VICTORIA—Restoration companies and contractors in British Columbia that are about to help launch a massive flood cleanup and repair effort must be aware of the risks and hazards their work could pose to employees, says the province’s worker protection agency. The risks may be different depending on the flood and slide damage, but potential problems include building materials with asbestos, chemical or biological contamination, structural or electrical damage and animal carcasses, Barry Nakahara, WorkSafeBC’s senior prevention services field manager, said Tuesday. Numerous homes, farms and infrastructure sites in southern B.C. were damaged or destroyed in a series of so-called atmospheric rivers that caused flooding and landslides, cutting off transportation routes, swamping agricultural operations and forcing thousands of people to evacuate their homes. “Employers have an obligation to ensure healthy and safe workplaces,” said Nakahara in an interview. “As we move into this cleanup and recovery and rebuilding effort, it’s going …