Hanson Aggregate is a subsidiary of Heidelberg Cement, the largest supplier of aggregate in the world. Most of the aggregate used to develop Los Angeles and the surrounding area has come from Irwindale. The rich supply of aggregate comes from the San Gabriel River which carried rock out of the nearby San Gabriel Mountains and deposited it in the area known as Irwindale over the past thousands of years. Aggregate mining in Irwindale began in 1900 and continues today.
Geocon began work on the Hanson Aggregate Irwindale Plant in 2005 with a slope stability analysis to aid in approval of a Stability Plan for submittal to the City of Irwindale and a Reclamation Plan for submittal to the Office of Mine Reclamation. Since that initial work, Geocon has prepared a Quality Assurance program, geotechnical investigations, slope evaluations and testing and observation of fill placement.
Interesting Fact: Irwindale has 17 gravel mines but less than 2,000 residents.
Gerry Kasman, CEG