Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-32 - REGULATION NO. 32 - CLASSIFICATIONS AND NUMERIC STANDARDS FOR ARKANSAS RIVER BASIN
Section 5 CCR 1002-32.13 - STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE SEGMENT 8a, IOWA GULCH, UPPER ARKANSAS RIVER ARKANSAS RIVER BASIN

Current through Register Vol. 47, No. 5, March 10, 2024

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 the specific statutory authority for adoption of the attached regulatory amendments. The Commission also adopted, in compliance with 24-4-103(4) C.R.S., the following statements of basis and purpose and fiscal impact.

BASIS AND PURPOSE:

Leadville Corporation owns and operates the Sherman Mine at the upper end of Iowa Gulch on the side of Mount Sherman, a 14,000 foot peak. Under the provisions of C.R.S. 25-8-207, Leadville Corporation petitioned for a rulemaking hearing regarding Segment 8a, Iowa Gulch, to review whether new material facts demonstrate that the aquatic life classification is in error for Segment 8a, due to severe physical, natural, climatic, and structural constraints existing in Segment 8a which preclude a viable habitat for fish or shellfish life. Leadville Corporation also sought review of the agriculture classification for Segment 8a, stating that Segment 8a has no existing use or reasonably anticipated future use for agricultural purposes.

Leadville Corporation also sought a change in the applicable water quality standards for Segment 8a to reflect protection only of the domestic drinking water supply and recreation class 2 classifications of Segment 8a. The water quality standards for protection of the two uses proposed to be retained were proposed to be the table values from the Commission's Basic Standards and Methodologies Regulation.

In 1985, a hearing was held in which similar requests were made to delete classifications and modify water quality standards. Those 1985 requests were denied, but the Commission granted a temporary modification to the water quality standards for lead and copper in Segment 8a, Iowa Gulch. This temporary modification altered the standard for copper from 0.007 mg/l to 0.05 mg/l and the standard for lead from 0.022 mg/l to 0.05 mg/l. The temporary modification expires March 5, 1987.

In connection with granting the temporary modification the Commission directed Hecla Mining Co., the predecessor of Leadville Corporation, to conduct a water quality sampling program on Iowa Gulch, Segment 8a, and to analyze the results according to a laboratory method recommended by the Water Quality Control Division. The purpose of the sampling and analysis program, in part, was to ascertain whether the ambient water quality of Segment 8a, Iowa Gulch, justifies the standards which had been previously set by the Commission for this Segment.

Leadville Corporation asserted that the sampling and analysis program showed that the ambient water quality of Iowa Gulch, Segment 8a, exceeds the values the Commission set for at least three metals: copper, lead and cadmium, and that the existing and reasonably anticipated water uses in Segment 8a would not be adversely affected by a change in water quality standards to the table values, and, further, that the existing uses of Segment 8a would be protected if the requested rulemaking proposal were adopted by the Commission. Prior to the hearing, Leadville Corporation and Parkville Water District requested resegmentation of Segment 8a into two separate stream segments.

Summary of Action:

Segment 8a of Iowa Gulch is resegmented into Segments 8a1 and 8a2, with the division between the new segments being at a point immediately below the confluence of the Hilltop Saddle drainage with Iowa Gulch. The existing classifications for Segment 8a are retained for new Segments 8a1 and 8a2. The existing numerical standards for Segment 8a are retained for new Segments 8a1 and 8a2, except for the following revisions:

For the reasons elaborated below, the Commission has determined that these changes are economically reasonable, even if they result in higher treatment costs for the Sherman Mine Portal discharge.

Resegmentation:

The Commission finds that resegmentation of Segment 8a of Iowa Gulch into Segments 8a1 and 8a2 is appropriate. The evidence presented demonstrates that the stream has different physical characteristic above and below the Hilltop Saddle drainage confluence. For example, there is increased stream flow below this confluence. In addition, ambient water quality differs significantly above and below this point.

Finally, this resegmentation will allow the adoption of more stringent water quality standards for Segment 8a2 to fully protect the domestic water supply and other uses of that segment, while avoiding more stringent standards for the upstream Segment 8a1. This results from handling the water quality data for these two segments separately, rather than averaging all Segment 8a data. Leadville Corporation, Parkville Water District, and the Water Quality Control Division agreed that this resegmentation is appropriate.

