Water Quality Standards Triennial Review Information

capital 'S'ection 303 of the Clean Water Act established the principle of the total maximum daily load (TMDL) as a means of reducing water pollution in impaired waters.  A TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards. In other words, it is the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources and includes a margin of safety and consideration of seasonal variations. 

In addition, a TMDL contains the reductions needed to meet water quality standards and allocates those reductions among the sources in the watershed. The calculation must include a margin of safety to ensure that the waterbody can be used for the purposes that have been designated. The calculation must also account for seasonal variation in water quality. Water quality standards for South Carolina are promulgated by the Department of Health and Environmental Control with approval by the SC General Assembly. They identify the uses for each waterbody, for example, drinking water supply, contact recreation (swimming), and aquatic life support (fishing) as well as the scientific criteria to support  these uses. Streams, lakes, and other waterbodies that do not meet the standards are impaired and are required by the Clean Water Act to be listed as such (the 303d list).  Section 303(d) also requires development of TMDLs for listed waters. TMDLs are an important step in the restoration of these impaired waterbodies.

303(d) List  

South Carolina develops a 303(d) list every two years. DHEC solicits and considers all existing and readily available water quality data, including non-DHEC data, in developing South Carolina’s 303(d) list. All Non-DHEC Data are accepted for consideration at any time during the listing cycle; however, only data submitted before September 1 of each odd-numbered year will be considered for the following year’s 303(d) list. To be considered for the any 303(d) list, data must be representative of current water quality conditions and comparable to state water quality criteria. Any organization submitting data should use laboratories certified by the DHEC Office of Environmental Laboratory Certification for the test methods of record.

Persons wishin g to collect water quality data for DHEC use are encouraged to contact the DHEC Office of Quality Assurance and submit a Quality Assurrance Project Plan (QAPP) for approval prior to initiating sampling. For the Department to use any non-DHEC data in development of the 303(d) list, submittal of non-DHEC data should be accompanyed with an approved QAPP.

Additional information regarding DHEC QAPP development can be found at the following link: www.scdhec.gov/environment/envserv/qapp.htm.

If you have data that you would like DHEC to consider in developing South Carolina’s 303(d) list, please e-mail Mihir Mehta.

watershed map Savannah Saluda Broad Catawba PeeDee Santee Edisto Salkehatchie

2006 305(b) Report - State of South Carolina Integrated Report Part II: Assessment and Reporting

2004 305(b) Report - State of South Carolina Integrated Report Part II: Assessment and Reporting

Link

EPA Region IV TMDL Program
SCDHEC Watershed Management Program

EPA BASINS Training for TMDL Development
Hosted by: Utah State University http://www.scdhec.gov/exit.htm?url=http://www.tmdl.org/basins/

Contact:

Mihir Mehta - (803) 898-4011

Bureau of Water . Phone: (803) 898-4300 . Fax: (803) 898-4215 . Contact Us