SR - 710 Tunnel Technical SR - 710 Tunnel Technical Study Study

Presentation forPresentation for City of Pasadena City of Pasadena

City Council City Council

January 26, 2009January 26, 2009

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Purpose of the studyPurpose of the study

• Consider all practical routes for the extension of Route 710

• Gather information on soil and sub-surface conditions

• Provide for public input and involvement

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Why Tunnels?Why Tunnels?

• Reduce impacts to communities and sensitive areas

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Objective of the Objective of the Exploration ProgramExploration Program• A total of 5 potential zones will be

investigated

• Collect geotechnical, geological, and hydro-geological information for each zone

• Information to be used for screening purposes

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Exploration Plan ZonesExploration Plan Zones

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Key Factors Influencing Key Factors Influencing TunnelingTunneling• Faulting

• Fault displacement • Rupture zone length

• Uniformity of geologic material• Potential for adverse tunneling conditions

• Flowing/squeezing soils, boulders

• Properties of geologic materials• Groundwater conditions • Hazardous materials

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Geotechnical Exploration Geotechnical Exploration ProgramProgram

• Data collection and review

• Geologic mapping• Geophysical surveys• Drilling, sampling, and

logging• Laboratory testing

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Boring ActivitiesBoring Activities

• 33 small diameter borings; six locations in Pasadena

• Vertical and Inclined drilling

• Each boring will take 7 to 10 days to complete

• Work area is about 12 feet by 60 feet

• Drilling performed daytime hours

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Seismic Reflection Seismic Reflection TestingTesting

• 20 seismic reflection surveys; two locations in Pasadena

• Non-destructive• Most Geophysical testing

will be performed at night• One location per night

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SummarySummaryZones # of

BoringsTotal Lineal

feet (ft)# of Geophysical

LinesLength of Tunnel

(mi)

1 8 2,800 5 5.2 – 5.7

2 5 1,600 3 4.9 – 5.6

3 12 3,700 7 4.4 – 5.4

4 4 1,100 2 6.2 – 7.4

5 4 1,100 3 9.6 – 11.5

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Exploration Program Exploration Program ScheduleSchedule

6/09 20103/09 9/099/08 2009

Encroachment Permit

Site Reconnaissance

Geologic Mapping

Summary Report

NTP

Drilling by Caltrans

Drilling by CH2M HILL

Lab Testing

Data Evaluation

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Recent FindingsRecent Findings

• Two superfund sites were identified• The sites are located within Zones 4 and 5• Groundwater in this area is known to be

contaminated with Volatile Organic Compounds

• Depth of groundwater ranges from 50 feet to 150 feet below ground surface

• Tunnel is expected to be at about 200 feet below ground surface

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Superfund Site Superfund Site Locations within Zones Locations within Zones 4 and 54 and 5

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Planned ActivitiesPlanned Activities

• Proceed with the borings in Zones 1, 2 and 3.• Postpone borings in Zones 4 and 5, pending

additional information related to the Superfund Sites.

• Borings to be done by both Caltrans and CH2M HILL

• Borings to begin in early January 2009• Each boring is expected to take about 7 to 10

days to complete

City Exploration Activity # of Visits# of Stakeholders

added to Database

Alhambra Borings: 3 Geophysical Line: 2 294 34

Los Angeles Borings: 6 184 5

Pasadena Z3-B2 (Caltrans 710 ROW north of Del Mar

Blvd)Boring: 1

12 3

Total visits to Homes/Businesses: 490 # of Stakeholders added to database: 42Total visits to Homes/Businesses: 490 # of Stakeholders added to database: 42

Summary of Public Outreach Summary of Public Outreach ActivitiesActivities

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Public Outreach and Public Outreach and Notification ProgramNotification Program• Field Surveys of Boring Sites• Federal, State and Local Elected Officials

Briefings• Public Notices and Fact Sheet• Posting and Distribution of Notices

• Public Facilities• Websites• Canvassing

• Field Outreach to affected/sensitive users• Information Line

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SR-710 Community SR-710 Community Facilitation Scope of WorkFacilitation Scope of Work • Coordinate Study Meetings• Conduct Community Awareness Campaign & Report

Public Input• Study Information Office and Website• Events & Presentations• Community Workshops• Focus Groups

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For more information:For more information:

SR-710 Technical Tunnel Study Information Office

3412 N. Eastern Ave.Los Angeles, CA 90032

Toll Free: (877) 710-INFOTel. (323) 222-1710Fax: (323) 222-9710

http://www.710tunnelstudy.info

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Question and Answer