Classifications:

The Commission finds that there has been no demonstration that the existing aquatic life and agriculture use classifications for Segment 8a were based upon material assumptions that were in error or no longer apply, and accordingly the Commission reconfirms the decision made in 1985 to retain the existing classifications. Moreover, the Commission finds that there has been no demonstration that the aquatic life classification for Segment 8a is more stringent than is necessary to protect fish life, shellfish life, and wildlife in a water body segment which is reasonably capable of sustaining such fish life, shellfish life, and wildlife from the standpoint of physical, streambed, flow, habitat, climatic, and other pertinent characteristics.

Notwithstanding the presence of certain physical barriers to fish in the new Segments 8a1 and 8a2, both are typical high mountain streams. For example, the macroinvertibrate populations are representative of typical streams of this type. No substantial evidence was presented to demonstrate that the previously established agriculture classification is erroneous. There was evidence presented of possible agricultural use of Segments 8a1 and 8a2. Therefore, the Commission has decided to retain the existing use classifications for both Segment 8a1 and 8a2. Leadville Corporation, Parkville Water District and the Water Quality Control Division stipulated to the retention of all existing classifications for Segment 8a2.

Standards:

Based upon the new ambient water quality data submitted at the hearing, the Commission has revised the water quality standards for Segment 8a of Iowa Gulch for four parameters: copper, lead, cadmium, and zinc. Separate standards have been established for new Segments 8a1 and 8a2. For Segment 8a2, Leadville Corporation and Parkville Water District stipulated their agreement with the standards recommended by the Division. At the hearing, Leadville corporation objected only to the Division's proposed lead standard for Segment 8a1.

In establishing revised standards for Segment 8a1, the Commission rejected as a matter of policy the position of Leadville Corporation that ambient water quality data from samples taken at the Sherman Mine Portal should be included in the calculation of standards. The Sherman Mine Portal drainage is a permitted point source discharge. Even if the source of this discharge is essentially ground water, this discharge to the stream would not exist except for the presence of mining operations.

The final revised standards take into account additional data submitted by Leadville Corporation and admitted into the record by the Commission on February 3, 1987. The revised standards are merely a recalculation of ambient quality for the relevant segments based on new data. Recalculation of ambient water quality for Segments 8a1 and 8a2 was done consistently with the policy of excluding certain "outliers" based on the screening process known as Chauvenet's criteria and two "outliers" for lead were excluded from the Division's data base as a result. The revisions do not constitute a downgrading of classified uses for these segments and do not authorize any change in the existing water quality of these segments. For lead and zinc in both segments, and for cadmium in Segment 8a2, the revised standards are in fact more stringent than existing standards.

FISCAL IMPACT STATEMENT:

The retention of the existing classifications for the resegmented Segments 8a1 and 8a2 of Iowa Gulch creates no new fiscal costs of benefits. The revised numerical standards for these segments may have fiscal impacts. The establishment of more stringent numerical standards for Segment 8a2 will provide better protection for the uses in that segment, including the domestic water supply diversion by the Parkville Water District. The water users and ratepayers of the Parkville Water District may benefit economically in terms of water treatment costs and reduced health impacts.

Leadville Corporation submitted evidence that adoption of the revised numerical standards for Segment 8a1 will require an expenditure of $400,000 for treatment of the Sherman Mine Portal discharge. Currently, this is the only permitted mine water discharge in the State that is not treated. Although a determination whether such treatment will be required was not a subject of this hearing, the Commission finds that even if such costs are incurred, this economic impact is justified since the standards established are reasonably necessary to protect the uses of this segment of Iowa Gulch.

The actions taken are not expected to have a significant fiscal impact on the State's administration of water quality control programs.

Dated this 2nd day of March, 1987, at Denver, Colorado.

FINDINGS REGARDING BASIS FOR EMERGENCY RULE SEPTEMBER 11, 1990:

The Commission finds that the immediate adoption of this regulation is imperatively necessary for the preservation of public health, safety, or welfare and that compliance with normal notice requirements would be contrary to the public interest. The reasons for this finding are that action needs to be taken during this winter season to minimize the risk of uncontrolled releases of highly saline water from Cheraw Lake. Specifically, there is a possibility of significant damage to agricultural and domestic water supply uses downstream of Cheraw Lake if undiluted releases occur. There was evidence that the water level in Cheraw Lake currently is near the top of the outlet structure and that therefore releases could occur in the near future, depending on precipitation and return flows into the Lake.

The two release prohibitions which are scheduled to go into effect in 1990 would, of course, not become effective during the life of this emergency rule. However, the Commission finds that the two-year period established in the regulation is necessary for affected entities to take the actions necessary to come into compliance by that time. Necessary actions would include assessment of the problem, analysis of the feasibility of compliance options, arrangements for financing, and completion of design and implementation of any structures or facilities to achieve compliance. Therefore, the Commission finds there is an emergency basis for adopting these provisions, in order to provide adequate notice to affected entities, should these or similar provisions be adopted as permanent regulations. At the same time, the Commission intends to consider at the permanent adoption hearing any other options that may be developed by the Division or outside parties prior to that time.

