This 60-page manual is intended as a review of current backfill operating practices and potential hazards associated with these practices at underground mining operations in Ontario. Targeted at workers, supervisors and technical personnel involved in backfilling operations, the manual focuses on the two most prevalent types of backfilling: hydraulic (or slurry) backfill and paste backfill. Topics include surface supply operations, backfill plant operations, underground distributions systems, stope placement operations, plus glossary.