Proposed Turtle Ridge Elementary School Site - Removal Action Work Plan (RAW) Approval


SCH Number
Lead Agency
Toxic Substances Control, Department of (Department of Toxic Substances Control)
Document Title
Proposed Turtle Ridge Elementary School Site - Removal Action Work Plan (RAW) Approval
Document Type
NOE - Notice of Exemption

Document Description
The Removal Action Workplan (RAW) has been prepared to address the removal of methane gas at the proposed Turtle Ridge Elementary property. The Irvine Unified School District (IUSD) has elected to pursue the construction of the school, and therefore has prepared a RAW. The draft RAW presents an evaluation of several removal action alternatives to address the presence of methane at the site, and to reduce the potential for methane accumulation underneath the proposed classroom building at the site, where it may become an explosion hazard. Due to the concentrations and pressures of methane detected, and the depth of the detections, the RAW proposes a Passive Methane Venting System (mitigation system) as the preferred alternative. The selected methane control measures include a sub floor membrane barrier, a passive venting system, and permanent sampling and detection probes above the membrane. An Operation and Maintenance (O&M) Agreement will ensure the school district will implement on-going operation, monitoring, data acquisition, reporting, and maintenance activities. The mitigation system measures, proposed under this alternative, are in accordance with DTSC's Advisory on Methane Assessment and Common Remedies at School Sites and meet or satisfy all applicable or relevant and appropriate requirements as identified in the RAW.

Contact Information
Ryan Atencio
Department of Toxic Substances Control
School Property Evaluation and Cleanup Division 5796 Corporate Street
Cypress, CA 90630

Phone : (714) 484-5340



Notice of Exemption

Exempt Status
Categorical Exemption
Type, Section or Code
Section 15330
Reasons for Exemption
This Class 30 action is a minor cleanup action to be taken to prevent, minimize, stabilize, mitigate, or eliminate the release or threatened release of a hazardous waste or substance and is considered a small or medium removal action costing approximately $510,000. The RAW includes Methane Mitigation Design Plans, Methane Mitigation Specifications, an Engineering Evaluation/Cost Analysis, an Engineers Cost Estimate, a Health and Safety Plan, a Construction Quality Assurance Plan, a Removal Action Implementation Plan, and an Operation and Maintenance Plan. The project will not have a significant effect on the environment due to the relatively low concentrations detected across the site, depth of contaminant, low pressure of contaminant, short project duration, and controlled manner in which the mitigation system is to be implemented during construction. The proposed Turtle Ridge Elementary School site is not on the Hazardous Waste and Substances List, nor is it located in a sensitive cultural or biological resource area.

Disclaimer: The document was originally posted before CEQAnet had the capability to host attachments for the public. To obtain the original attachments for this document, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at or via phone at (916) 445-0613.

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