Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-35 - REGULATION NO. 35 - CLASSIFICATIONS AND NUMERIC STANDARDS FOR GUNNISON AND LOWER DOLORES RIVER BASINS
Section 5 CCR 1002-35.71 - STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE; JULY, 2001 RULEMAKING

A. Resegmentation

Some renumbering and/or creation of new segments were adopted in tine basin due to information winicin sinowed tinat:

B. Manganese

The aquatic life manganese criterion was initially changed in the 1997 revisions to the Basic Standards (5 CCR 1002-31) from a single chronic dissolved criterion to acute and chronic hardness-based equations. The equations were further modified in the 2000 revisions to the Basic Standards. The new manganese acute and chronic equations were added as table value standards in 35.6(3). As a result of the adoption of these new TVS, all segments classified for aquatic life use that had a chronic total recoverable manganese standard of 1,000 µg/L had the 1,000 standard stricken and replaced with Mn(ac/ch)=TVS.

C. Selenium

The regulation in 35.6 (3) listed the table value standards for selenium as Acute=20 µg/L and Chronic=5 µg/L. This was updated to reflect the existing acute and chronic criteria for selenium listed in the Basic Standards as Acute=18.4 µg/L and Chronic=4.6 µg/L which was adopted in 2000 by the Commission. This change means that all segments with standards for selenium given as TVS now have these lower acute and chronic standards.

The Commission adopted the table value standards for selenium and temporary modifications of existing ambient quality for selenium for Uncompahgre segment 12, Lower Gunnison segments 4a and 4b, and North Fork segment 6. The Commission also extended the temporary modifications for selenium for Uncompahgre segments 4a, 4b, 4c, and 14 Lower Gunnison segment 2, and North Fork segment 5. The temporary modifications were adopted or extended pursuant to section 31.7 of the Basic Standards regulation, based on the fact that there is significant uncertainty as to the appropriate underlying selenium standard for these segments. The reason for the adoption of the temporary modifications is noted in temporary modifications and qualifiers column of the table.

Water quality monitoring has demonstrated a severe selenium problem in the Lower Gunnison and Uncompahgre River Basins. The Gunnison River Selenium Task Force has been working since 1998 to evaluate the sources of selenium loading to the mainstem of the Uncompahgre and Gunnison rivers and methods to reduce those loads. To date, the effort has focused on attempting to meet the standards in the Uncompahgre and Gunnison River mainstems. Much of this effort has involved evaluating opportunities to reduce the loading, but not necessarily the concentrations, in the tributaries to both the lower Uncompahgre and lower Gunnison Rivers.

Selenium reduction in tine Uncompalngre and Gunnison River Basins is a very complex issue. The tributaries to the Uncompahgre and Gunnison River pass through selenium-laden Mancos shale soils, and the extent to which the current levels of selenium are the result of natural sources, reversible activities, and/or irreversible activities is unknown at this time. Therefore, it is not clear whether the table value standards are achievable in these segments. The Commission does not intend its actions to in any way impede the efforts of the Selenium Task Force to reduce selenium loading in the Uncompahgre and Gunnison Rivers. The Commission intends that the actions taken in this hearing will mark the beginning of a process to identify the appropriate long-term selenium standards for these segments. It is expected that the efforts of the Selenium Task Force and others may result in the adoption of site-specific standards for selenium in some or all of the affected segments.

D. Removal of Use Protected Designation

The Division proposed that a number of aquatic life class 2 waterbodies be assigned undesignated status under the state antidegradation regulation due to the presence of Colorado State species of special concern. State regulations governing the "use-protected" designation allow this exception if the Commission determines that the waters are of exceptional ecological significance. The Commission believes that a number of important issues have been raised in this hearing regarding when and how this exception should be applied, and that further examination of these issues should occur. Nevertheless, for purposes of this hearing, the Commission, based upon a concern over the protection of classified uses and the absence of evidence of potential injury to permitted entities, has decided to accept the change to reviewable water status for the following:

Lower Dolores, Segment 4

Based upon representations made by certain parties to this rulemaking, the Commission endorses the formation of a workgroup to address the following topics and develop recommendations to be submitted to the Commission

The relationship between the "exceptional ecological significance" exception to use-protected designations and the aquatic life class 2 basis for applying use-protected designations

The need for and content of guidance to determine what water bodies are exceptionally ecologically significant

The roles of a) water quality data; b) the nexus between water quality conditions and species decline, and c) other stressors, in using this exception

The need for and nature of any amendments to the state antidegradation regulation if the presence of species of special concern constitute a basis for modification to the antidegradation designation of a water body.

