The otter lake water treatment plant was built in 1969 and is permitted by the IEPA to produce up to 2.7 million gallons per day (MGD). On an average day the water plant will produce approximately 1.5 MGD, with a peak day as high as 2.5 MGD. The treatment process is typical for a surface water plant of its age. Lime is used as a ph adjustment, alum is fed as a coagulant, polymers are fed depending on the time of year and lake conditions. Carbon is fed to reduce taste and odor causing compounds as well as to reduce atrazine levels in the finished water. Chlorine is fed in conjunction with ammonia as a disinfectant. Fluoride is also added to the water to enhance dental hygiene.