Frequently Asked Questions (FAQ)

Question:
How do BMPs relate to TMDL regulations?


ANSWER:
Total Maximum Daily Loads fall under Sect. 303 of the federal Clean Water Act, a section different from the NPDES permit section. If a water body is deemed to be impaired, even when all discharges to it are regulated under permit, each discharger is allotted a diminished amount of the offending pollutant. TMDLs apply to both wastewater and stormwater discharges. In the case of stormwater, pollutant concentrations and loads are to be controlled through the use of Best Management Practices. Unlike SUSMP requirements, TMDL requirements can relate to storms greater than 3/4" rainfall in 24 hours. For example, current trash TMDL regulations will require that man-made trash 5 mm and greater in size will not be allowed into an impaired water body from flows up to and including the runoff from a 1-year 24-hour rainfall.


Links:
  Total Maximum Daily Loads (TMDL)

  LACDPW Trash TMDL Technical Report
BMP WMD Watershed groundwater stormwater conservation runoff quality FEMA NPDES TMDL BMP Levees Levee certification Flood insurance NFIP Flood zone determination IRWMP