The above listed segments would then be reviewed in light of the work group recommendations in the next triennial review of these basins.

The Commission urges that the work group process to address these issues move forward as expeditiously as possible. The Commission intends that the actions taken in this rulemaking not serve in any way as a precedent with respect to decisions in future Commission rulemaking proceedings.

E. Recreation Classifications/Fecal Coliform and E. Coli Standards

The biological standards were updated to include the dual standards for E. coli and fecal coliform, which were adopted by the Commission in the 2000 revisions to the Basic Standards. As stated in the statement of basis for the Basic Standards revisions, the Commission intends that dischargers will have the option of either parameter being used in establishing effluent limitations in discharge permits. In making section 303(d) listing decisions, in the event of a conflict between fecal coliform and E. coli data, the E. coli data will govern. The Commission believes that these provisions will help ease the transition from fecal coliform to E. coli standards.

In a continuation of the Commission's efforts to comply with the requirements contained in the federal Clean Water Act that all waters of the nation should be suitable for recreation in and on the water (known as the "swimmable" goal), the Commission reviewed all Recreation Class 2 segments. In Colorado, the "swimmable" goal translates into Recreation Class 1a, with the 200/100 ml fecal coliform and 126/100 ml E. Coli standard, and Class lb with the 325/100 ml fecal coliform and 205/100 ml E. coli standard. Class la indicates waters where primary contact uses have been documented or are presumed to be present. Class 1 b indicates waters where no use attainability analysis has been performed demonstrating that a recreation class 2 classification is appropriate, but for which no existing primary contact uses have been documented following a reasonable level of inquiry. A Recreation Class 2 classification must be supported by a use attainability analysis that shows that there is not a reasonable potential for primary contact uses.

There was considerable evidence and testimony submitted in this hearing regarding what activities should be considered primary contact recreation. Section 31.13 (1)(a) of the Basic Standards provides a nonexclusive list of primary contact activities. In this hearing, much discussion focused on the issue of whether "child's play" in streams that are too shallow to accommodate the primary contact uses listed in the Basic Standards should be considered a primary contact use. The Commission does not believe that a theoretical potential for child's play means that all streams should be classified Recreation Class la or lb. However, the Commission concludes that the evidence submitted demonstrates that there is a potential risk of ingestion of small quantities of water by children playing in relatively shallow streams, based on the hand-to-mouth pathway, which warrants Recreation Class 1 protection in appropriate circumstances as elaborated below. Thus, such ingestion may occur in streams where whole body immersion is not likely.

This does not mean, as suggested by some, that all water bodies would be reclassified as Recreation Class la or lb based on some potential for child's play. Rather, the Commission intends that a stream should be classified Recreation Class la or lb due to the presence or potential for child's play only where the evidence demonstrates a likelihood of such activity on a frequently occurring basis. Therefore, child's play may be an appropriate basis for a Recreation Class la or 1 b classification in a developed area where there is easy access to a stream for children and it is likely that children will desire to play in the stream; it may not be an appropriate basis for such classifications in areas where it is not expected that children will be playing in a stream on a frequently occurring basis. Factors such as lack of adequate flow, excessive flows, remoteness from developed areas, physical limitations to access, steep banks, and visibly poor water quality may make it unlikely that child's play will take place on a frequently occurring basis. The Commission anticipates that these classification decisions will require case-by-case judgments until more experience is gathered with this issue.

A recreation Class la or lb classification of a segment is not intended to imply that the owner or operator of property surrounding any waterbody in a segment would allow access for primary contact recreation. The application of recreation classifications to state waters pursuant to these provisions does not create any rights of access on or across private property for the purposes of recreation in or on such waters. A recreation Class la classification is intended to only affect the use classification and water quality standards of a segment, and does not imply public or recreational access to waters with restricted access within a segment.

