To: Honorable Mayor and Members of City Council
From: Joy Eldredge, Utilities Director
Prepared By: Chris Jones, Senior Civil Engineer
TITLE:
Title
Hidden Glen Remediation Project
LABEL
RECOMMENDED ACTION:
Recommendation
Adopt a resolution: (1) adopting a Final Initial Study/Mitigated Negative Declaration and a Mitigation Monitoring and Reporting Program for the Hidden Glen Remediation Project; (2) authorizing staff to finalize construction plans for the Hidden Glen Remediation Project; and (3) authorizing staff to advertise the Hidden Glen Remediation Project for bids.
Body
DISCUSSION:
The City of Napa is proposing to conduct remedial action activities on City-owned property (the “Project”) to comply with County of Napa Environmental Health, Solid Waste Local Enforcement Agency (LEA) requirements. The City-owned property is 2.18- acres which includes the former Hidden Glen Dump (approximately 1.06 acres) listed in the CalRecycle Solid Waste Information System (SWIS) database and assigned SWIS NO. 28-AA- 0028 (the “Project Site”). The Project Site (APN #045-411-022-000) is near the intersection of Pascale Place and Glory Court near Coombsville Road in East Napa. See Attachment 2 for Site Plan.
The Project Site was initially an excavated quarry that operated into the 1940’s. After quarry operations were abandoned, the Project Site was used as a general garbage dump by a private operator until it was abandoned in the 1960’s. In 2001, a landfill cap was installed at the dump site. In 2020, three (3) methane monitoring wells were installed by the City to monitor landfill gases based on directive from the LEA. Methane monitoring results have been below regulatory limits during all monitoring events. These wells would remain in place under the Project.
The Project Site is a vacant City-owned property and consists of a capped portion of the Hidden Glen Dump and the area between the capped area and the adjacent properties that extends beyond the area that was capped, referred to as the “buffer zone” (see Attachment 2). Waste-impacted soils were identified in the buffer zone and flag section that contain elevated lead concentrations and require remediation.
On November 26, 2019, the LEA issued a letter to the City of Napa requiring submittal of a workplan to ensure that State Minimum Standards are addressed at the City-owned parcel and in compliance with Title 27 of the CCR. To comply with State Minimum Standards, the letter requires the City to remove and/or cover waste-impacted soil along the flag section and the buffer zone.
A Remedial Action Plan (RAP) was prepared by Ninyo & Moore in October 2024 and approved by the LEA on December 20, 2024 (see Appendix B in Attachment 4). Under the RAP (and the Project), waste-impacted soil around the perimeter of the landfill cap would be excavated to bedrock or would be covered with 2 feet of clean imported soil. The waste-impacted soil may be hauled offsite to an appropriate landfill for disposal. Alternatively, the waste-impacted soil would be reconsolidated onsite and covered with a minimum of two feet of clean fill essentially capping it
The planned remedial action activities would be conducted on City-owned property (Project Site). However, the City is in negotiations to accept waste-impacted soil from the adjacent residential properties, and the RAP (and the Project) includes the possibility of accepting waste-impacted soil from adjacent properties (Lots 6 through 10, as shown on Attachment 2). If waste-impacted soil from adjacent properties is accepted at the Project Site, adjacent property owners would be required to conduct and finance their own separate and distinct project, with separate approvals from the LEA, to perform all remediation work on their property and deliver the waste-impacted soil to the Project Site.
The City prepared preliminary construction plans for the Project and submitted them in the RAP and used them for the Draft Initial Study/Mitigated Negative Declaration. The preliminary plans include the possibility of receiving waste-impacted soil from adjacent properties (see Attachment 3 for preliminary grading plan and sections). Construction plans need to be finalized and publicly advertised for bids to complete the work.
The City applied for and received a grant from the Department of Resources Recycling and Recovery (“CalRecycle”) Legacy Disposal Site Abatement Partial Grant Program for reimbursement up to a maximum amount of $473,415. The grant only covers work on the Project Site to grade and cover waste-impacted soil from the City property or accepted from adjacent properties. The grant may also cover reimbursement of trucking and disposal costs incurred by private property owners if the waste-impacted soil is transferred to an appropriate landfill as part of their separate remediation projects.
City staff recommends that the City Council adopt a resolution adopting a Final Mitigated Negative Declaration and Mitigation Monitoring and Reporting Program for the Project and authorizing staff to finalize construction plans and advertise the Hidden Glen Remediation Project for bids.
FINANCIAL IMPACTS:
The estimated cost of construction activities to implement the RAP and complete the Project is $1,200,000. The City’s Risk Fund will use reserves to fund the Project. Grant funds for eligible grading and covering of waste-impacted soil on the Project Site up to a maximum of $473,415 will reduce the Risk Fund expenditures.
CEQA:
An Initial Study was prepared for the Project pursuant to the requirements of the California Environmental Quality Act (CEQA). The Initial Study identified certain impacts resulting from this project and concluded that the impacts were either not significant or identified mitigation measures to reduce the impacts to an insignificant level. Based on the conclusions of the Initial Study, a Draft Mitigated Negative Declaration was prepared (see Attachment 4).
The City posted a Notice of Availability and Intent to Adopt an Initial Study/Mitigated Negative Declaration (see Attachment 5) which identified the review period from July 10, 2025 to August 8, 2025, for review and comment by the public and public agencies having jurisdiction by law with respect to the Project. The City also submitted the Project to the State Clearing House (SCH Number 2025070497) for review.
Within the review period, two comment letters were received from residents in the Hidden Glen neighborhood and one comment letter was received from the California Department of Transportation. City staff have prepared responses to comments and made minor modifications to the Draft Initial Study/Mitigated Negative Declaration document as part of the Final Initial Study/Mitigated Negative Declaration , which is attached to the staff report as Attachment 6 and is also available for review upon request at the City of Napa Utilities Department, 1700 Second Street, Suite 100, Napa, CA 94559.
DOCUMENTS ATTACHED:
ATCH 1 – Resolution
EX A – Mitigation Monitoring and Reporting Program
ATCH 2 – Site Plan
ATCH 3 – Preliminary Grading Plan and Sections
ATCH 4 – Draft Initial Study/Mitigated Negative Declaration
ATCH 5 – Notice of Availability and Intent to Adopt an Initial Study/Mitigated Negative Declaration
ATCH 6 – Final Initial Study/Mitigated Negative Declaration
ATCH 7 – PDF of Staff Presentation
NOTIFICATION:
None.