HISTORICAL PERSPECTIVE ON THE ROAD FROM AGGREGATE AVAILABILITY TO AGGREGATE SUSTAINABILITY IN CALIFORNIA

As of 2021, California continues to lead the nation in the production of sand and gravel and ranks third in the production of portland cement. California's interest in sand and gravel began with the efforts of State Geologist Ian Cambell when in 1960 he initiated a small geologic mapping program in the Palos Verdes area, among others in the Los Angeles region. Key publications by the California Geological Survey during the 1960s would show sand and gravel plants, pits and deposits. To address the loss of mineral resources due to urbanization, the survey published in 1973 "Urban Geology - Master Plan for California". The first mineral classification report was published in 1979 which incorporated the concept of "distance matters". In 1999 the State Mining and Geology Board implemented the SMARA Regional Synthesis Map series of which only one would be published - the Los Angeles Basin "placemat" map, followed by publication of designation reports starting in 1981. The Aggregate Availability in California map would be published by the survey in 2002, with revised based on program performance as Aggregate Sustainability in California in 2012. Recently updated in 2018, the purpose of Map Sheet 52 is to compare projected aggregate demand for the next 50 years with currently permitted aggregate resources in over 30 study areas and/or “production-consumption” regions of the state, and flag regions where there were less than 10 years of permitted aggregate supply remaining. These study areas cover about 30 percent of the State’s geography, but about 85 percent of California’s population. As of 2018, 7.6 million tons of permitted aggregate is available, in addition to 74 billion tons of nonpermitted construction aggregate. In 2012, efforts to further enhance the state's effectiveness in protecting aggregate resources were considered. New conceptual maps were developed to incorporate additional factors such as the pace of urbanization, mineral resource quality, environmental factors, material haul distances, infrastructure condition, and greenhouse gas emissions. These conceptual maps were well received by industry and state policy stakeholders but were not implemented. Such innovative maps however continue to warrant merit as California deals with continued urban sprawl and not-in-my-backyard sentiment toward aggregate mines being situated in close proximity to where such needs are.