Engineering Cap Repair & Streambank Stabilization

Project Overview:

Summit's Remediation Division was contracted by a large engineering & environmental consulting firm to perform restoration and stabilization work on a compromised engineering cap system at a site in Spartanburg, SC. The multi-layer cap, designed to prevent historic contaminant impacts from migrating toward a nearby stream, had been damaged by significant storm events, resulting in embankment loss and exposure of the vegetative cover layer.

Challenge/Conditions:

The affected area was located within dense woodlands, limiting access for heavy equipment and material delivery. Prior storm activity had destabilized approximately 200 linear feet of streambank, requiring precise reconstruction to restore containment integrity while tying into the existing engineered cap system.

Services Provided:

• Clearing, widening, and improving woodland trails for safe access
• Restoration of 200 linear feet of streambank
• Placement of stone, riprap, and grid materials to rebuild embankment
• Regrading slopes to support long-term stability and erosion control
• Integration of new materials with remaining undisturbed engineered cap
• Creation of conditions favorable for native vegetation regrowth
• Controlled backfilling and compaction with shoring removal
• Protection and reinforcement of multi-layer cap system (soil, stone, riprap, liner, geo-cell grid)

Solutions/Approach:

Summit began by upgrading an existing trail to safely mobilize tracked excavation equipment and deliver high-volume stone and construction materials to the remote repair area. Once access was established, crews reshaped the damaged embankment, installing stone, riprap, and geo-grid materials to rebuild the shoreline and stabilize the slope. The restored section was seamlessly integrated with the undisturbed portions of the engineered cap, ensuring consistent performance across the system. Regrading supported long-term structural stability while promoting natural re-vegetation to reinforce erosion protection over time.

Outcome/Results:

The project was successfully completed in Spring 2025, restoring the streambank stabilization system to full function. Summit's work reestablished containment controls designed to prevent migration of historic contaminant impacts, improved long-term slope stability, and ensured the engineered cap could continue performing as intended.