Handex was contracted by Palmdale Oil Company to perform a source removal of petroleum-impacted soils inside the warehouse building and outside between the vertical AST farm and the building. The source originated from a leaking concrete sump historically utilized for mixing and containment of oil products located on the interior of the building, which was subsequently demolished by Handex.
Based on the excavation depths, and to facilitate the work, Handex coordinated with a structural engineer to design and install an underpinning system consisting of 16 helical piles/anchors to support the building and vertical AST farm foundations during the excavation work. The interior excavation measured 40 feet (L) by 23 feet (W) with a maximum dig depth in the sump area of around 13 feet below the existing floor elevation. The exterior excavation measured 56 feet (L) by 14 feet (W) with a maximum dig depth of 9 feet below existing grade. Prior to initiating the interior work, the metal building skins were removed from the east side of the building to allow for natural air flow through the space in an effort to reduce equipment emissions. A temporary ramp was also constructed to allow equipment access into and out of the space. Other work scope activities performed by Handex included; saw cutting the interior and exterior concrete slabs, backfilling, compacting, density testing, contaminated soil and concrete T&D, etc. The crew worked diligently to control contamination from migrating by deploying containment boom, covering the soil stockpiles, and keeping the site swept each day.
This was a unique project for Handex in terms of scope, complexity, and safety. The success of the project can be attributed to the daily efforts of the crew, implementation and follow through of the plan, overcoming site obstacles, and strategic planning and coordination to reduce overall project costs.