Morro Bay Pathogen TMDL


Problem Statement - Numeric water quality objectives for fecal coliform set by the Regional Board and standards enforced by the California Department of Health Services (DHS) pursuant to the United States Department of Health Services Food and Drug Administration’s National Shellfish Sanitation Program have been exceeded for shellfish harvesting and water contact recreation in Morro Bay. Elevated levels of fecal coliform in Morro Bay and Chorro and Los Osos Creeks indicate that pathogens are impairing water contact recreation and shellfish harvesting in these water bodies. High levels of pathogens may cause disease in humans and may also adversely affect marine animals. Portions of Morro Bay have been closed by DHS for commercial shellfish harvesting since 1996, and advisories have been posted to warn the public to avoid water contact activities. Morro Bay was identified as impaired for pathogens on the 1998 Clean Water Act Section 303(d) list of impaired water bodies.


  • January 20, 2004 - USEPA approves the Morro Bay Pathogen TMDL
  • November 19, 2003 - OAL approves the Morro Bay Pathogen TMDL
  • September 16, 2003 - State Water Resources Control Board approves the Morro Bay Pathogen TMDL
  • May 16, 2003 - Central Coast Water Board adopts the Morro Bay Pathogen TMDL
  • March 29, 2002 - Special Study to aid in determining the sources of E. coli in the Morro Bay Estuary


Status and Public Notices

  • Status: fully approved and effective.
  • Public Notice: none at this time.

Approval status

  • Central Coast Water Board
    - adopted May 16, 2003.
  • State Water Resources Control Board
    - approved September 16, 2003.
  • Office of Administrative Law (OAL)
    - approved November 19, 2003, which is the effective date.
  • US Environmental Protection Agency
    - approved January 20, 2004.