On June 22, the Santa Clara County Board of Supervisors voted unanimously, 5-0, to direct county staff to work with Midpen on drafting an agreement granting Midpen enforcement rights to a 1972 Ridgeline Protection Easement, which preserves the scenic ridge between Rancho San Antonio County Park and Open Space Preserve and Lehigh Quarry. Santa Clara County Ridgeline Easement Report

On June 23, the Midpen Board of Directors also voted unanimously, 7-0, to direct Midpen staff to work with Santa Clara County on drafting the enforcement rights agreement. Midpen Ridgeline Easement Report

Recommendations to the county Board of Supervisors and Midpen’s Board of Directors are tentatively scheduled for August 2021.

Ridgeline Protection Easement

Lehigh Hanson is a cement company, owned by Heidelberg Cement, that operates the Permanente Quarry near the city of Cupertino.

In 1972, the Santa Clara County Board of Supervisors and Kaiser Cement & Gypsum Corporation, Lehigh’s predecessor, agreed to protect the ridgeline between the quarry and what is now Rancho San Antonio Preserve by entering into a Ridgeline Protection Easement to permanently prevent mining, quarrying or other activities from lowering the ridgeline.


Lehigh Hanson has proposed an amendment to their existing Reclamation Plan that includes an expansion of mining activities, including in the area of the Ridgeline Protection Easement. Midpen is concerned about the potential environmental impacts of the proposal and has formed an Ad Hoc committee of its Board of the Directors to focus on the 2019 Reclamation Plan Amendment. Midpen has identified a number of critical issues and concerns and shared those in writing with Lehigh Hanson: March 23, 2021, Letter to Lehigh re Reclamation Plan

Midpen has no regulatory authority over Lehigh Hanson and has no permitting or regulatory discretion over the quarry operations.

Regulatory Agencies

The quarry operations are regulated by numerous government agencies including agencies that regulate air quality, water quality and wildlife. Santa Clara County has oversite and approval authorities over Lehigh Quarry in regard to the approval of reclamation plan approvals (through state mining reclamation law), permitting and the determination of the extent of vested mining rights. Santa Clara County also owns the Ridgeline Easement. Midpen is not a regulatory agency but is engaged in protecting the Ridgeline Easement and has a number of concerns about the proposed 2019 Reclamation Plan.

The county is responsible for conducting the environmental analysis for proposed the Reclamation Plan, selecting any alternative versions of the Reclamation Plan, and determining the scope and extent of “vested rights” to mine on the property (which are rights that permit uses that occurred prior to County regulations to continue). The county also has the full authority to approve or deny Lehigh’s request in the 2019 Reclamation Plan to modify the Ridgeline Easement but does not have discretionary approval of other aspects of the reclamation plan amendment within the vested rights. To stay up to date on the county’s review of the Reclamation Plan, sign up for the county’s e-mail distribution list here. 


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Staff contact: Senior Resource Management Specialist Aaron Hebert, ahebert@openspace.org, 650-691-1200.