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
    • 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.

Request for Full Capture Received From:
Full Capture Certifications Issued:
  • California Department of Transportation (Caltrans)
  • For any question regarding Full Capture Certification, please contact Carlos Santos, phone: (213) 620-2093.


Regional Programs Section
LB Nye
(213) 576-6622
Environmental Program Manager I (Supervisor)