This document summarizes a study on the impact of conventionally and non-conventionally treated waste water on the characteristic strength of concrete. The study investigated using secondary treated water from two treatment plants (one conventional, one non-conventional) for mixing and curing concrete cubes, compared to using tap water. The compressive strength of the cubes was tested at 7, 14, and 28 days to determine the optimum type of secondary treated water for concrete mix and curing. Test results showed that the compressive strengths of concrete made with conventionally and non-conventionally treated water were similar and met design standards, indicating treated waste water can be used as an alternative to fresh water in concrete.