5 Colo. Code Regs. § 1002-34.23

Current through Register Vol. 47, No. 11, June 10, 2024
Section 5 CCR 1002-34.23 - STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE; SEPTEMBER 12, 1994 HEARING:

The provisions of 25-8-202(1)(a), (b) and (2); 25-8-203; 25-8-204; and 25-8-402 C.R.S. provide the specific statutory authority for adoption of these regulatory amendments. The Commission also adopted in compliance with 24-4-103(4), C.R.S., the following statement of basis and purpose.

BASIS AND PURPOSE

A.BACKGROUND

Between 1991 and 1993 the Water Quality Control Division, in cooperation with several federal, state, local and private interests conducted an intensive water quality investigation of the Animas River and its tributaries from Elk Creek to the headwaters. The objectives of the study were to characterize the current chemical, biological, and physical conditions of the Animas River and selected tributaries above Elk Creek and to quantify the areas of highest metal loadings and determine the potential for water quality improvement sufficient to allow naturally reproducing trout populations; and to prioritize sites for remedial projects based on relative loading, environmental impact, feasibility, cost, and benefits.

The water quality of this area is extensively impacted by heavy metals which are attributed to both natural and anthropogenic factors. The results of the investigation have been used to identify the beneficial uses and water quality that are currently being achieved or that may reasonably be achieved within a twenty year period through restoration of disturbed sites.

B.OVERVIEW

The starting point for the Commission's analysis is a conclusion that appears to be shared by most, if not all, of the participants in this rulemaking proceeding: current water quality in the Animas River Basin can and should be improved. For example, quoting from the Statement of the Animas River Stakeholders' Group:

All stakeholders agree that current water quality can and should be protected from any further degradation; all agree that there are opportunities to make improvements, and that improvement is desirable even if it were not mandated; all agree that the task before us now is to identify the sources of significant human-caused loadings and find ways to remediate them.

Beyond this starting point, there was considerable debate in the hearing, and among Commission members in its initial deliberations, regarding the most appropriate and constructive way to encourage and stimulate the desired water quality improvement. One perspective offered was that the Commission should adopt underlying numerical and narrative standards for the critical segments in question that would establish goals for water quality improvement, tempered by temporary modifications that recognize current water quality. An alternative perspective suggested that adopting such goals as legally effective standards before the feasibility of specific clean-up projects had been determined-and the achievable improvement quantified-may hinder the cooperative, community-based effort that has been evolving to identify, prioritize and acquire funding for remediation projects.

Following extensive discussion and debate, the Commission has decided to adopt a hybrid result that consists of two components. First, the set of proposals advanced by the Water Quality Control Division staff, based on the promulgation of underlying goal-based numerical and narrative standards for the critical segments, is adopted by the Commission with a three-year delayed effective date. The Commission finds that the evidence submitted in the hearing provides a sound scientific basis for the adoption of the Division's proposal, with the caveat that three-year temporary modifications almost certainly will not provide an adequate period in which to achieve water quality improvement that will attain the underlying standards. The issue of temporary modifications is discussed further below.

The second component of the action being taken by the Commission is the adoption of ambient quality-based standards that will be in place for the critical segments until the effective date of the goal-based standards described above. The purpose of taking this step, as opposed to adopting the goal-based standards with an immediate effective date, is to encourage the cooperative, community-based effort toward water quality improvement that has begun in the basin, unencumbered by the potential implications of the goal-based standards being in effect. This action is an experiment, intended to assess the ability of a cooperative process to achieve meaningful progress toward water quality improvement without the underlying improvement goal being reflected in currently effective, legally binding water quality standards.

If substantial progress toward water quality improvement-through the identification, prioritization and implementation of remediation projects-is achieved within the next three years, and if it appears three years from now that the lack of legal effectiveness of the goal-based standards will provide the best stimulus for further progress, further delay in the effective date of the goal-based standards can be considered by the Commission at that time. Of course, such progress could also demonstrate that the identified goals are achievable, or that they should be refined in some manner.

