Section 303(c)(2)(B) of the Federal Clean Water Act (CWA) requires that South Carolina's water quality standards be reviewed and revised, where necessary, at least once every three years for the purposes of considering the Environmental Protection Agency's most recent numeric and narrative criteria and to comply with recent Federal regulatory revisions and recommendations. This process is commonly referred to as the triennial review . Regulations to be reviewed during the triennial review include Regulation 61-68, Water Classifications and Standards, and Regulation 61-69, Classified Waters. Topics that are typically considered during each triennial review include, but are not limited to:
- Review and, where appropriate, adoption of revised federal water quality criteria to reflect the most current final published criteria according to Sections 304(a) and 307(a) of the CWA.
- Addition or revision of definitions.
- Stylistic changes which may include corrections for: readability, grammar, punctuation, typography, codification, references, and language style.
Additional topics are addressed during the triennial review process as needed.