Standard Gypsum Mine Surface Mining Permit No.102 Revision 1

2 Documents in Project


SCH Number
Lead Agency
Riverside County
Document Title
Standard Gypsum Mine Surface Mining Permit No.102 Revision 1
Document Type
MND - Mitigated Negative Declaration
Present Land Use
General Plan Land Use: Open Space-Rural Land Use Zoning: Natural Assets
Document Description
Revision to approved Surface Mine Permit SMP00102 to allow an approximately 59-acre expansion of an existing, 110.3-acre surface mine to include additional extraction of gypsum, as well as temporary stockpiling of excavated surface materials (overburden) for a period of 50 years. The proposed expansion would occur in two phases, with the first to occur through the year 2060, and the second, final phase comprising the last 10 years of the permit’s approval through 2070. The expanded mine would comprise 169.5 acres of a total 611-acre Project site, with an average of 450,000 tons (maximum 900,000 tons) of material to be extracted annually. The total volume to be removed is estimated at 61 million tons over the lifetime of the mine. Following conclusion of Phase Two, the entirety of the mine, in addition to 21 acres outside of the footprint of proposed operations, would be “reclaimed” – restored in accordance with a revised Reclamation Plan, requirements of the Surface Mine and Reclamation Act (SMARA) and County Ordinance 555 – ultimately returning a total of 190.5 acres to open space, habitat and restored drainage courses.

Contact Information

Evan Langan
Agency Name
Riverside County Planning Department
Job Title
Urban/Regional Planner IV
Contact Types
Lead/Public Agency


Unincorporated Riverside County
Cross Streets
Midland Road and Arlington Mine Road
Total Acres
Parcel #
809-170-024; 809-170-025; 809-170-016; 809-170-026
State Highways
Highway 95; Interstate 10

Notice of Completion

State Review Period Start
State Review Period End
State Reviewing Agencies
California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Parks and Recreation, California Department of Resources Recycling and Recovery, California Department of Transportation, District 8 (DOT), California Department of Water Resources (DWR), California Governor's Office of Emergency Services (OES), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, Colorado River Basin Region 7 (RWQCB), Department of Toxic Substances Control, Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, State Water Resources Control Board, Division of Water Quality, California Department of Fish and Wildlife, Inland Deserts Region 6 (CDFW)
State Reviewing Agency Comments
California Department of Fish and Wildlife, Inland Deserts Region 6 (CDFW)
Development Types
Industrial (Sq. Ft. 408, Acres 611, Employees 24)
Local Actions
Surface Mine Permit Revision
Project Issues
Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Cultural Resources, Drainage/Absorption, Energy, Flood Plain/Flooding, Geology/Soils, Greenhouse Gas Emissions, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mandatory Findings of Significance, Mineral Resources, Noise, Population/Housing, Public Services, Recreation, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Vegetation, Wetland/Riparian, Wildfire
Local Review Period Start
Local Review Period End


Notice of Completion [NOC] Transmittal form
State Comment Letters [Comments from state reviewing agencies]

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