Columbia Energy provided below-grade remediation design including pipeline grout injection and tank removal at the Hanford 300 Area north of Richland, WA.  Grout was injected into hazardous waste pipelines in order to stabilize them prior to segmentation, removal, and packaging for final disposal.


  • Engineering and Design
  • Construction
  • Testing
  • Documentation
  • Project Management


  • Two grout types: standard injection and a sulfur amended injection grout
  • Grout flow ability over 500-feet in length


  • U.S. Department of Energy (DOE)
  • Office of River Protection (ORP)
  • Washington Closure Hanford (WCH)

During the design phase, qualification testing of the grout injection and ventilation systems was performed to ensure proper grout flow, optimal connector design and grout placement, and proper pipeline venting. The design phase also determined that grouting was not effective for small diameter pipes (<1-inch nominal). Columbia Energy selected a two-part epoxy in place of grout to produce the same effect to stabilize the waste in the small diameter pipes.

Columbia Energy also provided design for the removal of two below-grade, highly-contaminated tanks, one located within the 309 Building and one adjacent to the structure.

The design integrated tank removal, including the development of lift calculations and lift plans, with contaminant stabilization, transportation, packaging and disposal.  Included in the design features were minimized weight and disposal volume while meeting the requisite hoisting, rigging, stabilization, transportation, and disposal requirements.