The Pacific Rock Mine between Camarillo and Thousand Oaks can now operate through June 2086 after the Ventura County Board of Supervisors approved a major expansion on a 4-1 vote.

The Oct. 20 decision, first reported by the Thousand Oaks Acorn, rejected an environmental appeal by the Center for Biological Diversity. Supervisor Vianey Lopez cast the lone dissenting vote.

The permit area in unincorporated Ventura County will grow from 111.5 to 204.4 acres. The mining and facility area will expand from 62.5 to 172.8 acres. The approval allows excavation and export of about 29.7 million tons of rock, along with concrete and asphalt recycling and imported reclamation soil.

What residents will see

Expanded excavation will permanently alter Conejo Mountain's hillside, creating exposed slopes and stepped cuts visible from U.S. 101, according to the county's environmental impact report (EIR). Landscaping could soften but not eliminate the change, county planning manager John Novi said, calling the visual impact "significant and unavoidable."

The mine at 1000 S. Howard Road supplies rock and riprap for construction, flood control and coastal stabilization.

Wildlife and rare plants at stake

Tiffany Yap, a senior conservation scientist with the Center for Biological Diversity who studies wildlife connectivity and mountain lions, said the mine sits within a narrow corridor linking the Santa Monica Mountains with habitat to the north. The expansion would destroy more than 100 acres of habitat and narrow a key passage from about 1,500 feet to 800 feet, she said.

"Any habitat destruction in this area is going to affect how these mountain lions move," Yap said.

Conejo Mountain also supports Conejo buckwheat, a plant found nowhere else in the world. Yap said the expansion would reach the world's largest contiguous patch of buckwheat, while dust and invasive species could affect plants and pollinators.

The appeal

The Center for Biological Diversity appealed the Planning Commission's 4-0 approval in June, arguing the EIR inadequately analyzed impacts to wildlife, rare plants, oak woodlands, greenhouse gas emissions and air quality. The group also argued the report evaluated a 30-year permit, not the proposed 60-year term, and should have been recirculated.

County staff said the review complied with the California Environmental Quality Act (CEQA) and that the longer permit did not require a new review. The report evaluated six alternatives and includes 61 mitigation measures.

Associate attorney Evan Levy of the Center said the report downplays the wildlife corridor and relies on outdated science. "If the board approves this project you can't walk it back. A future board can't walk it back for 60 years," Levy said.

Public speakers cited habitat loss, dust, emissions, noise and the lengthy permit. The Center said all 62 comment letters opposed the project. The board's summary minutes note 34 public comment letters were submitted for the item at the Oct. 20 hearing.

How supervisors voted

Board Chair Jeff Gorell, whose District 2 includes the mine site and who lives in Dos Vientos, said he felt "anxiety and apprehension" about the expansion and was concerned about the wildlife corridor. He ultimately voted to approve, saying a local rock source avoids trucking materials from elsewhere.

Supervisor Janice Parvin supported the 60-year permit, saying truck traffic and community impacts would not increase significantly. She noted some mines in her area have 100-year permits.

Lopez said she remained concerned about the environmental impacts and urged the board to consider limiting the permit to 30 years, despite the EIR finding little difference between the two terms.

Project consultant Graham Stephens called the mitigation package the most extensive he had seen for a mining project. Pacific Rock representative Nicole Corey said the family business has served the region since the late 1800s.

Whether the Center for Biological Diversity will pursue a legal challenge is not addressed in available public records. The next regular meeting of the Board of Supervisors is scheduled for Tuesday, Nov. 17.