The Frankfort Electric and Water Plant Board (FPB) treats up to 18 million gallons a day at its water treatment plant (WTP) sourced from the Kentucky River. The WTP has a traditional treatment system including flocculation, sedimentation, filtration, and disinfection with sodium hypochlorite. Since 2008 the WTP has used anhydrous (gaseous) ammonia to form chloramines at the discharge. The FPB operators wanted to explore different sources of ammonia for chloramination due to the safety and operations concerns of gaseous ammonia, including risk of gas leak, bulky softening tanks, and ammoniators for chemical injection. FPB decided to use Liquid Ammonium Sulfate (LAS) for its relative safety, ease of injection, and ease of storage. The FPB started planning their switch to LAS in 2020 and completed startup of the new system in March 2023. The new LAS system includes two 3,900 bulk storage tanks, a chemical transfer pump, a 125-gal day tank, and peristaltic metering pumps. This presentation will cover a history of LAS in water treatment, design considerations for LAS storage and injection, and lessons learned from implementing a conversion from gaseous ammonia to LAS.