[caption id="attachment_58615" align="alignright" width="371" caption="Burke's goldfields (credit: Jo-Ann Ordano, California Academy of Sciences)"][/caption]

SANTA ROSA -- A project to lengthen runways to new federal standards at Charles M. Schulz--Sonoma County Airport will be delayed by one year, after federal regulators required further environmental study.

While the Federal Aviation Administration approved of the determination that a 4.5-acre wetland area impacted by the expansion did not contain the endangered Burke's goldfields flower as of late February of this year, the U.S. Fish and Wildlife service told airport officials this summer that construction should assume that the habitat was indeed occupied, according to Airport Manager Jon Stout.

"We did not find any when we did the survey, but they exist elsewhere on the property," he said.

The new environmental assessment includes a higher standard of securing new habitat for the flower, at a 3.5-to-1 acre ratio versus 1.5-to-1 in the previous plan. Mr. Stout said that the assessment is expected to be complete within two weeks, but the delay has pushed the construction timetable too close to the rainy months -- officially starting Oct. 15 -- and required a delay until next summer.

Work is now expected to be completed in July 2014, versus an original estimate of November 2013, he said. The new environmental mitigation has contributed to approximately $10 million in estimated cost increases since the county Board of Supervisors first approved plans in January. The $53 million expansion project now needs $23 million in environmental measures. Federal aviation grants will pay for approximately 95 percent of the expansion.

The airport's main runway will be extended by 885 feet to a new length of 6,000 feet. The second runway will be extended 200 feet to 5,200 feet. New taxiways will be constructed, and lighting will be added so the second runway can take the place of the main runway during construction.

In addition to the runway expansion, the airport's 20-year master plan also includes more than $50 million in other upgrades that include a new passenger terminal, cargo terminal and traffic control tower. Mr. Stout said that there is no firm timetable for those measures, though the new terminal is expected to be completed in eight to 10 years.

Yet before the additional expansion, a number of commercial carriers have expressed interest in providing flights from the airport, he said. Officials have held discussions with Delta Air Lines, Frontier Airlines, United Airlines and US Airways.

While the airport can currently support aircraft as large as a Boeing 737 with as many as 140 seats, those aircraft may be too large for the current passenger market, Mr. Stout said. The longer runways will give future carriers more options, allowing smaller aircraft room to accelerate while at full passenger capacity.

Horizon Air, a division of Alaska Airlines, currently offers six flights a day during summer months. Recent numbers show that passenger volume for the carrier rose 2.4 percent from last June to 19,060 passengers.