On this page:
State Standards in Effect for CWA Purposes
- [See Rules of Department of Natural Resources: Division 20- Chapter 7 - 10 CSR 20-7.010 - 10 CSR 20-7.050 (2012) ]
(Effective September 27, 2013) Water quality standards for waters of the state. Please note that some provisions in this document have not been approved by EPA and are therefore not in effect for CWA purposes. See the cover page for more information. - [See Variances to Missouri Surface Water Quality Standards ]
(Effective February 25, 2015) Information detailing EPA-approved variances from water quality standards for dischargers to Missouri surface waters.
Federally Proposed or Promulgated Standards
None at this time.
Federal Clean Water Act Determinations that New or Revised Standards Are Necessary
EPA has issued the following determinations under Clean Water Act section 303(c)(4)(B) that new or revised standards are necessary. EPA may propose federal replacement standards in these cases if the state does not adopt standards consistent with the Act.
- Determinations that New Water Quality Standards are Necessary to Protect the Mississippi River for Recreation
- For segments upstream and downstream of St. Louis
- For the segment near St. Louis
- Determination that New Water Quality Standards are Necessary to Protect Water Body Segments in the State of Missouri
- Rules of Department of Natural Resources: Division 20- Chapter 7 - 10 CSR 20-7.010 - 10 CSR 20-7.050 (2012) (PDF)(154 pp, 1 MB)
- Variances to Missouri Surface Water Quality Standards (PDF)(2 pp, 232 K)
- Determination Letter (PDF)(7 pp, 553 K)
- EPA's Detailed Analysis (PDF)(17 pp, 137 K)
- Determination Letter 12/12/2008 (PDF)(6 pp, 272 K, 12/12/2008)
- Determination Letter 10/29/2009 (PDF)(10 pp, 182 K, 10/29/2009)