This standard describes the use of anhydrous ammonia in the treatment of potable water, wastewater, and reclaimed water. Anhydrous ammonia is expressed by the formula NH3. Anhydrous means free from water. Major changes made to the standard in this revision include the following: inclusion of a requirement for compliance with the Safe Drinking Water Act and other federal regulations (Sec. 4); and inclusion of a requirement for tamper-evident packaging (Sec. 6.2.3 and 6.2.4).