Bay Nature magazineSpring 2004


Apperson Ridge Quarry

April 1, 2004

In 1984, Alameda County approved Oliver de Silva, Inc.’s plans to build a hard rock quarry at Apperson Ridge, east of Sunol Valley. Twenty years later, de Silva has yet to begin construction. Now, though the company denies having a specific schedule, Jeff Miller of the Alameda Creek Alliance (ACA) reports that local officials expect de Silva to begin grading for roads as early as this spring. The county issued the company all the necessary permits in 1984, but the San Francisco Bay Regional Water Quality Control Board is now seeking additional documentation regarding the likely environmental impacts of the project, including impairment of creek crossings, destruction of wildlife habitat, and changes in stormwater flows. Miller is concerned that without proper oversight from the water board and other agencies, road-building and mining will harm the nearby Sunol Regional Wilderness Area and the San Antonio Reservoir. Of particular concern are the tule elk in the reservoir area and threatened species such as the California red-legged frog and Alameda whipsnake. The ACA will hold public meetings on the issue this spring, and the organization has also planned hikes to Maguire Peaks in Sunol to view the quarry site and discuss potential impacts of the project. For more information, including specific meeting dates, contact, or visit

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