If, however, substantial and diligent progress toward water quality improvement is not achieved over the next three years, it is the intent of the Commission that the goal-based standards should and will be allowed to go into effect at that time to stimulate further progress. In a new rulemaking hearing, the burden should be on those that have argued that clean-up will be more successful with a cooperative effort working toward a goal, without that goal being reflected in currently effective water quality standards, to demonstrate the success of this experiment.

The Water Quality Control Commission expects that the cooperative effort will be successful and is attempting by this action to send that message to all stakeholders. To those concerned about the potential impacts on property owners of goal-based standards being in effect, the message is that the Commission wants to encourage this locally-driven, cooperative watershed improvement initiative by demonstrating as much flexibility as possible. To federal agencies or others with potential resources to devote to water quality improvement efforts, the message is that working toward such improvement in this basin is an extremely high priority for the State of Colorado. To the Water Quality Control Division and those that supported their proposal in this rulemaking proceeding, the message is that the Commission has been persuaded-based on the unprecedented level of monitoring and analysis that has occurred in this basin-that a sound scientific justification has been provided for the adoption of goal-based water quality standards, and that these standards should be allowed to go into effect unless it is demonstrated that the pending experiment in cooperative watershed management can succeed without this legal impetus. To all of the residents of the Animas River Basin, the message is that the Commission is concerned about water quality in your basin and is willing to work with you to explore whatever options appear most likely to facilitate progress toward water quality improvement in the least disruptive and most expeditious manner.

In summary, the Commission's action in revising the Animas River Basin water quality classifications and standards should in no way be interpreted as a sanctioning of the status quo. To repeat, current water quality in the Animas River Basin can and should be improved. The purpose of the Commission's action is to establish a clear goal of attaining such improvement, while providing regulatory flexibility intended to encourage cooperative efforts toward such improvement.

C.IMPLICATIONS OF THE HYBRID ACTION

Because of the unorthodox nature of the hybrid action being taken, the Commission believes that it may be important to clarify its understanding regarding the implications of this action for various activities or decisions that will need to be undertaken by others during the next three years.

For any existing point source discharge permit that may come up for renewal during the next three years, or for any new wastewater discharge permit issued during this period, the Commission intends that the permit would be written based on the ambient quality-based standards then in effect, along with other applicable effluent quality restrictions. The Commission also understands that ambient quality-based standards would require the continuation of current treatment levels for permit renewals, to assure that further degradation of water quality does not occur.

To the extent that general or individual storm water permits may be required for some sites in the basin, the Commission understands that the water quality standards now being adopted are not likely to affect the content of the first round of any such permits, which are anticipated to be based principally on the implementation of best management practices (BMPs). Such initial BMPs are not likely to be significantly different whether they are deemed to be technology-based or water quality-based.

Finally, as discussed above, the Commission intends this action to provide a clear message to other agencies, entities and persons involved with potential nonpoint source clean-up projects that the Animas River Basin is in fact a high priority for such efforts. The delayed effective date for goal-based standards should not be interpreted to in any way lessen the priority of this basin; rather, as discussed above, this hybrid action is intended to provide flexibility for the cooperative, community-based efforts toward clean-up while at the same time clarifying that improvement is the goal.

D.DELAYED CLASSIFICATIONS AND STANDARDS

This portion of this statement describes the basis for the goal-based standards that are scheduled to go into effect three years after the effective date of this action.

