Lehigh submits application for new mine area, updated water safety and revegetation plans at Permanente Quarry

Aerial view of the Lehigh Permanente Quarry

A major mine operator in Santa Clara County has gone public with its plans for the future.

Lehigh Southwest Cement Company, which operates the Permanente Quarry in the hills west of Cupertino, submitted an application yesterday to Santa Clara County officials. The proposal, which involves a number of facets, is an update to the company’s existing – and previously approved – 2012 plan.

The company, which been mining at the quarry site since 1903, and has had its adjacent cement plan since 1939, began the pre-application process with Santa Clara County officials in recent months.

A new mine area

Perhaps the most significant aspect of the new plan is Lehigh’s proposal to open a new mining area at its Rock Plant Reserve site, located on the south side of the company’s property, adjacent to the neighboring Stevens Creek Quarry. In a statement to press, the company noted that this new mining area is within its vested rights area – as approved by the County’s Board of Supervisors in 2012.

Lehigh would be required, under the terms of this plan, to revegetate this new mine area once material extraction is completed.

“It is imperative to our economy and our environment that we continue to operate and produce material from this facility to serve the region’s construction and infrastructure needs in a timely manner,” said Erika Guerra, Environmental and Land Management Director for Lehigh, in a statement.

Changes to its current pit plans

In addition to the new mine area, Lehigh is asking for approval to improve the stability of its current pit and in turn support the long-term stability of the ridgeline to the north of the site.

Additionally, the company plans to fill its large existing pit mine with excess soil from regional construction projects. Numerous major infrastructure projects in the region have difficulty finding local sites to dispose of clean soil, and Lehigh is hoping to capitalize on that market opportunity. It says this solution will improve water quality management at the site while providing economic and environmental benefit to the region.

“We believe this plan will benefit our local economy and provide environmental improvements while meeting the region’s construction needs,” Guerra said.

Lehigh says that more than 180 employees, including many union members, work at the quarry and cement plant on site.

Community meetings and next steps

The review and approval process for this application is likely to last several months, as numerous local and state agencies will have to sign off before the company can begin implementing its proposed changes.

According to its website, Lehigh has scheduled two community open houses for area residents to hear about its plans. Both are 6 p.m. to 7:30 p.m.

  • Thursday, June 20th, at Cupertino Community Hall, 10350 Torre Ave.
  • Thursday, June 27th, at Quinlan Community Center, 10185 North Stelling Road.

For more information about Lehigh’s proposal, visit their website here.