PERMFILE48500

• Permit No: M2001001
• IBM Index Class Name: Permit File
• Doc Date: 3/21/2001
• Doc Name: STATEMENT OF ISSUES
• Media Type: D
• Archive: No

' REGULATION NO. 31
THE BASIC STANDARDS AND METHODOLOGIES FOR SURFACE WATER
' 31.1 AUTHORITY AND SCOPE
This regulation is promulgated pursuant to 25-8-101 et sec ., and in particular, 25-8-203 and
25-8-204, C.R.S. It provides basic standards, an antidegradation rule and implementation
process, and a system: for classifying state surface waters; for assigning water quality
1 standards; for granting temporary modifications and for periodic review of the classifications and
standards.

1

31.2 PURPOSE
This regulation establishing basic standards and an antidegradation rule and implementation
process and establishing a system for classifying state surface waters, for assigning standards,
and for granting temporary modifications (hereinafter referred to as "Regulation") is the
foundation for the classification of the state surface waters of Colorado, as prescribed by the
Colorado Water Quality Control Act.
It is intended to implement the state Act by maintaining and improving the quality of the state
surface waters. This regulation is based on the best available knowledge to insure the
suitability of Colorado's waters for beneficial uses including public water supplies, domestic,
agricultural, industrial and recreational uses, and the protection and propagation of terrestrial
and aquatic life.
It is further intended to be consistent with the 1983 and 1985 goals and objectives of the federal
Act. This regulation shall be constructed in a manner consistent with these purposes and shall
be considered part of the implementation of the 1983 and 1985 goals and objectives.
31.3 INTRODUCTION
This regulation presents a classification system which establishes beneficial use categories
together with basic standards (section 31.11), an antidegradation rule (section 31.8), and
numeric tables which define the conditions generally necessary to maintain and attain such
beneficial uses. In addition, it establishes procedures for classifying the waters of the state, for
assigning water quality standards, and for continued review of the classifications and standards.
The classifications set forth in section 31.13 will be assigned by applying the system to specific
state surface waters, in accordance with proper procedures, including public hearings. The
basic standards and the antidegradation rule will apply to all state surface waters at the effective
date of this regulation. Whenever a specific stream segment or body of water receives a
classification for one or more of the uses, additional numeric standards may be assigned.
When appropriate, achieving water quality standards through innovative solutions or
management approaches may be implemented through control regulations. All classified uses
will be protected. This does not mean that any entity has the right to rely on the presence of
specific pollutants in the stream even though those pollutants may be utilized by the entity.