BC Hydro’s Strathcona Hydroelectric facility is an earthfill dam 511 m in length and 53 m high with a 64 MW generating station. The Strathcona Dam is located on Vancouver Island about 25 km west of the City of Campbell River, and impounds Upper Campbell Reservoir and Buttle Lake.
ECODynamic Solutions (EDS) Inc. was retained by Hemmera Envirochem Inc., on behalf of BC Hydro, to provide environmental monitoring services during Phase I and II of the Strathcona Dam Intake Tower Seismic Upgrade Project. The Pre-Work (Phase I) Program took place throughout the Fall of 2009 and Spring 2010, and included upgrade of the Intake Tower Superstructure, and modifications to the dam-side abutment of the Intake Tower Access Bridge. Phase II took place between April 2010 and November 2010, consisted of coring, drilling, and the installation of passive steel anchors on the Strathcona Dam intake tower.
EDS services included providing input on the creation and implementation of the Project Environmental Management Plan (EMP). Working in proximity to a municipal drinking water source, effective mitigation planning was required for various tasks at the Dam, including: 1) fuel and oil–bearing equipment containment, 2) the creation of a cuttings and grout waste management system using mud recirculation tanks, wilden pumps, high pressure cuttings transport lines, and Above-ground Storage Tanks for cuttings storage and filtration, 3) intake tower perimeter containment to prevent the migration of fluids, 4) an intake pump system with fish screens, and 5) drill mitigation for an HT750 and HT2000 Drill Rigs. Construction activities also requiring mitigation and monitoring included drilling 3”, 6” and 12“ diameter holes down to the footing of the concrete intake tower, air-assisted hammer-drilling in bedrock to final depth, management of lead paint waste from the superstructure, and grouting of large deep holes. Seismic works were completed successfully. EDS prepared a post-construction monitoring reports following completion of both phases of the project.