This test method is based on Standard Methods for the Examination of Water and Wastewater and is used to determine alkalinity in water samples. Alkalinity measures the water’s capacity to neutralize acids. A measured volume of water sample is placed in a beaker. The sample is titrated with a standardized sulfuric or hydrochloric acid solution to a specific pH. Indicators (like methyl orange or phenolphthalein) or a pH meter are used to detect endpoints. Alkalinity is calculated and typically expressed as mg/L of CaCO₃.