5 Colo. Code Regs. § 1002-35.14
The provisions of 25-8-202 (1)(a), (b) and (2); 25-8-203; 25-8-204; and 25-8-207 C.R.S., provide tine specific statutory autlnority for adoption of tine attaclned regulatory amendments. Tine Commission also adopted, in compliance with 24-4-103(4) and 24-4-103(8)(d) C.R.S., the following statements of basis and purpose and fiscal impact.
BASIS AND PURPOSE:
The hearing that resulted in these amendments was held as the result of a petition submitted by the Idarado Mining Company (Idarado). Idarado requested that the Commission, pursuant to 25-8-207 C.R.S., make a finding of inconsistency regarding certain use classifications and water quality standards in effect for the San Miguel River and related tributaries and that those classifications and standards be declared viod ab initio. Idarado also requested that the Commission establish and adopt revised segment boundaries, use classifications and water quality standards for those waters. The Idarado proposal was opposed by the Division of Wildlife (DOW), the Town of Telluride, and San Miguel County (who were also parties to the proceeding), and by the Water Quality Control Division (WQCD).
Idarado owns the Idarado Mine located, in part, approximately one-half mile east of the Town of Telluride, County of San Miguel, Colorado. That portion of the mine is located in the San Miguel river drainage basin which is a part of the Lower Dolores river Basin (3.5.0) 5 CCR 1002-8.
The headwaters of the San Miguel River, Formed by the confluence of Bridal Veil and Ingram Creeks, are located approximately one mile east of the Idarado mine and Pandora Mill site. The San Miguel River then flows past Idarado's properties, through the town of Telluride, and eventually to the Dolores River several miles downstream.
Idarado presently discharges water from the mine pursuant to a National Pollutant Discharge Elimination System permit (No. CO-0026956). Discharges from the mine are to the ground, not directly to surface waters.
The State of Colorado, in 1983, sued Idarado under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 ("CERCLA"), 42 U.S.C. & 9601 et sect. In that action, the State alleges that Idarado's operations have resulted in injury to the environment. Idarado has vigorously contested that allegations and that action is presently pending in federal district court. Much of the information presented in this proceeding originally was generated in connection with the State CERCLA litigation.
Summary of Action:
Segment 3 of the San Miguel is resegmented into segment 3a above Marshall Creek and segment 3b below. Marshall Creek and Ingram Creek are divided into separate segments segment 6a for Ingram Creek and segment 6b for Marshall Creek. The existing classifications are retained for all segments.
For new segment 3a, the existing numeric standards are retained except that the zinc standard is changed to 0.19 mg/l, a table value standard (for the 0 to 100 hardness range) is adopted for lead, and 6-yearfor Marshall Creek. The existing classifications are retained on all segments.
For new segment 3a, the existing numeric standards are retained except that the zinc standard is changed to 0.19 mg/l, a table value standard (for the 100 to 200 hardness range) is adopted for lead, the table value standard for nickel is revised, based on the new hardness range, and 6-year temporary modifications based on the existing ambient quality are adopted for cadmium, copper, lead and zinc.
For new segments 6 a and 6b, the existing numeric standards are retained except tinat tine zinc standard is cinanged to 0.19 mg/l, table value standards (for the 0 to 100 hardness range) are adopted for cadmium, copper, and lead, and 6-year temporary modifications based on the existing ambient quality (except where it is already better than table values) are adopted for cadmium, copper, lead and zinc.
For the reasons elaborated below and in the Fiscal Impact Statement, the Commission has determined that these changes are economically reasonable. This is particularly the case since the costs that will be incurred by Idarado to achieve the revised standards are the result of a need to remedy prior impacts caused by Idarado.
Resegmentation:
The resegmentation of the San Miguel mainstem into segments 3a and 3b is warranted because water quality differs above and below Marshall Creek and significantly different aquatic life habitat is attainable above and below this point. Because of the influence of Marshall Creek, water quality in the San Miguel is significantly different below their confluence.
There was evidence that habitat limitations in the mainstem are significantly more pronounced above Bear Creek (downstream of Marshall Creek) due in part to rechannelization as the result of Idarado's operations and due to lower stream flows. The mainstem has been resegmented at Marshall Creek rather than Bear Creek because there was evidence that habitat limitations on the mainstem between those two creeks are largely correctable.
