In California, the
State Water Resources Control Board (SWRCB) has interpreted State law (Porter-Cologne
Water Quality Control Act, California Water Code secs.13000 et seq.) to require that implementation be addressed when TMDLs are incorporated into basin plans (water-quality-control plans). The Porter-Cologne Act requires each regional board to formulate and adopt water-quality-control plans for all the watersheds within its region. It also requires that a program of implementation be formulated that describes how water-quality standards will be attained. TMDLs can be developed as a component of the program of implementation, thus triggering the need to describe the implementation features, or alternatively as a water quality standard.
California has dedicated itself to developing TMDLs, including programs of implementation, in an open and public forum that enlists the opinions of all affected parties. The TMDL strategy in California relies on an adaptive process that matches management capabilities with scientific understanding. It relies heavily on engaging the public and cultivating a holistic, comprehensive understanding of watershed issues. The Central Valley Regional Water Quality Control Board (CVRWQCB) released a
mercury report for the Cache Creek Watershed outlining the numeric targets for methyl-mercury, the types of mercury sources, linkages between methyl-mercury concentrations in water and large fish, and load allocations.
