Geology and Soils/Hydrology and Water Quality Evaluation

APPENDIX F
Geology and Soils/Hydrology and Water Quality Evaluation

GEOLOGY AND SOILS/HYDROLOGY AND WATER QUALITY EVALUATIONS
MITSUBISHI CEMENT SOUTH QUARRY EIR/EIS
CUSHENBURY MINE SAN BERNARDINO COUNTY, CALIFORNIA
PREPARED FOR: ECORP Consulting 215 North 5th Street Redlands, California 92373
PREPARED BY: Ninyo & Moore
Geotechnical and Environmental Sciences Consultants 5710 Ruffin Road
San Diego, California 92123
September 11, 2013 Project No. 107331001

Mitsubishi Cement South Quarry EIR/EIS Cushenbury Mine, San Bernardino County, California

September 11, 2013 Project No. 107331001

TABLE OF CONTENTS

Page

1. INTRODUCTION ....................................................................................................................1

2. SCOPE OF SERVICES............................................................................................................1

3. REGULATORY FRAMEWORK ............................................................................................2

4. SITE LOCATION AND DESCRIPTION................................................................................2

5. PROJECT DESCRIPTION ......................................................................................................3

6. GEOLOGY AND SOILS .........................................................................................................3 6.1. Regional Geologic Setting............................................................................................3 6.2. Site Geology .................................................................................................................4 6.2.1. Fill .......................................................................................................................5 6.2.2. Topsoil ................................................................................................................5 6.2.3. Young Landslide Deposits ..................................................................................5 6.2.4. Bird Spring Formation ........................................................................................5 6.2.5. Monte Cristo Formation......................................................................................5 6.2.6. Sultan Formation.................................................................................................6 6.3. Faulting and Seismicity ................................................................................................6 6.3.1. Strong Ground Motion ........................................................................................7 6.3.2. Ground Surface Rupture .....................................................................................8 6.3.3. Liquefaction and Seismically Induced Settlement..............................................8 6.4. Landsliding ...................................................................................................................8 6.5. Expansive Soils.............................................................................................................9 6.6. Compressible Soils .......................................................................................................9 6.7. Corrosive Soils..............................................................................................................9 6.8. Agricultural Soils........................................................................................................10 6.9. Mineral Resources ......................................................................................................10

7. HYDROLOGY AND WATER QUALITY ...........................................................................10 7.1. Water Regulatory Setting ...........................................................................................10 7.2. Environmental Setting ................................................................................................11 7.3. Watershed Hydrology.................................................................................................11 7.4. Floodplains .................................................................................................................12 7.5. Dam Inundation, Seiche and Tsunami........................................................................12 7.6. Climate Setting ...........................................................................................................12 7.7. Groundwater and Wells ..............................................................................................14 7.8. Groundwater Quality ..................................................................................................14

8. CONCLUSIONS ....................................................................................................................15

9. RECOMMENDATIONS........................................................................................................16

10. IMPACT ANALYSIS ............................................................................................................17 10.1. Significance Thresholds..............................................................................................17 10.2. Project Impacts and Significance: Geology and Soils................................................18 10.3. Project Impacts and Significance: Hydrology and Water Quality..............................19

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Mitsubishi Cement South Quarry EIR/EIS Cushenbury Mine, San Bernardino County, California

September 11, 2013 Project No. 107331001

11. LIMITATIONS.......................................................................................................................22
12. REFERENCES .......................................................................................................................23
Table Table 1 – Principal Active Faults .....................................................................................................7
Figures Figure 1 – Project Area Location Figure 2 – Site Plan Figure 3 – Earthquake Fault Zones Figure 4 – Geology Figure 5 – Fault Locations Figure 6 – USDA Soils Figure 7 – Topography and Hydrology Figure 8 – Hydrologic Basins Figure 9 – FEMA 100-Year Flood Zones

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Mitsubishi Cement South Quarry EIR/EIS Cushenbury Mine, San Bernardino County, California

