Pier 23 is located on the southeastern shore of Commencement Bay. Originally built around 1946, the pier serves to support the equipment, personnel, and operations of the 70th Regional Readiness command of the US Army Reserves. A concrete extension was added to the pier a few years later, making the pier approximately 1,216-feet long by 56-feet wide. The landward 606 feet of the pier consisted of timber construction and the outboard 610 feet of the pier consisted of concrete construction. Tetra Tech INCA provided engineering during construction services and developed 23 construction drawings, 13 project specific specification sections, and a detailed MCACES construction cost estimate.

The existing timber portion of the pier was demolished and replaced with a new concrete pier for this project. The replacement pier was constructed of precast/prestressed concrete piles supporting cast-in-place (CIP) pile caps and precast deck panels. The new pier is approximately 600 feet long and lies between the existing concrete pier and the existing sheet pile bulkhead wall, which extends along the shore bank. The pier foundation system supports the vertical loads and lateral loads through a foundation system consisting of pile caps supported by vertical and battered piles, which transfer the load to the soil in friction and end bearing.