Total Maximum Daily Loads (TMDLs)

The Total Maximum Daily Load (TMDL) is a number that represents the assimilative capacity of a receiving water to absorb a pollutant. The TMDL is the sum of the individual wasteload allocations for point sources, load allocations for nonpoint sources plus an allotment for natural background loading, and a margin of safety. TMDLs can be expressed in terms of mass per time (the traditional approach) or in other ways such as toxicity or a percentage reduction or other appropriate measure relating to a state water quality objective. A TMDL is implemented by reallocating the total allowable pollution among the different pollutant sources (through the permitting process or other regulatory means) to ensure that the water quality objectives are achieved

• TMDL Implementation Status
• TMDLs Adopted as Basin Plan Amendments
• TMDLs Adopted as Single Regulatory Actions
  • El Dorado Park Lakes Copper TMDL
  • McGrath Beach Coliform TMDL
  • Santa Clara River Estuary Toxaphene TMDL
  • Avalon Bay Bacteria TMDL

• EPA - Established TMDLs
  • Santa Clara River Reach 3 Chloride TMDL
  • Malibu Creek Nutrient TMDL
  • San Gabriel River Metals TMDL
  • Los Cerritos Channel Metals TMDL
  • Oxnard Drain No. 3 Peticides, PCBs and Sediment Toxicity TMDL
  • Ballona Creek Wetlands Sediment and Invasive Exotic Vegetation TMDL
  • Long Beach City Beaches and Los Angeles River Estuary TMDLs for Indicator Bacteria
  • Los Angeles Area Lakes Nitrogen, Phosphorus, Mercury, Trash, Organochlorine Pesticides and PCBs TMDLs (15.3 MB)
  • Santa Monica Bay DDTs and PCBs TMDL
  • Malibu Creek and Lagoon TMDLs for Sedimentation and Nutrients to Address Benthic Community Impairments (7.3MB)
    • Malibu Creek and Lagoon TMDL Appendices
  • EPA-Established TMDLs Website
  • EPA-led TMDLs in Progress Website
  • DRAFT Strategy for Developing TMDLs and Attaining Water Quality Standards in the Los Angeles Region
    • TMDL Strategy Fact Sheet