Shaffer Plaza Removal Action Workplan
3 Documents in Project
Summary
SCH Number
2020089018
Lead Agency
City of Orange
Document Title
Shaffer Plaza Removal Action Workplan
Document Type
NOD - Notice of Determination
Received
Posted
4/13/2026
Document Description
The project includes the installation of a vapor intrusion mitigation system (VIMS) beneath the future residences to address residual tetrachloroethene in soil vapor resulting from the historical dry cleaner operations at the site. The existing on-site SVE system, including the blower, GAC canisters, and heat exchanger, would be removed by the equipment provider. Aboveground vapor extraction piping would also be removed and disposed of off-site as part of demolition activities. The VIMS design is recommended to include the following key elements:
• Sub-Slab Section – Installation of a chemical-resistant 79-mil-thick (Geo-Seal EV-80) vapor barrier beneath the building slabs.
• Gravel Gas Conveyance Layer – A gravel blanket with a minimum thickness of four inches would be installed beneath the sub-slab section and above the native soil.
• Vapor Collection System – Within the gravel blanket would be a low-profile passive vent system (EPRO Vapor-Vent). The Vapor-Vent is a pressure relief and collection system designed to passively mitigate the build-up of VOCs in soil vapor.
• Vent Risers – The Vapor-Vent would be connected to vertical vent risers extending to approximately 12 inches above the parapet wall of the roof and fitted with wind driven turbines at the top.
• Fresh Air Inlets – Fresh air inlets would be installed around the perimeter of each building, stubbed into the sub-slab gravel layer, to provide fresh air to the sub-slab areas and to allow for soil gases to be diluted.
• Sub-Slab Probes – Sub-slab probes would be placed within the sub-slab gravel layer and routed to an exterior-mounted housing box to facilitate monitoring of sub-slab vapor concentrations.
An Initial Study/Mitigated Negative Declaration (IS/MND) for the project was adopted by the City of Orange as lead agency under CEQA on December 8, 2020. An Addendum to the IS/MND was prepared to address the RAW activities and was approved on April 8, 2026. The NOD will be filed with the State of California Governor’s Office of Land Use and Climate Innovation, State Clearinghouse concurrent with RAW approval.
Contact Information
Name
Mario Cazares
Agency Name
Department of Toxic Substances Control
Job Title
Sr. Hazardous Substances Engineer
Contact Types
Responsible Agency
Phone
Name
David Cohen
Agency Name
301 Grove LLC
Job Title
Project Representative
Contact Types
Project Applicant
Phone
Email
Location
Cities
Orange
Counties
Orange
Regions
Citywide, Countywide, Southern California
Cross Streets
Northeast corner of Grove Avenue and North Orange Olive Road
Zip
92865
Total Acres
3.5
State Highways
Riverside (91) Freeway
Other Location Info
301-349 East Grove Avenue & 1997 North Orange Olive Road
Notice of Determination
Approving Agency
Department of Toxic Substances Control
Approving Agency Role
Responsible Agency
Approved On
County Clerk
Orange
Final Environmental Document Available at
https://www.envirostor.dtsc.ca.gov/public/profile_report?global_id=60003198 or Department of Toxic Substances Control Site Mitigation & Restoration Program 5796 Corporate Avenue Cypress, CA 90630
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
Yes (Addendum to the IS/MND)
(3) Mitigated measures were made a condition of the approval of the project
Yes
(4) A mitigation reporting or monitoring plan was adopted for this project
Yes
(5) A Statement of Overriding Considerations was adopted for this project
No
(6) Findings were made pursuant to the provisions of CEQA
Yes
Attachments
Notice of Determination
Disclaimer: The Governor’s Office of Land Use and Climate Innovation (LCI) accepts no responsibility for the content or accessibility of these documents. To obtain an attachment in a different format, please contact the lead agency at the contact information listed above. For more information, please visit LCI’s Accessibility Site.