Full Capture Certification for Trash TMDLs

• Definition of Full Capture Certification:
  A full capture system is any single device or series of devices that traps all particles retained by a 5 mm mesh screen and has a design treatment capacity of not less than the peak flow rate Q resulting from a one-year, one-hour, storm in the subdrainage area.
  
  Rational equation is used to compute the peak flow rate:
  
  

  Q = C I A

  where:

  • Q = design flow rate (cubic feet per second, cfs);
  • C = runoff coefficient (dimensionless);
  • I = design rainfall intensity (inches per hour, as determined per the rainfall isohyetal map in Figure A), and
  • A= subdrainage area (acres)
    
    

• For the purpose of the trash TMDLs, the Los Angeles Regional Board considers Vortex Separation Systems to be full capture devices
  
  
• Procedures and Requirements for Certification of Best Management Practices (BMPs) for Trash Control as a Full Capture System.
  
  

• For any question regarding Full Capture Certification, please contact Carlos Santos, phone: (213) 620-2093.