§ 25-8-204 — Water quality standards

Colorado § 25-8-204

• Jurisdiction: Colorado
• Title 25: Public
• Art.: Water Quality Control

Text

(1) Water quality standards shall be
promulgated by the commission by regulations which describe water
characteristics or the extent of specifically identified pollutants for state waters.

(2) Water quality standards may be promulgated with respect to any
measurable characteristic of water, including, but not limited to:

(a) Toxic substances;

(b) Suspended solids, colloids, and combinations of solids with other
suspended substances;

(c) Bacteria, fecal coliform, fungi, viruses, and other biological constituents
and characteristics;

(d) Dissolved oxygen, and the extent of oxygen demanding substances;

(e) Phosphates, nitrates, and other dissolved nutrients;

(f) pH and hydrogen compounds;

(g) Chlorine, heavy metals, and other chemical constituents;

(h) Salinity, acidity, and alkalinity;

(i) Trash, refuse, oil and grease, and other foreign material;

(j) Taste, odor, color, and turbidity;

(k) Temperature.

(3) Water quality standards may be promulgated for use in connection with
any one or more of the classes of state waters established by the commission
pursuant to section 25-8-203 and may be made applicable with respect to any
designated portion of state water or to all state waters.

(4) In promulgating water quality standards, the commission shall consider:

(a) The need for standards which regulate specified pollutants;

(b) Such information as may be available to the commission as to the degree
to which any particular type of pollutant is subject to treatment; the availability,
practicality, and technical and economic feasibility of treatment techniques; the
impact of treatment requirements upon water quantity; and the extent to which the
discharge to be controlled is significant;

(c) The continuous, intermittent, or seasonal nature of the pollutant to be
controlled;

(d) The existing extent of pollution or the maximum extent of pollution to be
tolerated as a goal;

(e) Whether the pollutant arises from natural sources;

(f) Beneficial uses of water; and

(g) Such information as may be available to the commission regarding the
risk associated with the pollutants including its persistence, degradability, the
usual or potential presence of the affected organism in any waters, the importance
of the affected organisms, and the nature and extent of the effect of the pollutant
on such organisms.

(5) In establishing water quality standards using statistical methodologies or
in requiring the use of statistical methodologies for permit or enforcement
purposes, statistical methodologies used must be based on assumptions that are
compatible with the water quality data.

(6) For the purpose of implementing section 303(c)(2)(B) of the federal act,
the commission may adopt numerical water quality standards for toxic pollutants
listed pursuant to section 307(a)(1) of the federal act for which criteria have been
published under section 304(a) of the federal act, and these standards may be
applied in accordance with this article to discharges of pollutants to specified
portions or segments of surface waters where such pollutants may be discharged
or are present in the affected surface waters and could reasonably be expected to
interfere with classified uses. Monitoring requirements for discharges of such
pollutants shall be reasonably related to the potential for the presence of such
pollutants in the discharge at levels inconsistent with water quality standards and
shall be imposed to the maximum extent practical on those responsible for the
presence of the pollutants. This subsection (6) does not in any way limit the
commission's authority to adopt water quality standards in order to comply with
provisions of the federal act.

(7) If, after full application of publicly owned treatment work authority
pursuant to section 307(b)(1) of the federal act, stream standards or effluent
limitations established pursuant to subsection (6) of this section are exceeded as a
result of a discharge from a publicly owned treatment work, the commission, upon
request of a publicly owned treatment work, shall conduct a public hearing to
investigate the source of pollution causing such exceedance.

Legislative History

Source: L. 81: Entire article R&RE, p. 1317, � 1, effective July 1. L. 85: (3) amended, p. 907, � 4, effective June 4. L. 89: (6) and (7) added, p. 1174, � 3, effective June 8. L. 96: (7) amended, p. 1260, � 162, effective August 7.