Former Power Plant Site Restoration

PG&E Former Hunter’s Point Power Plant

PIVOX Corporation served as construction project manager, general contractor and construction manager for site restoration, grading, and drainage improvements at the former Hunter’s Point Power Plant, following completion of PG&E’s soil remediation activities.

Work included grading, surface topographic improvements and construction of storm water management improvements, including installation of reinforced concrete storm drains, concrete valley gutters, and environmentally sustainable bioswales. The total surface area of PIVOX’s restoration work exceeded 17 acres.

The primary technical constraint at this project was the extensive presence of naturally occurring asbestos (NOA) in the historical fill at the site. PIVOX was selected to lead this project due to PIVOX’s expertise with completing earthwork and excavation work at sites with significant worker and public exposure risks due to contaminated soil or NOA. PIVOX developed an active site perimeter dust control system, where tower-mounted misters connected to a high-flowrate temporary water circulation system sprayed water supplemented with sequestration agent inwards into the site, which knocked down any airborne dust before the dust could leave the site, protecting the surrounding community, including residences and a municipal park.

PIVOX also constructed a surface water drainage scheme that used site topography to direct surface water to valley gutters, which then directed water into four large-capacity bioswales which themselves were connected to the municipal combined sewer system. The bioswales were sized to handle and treat surface water flows from the entire area of the site.

PIVOX served as the design-build general contractor and construction project manager for the project, including subcontracting the restoration design and construction, with over 90% of the labor hours completed by PIVOX subcontractors. PIVOX also served as design engineer for isolation and closure of the former power plants intake and discharge tunnel openings, which were completed after site restoration by others. During restoration, PIVOX implemented the project’s extensive local hire program, which provided construction jobs to more than 20 local community members over the duration of the project. PIVOX also identified and worked with a local nursery to specify and supply plants used for the bioswales and to supply the native hydroseed mix used as temporary erosion control on graded slopes at the site.