A landfill had an existing single basin SBR plant to process the leachate which is notable for its high nitrogen load. The original system was installed with a fine pore diffuser aeration system and due to the chemical/biological composition of the mixed liquor it was prone to diffuser fouling and premature membrane failure. Over time this was detrimental to the biological process due to reduced oxygen transfer capacity of the diffusers, as well as an increase in energy usage as a result of the higher blower pressure. After several years of operation there came the need to add more treatment capacity so a second SBR tank was planned for. During the design phase it was decided to use a more robust aeration system for the new tank as well as to replace the fine pore diffuser aeration system in the existing SBR tank. The KLa Systems Slot Injector Aeration System was selected due to its superior aeration efficiency in complex wastewaters, flexible design features, and its proven long term, trouble free operation.