SUMMARY Nutrient-rich discharges from the Everglades Agricultural Area (EAA) and the C-139 basin have been identified as contributors to Everglades enrichment and are the primary focus of the Everglades Regulatory Program and the Everglades Construction Project. Substantial efforts in Best Management Practices (BMP) implementation, research, and education have been directed at reducing phosphorus (P) loading at the source as part of the Everglades Regulatory Program. The combined efforts of implementing BMPs and construction of the Stormwater Treatment Areas (STAs) are responsible for a declining trend in the loads and concentrations of total phosphorus (TP) attributable to the EAA basin and conveyed to the Everglades Protection Area (EPA). The objective of this chapter is to provide an update on the effectiveness of controlling phosphorus at the source through the implementation of BMPs. Information in this chapter and its associated appendices include the current year’s data, and recommendations and conclusions which are similar to those presented in previous years. This chapter discusses the methodology for compliance determination for the EAA and C-139 basins and includes a summary of the EAA and C-139 basin-level data and the permit-level data from individual permittee-operated discharge structures within the EAA basin. Permit-level data are not available for the C-139 basin because monitoring for individual permittees in the C-139 basin is optional and voluntary on the part of the permittees and none of them have elected to submit monitoring results for their discharge at this time. The BMP Regulatory Program in the EAA and C-139 basins, mandated by State of Florida legislation, is one aspect of the South Florida Water Management District (SFWMD or District) Everglades Restoration Program. The overall effectiveness of BMPs in the EAA is best demonstrated by the measured TP load reduction in the basin since BMPs were implemented in