Site Specific Interpretations of the Narrative Nutrient Criterion

Numeric nutrient criteria that are approved Hierarchy 1interpretations of the narrative nutrient criteria under Rule 62-302.531(2)(a), F.A.C., can include Total Maximum Daily Loads (TMDLs), Level II Water Quality-Based Effluent Limits (WQBELs), Reasonable Assurance Plans (RAPs) and Site Specific Alternative Criteria (addressed below).

Site Specific Alternative Criteria

Site specific alternative criteria (SSAC) replace the criteria applicable statewide in cases where site specific information supports different numeric criteria. Any SSAC must fully support and protect the designated use of the waterbody. SSACs fall into three types: Type I, Type II and Type III.

  • Type I SSACs (Rule 62-302.800(1), F.A.C.) are established to reflect natural background conditions, such as lower dissolved oxygen levels than the statewide default criteria.
  • Type II SSACs (Rule 62-302.800(2), F.A.C) are established for situations other than natural background conditions.
  • Type III SSACs (Rule 62-302.800(3), F.A.C.) are limited to nutrient criteria.

All types of SSACs must still fully protect the designated use of the water body.

Examples of site specific criteria include the Everglades phosphorus criterion (Rule 62-302.540, F.A.C.) and the Site Specific Alternative Criteria described in Rule 62-302.800, F.A.C.

Type III Nutrient SSACs for Lake Tarpon in Pinellas County

The Florida Department of Environmental Protection (DEP) issued a final order on April 24, 2026, establishing Type III Site Specific Alternative Criteria (SSAC) for chlorophyll-a (Chl-a), total nitrogen (TN) and total phosphorus (TP), for Lake Tarpon proper (WBID 1486A) in Pinellas County pursuant to subsection 62-302.800(3) of the Florida Administrative Code (F.A.C.)

Links to the agenda for the public hearing, a map of the proposed SSAC area, hearing presentation, Final Order, and technical documentation supporting the proposed SSACs are located below.

Please contact Kaitlyn Sutton (850-245-8819) or Nia Wellendorf (850-245-8190) if you have any questions about the public hearing or proposed SSACs.

Water Quality Standards Variances

 

Last Modified: Tuesday, May 05, 2026 - 11:37am