Protecting existing structures and maintaining deep excavations were two reasons trench shoring was crucial to the success of the Lacey and Lynnwood Costco projects. The 20’ deep excavations required a similar approaches in the form of engineered slide rail shoring systems. Auguring vertical steel piling and installing double wall steel plates between the piles allowed a safe, efficient excavation. Once the excavation was complete the multiple 30,000 and 20,000 gallon tanks were installed. OSG is currently completing a similar project with Costco in Seattle.