Aggregates are used in construction, including sand, gravel, crushed stone, slag, recycled concrete, and geo-synthetic aggregates. Aggregates are the most mined material in the world by tonnage, including mining in California. Aggregates can be produced by hard rock mining (drilling, blasting, excavating and hauling, crushing, and sizing) or by alluvial mining (excavating, hauling, crushing, and sizing). Both types of aggregate mining occur in the Sierra Nevada Mountains.
Aggregates are also used as a base material under foundations, roads, and railroads. They are also a component of composite materials such as concrete and asphalt. The aggregates serve as reinforcement to add strength to the overall composite material. Aggregates are widely used in drainage applications such as foundation and French drains, septic drain fields, retaining wall drains, and road side edge drains.
Aggregate mining is very important to us because it produces materials that are used in building our homes, businesses, public facilities, and infrastructure. For example, all the roads and freeways in California are constructed using aggregates. It is important to have operations producing aggregates, cement, and asphalt close to our communities so these product can be produced and use locally and minimize transportation costs and to keep material costs as low as possible.
Sand, gravel, and cement production in California employs thousands of people and added over one billion dollars to California's gross domestic product. The Sierrans for Responsible Resource Development (the "Sierrans") believe that deposits containing resources of aggregate that can be used for building and construction need to be identified and protected for development by current and future generations. The Sierrans believe the State needs to adopt policies that encourage the discovery, exploration, permitting, and development of aggregate deposits in the Sierra Nevada Mountains.