Special Report 245: Mineral Land Classification: Concrete Aggregate in the Greater Sacramento Area Production-Consumption Region (2018)
Released June 3, 2019
by Matt D. O'Neal and Fred W. Gius
Background of Special Report 245
California's Surface Mining and Reclamation Act of 1975 (SMARA) requires the State Geologist to classify land into Mineral Resource Zones (MRZs), based on the known or inferred mineral resource potential of that land. The process is based solely on geology, without regard to existing land use or land ownership. The primary goal of mineral land classification (MLC) is to help ensure, through appropriate local lead agency policies and procedures, that mineral resources will be available when needed and do not become inaccessible because of inadequate information during the land-use decision‑making process.
Summary of Special Report 245
This report is the first MLC study of concrete aggregate resources to cover all lands within the newly defined Greater Sacramento Area Production-Consumption (P-C) Region. The region is 6,080 square miles in area, of which 2,580 square miles were classified for a variety of mineral commodities for different purposes between 1975 and 2010. The remaining 3,500 square miles of the P-C Region are newly classified for concrete aggregate resources in the present report.
Urban expansion in the P-C Region threatens to preclude mineral resource extraction. At present, the P-C Region contains sufficient concrete aggregate resources to meet the projected 50-year demand. However, there is a substantial and important disparity between the geographic distribution of mineral resources and population centers. Only a minor proportion of resources are located near population centers. Utilization of more distant resources results in a significant increase in cost to the aggregate consumer, road wear and tear, traffic congestion, greenhouse gas emissions, and air pollution. For example, each additional mile of aggregate transport costs 15 cents per ton, and one mile of a six-lane highway consumes more than 110,000 tons of aggregate.
In this update report, the following conclusions are reached:
- The 10 historic reports identified 85 concrete aggregate resource sectors, with a total area of 42,033 acres (66 square miles).
- Of this area, 2,417 acres (about 6 percent) have become lost due to changing land use, resource depletion, or re-evaluation based on new data.
- The remaining 39,616 acres host a total of 3,565 million tons of concrete aggregate resources.
- This report identifies an additional nine concrete aggregate resource sectors with a total area of 3,880 acres.
- These newly identified sectors host a total of 769 million tons of concrete aggregate resources.
- An estimated 4,334 million tons of resources are identified in the P-C Region.
- The projected demand of construction aggregate in the P-C Region for the next 50 years (through the year 2066) is 1,367 million tons. Of this total, 889 million tons will likely be used for concrete aggregate.
- The 1,446 million tons of currently permitted concrete aggregate reserves are projected to last beyond the year 2066.
- Presently, the P-C Region consumes approximately as much as it produces, with imports and exports estimated to account for less than 5% of consumption and production within the region.
- Land-use planners and decision-makers in the P-C Region are faced with balancing a wide variety of needs in planning for a sustainable future for their communities. These include the need to plan carefully for the use of lands containing construction aggregate resources, to consider the permitting of additional aggregate resources in the P-C Region, and to take into consideration the demands of neighboring areas, within the P-C Region, that are competing for resources.
Availability of Special Report 245
Special Report 245 and its associated plates (maps) are available as free downloads or as printed products. (NOTE: The plates measure 36 inches by 48 inches each.) To purchase printed copies, contact our
Publications Sales Desk or visit the California Geological Survey Library in Sacramento.
View/download Special Report 245: Mineral Land Classification: Concrete Aggregate in the Greater Sacramento Area Production-Consumption Region 2018 (2.6 MB PDF)
Plate 1: Mineral Land Classification Map (23 MB PDF)
Plate 2A: Resource Sector Map 1 of 2 (13 MB PDF)
Plate 2B: Resource Sector Map 2 of 2 (19 MB PDF)