Syar - Lake Herman Quarry

Lake Herman, Vallejo is a quarry producing 100% crushed basalt rock. This is currently mostly used for asphalt and aggregate base, since thus far it has been uneconomical to use for concrete aggregates.

Quarry total output is approximately 2 million tons per year, and supply is estimated at 50 years, although the quarry is up for re-permitting in three years.