Southern California -- this just in

« Previous Post | L.A. NOW Home | Next Post »

710 tunnel soil sample drilling begins Tuesday

January 5, 2009 | 12:57 pm

710map Here's one sure to provide a little indigestion to those who have been fighting the 710 extension for years: Caltrans this week is starting to drill for soil samples to see if it's geologically feasible to build a tunnel to complete the 710. The road currently ends along the city of Los Angeles-Alhambra boundary but was intended to run north to a junction with the 210 and 134 in Pasadena.

Caltrans is saying the drilling will be route neutral. By that, the agency means that it will test soil in the coming months to consider a wide variety of routes instead of just the traditional one it has looked at for years that runs pretty much straight north along the L.A.-Alhambra line and then straight up the gut of South Pasadena. That means there's going to be drilling in Pasadena, Glendale, La Canada-Flintridge, Monterey Park and San Marino.

Which, of course, begs the question: Is there anyone out there who really thinks a tunnel route will one day be proposed to go under either wealthy La Canada-Flintridge or San Marino? Please. I cut through San Marino on my drive to work some days, and on garbage day, homeowners (or their employees) have to wheel dumpsters to the curb. If you can create a dumpster worth of trash each week, you likely have the resources to fight a freeway.

The above map shows the areas that Caltrans is going to study -- click on it to see a larger image. Here's a link to a Caltrans and Metropolitan Transportation Authority website on the 710 study. The news release from Caltrans follows.

-- Steve Hymon

Caltrans news release:


                  State Route 710 Tunnel Technical Study
                     Geotechnical Exploration Program

City  of  Alhambra - The California Department of Transportation (Caltrans) and  Metro,  as  part  of  the State Route 710 Tunnel Technical Study, will conduct  geotechnical  exploratory  borings in two locations in the City of
Alhambra   beginning   Tuesday,   January   6,   2009  and  continuing  for
approximately seven to ten days.

The schedule is as follows:

Westmont Drive and Sherwood Avenue
Daily, Tuesday, January 6 through Wednesday, January 14
Time: 7 a.m. to 5 p.m.

North  of  Valley Boulevard, Near Westmont Drive and Front Street (Caltrans Right of Way) Daily, Tuesday, January 6 through Monday, January 12
Time: 8 a.m. to 5 p.m.

This  Exploration  Program  phase  of  the two-year SR-710 Tunnel Technical Study will involve research, exploration and technical analysis of the soil and sub-surface conditions found while tunneling at depths of more than 250 feet. The Exploration Program is comprised of two integrated activities:

Boring:   Information  about various soil types, such as rock or sand, will
be  gathered  by  drilling (boring) deep into the ground and producing soil
samples  to  be  analyzed.   Boring  will  take  place  at approximately 33
locations throughout the study area.

Seismic  Reflection: This activity will provide an electronic image of soil conditions along a specific area.  Information on rock layers and layering, near-surface  faulting, sub-surface voids, and bedrock elevations or depths will be provided.

Borings  and  seismic reflection testing activities will take place between January  and  May, 2009, weather permitting, in the cities of Alhambra, Los
Angeles,  South  Pasadena  and  Pasadena.   Caltrans  and  CH2M  HILL,  the
geotechnical contractor for the Study, will conduct the borings.

In June 2008, Caltrans and Metro began the SR-710 Tunnel Technical Study to examine  the  possibility  of  constructing  a tunnel to complete the route between  the northern SR-710 termini and the Foothill Freeway (I-210).  The study  is  being  conducted in a route neutral manner.  This means that all reasonable  and practicable alternatives for completing the route are being considered within the Study area, which encompasses the cities of Alhambra, Glendale,  La  CaƱada-Flintridge,  Los  Angeles, Monterey Park, San Marino, South Pasadena and Pasadena. Information gathered throughout the Study will describe soil and sub-surface conditions and will determine the feasibility
of   building   a  tunnel  to  complete  SR-710.   This  study  is  not  an
environmental assessment.

Local  community  members can obtain information and become involved in the
Study   process  through  public  meetings,  workshops,  focus  groups  and
community  events.  More  information  about  the  Study  is  available  by contacting  or  visiting  the  SR-710 Tunnel Study Information Office, 3412 North  Eastern  Avenue,  Los  Angeles, CA 90032.  Phone: 323-222-1710; Toll
Free:    877-710-4111;    Fax:    323-222-9710;    or    the   website   at