September 11, 2013 Project No. 107331001

1. INTRODUCTION In accordance with your request, Ninyo & Moore has completed an evaluation of geologic and soil conditions as well as hydrology and water quality for the proposed South Quarry project (the project) located south of the existing East Pit at Mitsubishi Cement’s Cushenbury Mine in San Bernardino County (Figure 1).
Our evaluation is based on geologic reconnaissance, reviews of published and unpublished geologic, geotechnical, and hydrologic reports, aerial photographs, in-house data, and our assessment of the potential geologic hazards the project. The purpose of this survey was to estimate the potential for impacts to the project from geologic, soil, hydrologic, and water quality conditions on or in close proximity to the site, and to discuss measures that might be considered during project design to reduce or mitigate the potential impacts with respect to the development of the proposed project.
2. SCOPE OF SERVICES Ninyo & Moore’s scope of services for this geologic and soils evaluation included the activities listed below:
 Review of readily available regional and site-specific geologic and geotechnical reports.
 Review of readily available background information including topographic, soils, mineral resources, geologic, and seismic and geologic hazard maps, and stereoscopic aerial photographs.
 Performance of a geologic reconnaissance of the site and vicinity.
 Compilation and analysis of the data obtained from our background review and site reconnaissance.
 Review of the Assessment of Slope Stability and Hydrologic Conditions prepared by Golder Associates (2010) and plans for the proposed South Quarry prepared for the Mitsubishi Cement Corporation with respect to geotechnical and hydrologic conditions.
 Preparation of this report documenting findings and providing opinions and recommendations regarding possible geologic and soil impacts at the site. The findings were evaluated with respect to questions listed in Section 6 (Geology and Soils) and Section 8 (Hydrology and Water Quality) within Appendix G, “Environmental Checklist Form” of the “Guidelines for Implementation of the California Environmental Quality Act (CEQA).”

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Mitsubishi Cement South Quarry EIR/EIS Cushenbury Mine, San Bernardino County, California

September 11, 2013 Project No. 107331001

3. REGULATORY FRAMEWORK Geologic resources and geotechnical hazards within the proposed project area are governed by the United States Forest Service (Forest Service), County of San Bernardino, and the State of California. The Forest Service administers mining regulation on Forest Service land. The County Building Division plans contain conservation and safety elements for the evaluation of geologic hazards. The procedures for construction related earthwork and excavation are established by local grading ordinances developed by the County of San Bernardino Department of Public Works, Land Development Division. The site is also governed by the regulations of the California Code of Regulations (CCR) and the 2010 California Building Code (CBC).
The CBC is promulgated under CCR, Title 24, Parts 1 through 12, also known as the California Building Standards Code, and is administered by the California Building Standards Commission (CBSC). The CBSC is responsible for administering California’s building codes.
The Surface Mining and Reclamation Act of 1975 (SMARA) was enacted to promote conservation of the State’s mineral resources and to ensure adequate reclamation of lands once they have been mined. Among other provisions, SMARA requires the State Geologist to classify land in California for mineral resource potential. The four categories include: Mineral Resource Zone MRZ-1, areas of no mineral resource significance; MRZ-2, areas of identified mineral resource significance; MRZ-3, areas of undetermined mineral resource significance; and MRZ-4, areas of unknown mineral resource significance. The distinction between these categories is important for land use considerations.
4. SITE LOCATION AND DESCRIPTION The Mitsubishi Cement Corporation Cushenbury Mine is located at 5808 State Highway 18 in an unincorporated area of southwestern San Bernardino County, California near Lucerne Valley (Figure 1). The proposed South Quarry consists of approximately 150 acres of land within the mine site, located south of the West Pit, which is under development, and the existing East Pit (Figure 2). The majority of the South Quarry site is on unpatented claims owned by the Mitsubishi Cement Corporation (MCC) within the jurisdiction of the San Bernardino National Forest, and the remainder is on MCC owned land.

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Mitsubishi Cement South Quarry EIR/EIS Cushenbury Mine, San Bernardino County, California

