DEL MAR, Calif. (AP) - Santa Anita will replace its synthetic surface with dirt in time for the track's winter-spring meet in December.

Owner Frank Stronach told about 250 horsemen gathered Wednesday night at Del Mar near San Diego that installation will begin immediately following the Oak Tree, which ends Oct. 31. He said the project will be completed by the first week in December.

Stronach estimates it will cost $6 million to install the new surface.

He has never been a proponent of artificial surfaces, and Stronach said he hopes everyone learned from trying it and that ``we never do something similar like that again.''

In 2007, the California Horse Racing Board mandated all of the state's major thoroughbred tracks install synthetic surfaces or risk losing their racing dates.

During Thursday's meeting at Del Mar, Stronach was advised by the board that he would have to file an application at the group's September meeting to change Santa Anita's surface. The owner said that if Oak Tree officials decide not to run their meet at Santa Anita this fall, then he would begin the surface change sooner.

``There's a group of trainers that would not like to race at Santa Anita this year,'' said Sherwood Chillingworth, Oak Tree's director and executive vice president. ``We also have a group of owners that think the track is perfectly safe and would testify to that.''

The California Horse Racing Board assigned an engineering expert to review repairs of Santa Anita's synthetic surface, which has drainage problems. Dr. Michael Peterson of the University of Maine addressed the board on his findings, noting he has found rocks and poor drainage.