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Mill Valley School District

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Middle School Modernization Updates

Facilities Modernization Projects

AT A GLANCE

Preliminary Endangerment Assessment (PEA) Update

Public comments received on the PEA are being reviewed by DTSC and will help to inform the agency’s final determination on the PEA.

EIR Update

The District is reviewing all comments received. Comments will be addressed in the Response to Comments section of the Final EIR which is anticipated to be available in December 2025. 

Modernization Project Overview 
This page provides current information on the Mill Valley Middle School Modernization Project, part of the District’s Measure G bond program.  The modernization effort is designed to provide a safe, modern learning environment that supports next-generation education while maintaining fiscal responsibility and transparency.

EIR Overview

The Draft Environmental Impact Report (EIR) evaluated multiple alternatives for modernizing the middle school. While the original proposal considered construction of an entirely new campus, rising geotechnical and soil disposal costs have made this option exceed the current Measure G bond budget. The District is therefore focusing on two cost-feasible alternatives:

1. Renovate the Existing MVMS Campus (425 Sycamore Avenue)

  • Modernizes the existing school through interior and exterior building upgrades, new landscaping, and a potential new STEM classroom building.
  • Provides a significantly upgraded campus with the look and function of a new school while staying within the current budget.

2. Build a New Middle School at 70 Lomita Avenue

  • Constructs a new middle school co-located with Edna Maguire Elementary.

Both options meet modern safety, security, and accessibility standards, enhance STEM learning opportunities, and replace aging infrastructure.

The District is reviewing all comments received. Comments will be addressed in the Response to Comments section of the Final EIR which is anticipated to be available in December 2025. 

MVSD remains committed to transparency and collaboration with families, residents, and local agencies as it moves toward final environmental approvals and project selection.

PEA Findings

The Preliminary Endangerment Assessment (PEA) confirms that the current Mill Valley Middle School campus is safe for students and staff under present conditions. 

Further testing requested by DTSC and Marin County was conducted over the summer and included taking samples of soil vapor, sub-slab vapor, and shallow soil sampling. The results of this testing are included in the PEA.

Key Findings:

  • The campus is safe for students and staff, and existing environmental conditions do not present a health hazard or elevated cancer risk.
  • Methane monitors located in all buildings and lower-level classrooms as an early warning system have detected no exceedances. 
  • Vapors in soil are not entering indoor air at levels of concern.

To enhance long-term protections, MVSD will install a sub-slab vapor mitigation system beneath the existing building if it is renovated. This system will be designed to prevent the potential infiltration of landfill gases and will be reviewed with DTSC and Marin County Environmental Health.

The public comment period closed on November 18 and a public hearing was held on November 20, 2025. DTSC is reviewing all comments received before making a final determination on the PEA.

Oversight and Next Steps

  • DTSC will complete its review of the PEA and public comments before issuing a final determination.
  • The District will prepare a Mitigation Plan for installation of a sub-slab vapor mitigation system and any additional mitigation measures.
  • Ongoing post-closure monitoring of the former landfill area will continue under Marin County’s Local Enforcement Agency, with coordination from CalRecycle, regardless of which project option is selected.

Key Documents

Key documents associated with the modernization project are available below and on the DTSC’s Envirostor webpage for review.