The proposed project activities involve excavation, transportation, and off-site disposal of 180 cubic yards of contaminated soil. Project activities would be accomplished through approval and implementation of a Removal Action Workplan (RAW) for volatile organic compounds (VOCs) in groundwater and lead-impacted soils at the Kiku Crossing site (480 East Fourth Avenue and 400 East Fifth Avenue) in the downtown area of the City of San Mateo (Site).
The RAW proposed excavation, transportation, and off-site disposal of contaminated soil over a period of 6 to 8 weeks. In addition, clean import soil will be used to backfill excavated areas. The following project-specific activities are intended to prevent exposure of contaminants to future site occupants and protect the environment.
• Excavation – Approximately 180 cubic yards (13 truckloads) of contaminated soil will be excavated and loaded onto trucks for disposal. Standard equipment including backhoes, excavators, and front-end loaders and/or other appropriate equipment will be used to conduct excavation activities. Depending on the engineering characteristics of the existing onsite soil, clean import soil may be used to backfill excavated areas (up to 13 additional truckloads assuming all excavated soil will be backfilled). Confirmation sampling will be conducted to ensure cleanup goals have been met.
• Transportation and Off-Site Disposal – Based on the results of sample analysis, soils will be classified as either non-hazardous, California hazardous, or federal Resource Conservation and Recovery Act (RCRA) hazardous waste. Contaminated soil will be transported by truck to an approved off-site disposal facility. An approved truck route and haul hours, and traffic control will be followed for trucks disposing contaminated soil, in accordance with a Department of Toxic Substances Control (DTSC)-approved Site Remediation Traffic Management Plan.
• Land Use Covenant– Based on the current site conditions, groundwater exceeds the PCE Maximum Contaminant Level, but is a de minimis risk. A Land Use Covenant will be recorded to prevent the use of on-Site groundwater.
The DTSC utilized information and analysis in the Initial Study/Environmental Assessment (IS/EA) for the City-Owned Downtown Affordable Housing and Parking Garage Site PA19-033 to support a final determination about the type of environmental document required to be prepared for the Kiku Crossing Removal Action Workplan as provided by Sections 15162, 15163, and 15164 of the CEQA Guidelines, which was determined to be a Statement of Findings. The IS/EA was adopted by the City of San Mateo on August 17, 2020. The IS/EA evaluated the potential environmental effects of the RAW, specifically the cleanup and haul away of contaminated soils associated with the proposed remediation action of the Site.
As Responsible Agency under the California Environmental Quality Act (CEQA), DTSC approved the above-described project on September 22, 2021 and has made the following determinations:
1. The project will not have a significant effect on the environment.
2. A Mitigated Negative Declaration was prepared for this project pursuant to the provisions of CEQA.
3. Mitigation measures were made a condition of project approval.
4. A Statement of Overriding Considerations was not adopted for this project.
5. Findings were made pursuant to the provisions of CEQA.
The administrative record for this project is available to the public by appointment at the following location:
Department of Toxic Substances Control
Site Mitigation and Restoration Program
700 Heinz Avenue, Suite 200
Berkeley, CA 94710
Additional project information is available on EnviroStor: https://www.envirostor.dtsc.ca.gov/public/profile_report?global_id=60002987