Florida Power and Light, Inc. (FPL), has submitted a petition to initiate rulemaking to establish a Site Specific Alternative Criterion (SSAC) for Total Ammonia Nitrogen (TAN) in the Northwest Mitigation Area wetlands and Barley Barber Swamp in Martin County, Florida. The waterbodies are both classified as Class III waters, with a designated use of “Fish Consumption; Recreation; Propagation and Maintenance of a Healthy, Well-Balanced Population of Fish and Wildlife.” The draft SSAC is consistent with USEPA’s Chronic Criterion Magnitude for TAN for waters where unionid mussels are absent and Early Life Stage fish protection is maintained. FPL has demonstrated that unionid mussels are not present in the mitigation area or Barley Barber Swamp. The draft rule amendment would revise the surface water quality criterion for TAN in these waterbodies. The draft SSAC for TAN is intended to fully protect its Class III designated use. Comments on the draft SSAC may be submitted through October 21, 2020 to Kaitlyn Sutton, Standards Development Section, Florida Department of Environmental Protection, 2600 Blair Stone Road, MS 6511, Tallahassee, FL 32399-2400; telephone 850/245-8819; email Kaitlyn.sutton@floridadep.gov .