The location of a former manufactured gas plant, the site was characterized by a tar body that extended 400 feet onto and across a marine mudflat. An articulated block mat (ABM) covered with habitat material was installed as the composite cap.

DOF’s initial project involvement included:

  • Updating the original site characterization report
  • Creating the conceptual design for the remedial cap
  • Developing a conceptual construction strategy to place ABM and fill with concrete during daylight low tidal cycles
  • Preparing engineering evaluation and cost analysis report

The owner chose to use another firm for the design. Post-construction coastal erosion degraded the habitat layer and shoreline armoring.

DOF’s additional project involvement included:

  • Completing an erosion analysis and repair design for habitat capping material, riprap and ABM
  • Providing construction management for repairs and documenting observations in daily reports and photos
  • Completing ongoing inspections and monitoring, sampling, analysis and report preparation
  • Assisting with regulatory agency negotiations
  • Preparing support documents including permit applications, O&M Plan, design memorandum and construction completion reports