Paragraph 4.4.2(3) prohibits any release of water from water collection systems into Cheraw Lake after March 15, 1990, irrespective of the quality of such releases. From the evidence provided, it appears that even if distilled water were released into Cheraw Lake, after mixing there is a substantial risk that the water released from Cheraw Lake would be of an unacceptable quality. Moreover, long-term downstream protection can not be accomplished solely by regulating controlled releases, since uncontrolled releases are likely to occur, depending on precipitation and return flows. Therefore water releases into Cheraw must be controlled in order to control outflows.

From the information currently available to the Commission, the limitation on releases into Cheraw Lake should have no adverse impact on water rights. The testimony indicated that there are no current water rights to the water in Cheraw Lake, and did not indicate that any water users upgradient of the Lake currently use the return flows that run into the Lake. In fact, diverting water around Cheraw Lake to comply with section 4.4.2 may have a beneficial impact on water rights by increasing the water supply downstream. Of course, should different information regarding a potential impact on water rights become available prior to the permanent adoption hearing, that may affect any action that the Commission would take as a result of that hearing.

Because of the Commission's extremely full agenda and the time necessary to develop a proposed regulation on this complex issue, the Commission finds that it may be necessary for the emergency regulation to be in effect for up to one year. Therefore, the regulation is to be effective immediately and continue in effect until the effective date of permanent regulations or for one year, whichever comes first. The Commission has agreed to schedule a permanent adoption hearing for November 7, 1988, which is the earliest available time on the Commission's agenda.

The purpose of this regulation is to protect the agricultural uses of water in Horse Creek (Otero and Bent counties) from the highly saline discharges from tributary Cheraw Lake, while also avoiding an unacceptable adverse impact on other downstream water uses, particularly domestic water supplies.

The saline condition of water in Cheraw Lake appears to be caused by highly alkaline native soils in the area together with routing of irrigation return flows to the lake. Traditionally, the shortage of water in the Arkansas River Basin has prevented the lake from overflowing into Horse Creek. Evaporation losses then contributed to the increase in salinity which has exceeded 17000 mg/l (TDS) in the upper layer and 60,000 mg/l at the bottom of the lake based on samples collected by the Division and the USGS. The excess of water caused by the past "wet" years has caused levels in the lake to rise significantly which, in turn, threatened to cause property damage to State Highway 109 and the Town of Cheraw. This led several parties to effect releases from the lake which have damaged and endangered the agricultural use downstream on Horse Creek. This statement is supported by the EPA "Red Book: criteria for irrigation water and Division water quality investigations of the Lake and Horse Creek.

The ambient quality of Horse Creek has exceeded 5000 ppm TDS without influence from Cheraw Lake based on the existing water quality database. Since the agricultural use of the Horse Creek water under those conditions did not appear to be impaired, the salinity levels of Horse Creek will be controlled based on the mean plus one standard deviation of the measured TDS levels in Horse Creek, which is 5270 mg/l. The TDS standard adopted for Horse Creek should help assure that this level is met in the future.

FISCAL IMPACT STATEMENT REGARDING CHERAW LAKE EMERGENCY CONTROL REGULATION AND HORSE CREEK SALINITY STANDARD; AS ADOPTED JANUARY 22, 1988

One group of persons who may incur additional costs as a result of these emergency regulations is anyone who may effect a controlled release of water from Cheraw Lake. Costs, which have not been quantified, would be incurred principally by acquiring a source of dilution water so that releases comply with the salinity limitation. In addition, if the provisions of the emergency regulations are permanently adopted, the prohibition of the release of water from water collection systems into Cheraw Lake after March 15, 1990 may impose substantial costs on the owners of water collection systems who would have to reroute such water away from Cheraw Lake.

The primary persons potentially benefiting from the regulations are agricultural and domestic water users downstream. These persons may benefit by the requirement for water released from Cheraw Lake to be diluted, and from the prohibition of releases of water into Cheraw Lake if that becomes permanent (since that prohibition would minimize the likelihood of further releases from Cheraw Lake). There was evidence submitted that even diluted water released from Cheraw Lake adversely impact downstream users. However, whether any such impacts would be greater or less than would occur without the emergency regulations depends on speculation regarding future precipitation and resulting water use patterns.

The emergency regulations should not have a significant fiscal impact on the State's administration of the water quality control program.