The Sonoma County Fair plans to build a $3-million turf course by 2004 in hopes of enhancing its summer racing schedule. But the longtime leading trainer on the Northern California circuit said it wouldn't affect his plans."It won't change what I do because the turf races that will go there won't be for allowance horses," Jerry Hollendorfer said. "They will be the lower-level races."For the past two summers, Hollendorfer said he has taken about 55 horses to Arlington Park in Illinois. A major reason, he said, is they can compete in allowance- and stakes-level turf races. At his home base in the San Francisco Bay Area, the summer months mean the fair circuit.A turf course, though, could provide an alternative to horsemen planning to ship elsewhere for the brief period the Sonoma County Fair is open for racing, officials said. Other horsemen have suggested turf racing at one or a few of the Northern California fairs would help the racing program.Santa Rosa, which has live racing for 12 days in late July and early August, would be the first among the county fairs in Northern California to install a turf course. The proposal is to be aired Jan. 7 before the Sonoma County Board of Supervisors.The facility currently has a one-mile main track with a popular nine-hole golf course in the infield. The turf course would be constructed inside of the main track and require only a minor reconfiguration of the golf layout. The Santa Rosa meet is probably the most successful in Northern California. It accounted for 41% of the Sonoma County Fair's $8.2 million in revenue. But like the rest of the circuit, it is struggling to keep its place. The track reported a 2% decline in attendance and a 5% decrease in live handle this past season. Meet officials began serious discussion of a turf course during the summer.Jim Moore, Sonoma County fair manager, is on vacation and could not be reached for comment. He told the Santa Rosa Press Democrat that unless things change, the downward spiral will continue."There is so much fair racing available these days that to stay competitive, you have to take things up a notch," Moore said. "Even though the new turf course may not result in a whole lot more revenue right now, we feel this will establish the fair as a substantial entity and hopefully guarantee our long-term existence."The fair proposed to pay for half of the construction through its capital improvement fund and finance the rest.