The upper Animas water quality study found that the Animas River and several tributaries above Maggie Gulch (segment 2), the Animas River from Cement Creek to Mineral Creek (segment 3b), Cement Creek and its tributaries (segment 7), and Mineral Creek above the confluence with South Mineral Creek (segment 8) do not support diverse forms of aquatic life owing to poor water quality and limited physical habitat. The imposition of effluent limits required under the Federal Act for point sources and cost-effective and reasonable best management practices (BMP's) for nonpoint sources are not likely to lead to the establishment of aquatic life in these segments. Additionally, federal regulation (40 C.F.R. 131.10) allows excluding an aquatic life classification where naturally occurring pollutant concentrations prevent the attainment of the use and/or human caused conditions or sources of pollution prevent the attainment of the use and cannot be remedied or would cause more environmental damage to correct than to leave in place. Therefore, an aquatic life classification is not being adopted for these segments. Downstream use classifications, however, depend on maintaining or improving the water quality in these segments. The Commission has therefore, determined that narrative standards for metals based on the application of BMP's to nonpoint sources and the continuation of current treatment levels for existing point sources for these segments establish an appropriate goal for water quality in these segments. Narrative (and for zinc in segment 3b, numerical) temporary modifications have been adopted based on current ambient quality in these segments, to assure no additional degradation of downstream segments.

The Commission recognizes that even with aggressive clean-up efforts, it may take many years to achieve in-stream quality that attains the underlying goal-based standards. Three-year temporary modifications are being adopted in an attempt to avoid conflict with the current EPA policy that temporary modifications are variances that can not be extend for longer than three years without being readopted. The Commission anticipates that many, if not all, of the temporary modifications being adopted in this proceeding will need to be extended beyond three years to attain the underlying standards, even considering the delayed effective date of that portion of the action that includes temporary modifications.

The Commission has further determined that the Animas River between Maggie Gulch and Cement Creek (segment 3a) supports a population of brook trout that appears to be naturally reproducing in that it consists of multiple age classes. The segment also contains a diversity of macrobenthos and possesses physical habitat similar to other streams in the Southern Rocky Mountain ecoregion. Although the concentration of several metals, especially cadmium and zinc, are higher than what is required to protect the most sensitive aquatic life species, they are lower than the chronic toxic criteria for brook trout. Therefore a cold water aquatic life class 1 classification is being established to protect the resident aquatic life found in this segment. Ambient standards for cadmium and zinc are adopted to ensure that downstream use classifications and standards are not jeopardized. The imposition of effluent limits required under the Federal Act for point sources and cost- effective and reasonable best management practices for nonpoint sources are not likely to lead to the establishment of the most sensitive aquatic life species in this segment. However, consistent with its prior practice, the Commission has determined that the most sensitive species need not be present to find that a segment is "capable of sustaining a wide variety of cold water biota, including sensitive species", warranting a cold water class 1 classification. Section 3.1.7 authorizes ambient standards where natural or irreversible man-induced ambient levels are higher than TVS but are adequate to protect the classified uses.

Mineral Creek between South Mineral Creek and the Animas River, renumbered segment 9b, was already classified aquatic life cold water class 1, with total recoverable table value standards. The upper Animas water quality study showed that pH, aluminum, copper, iron, and zinc greatly exceed TVS in this segment and that both fish and macroinvertebrates are absent from the segment. The physical habitat assessment, however, found it comparable to other habitats within the Southern Rocky Mountain ecoregion. Because most of the aluminum, copper, iron, and zinc are contributed from two areas, there may be a potential to reduce loading from either or both of these areas. The Commission chose not to remove the aquatic life classification until it has been demonstrated that sources cannot be remedied within a twenty year period or would cause more environmental damage than to leave it in place. The Commission adopted TVS for segment 9b, together with temporary modifications for aluminum, copper, iron, and zinc based on ambient quality until the feasibility of remediation has been established. A use-protected designation has been added to this segment based on four key parameters with existing quality worse than table values.

