Project Location: Tukwila, Washington

Client: CH2M Hill


Construction Cost: $2.7 million

Wilder’s Role: Subcontractor

Construction Period: 8/96 – 6/97

Wilder performed the project in a partnership with CH2M Hill to design and build a remotely operated deep-well groundwater extraction, collection, and treatment system at the Western Processing Superfund Site.  This project will prevent migration of groundwater from within the perimeter of the slurry wall, treat the groundwater, and allow preparation of the site for final capping.  The CH2M Hill / Wilder team was chosen in a competitive, firm bid competition with other engineer / contractor teams. All work was completed around an existing well system that had to remain in operation until the deep well system was completed and operational.  The water treatment system, procured and installed by Wilder, included an air stripper, carbon absorption units and treated water discharge to POTW.  The system includes the capability to individually monitor wells and contaminant levels, and adjust individual well flow rates from a remote location.

Wilder constructed a steel building to house the treatment system.  All associated site work and utility installation was self-performed by Wilder.  The facility included elaborate mechanical conveyance systems and a 60-foot tall exhaust stack. The use of the design / build process proved to be a very effective approach to this challenging project allowing concurrent design and construction operations to shorten the overall schedule, and value engineering sessions to optimize the design and control costs. 

The contractual relationship between Wilder and CH2M Hill included clauses to share savings in order to provide maximum incentive to both the engineer and the contractor to evaluate and control costs while maintaining design quality.  Wilder truly teamed with CH2M Hill in this effort.  The 2.7 million-dollar project was completed on schedule and on budget, in June of 1997.

Wilder was invited to bid additional phases of work by the Western Processing Trust and has teamed with CH2M HILL on subsequent projects.