Valley, and elsewhere in Sonoma County, as well as a type of apple brandy beverage reflecting the west county’s agricultural heritage.

The proposal is still very early in planning stages, and it could be some months before Wagner’s applications for a county permit and design review are ready for public hearings, said Traci Tesconi, a county planner.

But concerned residents began mobilizing within hours of learning about the proposal late last week. They are worried about the size of the project, its anticipated effect on traffic, and environmental impacts that include potential demands on the groundwater basin, particularly as the drought continues.

The project would generate both production and tasting room traffic on a two-lane stretch of Highway 12 that’s already congested, critics said, and a driveway that crosses the Joe Rodota multi-use trail.

“It’s the wrong place, and it’s the wrong size,” said Shepherd Bliss, a Sebastopol farmer and sometimes activist. “It’s too big for that area.”

Though nowhere near the 4.9 million-case production capacity held by wine giant Gallo of Sonoma, or even the estimated 840,000 cases produced under the Wagner Family’s Caymus and Conundrum labels, the Dairyman winery would be tied with four others for the 15th largest permitted winemaking facility in Sonoma County.

But Wagner said he wants to improve and upgrade the site, whose dilapidated dairy buildings have been used in recent years for a variety of fairly intensive uses like composting, dry-wall reclamation and concrete pumping.