The determination of sulfate concentration in water by indirect EDTA titration is an instructive experiment that is easily implemented in an analytical chemistry laboratory course. A water sample is treated with excess barium chloride to precipitate sulfate ions as BaSO[subscript 4](s). The unprecipitated barium ions are then titrated with EDTA. Students are exposed to a number of important concepts including chelation, indirect and back titrations, precipitation, and water quality. A variety of adaptations can be made to the procedure to fit the needs of different lab courses, including general chemistry and environmental chemistry. (Contains 1 table.)