The South Carolina Department of Health and Environmental Control (SCDHEC) conducts water quality monitoring to assess the health of the state's streams, rivers, and lakes. The water samples are analyzed for several different parameters such as bacteria (E. coli), pH, dissolved oxygen, suspended solids, nutrients, and metals. The results are then compared with water quality standards established by SCDHEC that take into consideration the use and value of the waterbody for public water supply for the protection of fish, shellfish, and wildlife and for recreational, agricultural, industrial, and navigational purposes. For more information on water quality standards: http://www.scdhec.gov/HomeAndEnvironment/Water/ImpairedWaters/Overview/#8
When monitoring finds that water quality standards are not being met, the waterbody is designated as impaired and placed on the 303(d) list. The list gets its name from the requirements of section 303(d) of the Clean Water Act. The list is updated every two years. The most recent list was updated in 2014 and includes 24 monitoring stations located in Anderson County. An excel spreadsheet listing those can be downloaded here: 2014 303d AC List.xlsx. Waterbodies can be delisted if monitoring finds that they meet the water quality standards or if a Total Maximum Daily Load (TMDL) is created and approved by EPA for the waterbody and the pollutant exceeding the water quality standard.
SCDHEC Impaired Waters Information
Total Maximum Daily Loads (TMDL)
What is a TMDL?
A TMDL, or Total Maximum Daily Load, is the amount of a single pollutant (such as bacteria, nutrients, metals) that can enter a waterbody on daily basis and still meet water quality standards set fort by the state. “TMDL” refers to both a calculation of a pollutant entering a waterbody as well as a document which includes this calculation along with a source assessments, watershed and land use information, reductions and allocations information, implementation and other relevant information, maps, figures, and pictures.
TMDLs are a requirement found in Section 303(d), of the Clean Water Act. Once a site is included on the 303(d) list of impaired waters, a TMDL must be developed within two to thirteen years of initial listing. In South Carolina, TMDLs are developed and proposed by SCDHEC and then forwarded to EPA Region 4 for final approval.
TMDLs are calculated by adding all the point and nonpoint sources for the pollutant causing the impairment. After a TMDL is calculated, the amount of load entering from point and nonpoint sources is compared to the water quality standards for that waterbody. Then this total load is reduced to the levels of meeting water quality standards. This reduced load is then divided among all the point and nonpoint sources.
The goal of a TMDL is to identify potential pollution sources, calculate, and quantify the reduction of those sources and to implement general information needed in order to meet water quality standards and improve water quality. After the approval of the TMDL, an implementation plan can be developed to realize the goals of the written TMDL document. Implementation of a TMDL has a potential to reduces sources of pollution within a watershed and a potential to restore the full use of the waterbody.
SCDHEC’s TMDL Regulations (R 61-110) can be found at: TMDL Regulation
Anderson County TMDL Documents
Big Generostee Creek
Broad Mouth Creek
Rocky River Watershed and Wilson Creek
Upper Saluda River Basin
Upper Savannah River Basin
Anderson County Watershed Map.pdf