For segments changing to recreation Class 1a because no evidence or inadequate evidence was submitted on tine record about actual or potential recreational uses, the last paragraph of section 31.6 will apply to future changes to the recreation classification where a proper showing is made through a use attainability analysis that a recreation Class 2 classification is appropriate, without application of the other downgrading criteria in this section. Moreover, the Commission is relying in part on the testimony from EPA that completion of a use attainability analysis showing that a lower recreation classification is appropriate satisfies applicable downgrading criteria. Based on these factors, the Commission intends that in a future rulemaking hearing, the test for adopting a recreation Class 2 classification would be the same as if it had been considered in this hearing.

Upper Gunnison Basin

Currently, there is a potentially explosive controversy escalating in the Upper Gunnison River Basin regarding public recreational floating use of waterways over private land. This controversy has greatly elevated the concern over consequences of some of the recreation use classifications being proposed in connection with this triennial review. The controversy also has greatly magnified the difficulty of conducting a water quality review process which is based on accurate, complete and neutral determinations of recreation uses of watenways.

The Commission recognizes the potential for being drawn into this non-water quality related issue through the process of the triennial review of recreational use classifications. The Commission intends that neither it nor the Division shall be drawn into the controversy.

The Commission has accomplished the majority of the current review in the Upper Gunnison Basin but has taken no action on the recreational use classification or standards for the following segments:

Upper Gunnison segments 5, 6a, 15, 16, 17, 18, 19, 21, 23, 24, and 26 (Under the National Park Service's proposal segments 27, and 28 have been combined into segment 26)

For these segments, the pre-existing recreation classifications and standards will continue. The Commission believes that these classifications and standards are protective of the current uses.

The Commission reiterates that a recreational use attainability analysis is required to support adoption of a Recreation 2 classification. Continuation of the current classification of Recreation 2, with a 200/100ml fecal conform standard until the next triennial review does not represent a decision that Recreation 2 or 200 fecal coliform are the ultimate classification or standards for these stream segments, or eliminate the need to conduct recreational use attainability analyses for any Class 2 stream segments in the future. In addition, the Commission agrees that it would be appropriate for the Basic Standards Implementation work group to address these and similar issues before the next Basic Standards rulemaking.

Otiier Gunnison River Segments

Based on the information received that showed Recreation Class la uses are in place or are presumed to be present in at least a portion of the segment, the Commission changed the following segments from Class 2 to Class la with a 200/100 ml fecal coliform and 126/100 ml E. coll standard:

Upper Gunnison, Segments: 11, 12, 13a, 20, 22, 31

Uncompahgre, Segments: 4a, 4c, 5,15b

Lower Gunnison, Segments: 3, 4b, 8, 11

San Miguel, Segments: 2, 3a, 6a, 6b, 7a, 7b, 12

Lower Dolores, Segments: 3, 4, 5

The following segments with existing Recreation Class 1 classifications were changed to Class la:

Upper Gunnison, Segments: 1, 2, 3, 4, 6b, 7, 8, 9, 10, 14, 25, 29, 30, 32

North Fork, Segments: 1, 2, 4, 7

Uncompahgre, Segments: 1, 3, 14

Lower Gunnison, Segments: 1, 2, 5, 6, 10, 13

San Miguel, Segments: 1, 3b, 4, 5, 8, 9, 10, 11

Lower Dolores, Segments: 1, 2

Based on the information received, where a reasonable level of inquiry failed to identify any existing class 1 uses of the waters in these segments, the Commission changed the following segments to Class lb with a 325/100 ml fecal coliform and 205/100 ml E. coll standard:

Upper Gunnison, Segment: 13b

North Fork, Segments: 5, 6

Uncompahgre, Segments: 9

Lower Gunnison, Segments: 7, 12

For the following segments, the Commission adopted seasonal recreation classifications, based on evidence differences in actual or potential uses at different times of the year:

The following segments retained their Recreation Class 2 classification with 2,000/100ml fecal coliform and 630/100 ml E. coll standards after sufficient evidence was received that a Recreation Class la use was unattainable.

