A Controlled Low Strength Material (CLSM) is a highly flowable self-compacting material that is primarily composed of sand, cement, water, and other filler materials. It is principally used as a replacement for soil backfill. The purpose of this project was to optimize the mixture proportions for performance using various fillers such as Quarry Dust and PS Sand, and cementitious materials such as Ground Granulated Blast Furnace Slag (GGBFS), Fly Ash (FA), and cement. The recycling of these waste materials contributes to construction sustainability. The mixes must possess the consistency, flowability, and strength which is required for CLSM. This was achieved through trial mixing, where the derivation of new mixes was based on the performance of previous pours. To investigate the performance of the mixes derived, tests for flowability and compressive strength were carried out.