The Animas River between Mineral Creek and Elk Creek, renumbered segment 4a, has not previously had an aquatic life classification. The upper Animas water quality study found that the water quality below Mineral Creek is suitable for brook trout and has physical habitat similar to other aquatic life streams in the Southern Rocky Mountain ecoregion. Some improvement in water quality from Cement Creek, Mineral Creek, and/or the Upper Animas may enable the water quality of the segment to support brown trout. However, the imposition of effluent limits required under the Federal Act for point sources and cost-effective and reasonable best management practices for nonpoint sources are not likely to lead to the establishment of aquatic life uses including the most sensitive species in this segment. The Commission adopted the aquatic life cold class 1 classification as a goal and TVS for this segment, except for the zinc standard which is based on the chronic toxic criterion for brown trout. Consistent with its prior practice, the Commission has determined that the most sensitive species need not be present or attainable to find that a segment is or may become "capable of sustaining a wide variety of cold water biota, including sensitive species", warranting a cold water class 1 classification. A temporary modification for zinc, based on the ambient quality, has been adopted until the feasibility for load reduction has been established.

E.AMBIENT QUALITY-BASED STANDARDS

This portion of this statement describes the basis for the ambient quality-based standards that are adopted for the three-year period starting with the effective date of this action.

For segments 2, 3b, 7 and 8, the Commission has adopted a narrative standard based on existing ambient quality for all metals to be applicable for the next three years. For segments 4a, 4b, and 9b, for this same time period the Commission has adopted ambient-quality based numerical standards for specific metals for which ambient quality currently is higher (worse than) table values. These standards are intended to protect the aquatic life that is currently in place in these segments until the goal-based standards go into effect. As discussed above, the primary basis for adopting these numerical and narrative ambient quality-based standards is to provide maximum regulatory flexibility to encourage the cooperative, community-based effort toward clean-up to proceed. This approach provides time in which additional information can be developed regarding the feasibility of specific remedial efforts that will result in water quality improvement.

Having ambient standards in place for the next three years means that any point source permits issued or renewed during this period will be based on those ambient standards, along with other applicable effluent quality restrictions, rather than being based on the more stringent goal-based standards. At the same time, the ambient standards should help assure that no additional degradation in water quality occurs for these segments in the next three years while clean-up actions are being examined and initiated.

For segment 4a, the aquatic life cold class 2 classification and the use-protected designation proposed by Sunnyside have been adopted for the next three years, since this classification and designation appear to be more consistent with the ambient standards applicable during that period. As discussed above, at the end of three years the use-protected designation would expire and the aquatic life classification would become cold water class 1.

For segment 9b, the currently applicable class 1 aquatic life classification has been left in place, even though ambient standards proposed by Sunnyside have been adopted for the next three years. The Commission believes that a downgrading of the classification of this segment is premature, pending additional analysis of clean-up opportunities. As noted above, the use-protected designation proposed by the Division and several parties has also been adopted.

F.OTHER ISSUES

The above discussion, like the evidence submitted at the hearing, focuses principally on appropriate aquatic life classifications and associated water quality standards. In this hearing the Commission also added an agriculture classification to segments 2, 3a, and 7, based on evidence regarding the presence of grazing. In addition, the Commission changed the recreation classification from class 2 to class 1 for segments 4a, 4b, 5a, and 5b, based on evidence regarding the presence of primary contact recreation. Finally, fecal coliform standards for segments 2 and 3a were changed from 2,000 to 200/ml, to provide additional protection that better reflects current ambient conditions. There are no affected point sources on these segments.

5 CCR 1002-34.23

37 CR 17, September 10, 2014, effective 3/1/2015
38 CR 03, February 10, 2015, effective 6/30/2015
39 CR 03, February 10, 2016, effective 3/1/2016
39 CR 03, February 10, 2016, effective 6/30/2016
40 CR 03, February 10, 2017, effective 6/30/2017
40 CR 17, September 10, 2017, effective 12/31/2017
42 CR 04, February 25, 2019, effective 6/30/2019
43 CR 03, February 10, 2020, effective 6/30/2020
44 CR 05, March 10, 2021, effective 6/30/2021
44 CR 17, September 10, 2021, effective 12/31/2021
45 CR 17, September 10, 2022, effective 9/30/2022
46 CR 10, May 25, 2023, effective 6/14/2023