Santa Anita will begin a renovation of its main track Monday to reduce clay content and add sand, a project expected to take at least 10 days and cause some disruption to training on the circuit. The project has been planned for months after studies conducted on the main track during the winter-spring meeting found the combination of sand, silt, and clay to be different than what was recommended when the track was installed last fall. The track is aiming for a composition of 87.5 percent sand, 8 percent silt, and 4.5 percent clay. Studies conducted at various times during the race meeting earlier this year showed the sand content ranged from 76.8 to 79.2 percent, silt content ranged from 13.1 to 15.8 percent, and clay content ranged from 6 to 8.7 percent. The upcoming renovation will remove approximately 7,500 tons of material, add 7,500 tons of sand, and then remix the upper layers of the surface in an attempt to remedy the problem. In the last month, a test plot covering more than a sixteenth of a mile of the seven-furlong chute underwent a renovation to add sand. The renovation project will be overseen by Ted Malloy, who handles racetrack maintenance for Santa Anita’s parent company, Stronach Holdings. “I think they were pretty satisfied with the chute, the mix, and how it turned out,” Santa Anita director of racing Mike Harlow said. Beginning Monday, maintenance crews will begin the renovation after the conclusion of training, Harlow said, and will work on the following days from late morning until dusk. The start of the work will be delayed until late morning daily so that crews are not on the track while the remaining horses based at Santa Anita are exercising on the infield training track. In coming days, the population of approximately 3,000 Thoroughbreds in Southern California will be split among Del Mar, which opens its summer meeting July 20; Hollywood Park, which closes its spring-summer meeting July 17; and Santa Anita, which will remain open for training through the summer. Hollywood Park’s barn area will remain open until the Santa Anita renovation project is completed, at which times horses in that stable area will be moved to Del Mar or Santa Anita. The renovation could take longer than 10 days, and the California Thoroughbred Trainers is urging a patient approach. “We want them to take the time and do it right,” CTT president John Sadler said Thursday. “It’s like remodeling a house. You don’t know how long it will take.” During the renovation, horses based at Santa Anita will be able to work on the infield training track or ship to Hollywood Park to work on its main track. Santa Anita-based horses that ship to Hollywood Park and then start at Del Mar will be reimbursed the approximately $180 in round-trip transport costs from Santa Anita to Hollywood Park “on a case-by-case basis,” Harlow said. “After they breeze and run at Del Mar, they can submit the names to the racing office, and they’ll be reimbursed,” Harlow said. It is unclear how many horses will take part in the program. Many Santa Anita-based trainers are expected to work their horses there this weekend, and ship to Del Mar at the beginning of the week, allowing time to acclimate to that surface before another workout is needed. Harlow said the horse population on the circuit stands at approximately 3,000 horses, up from 2,800 at the end of April. The increases, he said, are from trainers who have shipped to California for the summer and the annual influx of 2-year-olds.