Water resources on earth are diminishing rapidly and human activities continue to affect detrimentally the quality and quantity of existing fresh water resource. In the most common usages, waste water refers to the municipal waste water that contains a broad spectrum of contaminants resulting from the mixing of wastewaters from different sources. Present paper deals with the Hardness removal from municipal wastewater at sewage treatment plant (STP) Bhopal. Six samples were collected from inlet and outlet of Sewage Treatment Plant (STP) and analyzed for Total hardness, calcium hardness and magnesium hardness. Comparison between the hardness at inlet and outlet of STP shows that hardness reduces after the treatment. The treated wastewater can be used for irrigation purposes.