BF Goodrich 

PROJECT TITLE:  Remediation of L-Ditch at South Campus

CLIENT: Haley and Aldrich, Mr. Patrick Keddington

OWNER:  BF Goodrich

DESCRIPTION:   

         Fred North Construction was contracted by Haley and Aldrich to assist their consulting firm in the remediation of a half mile long drainage channel at the former BF Goodrich "South Campus" site located in Chula Vista, California.  The drainage channel, better known as the "L - Ditch," was remediated at a series of different source areas along its length.  In order to achieve this, and because of the constant movement of ocean water in and out of the channel, four 36" out fall pipes were mechanically plugged to limit the flow of tidal water within the channel.  Several onsite drainage vaults leading to the channel were slurry filled to prevent further storm water drainage from entering the channel. In addition, within the channel a series of lock out damns were constructed by FNC out of steel plates and beams so that the source areas could be properly excavated and processed for disposal.  Once sediment was removed from the channel, the material was processed within large "containment cells" built from k-rail and single piece liners that prevented the substantial amount of water still trapped within the sediment from escaping.  The cells proved to be a very effective method for the dewatering and aerating of the sediment allowing for trucking and disposal to take place once the material reached a feasible level of stability.

         With remediation of the channel completed, the project required several more engineering measures to be performed.  Approximately 4,000 additional yards of unstable sediment were excavated from the entire length of the channel to facilitate the placement of approximately 30,000 tons of crushed rock and Class 2 base.  This was done to stabilize the channel for future development.  The sediment, removed as an engineering measure, was processed in the same manner as the source removal sediment, using eight rotating containment cells to dry out and process the material for disposal.  No water or sediment was ever allowed to breach the cells, making for a very sterile and clean process.  A comprehensive SWPPs plan was created by Haley and Aldrich.  The implementation and daily maintenance of this plan was performed by the FNC crew to the satisfaction of Port inspectors.

          For the purpose of impeding the flow of ground water down the channel in the future, Fred North Construction was asked to solve the difficult problem of constructing a series of five subsurface concrete walls spaced out within the length of the channel.  Though challenging, the task was accomplished again by constructing temporary dams built of steel plates and heavy beams so that construction could be performed deep below the old flow line and into the native bay mud.  With lock out damns in place, shoring boxes were used to create the formwork needed to pour the massive underground walls.  Under a discharge permit over 1.2 million gallons of water were processed through a dewatering system constructed and maintained by Fred North Construction.  After construction of the subsurface walls was completed, the walls were backfilled to the specifications of the site grading plan and the entire channel was prepared for future development.

          Fred North Construction is proud to have been a critical team member in completing this complex project work plan.