Ohlone College Newark Center Student Housing Development Project Remedial Action Plan

Ohlone College Newark Center Student Housing Development Project Remedial Action Plan

The Department of Toxic Substances Control (DTSC) has approved a Remedial Action Plan (RAP) for Ohlone College Newark Center (OCNC) Student Housing Development Project (SHDP). The student housing would be in the southwest corner of the OCNC property, which is part of the Ohlone Community College District (OCCD) Site at Cherry Street near Mowry Avenue in Newark, CA (Site). OCCD is the CEQA lead agency for the SHDP. The student housing project area is 5.5 acres in size and part of the larger OCCD Site, which is approximately 81 acres in size. The RAP is associated with a student housing project being developed by the Site owner, OCCD, which entails construction of a 534-bed community for OCNC staff, students, and their families. The RAP presents and evaluates the existing Site conditions and provides proposed measures to address the effects of chemicals of concern (COCs) within the SHDP area prior to the development project to protect human health and the environment. The Site remediation activities included in the RAP consist of the following: • Soil Excavation and Relocation to Containment Area: Approximately 26,000 cubic yards (cy) of COC-impacted soil will be excavated from the future student housing area to a depth of 2.5 to 4.0 feet below ground surface (bgs). Excavated soil will be relocated to a designated containment area, located on 335,258 square feet (approximately 7.7 acres) within the southern-central section of the Site boundaries that is not associated with future developments. The trip length for trucks relocating soil will be one mile. To ensure protection of the containment area, a six-inch layer of imported clean fill soil (approximately 6,300 cy) will be placed as a cap, and fencing will be placed around the perimeter of the containment area. • Confirmation Sampling: Following the excavation work, confirmation soil samples will be taken to assess whether the COC levels in the soil are below the RGs identified in the RAP. If concentrations of COCs in confirmation samples exceed the RGs, additional targeted excavation will be performed to remove the impacted soils. • Grading: Approximately 35,000 cy clean soil will be imported to the Site to raise the overall grade of the SHDP area by approximately 2 to 6 feet. The trip length for trucks importing soil will be 10 miles. • Installation of an Under-Slab Vapor Barrier: Subsequent grading activities, a waterproofing and soil vapor under-slab barrier will be installed to prevent moisture infiltration and soil gas (e.g., radon, methane and sulfates) intrusion. • Institutional Controls: To monitor whether toxaphene in soil poses an ecological risk to the environment, at minimum, restrictions on groundwater use, annual groundwater monitoring, annual inspections, and five-year review reporting will be required for the containment area. Should toxaphene levels in groundwater exceed residential screening levels, the soil will undergo in-situ soil treatment for reuse or be disposed of off-Site to address potential risk. Additionally, the 2007 Land Use Covenant (LUC), the 2007 Operations & Maintenance (O&M) Plan, and the 2007 O&M Agreement will be revised to include modified land use conditions and updated operation and maintenance requirements following the completion of RAP remediation activities.

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