September 11, 2013 Project No. 107331001

The proposed quarry is situated along a NW-trending ridgeline and covers an area with elevations ranging from approximately 5,550 feet above mean sea level (MSL) and 6,675 feet MSL. The site is currently undeveloped and covered with sparse to moderate growth of trees, chaparral, and other native vegetation. Except for a mining operation to the west (Marble Canyon Quarry), the Cushenbury mine is surrounded by mostly vacant land.
5. PROJECT DESCRIPTION The Mitsubishi Cement Corporation is proposing development of the South Quarry to mine approximately 156 million tons of high- and medium-grade limestone. The project involves development of an approximately 128-acre quarry, associated landscape berm, stockpiles, and haul road. Mining of the quarry will involve four phases of conventional open-pit and benching methods. The anticipated depth of the quarry is up to approximately 1,200 feet.
Project improvements will include implementation of an Industrial Storm Water Pollution Protection Plan (SWPPP) to divert and collect runoff from storm water and snow melt. SWPPP’s include construction of vegetated earthen safety berms, containment catch basins, collection ditches, berms, and check dams; placement of erosion control materials, sediment fences, or straw bales; and other appropriate measures to reduce the flow and velocity of surface runoff.
6. GEOLOGY AND SOILS The following sections present our findings relative to regional and site geology, geologic hazards (e.g., faulting, seismicity, landslides, or expansive soils), groundwater, and agricultural soils.
6.1. Regional Geologic Setting The project site is situated in the San Bernardino Mountains, an eastern extension of the Transverse Ranges Geomorphic Province (Norris and Webb, 1990). The Transverse Ranges are a unique unit of several east- to west-trending mountain ranges with intervening valleys in Santa Barbara, Ventura, Los Angeles, and San Bernardino Counties. The San Bernardino Mountains are located in the eastern portion of the province and are bounded by Cajon Pass

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Mitsubishi Cement South Quarry EIR/EIS Cushenbury Mine, San Bernardino County, California

September 11, 2013 Project No. 107331001

on the west, Twentynine Palms Valley on the east, Mojave Desert on the north, and Morongo Valley on the south. The mountains are generally a complex of metamorphic rocks, including Proterozoic gneisses and schists and Late Paleozoic limestones and quartzites that have been intruded by Triassic to possibly Tertiary igneous rocks. Cenozoic deposits within the range include minor volcanics on the east end of the range and alluvial fans, lake bed deposits, and stream deposits within the intervening valleys.
The Transverse Ranges province has been tectonically active during the late Tertiary and Quaternary Periods. Rapid rates of uplift along bounding faults have produced the current regional landscape of rugged highlands with eroded material accumulating in alluvial fans along the base of the mountains. The San Andreas and San Jacinto faults are major active fault systems located southwest of the study area, and the North Frontal Thrust, Helendale, and LenwoodLockhart are active fault zones located north and northeast of the project (Figure 3). Major tectonic activity associated with these and other faults within this regional tectonic framework consists of south-dipping thrust faulting and right-lateral, strike-slip movement.
6.2. Site Geology Based on our background review and site reconnaissance, surficial soils at the project site consist of topsoils and minor fills. In addition, young landslide deposits have been mapped within the southern margin of the site (USGS, 2004 and Golder Associates, 2010). Golder Associates (2010) has also identified two other landslides within the proposed quarry. These surficial materials are underlain by Paleozoic meta-carbonate rocks (Figure 4) which are the source of ore for the planned quarry. The meta-carbonate rocks include various members of the Bird Spring, Monte Cristo, and Sultan Formations and range in age from Devonian to early Permian. A brief description of the geologic units, as described in the cited literature or as observed on the site, is presented below.

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Mitsubishi Cement South Quarry EIR/EIS Cushenbury Mine, San Bernardino County, California

September 11, 2013 Project No. 107331001

6.2.1. Fill Thin fill soils were observed during our site reconnaissance along the ridge top in the southeasterly portion of the proposed quarry. As observed at the surface, the fill soils are generally composed of locally derived, reworked rock and are on the order of 1-foot thick.
6.2.2. Topsoil In undisturbed areas of the site, a mantle of topsoil was observed overlying the native bedrock. Where observed, topsoils generally consisted of light colored, silty fine to medium sand with organic debris (plant matter).
6.2.3. Young Landslide Deposits Quaternary-age landslide deposits have been mapped within the southernmost portion of the proposed quarry (USGS, 2004). In addition, Golder Associates (2010) has identified two other landslides within the proposed quarry. Although not observed during our site reconnaissance, these landslide deposits are expected to be derived from erosion of local bedrock and may consist of silty sands with gravels, cobbles, and boulders.
6.2.4. Bird Spring Formation Two members of the Pennsylvanian-age Bird Spring Formation (the Lower and Middle Carbonate Members) have been mapped within the proposed quarry. These metacarbonate rocks are characterized as medium- to thick-bedded calcite, dolomite and siliceous marble (USGS, 2004).
6.2.5. Monte Cristo Formation Three members of the Mississippian-age Monte Cristo Formation (the Yellowpine, Bullion, and Lower Members) have been mapped across the majority of the site. These meta-carbonate rocks are characterized as medium- to very thick-bedded calcite and dolomite marble (USGS, 2004).

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