The Center has partnered with Bay Area watershed-protection group the Alameda Creek Alliance to aid species and preserve habitat in two already-approved quarry projects in the Sunol area in Alameda County, California. Sunol hosts one of the two herds of tule elk in the eastern San Francisco Bay Area, while in Alameda Creek, which flows through the Sunol Valley, efforts are underway to restore steelhead trout. Our efforts aim to reduce the quarries' biological impacts, improve measures to ease those impacts, and add restoration elements to plans for both quarries.

In December 2008, the Center and the Alameda Creek Alliance signed a historic conservation agreement with Oliver de Silva, Inc., regarding the proposed Apperson Ridge Quarry and the existing Sunol Valley Quarry.

The Apperson project is a hard-rock quarry approved by Alameda County in 1984, with a quarry footprint of approximately 116 acres, located within a 680-acre leasehold on a private ranch east of the Sunol Valley. The Sunol project is an existing gravel quarry approved in 1992, spread over 325 acres of public land in the Sunol Valley and under lease from the San Francisco Public Utilities Commission.

Under the conservation agreement, Oliver de Silva will fund and implement the cooperatively developed Apperson Ridge Conservation Plan, which will significantly reduce potential impacts of the approved Apperson Quarry operation on native wildlife species and their habitats, will provide extensive mitigation for any biological impacts, and will permanently protect and enhance habitat for special-status species in the vicinity of the project. Oliver de Silva will also fund the Sunol Quarry Conservation Plan , which will assist in fish-passage projects for steelhead trout and will significantly advance the restoration of Alameda Creek.

The conservation agreement proposes changes to both quarry operations that, if approved by regulators, would dramatically reduce impacts on biological resources at Apperson Ridge. Operations at Apperson Ridge would be deferred until 2030 or until the quarrying stops at the Sunol Quarry site — whichever comes later. Processing plants to produce asphalt and concrete would be moved from Apperson Ridge to the Sunol Quarry site, which is already impacted by quarrying and doesn't contain habitat for special-status species. Material from Apperson Ridge would be transported for processing using a conveyor system rather than the approved haul road, reducing grading, traffic, and noise disturbance associated with the access road.


The major mitigation measures in the Apperson Quarry conservation agreement are

• replacement of habitat lost due to the quarry's footprint and infrastructure through purchase and/or permanent protection of similar habitats on private land, at a replacement ratio of 3:1 and with a minimum parcel or parcels consisting of 600 acres protected;
• robust mitigation for any loss of breeding habitat for several focal species at a 4:1 replacement ratio;
• initiating an “incidental take” permit process, using a federal habitat conservation plan with the U.S. Fish and Wildlife Service;
• adoption of a comprehensive tule elk mitigation and monitoring plan, including $250,000 of initial funding and up to $250,000 annually when mining begins at Apperson Ridge to help establish a tule elk reserve in northern California and for enhancement and protection of elk habitat;
• up to $3 million in funding for several major fish-passage projects to help restore steelhead trout to Alameda Creek;
• revegetation of stream banks and restoration of more natural stream function to enhance habitat quality adjacent to the Sunol Quarry;
• financial support for a Sunol Valley Restoration Plan to stabilize and restore the Sunol Valley reach of Alameda Creek;
• reduction of the greenhouse gas emissions of the Apperson Quarry project and purchase of approved offsets for 100 percent of emissions; and
• funding to conservation groups for efforts to protect wildlife and wild areas in the greater San Francisco Bay Area.

The measures in the agreement to avoid biological impacts include
• focused species surveys to determine the presence of special-status species and the extent of their suitable habitat;
• potential stockpiling of quarried rock to allow for seasonal constraints on blasting operations to minimize potential noise disturbance to wildlife; and
• “take” avoidance measures to exclude special-status species from quarry and equipment areas before construction.

Sunol Valley photo by Jeff Miller, Center for Biological Diversity