Long Beach Unified School District
Long Beach, CA
A new generation navigates their careers.
The Leighton Solution.
When new areas of contamination were found during pre-construction excavations, the District contracted with Leighton to expedite remediation. The Leighton team reviewed dozens of previous technical documents prepared by other consulting firms and advised the District on additional potential areas of concern, as Leighton had considerable experience working on adjacent properties for many years. Roughly 3,000 cubic yards of impacted soil were identified and remediated through a full site geophysical survey, soil borings, trenching, and remedial excavation.
During grading, we provided environmental oversight and monitoring, conducted waste management, pipeline studies, pipeline ownership assessment, trenching, and pipeline abandonment to accommodate utilities relocation and sidewalk construction. Under the regulatory oversight of DTSC, Leighton collected additional strategically placed high-resolution confirmation/delineation samples which significantly reduced (about 50% reduction) the volume of impacted soils to excavate.
Our efforts resulted in considerable savings to the District in project costs and meet the tight construction schedule to open the classroom doors on schedule.
Due to the location of the site within the historic Signal Hill Oil Field trend, DTSC required a methane mitigation plan be prepared to protect the future school from potential methane intrusion from the underlying actively producing oil field. Leighton prepared design specifications for the methane mitigation system under the new buildings. We oversaw the installation and testing of the methane mitigation system and will provide necessary monitoring services per DTSC’s requirements.