Explanation of Significant Differences for GBF/Pittsburg Landfill to Document Secondary Remedy Technologies to 1997 Remedial Action Plan

2 Documents in Project

Summary

SCH Number
2021010135
Lead Agency
Department of Toxic Substances Control
Document Title
Explanation of Significant Differences for GBF/Pittsburg Landfill to Document Secondary Remedy Technologies to 1997 Remedial Action Plan
Document Type
NOD - Notice of Determination
Received
Posted
3/11/2021
Document Description
The Department of Toxic Substances Control (DTSC), pursuant to authority granted under Chapter 6.8, Division 20, section 25300 et seq is considering approving an Explanation of Significant Differences (ESD) which proposes secondary remedy technologies to the 1997 Remedial Action Plan (RAP) for the GBF/Pittsburg Landfill (Site). The Site is a capped and closed 84-acre landfill located northeast of the intersection of Somersville Road and James Donlon Boulevard in the City of Antioch (see Figure 1). Due to historical operations, groundwater beneath the landfill is contaminated with primarily volatile organic compounds. DTSC is supervising the long-term monitoring and restoration of the groundwater in the area. The proposed Explanation of Significant Differences (ESD) proposes the following secondary remedy technologies: (1) installation of a hydraulic barrier wall, (2) a redesigned on-site GWETS, (3) an on-site soil vapor extraction and treatment system (SVETS), (4) in-situ groundwater remediation at two off-site locations, and (5) risk-based mitigation, where unacceptable indoor air risk from off-site soil vapor would be addressed on a case-by-case basis. The secondary remedy technologies would not fundamentally alter the overall cleanup approach. The remedial action objectives (RAOs) are and will continue to be containment of contamination, reduction of contamination, and attainment of standards which protect the beneficial uses of the waters. Activities associated with the ESD would occur over an approximately 23-week period.

Contact Information

Name
Garrett Thornton
Agency Name
Department of Toxic Substances Control
Contact Types
Lead/Public Agency

Location

Cities
Antioch
Counties
Contra Costa
Cross Streets
Somersville Road and James Donlon Boulevard

Notice of Determination

Approving Agency
Department of Toxic Substances Control
Approving Agency Role
Lead Agency
Approved On

Determinations

(1) The project will have a significant impact on the environment
No
(2a) An Environmental Impact Report was prepared for this project pursuant to the provisions of CEQA
No
(2b) A Mitigated or a Negative Declaration was prepared for this project pursuant to the provisions of CEQA
Yes
(2c) An other document type was prepared for this project pursuant to the provisions of CEQA
No
(3) Mitigated measures were made a condition of the approval of the project
No
(4) A mitigation reporting or monitoring plan was adopted for this project
No
(5) A Statement of Overriding Considerations was adopted for this project
No
(6) Findings were made pursuant to the provisions of CEQA
Yes

Attachments

Final Document(s) [Approved_Certified draft environmental documents]

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