Newport Bay Fecal Coliform TMDL

Fecal coliforms are a type of fecal indicator bacteria (FIB) found in the digestive systems of humans and animals. The presence of fecal coliforms in surface waters is used as an indicator of human pathogens, which can cause illness in swimmers and recreators. Bacteria have historically been used as indicators of human pathogens because bacteria are easier and less costly to measure than pathogens themselves.

Newport Bay Fecal Coliform TMDL

In 1999 the Santa Ana Regional Water Quality Control Board adopted a Total Maximum Daily Load (TMDL) for fecal coliforms in the Newport Bay. Given the complexity of the problem, the paucity of relevant data on bacteria sources and fate, the expected difficulties in identifying and implementing appropriate control measures and uncertainty regarding the nature and attainability of the shellfishing beneficial use in the Bay, a prioritized, phased approach to the control of bacterial quality was developed. The phased approach is intended to allow for additional monitoring and assessment to address areas of uncertainty and for future revision and refinement of the TMDL. The TMDL is concentration based, and requires attainment of water contact recreation standards no later than December 30, 2014 and with shellfish standards no later than December 30, 2019.

Per California Water Code (Section 13267), the County of Orange and the Cities of Costa Mesa, Irvine, Lake Forest, Newport Beach, Orange, Santa Ana, and Tustin, the Irvine Ranch Water District (IRWD) and the Irvine Company are currently supporting studies and monitoring in the Bay towards developing a TMDL implementation plan to achieve the TMDL targets.

Monitoring and study efforts have included the development and implementation of a routine monitoring program, development of a water quality model for bacterial indicators, recreational and shellfish harvesting beneficial use assessments, a human health risk assessment, evaluation of the vessel waste program, and source identification and characterization of the Dunes Resort, agricultural, urban and natural runoff sources. The 2012 Newport Bay Fecal Coliform TMDL Annual Data Report (filed in the OC Public Works Document Library) describes the most current status of these tasks.

The County of Orange, on behalf of watershed stakeholders, implements a routine monitoring program to determine compliance with bacterial water quality objectives in the Bay. Orange County Health Care agency collects at least five samples per 30-day period at 35 stations throughout Newport Bay and publishes these data on-line at http://www.ocbeachinfo.com/. Data from the water quality monitoring program, along with analysis on attainment of the water quality objectives, and information on additional implementation tasks, are found in the Newport Bay Fecal Coliform TMDL Annual Data Reports.