Developers evaded county efforts to stop a new hotel near St. Helena Tuesday during a two-hour Napa County Board of Supervisors hearing regarding commercial uses on agricultural land.

St. Helena Outlet Partners is proposing to replace the St. Helena Premier Outlets with a 50-room hotel with a spa, restaurant and bar.

Located on a split-zoned parcel of unincorporated county land, the hotel would be built on land zoned for commercial use, but would require some development on the adjoining part of the site now zoned for agriculture.

The four acres of agricultural land on the 6.8-acre site would feature a new vineyard, housing for hotel employees and a residential driveway. Wastewater treatment and disposal facilities are also proposed on the agricultural land. Similar facilities are already in place to treat wastewater from the outlet stores.

The application was filed with the county in October 2007 by Lester Hardy and Eric Sklar. Hardy is an Upvalley attorney and Sklar is a consultant who also serves as vice mayor of St. Helena. The application was revised in March 2008.

The question now before the county is to what extent the proposed 50-room hotel would affect adjoining agricultural land, and whether or not those effects are allowed under the county’s zoning code and general plan.

Commercial uses on agricultural portions of split-zoned sites may continue if they have already been approved, according to a report prepared by Napa County Planning Director Hillary Gitelman. Previously approved commercial development on agricultural land may be altered “as long as there is no increase in the intensity of use.”

On Nov. 12, Gitelman found that the development would quadruple the use of wastewater on the agricultural land. She denied the project application, citing county law that restricts development if it increases “the volume of waste produced or natural resources consumed.”

Hardy appealed Gitelman’s decision on Nov. 19 to the Napa County Board of Supervisors. Hardy argues that “accessory uses are conforming when the primary use is conforming”— because the main project is proposed on commercially zoned land, the related uses on adjoining agricultural land should be permitted, as well.

The board’s hearing on the proposal Tuesday lasted more than two hours. Because the issue has never come before the Planning Commission, supervisors were limited to discussing the development only in terms of general policy without getting into the specifics of the project.

They had the option to uphold Gitelman’s interpretation of county policy, reject it or to send the matter to the Planning Commission for more discussion.

Supervisors heard a series of complicated land-use arguments, launching into debates over the definition of “intensification” and whether or not wastewater constitutes waste if it is treated on-site.

Ultimately, supervisors voted 4-1 to stay Gitelman’s decision and refer the matter to the Planning Commission. Supervisors also recommended that the developers seek an amendment to the county code to clarify language regarding intensification.

The proposal will go to the Planning Commission once the project is fully fleshed out and follows a series of environmental laws, possibly including an environmental impact review, said Elizabeth Emmett, Napa County’s public information officer. Emmett said the process could take several months.

Hardy said Wednesday that he wasn’t sure when or whether he would submit the application to the Planning Commission. As for supervisors’ suggestion that developers try to modify county code, Hardy said, “I don’t know that we will ask for a zoning text amendment. We may not.”

The vote Tuesday was significant for Keith Caldwell, Napa County’s newest supervisor, who was the sole vote to uphold Gitelman’s interpretation of county policy and effectively kill the proposal. It marks Caldwell’s first noteworthy dissent since being sworn in as supervisor at the beginning of the month, and is in line with his slow-growth campaign promises.