The resegmentation of Ingram and Marshall Creeks into segments 6a and 6b is warranted by the significantly different current water quality of those two streams
Idarado proposed the establishment of additional sub-segments on the San Miguel mainstem and of separate segments for several additional tributaries which currently are grouped together as part of segment 2. The additional mainstem resegmentation appears unnecessary at this time. While there is evidence of some variations in water quality and habitat in this stretch, they do not appear substantial enough to warrant further resegmentation. Also, there is not enough differences to warrant, separate segmentation for the other tributaries. Moreover, it is not apparent that further resegmentation would have significantly different regulatory impacts on potential affected entities.
Classifications:
Retention of the existing classifications is warranted by the evidence submitted. Marshall Creek and Ingram Creek retain their current cold water aquatic class 2 designation because of the evidence that they currently are, and are likely to remain, habitat-limited. No parties challenged this classification.
The other segments at issue retain their current cold water aquatic life class 1 designations. For the mainstem of the San Miguel, below Bear Creek all parties agreed that the class 1 designation is appropriate. From Bear Creek upstream to Marshall Creek, there was evidence of some degree of current habitat limitations, as well as water quality limitations on aquatic life. The Commission believes that any habitat limitations are correctable within a twenty year period.
For new segment 3a above Marshall Creek, there was some evidence that flows in this stretch are very limited, creating a significant habitat limitation. However, there was other evidence that there are substantial flows in this segment for significant parts of the year, adequate to support a variety of aquatic life.
For the other tributaries that were not resegmented or reclassified, there was some evidence that habitat limitations may be a significant factor on these streams, due primarily to flow and gradient conditions. However, the Commission does not believe this evidence was substantial enough to warrant reclassification. Moreover, it is not apparent that reclassification of these tributaries would have significantly different regulatory impacts on potentially affected entities.
Standards:
The revised metals standards for segments 3a, 3b, 6a and 6b have been adopted because the information currently available indicates that the more stringent levels should be attainable within a 20-year period. All parties agreed that significant improvement in water quality will occur as a result of the changes that will be implemented due to the legal actions that has been instituted under the Comprehensive Environmental Response, compensation and Liability Act (CERCLA). At a minimum,, the cleanup plan proposed by Idarado Mining Company will result in some water quality improvement. The standards are consistent with levels found to be achievable by the Record of Decision prepared by the State in the CERCLA action.
The Commission recognizes that the evidence demonstrates some uncertainty as to exactly what water quality levels will be achievable following any cleanup of the site. However, in view of (1) the evidence submitted, (2) the desirability of establishing specific standards that can serve as a goal for regulatory and planning purposes, and (3) the Water Quality Control Act's policy of encouraging water quality improvement where feasible, the revised standards are appropriate at this time. If additional information developed in the future demonstrates that any of these standards are in fact not attainable within a 20-year period, the standards can be revised accordingly.
For those revised standards based on table values, for segment 3b the values associated with the 100 to 200 hardness range have been used because the data indicates that hardness for this segment typically is in this range. Although the Commission typically has used alkalinity levels instead of hardness where that would result in more protective standards, harness has been used here because of the greater quantity of hardness data available.
The Commission also has adopted temporary modifications for the metals for which standards have been revised, based on the current ambient quality, as calculated by the "mean plus one standard deviation: methodology. The adoption of these temporary modifications recognizes that cleanup of past mining-related impacts and resulting water quality improvement will take time. Thus, the temporary modifications recognize current conditions, while the revised standards establish goals that should be using for purposes of cleanup and other planning decisions. The temporary modifications have been adopted for six years because it appears from the evidence that completion of any site cleanup as a result of the CERCLA litigation will take at least that long. It is anticipated that the need for the temporary modifications would be reviewed in the 1992 triennial review of the Gunnison and Lower Dolores River Basin standards. At that time, the temporary modifications may be extended if new information then available demonstrates that the underlying standards cannot be attained by the expiration date of the current temporary modifications.
The Commission rejected the argument by Idarado that permanent standards should be set equal to the existing instream quality. The Commission Believes that water quality does act as a limiting factor with respect to aquatic life in these segments. Moreover, as a matter of policy the Commission does not believe that only those aquatic life currently present in these segments warrant protection.
Summary:
The Commission Inas determined tinat tine "findings of inconsistency" requested by Idarado pursuant to 25-8-207, C.R.S. is not appropriate. Use classifications and water quality standards for aquatic life for the segment in question are not more stringent than is necessary to protect fish life, shellfish life, and wildlife in water body segments which are reasonably capable of sustaining such life. Moreover, use classification and water quality standards were not adopted based upon material assumptions that were ion error or no longer apply. Based on new developments and new information since the original classification and standard-setting proceeding, the Commission has adopted revisions to stream segmentation and standards, as described above.
5 CCR 1002-35.14