pg&e offshore central coastal california seismic …...geophone lines in southern survey area....
TRANSCRIPT
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Public Scoping MeetingPublic Scoping MeetingCalifornia State Lands CommissionCalifornia State Lands Commission
July 21, 2011July 21, 2011
PG&E OFFSHORE CENTRAL PG&E OFFSHORE CENTRAL COASTAL CALIFORNIA COASTAL CALIFORNIA
SEISMIC IMAGING PROJECTSEISMIC IMAGING PROJECT
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Project Area
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Project Commitments•
Assessment of the Hosgri, Shoreline, and other faults in the vicinity of Diablo Canyon Power Plant (DCPP)
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California Public Utilities Commission−
Fault survey using the following methods•
Offshore three-dimensional (3D) high energy survey
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Onshore two-dimensional (2D) high energy scope near coast
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Seafloor geophones nearshore in low water levels
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Project Objectives•
Obtain improved deep (>1 km [>0.6 mi]) imaging of the Hosgri and Shoreline fault zones to better define fault geometry - in the vicinity of the DCPP- at the intersection of the Hosgri and Shoreline
fault zones near Point Buchon- at the intersection of the San Simeon and Hosgri
fault zones near Point Estero•
Expand regional seismic database
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Offshore Seismic Imaging Survey•
Cambria to Point San Luis in water up to 1,400 ft.•
Specialized survey vessel approximately 240 ft in length•
Vessel-towed individual or multiple strings of tuned air guns with a volume of 3,300 in3
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Vessel-towed hydrophone streamer array of 3 to 5 miles length •
Additional scout and support vessels
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Towed Air Gun Array and Acoustic Streamers
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Seismic Survey Process
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Survey Track LinesNorthern Survey Area•
547 miles•
22 day survey duration (24/7)
Southern Survey Area•
765 miles•
30 day survey duration (24/7)
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Nearshore Seismic Imaging Survey•
Nearshore areas too shallow for larger survey vessels
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Seafloor geophones will be placed by smaller vessel
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Geophone strings to -300 ft water depth (approximately 3 miles offshore)
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Includes both offshore and onshore sound sources
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Geophone Lines in Southern Survey Area
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Onshore Source and Receiver Lines
Receiver Lines Only
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Source and Receiver Equipment
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Survey Schedule and Duration•
Proposed survey to be conducted September through December 2012
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Estimated work period is 3 months with 24 hour operations (6 months if daylight only operations)
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Offshore Survey Procedures•
Marine Wildlife Contingency Plan approved by NOAA Fisheries−
Pre-activity aerial surveys and equipment noise level testing
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Established Safety and Exclusion Zones
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Ramp-up of all air guns
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Marine mammal monitors onboard all survey vessels
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Scheduled to coincide with low marine mammal activity (late fall/early winter)
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Notification to mariners and commercial fishers
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Avoidance of sensitive resource areas to extent feasible
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Pacific Gas and Electric CompanyOffshore Central Coastal California Seismic Imaging Project
Anticipated Agency Approvals•
California State Lands Commission−
Geophysical Permit (Seismic Survey)−
California Environmental Quality Act (CEQA) Lead Agency•
NOAA Fisheries – Incidental Harassment Authorization (IHA)/Endangered Species Act (ESA) Consultation
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Army Corps of Engineers −
Section 10/404 Certification for marine operations−
National Environmental Policy Act (NEPA) Lead•
California Coastal Commission – Coastal Development Permit (CDP)/Federal Consistency
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County of San Luis Obispo – CDP for onshore sources/receiver line and Encroachment Permit
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U.S. Fish and Wildlife Service (FWS) - ESA Consultation•
California Department of Fish & Game – CESA Permits/MPA Authorization•
California Dept. of Parks and Recreation – Encroachment Permit•
Regional Water Quality Control Board – Section 401 Certification•
U.S. Coast Guard – Notice to Mariners
PG&E OFFSHORE CENTRAL COASTAL CALIFORNIA SEISMIC IMAGING PROJECTProject AreaProject CommitmentsProject ObjectivesOffshore Seismic Imaging SurveyTowed Air Gun Array and Acoustic Streamers�Seismic Survey ProcessSurvey �Track LinesNearshore Seismic Imaging SurveyGeophone Lines in Southern Survey AreaOnshore Source and Receiver LinesSource and Receiver EquipmentSurvey Schedule and DurationOffshore Survey ProceduresAnticipated Agency Approvals