This course outlines how stainless steels—especially Types 304L and 316L—perform in potable water treatment plants and explains the factors needed to ensure long-term, corrosion-free operation. It covers grade selection, piping design, fabrication practices, start-up procedures, and maintenance strategies that help prevent crevice corrosion, MIC, and under-deposit attack. Practical guidance is provided for managing chlorides, oxidizers, flow conditions, weld quality, and surface cleanliness to support reliable service in both raw and finished water systems.