5 Colo. Code Regs. § 1002-61.25
These amendments are necessary to facilitate the complementary amendments to the Basic Standards and Methodologies which resulted from extensive public hearing input identifying deficiencies in the stream classification and water quality standards-setting process. The Water Quality Control Commission determined that three areas of the Basic Standards Regulation should be examined -Metals/Methodologies, Nitrogen Standards, and the Aquatic Life Classification. These committees composed of experts in the various subject areas were organized to investigate and report on recommended improvements to those subjects. The Commission chose to revise the Basic Standards Regulation for Metals/Methodologies and the Nitrogen Standards initially, and to postpone revisions to the Aquatic Life Classification system.
Since there is a clear and necessary relationship between the stream classification/water quality standards system and the discharge permit system, it was considered vital to provide a clear implementation procedure for the changes to the stream standards resulting from the committees' work. This implementation procedure is embodied in the amendments to this regulation.
All revisions are confined to Section 6.9.2 of this Regulation, entitled Definition of Effluent Limitations. Since the recommendations of the committees to adopt an acute/chronic stream standard system for metals and nitrogen species, discharge permits should reflect this important change. Other changes to monitoring methods, low flow basis, compliance period, and increase in ambient metals level were incorporated in the procedures for establishing discharge limitations to assure that the Basic Standards Regulation is properly applied.
Fiscal Impact Statement
Since these amendments implement complementary changes to the Basic Standards and Methodologies, no separate and unique fiscal impact results. The fiscal impact to users of and dischargers to state waters is described in the Basic Standards and Methodologies' Statement of Basis and Purpose (1987 Revisions) and the accompanying Fiscal Impact Statement.
5 CCR 1002-61.25