TMDL: Total Maximum Daily Load
What is TMDL
According to the U.S. Environmental Protection Agency, "Total Maximum Daily Load is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources." For more info, visit EPA TMDL quick overview page at http://www.epa.gov/owow/tmdl/overviewfs.html
How it works?
The TMDL Program works to improve water quality in impaired or threatened water bodies in California. The program is authorized by and created to fulfill the requirements of Section 303(d) of the federal Clean Water Act.
Section 303(d) of the Clean Water Act (CWA) requires “states to submit lists of surface waters that do not meet applicable water quality standards (impaired waters) after implementation of technology-based effluent limitations, and establish TMDLs for these waters on a prioritized schedule.”
The goal of a TMDL is to restore the full use of a water body that has limited quality for one or more of its uses. Based on that target, the state and local stakeholders develop an implementation plan to reduce man-made sources of pollution within the watershed.
In California, The Total Maximum Daily Load (TMDL) Program works to improve water quality in impaired or threatened water bodies. A TMDL is like a budget for pollution. It defines an environmental target by determining the extent to which a certain pollutant must be reduced in order to attain and maintain a use of surface water that is limited because of a pollutant or adverse condition. Based on the environmental target in the TMDL, the state develops an implementation plan to mitigate anthropogenic (human-caused) sources of pollution within the watershed and restore full use of the water body. An implementation plan (IP) puts the TMDL into action by outlining the steps necessary to reduce pollutant loads through regulatory and voluntary activities. The TMDL program is authorized by and created to fulfill the requirements of Section 303(d) of the federal Clean Water Act and its implementing regulations.
TMDLs are developed by State Water Resources Control Board SWRCB personnel or by independent contractors working for the SERCB. The development of TMDLs is a scientifically rigorous process of intensive data collection and analysis. After adoption by the SWRCB, TMDLs are submitted to the U.S. Environmental Protection Agency for review and approval.
