SANTA ROSA -- The Sonoma County Board of Supervisors on Tuesday unanimously approved an $84 million upgrade to Charles M. Schulz--Sonoma County Airport that will enhance safety, add a new passenger terminal, provide longer runways and allow mid-sized commercial jets to land at the airport.

After four and a half hours of public comment and board discussion, the supervisors voted 5-0 to certify the project environmental impact report, amendments to the airport master plan and the county general plan. The matter will come back to the board Jan. 24 to consider adding a health and noise impact assessment. The cost of that study will be determined at that time.

The project, which now must be approved by federal officials, calls for extending the main runway by 885 feet to 6,000 feet and a second runway by 200 feet to 5,002 feet. That would in turn allow for larger and more frequent commercial aircraft to land and depart from the county, which proponents say could ease the reliance on San Francisco and Oakland airports while boosting the local economy. 

Business representatives -- from the North Bay Leadership Council to the North Coast Builders Exchange, among many others -- widely hailed the project as an economic boost that could draw visitors from a wider swath of the country.

"The approval is important to the continued success and growth in Sonoma County," said Brad Calkins, executive director of the Santa Rosa Convention & Visitors Bureau, adding that tourism is a vital sector to the economy that would likely benefit.

The county's general plan allows for up to 21 commercial flights per day by the year 2030, but that measure is unattainable with the current runway and needed repairs. The safety upgrades would cost about $42 million, while the remainder of the price tag would go toward improvements to the control tower, the new passenger terminal and cargo space. Timing of the latter would depend on attracting more airlines.

Approximately 95 percent of the improvements would be financed by federal aviation grants, according to Jon Stout, manager of the airport and a chief proponent of the project that is years in the making.

The airport's only carrier is Horizon Air, the sister carrier for Alaska Air, which operates five flights a day to Los Angeles, Las Vegas, Portland and Seattle from Santa Rosa. In 2011, passenger volume at the airport reached an all-time high and was up by 9.8 percent from the previous year.

With the larger runways, airport officials said more carriers would be inclined to stop in Santa Rosa, though none have yet committed. Possible new destinations include Denver, for which the county has received a $650,000 grant to support services to that hub, San Diego, a third flight to Los Angeles, Salt Lake City, Phoenix and others, according to airport staff.

Concerns have been raised regarding the plan, however, with some critics saying the expansion would negatively impact air and water quality while increasing noise pollution.  A contingent of Windsor residents opposed to the project told the board that the town of about 26,000 would bare the brunt of any negative impacts of the project, particularity an increase in noise. Other Windsor residents, including Mayor Debra Fudge, were supportive of the safety upgrades but expressed a need for carefully mitigating the impact of noise and construction. 

Airport staff and the board acknowledged there would be significant impact, but said the project does its best to mitigate such impacts while saying the overall economic benefit to the county outweighed the negative aspects. Particularity, numerous residents asked why the airport is extending the runway to the North, near residential areas instead of the West or South. Airport staff said that was not an option because of the impacts it would have on endangered species' habitats, and that the northern expansion was the best possible alternative.

Environmental mitigation efforts totaling $9 million include the allocation of $1 million toward habitat improvements at nearby Mark West and Windsor Creeks and to Riverfront Regional Park.

Supporters of the plan said the expansion would inject more life into the county's economy by creating jobs while possibly generating more visits to an already established tourism destination.

"There's no doubt that the Sonoma County Airport will have a positive economic impact," said Supervisor Mike McGuire, whose district includes Windsor. But, echoing much of his constituency, he said there needs to be "checks and balances" in the plan. "I'm very excited about this project, but I think we must also balance the interest  of Windsor  and the area."

Airport staff and the county listed numerous economic benefits from the project. Every new flight could generate approximately $23 million in economic impact and could create 70 jobs, they said. And concerns about greenhouse gases were countered with the possibility of reducing 120 miles traveled per North Coast resident who uses Sonoma County's airport instead of San Francisco or Oakland.

Alaska Air's five current daily flights generate an economic impact of $112 million and have created 414 jobs in the county, according to airport staff. They anticipate 11 or 12 commercial daily flights by 2015, which would carry an economic impact of $282 million while creating nearly 900 jobs.

The Planning Commission had recommended the county seek a voluntary curfew on commercial flights to limit late-night and early morning noise, which the board agreed to do while also saying it would continue talks with the Federal Aviation Authority about adjusting the flight path over residences and schools in Windsor.

"We really need to have a transportation link that connects us to the rest of the world," Supervisor David Rabbitt said in comments approving the action.