Treasure Island is one of the largest development sites in the San Francisco Bay Area, featuring plans for 8,000 new residential homes (from townhomes to mid- and high-rise towers), mixed-use spaces for retail and commercial ventures, and over 300 acres of public parks and open space. The master developer, Treasure Island Development Group (TIDG), is currently redeveloping the former Naval Station Treasure Island, which includes Treasure Island and Yerba Buena Island. To date, approximately 430 acres of land parcels have been transferred from the U.S. Department of the Navy (Navy), and approximately 67 acres are currently being investigated by the Navy for eventual transfer.

Scope of Services

During the entitlement process, Terraphase provided environmental due diligence support of land parcels to be transferred from the Navy to the developer under a Finding of Suitability to Transfer (FOST), implemented as part of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process.

Terraphase attends the Base Realignment and Closure (BRAC) Cleanup Team meetings on behalf of TIDG to assess and advise on outstanding environmental issues. In 2016, following the initial land parcel transfer process and prior to construction startup, Terraphase prepared a comprehensive Soil and Groundwater Management Plan (SGMP; formally accepted by regulators) to comply with the California Environmental Quality Act (CEQA) Final Environmental Impact Report (FEIR) Mitigation Measures, California Regional Water Quality Control Board (RWQCB) and Department of Toxic Substances Control (DTSC) land-use restrictions, and San Francisco Department of Public Health (SFDPH) requirements. Updated in 2023, the SGMP addresses all aspects of construction, including soil and groundwater management protocol for environmentally and non-environmentally restricted sites, soil import criteria (approximately 2.5 to 3 million cubic yards is required), contractor training, unknown conditions response, and dust and stormwater compliance practices.

Terraphase provides the following services to TIDG during construction: Phase I Environmental Site Assessments (ESAs), import soil review, environmental planning, regulatory support, and on-site oversight, including soil excavation for lead-based paint within building dripline areas, excavation and grading activities within environmentally restricted areas, site-wide dust monitoring compliance, hazardous materials assessment, and construction dewatering compliance under the National Pollutant Discharge Elimination System (NPDES). Terraphase also supports vertical lot developers with these same services on Treasure Island and Yerba Buena Island.

Notable Accomplishments

• Supported environmental due diligence for approximately 430 acres transferred from the Navy
• Advised TIDG through ongoing BRAC meetings and land entitlement processes
• Authored and updated the site-wide SGMP to meet multi-agency regulatory requirements
• Overseeing environmental compliance during large-scale excavation, grading, and dewatering activities
• Provided turnkey environmental support to both the master developer and vertical builders