The use of controlled low-strength materials (CLSM) or flowable fill for backfill of pipelines and adjacent to structures has become common practice because of ease of placement, lack of need for compaction, and relatively fast set time of the material. These properties are also ideal for backfill placed underwater or fill placed to allow sequential excavation.

CLSM was used to backfill excavations conducted to remove oil contaminated soil adjacent to foundations of existing structures and under standing water. The contaminated soil was sequentially excavated in narrow trenches and backfilled with CLSM, allowing excavation of subsequent adjacent trenches while minimizing soil movement into the open excavation. This sequential excavation would not have been possible with conventional compacted backfill. CLSM backfill was successfully placed underwater using tremie methods.