Anna Paris publishes Industry Paper: Sustainable cover system for ARD/ML mitigation at Site C: Integrating soil stabilization and HPTRM

Paper Abstract:

The Site C Clean Energy Project in northeastern British Columbia involved extensive earthworks along the Peace River, including the Left Bank Excavation (LBEx). During excavation, a unique geological unit was exposed: an Ancient Bedrock Colluvium (ABC). This unit presents both geotechnical and geochemical challenges due to its highly friable nature, susceptibility to erosion, and potential to generate acid rock drainage and metal leaching (ARD/ML). To mitigate long-term ARD/ML risks, a sustainable, low-maintenance cover system was implemented. The cover design featured a 0.5-meter topsoil layer over 0.1 meters of sand and gravel blended with agricultural lime for short-term pH adjustment. The topsoil was seeded, and the slope cover was reinforced with High-Performance Turf Reinforcement Mats (HPTRM) across 30,000 square meters. The HPTRM was pinned to secure the cover, prevent erosion, and support vegetation growth. The HPTRM’s 3D structure, high void index, and durability were critical in mitigating surface erosion by absorbing precipitation impact, minimizing runoff, and maintaining soil moisture. Its protective properties reduced evaporation from wind and sunlight while promoting rapid vegetation establishment by facilitating light penetration and water absorption. This innovative cover system, integrating soil stabilization with HPTRM, demonstrates a cost-effective and sustainable approach to mitigating erosion and promoting vegetation atop an ARD/ML unit. By preventing surface erosion and fostering vegetation growth, it balances environmental protection with minimal long-term maintenance.

Read full published paper here: Site C Paper by Anna Paris