Triennial Water Quality Standards Update

The Clean Water Act (CWA) requires states and authorized tribes to periodically review and, as appropriate, adopt new or revised water quality standards (WQS) to meet the requirements of the CWA and consider the latest science regarding water quality protection. States and tribes must submit any new or revised WQS resulting from such a review to the EPA for review and approval or disapproval action under CWA Section 303(c).

Tribes may revise their WQS in a variety of ways including additions of and revisions to designated uses, water quality criteria, antidegradation policies and adopted implementation procedures, or other general policies. The following are examples of items that states and tribes should consider when reviewing their WQS:

  • New federal, state, or tribal statutes, regulations, or guidance.
  • Legal decisions involving WQS.
  • New or updated scientific information (e.g., new or updated Section 304(a) national criteria recommendations).
  • Input from members of the public.
  • Available water quality monitoring data.
  • Other necessary or appropriate clarifications or revisions.

Our current WQS are available here

2021 Rational Document Available here

2021 Triennial Water Quality Standards Final Draft Redline Available here


The public comment period is open through February, 28 2022 and a virtual Hearing is scheduled February 1st  from 3 - 5 pm.  To attend the live virtual Hearing please use the following link and numbers:

Join Zoom Meeting: https://us02web.zoom.us/j/89029050867


Questions, comments and requests for additional information should be directed to Colin Larrick, Water Quality Program Manager via email or phone (970) 739-3741