Uncompahgre River, Segments: 2, 4b, 6a, 6b, 7, 8, 12, 13, 15a

Lower Gunnison, Segment: 4a

The classifications for Uncompahgre segments 2, 7 and 8 are based upon low flows, cold temperatures, limited access and streambed characteristics that prevent primary contact recreation. The classifications for Uncompahgre segments 12, 13 and 15a and Lower Gunnison segment 4a are based upon low flows, limited access and streambed characteristics that prevent primary contact recreation. The classification for Uncompahgre 4b is based upon low flows and the presence of numerous major irrigation diversion structures which are hazardous and preclude primary contact recreation. The classifications for Uncompahgre segments 6a and 6b are based upon the gradient and size of the streambed, cold temperatures, and the fact that the allowable pH in this segment precludes primary contact recreation.

F. Aquatic Life Segments witliout Fuii Standards

The Commission reviewed information regarding Aquatic Life Class 2 segments where the full set of inorganic aquatic life protection standards have not been applied. Generally, these are dry segments with only rudimentary aquatic life. The Commission's policy has been that rather than adopt the full set of inorganic standards for these segments, standards for dissolved oxygen, pH and fecal coliform provide sufficient protection.

Segments where investigation showed that aquatic life was present were upgraded with the addition of the full suite of inorganic standards. These segments are:

Upper Gunnison, Segments: 13, 15, 27

North Fork, Segment: 6

Uncompahgre, Segments: 6a, 10, 12

Lower Gunnison, Segment: 4

San Miguel, Segment: 12

G. Ambient Quality-Based Standards

TInere are several segments in the Gunnison Basin that contain standards based on existing ambient quality. Ambient standards are adopted where natural or irreversible man-induced conditions result in water quality levels higher (i.e. worse) than table value standards. EPA had requested that the Commission review the information that is the basis for these standards as well as any new information that would indicate whether they are still appropriate, need to be modified, or should be dropped. The Division reviewed the reason for the ambient standards and provided testimony that justified ambient standards being retained without adjustment on the following segments:

Upper Gunnison, Segments: 10(Pb), 20

San Miguel, Segment: 10

The Division reviewed the information about ambient water quality levels and provided testimony that justified revising or adopting the ambient standards on the following segments:

Upper Gunnison, Segments: 11, 12, 15

Uncompahgre, Segments: 3, 4, 7, 11, 12

Lower Gunnison, Segment: 2

San Miguel, Segment: 8

Ambient standards were removed from the following segments due to new data and/or changes to the basic standards which indicated ambient standards were no longer appropriate:

Upper Gunnison, Segments: 10(Zn), 12, 17, 18,21, 30 North Fork Gunnison, Segment: 4 Uncompahgre, Segment: 2 Lower Gunnison, Segment: 2 San Miguel, Segment: 6b

H. Temporary Modifications

There were several segments which had temporary modifications that were reviewed, and decisions were made as to delete or to extend them, either as is or with modification of the numeric limits.

Upper Gunnison, Segment 8: Slate Creek: This segment had temporary modifications for iron and manganese set at existing ambient quality. The revisions to the Water Supply standards resolved this issue and therefore the temporary modification is no longer needed. The temporary modification was deleted.

North Fork, Segment 5: Tribs to North Fork: This segment has a temporary modification for selenium. The Selenium Task Force is studying this issue. The expiration date of the temporary modification was extended from 8/30/02 to 12/31/06 to coincide with the next triennial review.

Uncompahgre, Segment 4a, 4b, 4c: Uncompahgre River, Montrose to Gunnison River: This segment has a temporary modification for selenium. The Selenium Task Force is studying this issue. The expiration date of the temporary modification was extended from 8/30/02 to 12/31/06 to coincide with the next triennial review. This segment also had a temporary modification for fecal conform which was deleted.

Uncompahgre, Segment 14: Sweitzer Lake: This segment has a temporary modification for selenium. The Selenium Task Force is studying this issue. The selenium temporary modification value was changed to reflect current conditions and the expiration date was extended from 8/30/02 to 12/31/06 to coincide with the next triennial review.

Lower Gunnison, Segment 2: Gunnison River, Uncompahgre to Colorado Rivers : This segment has a temporary modification for selenium. The Selenium Task Force is studying this issue. The selenium temporary modification value was changed to reflect current conditions and the expiration date was extended from 8/30/02 to 12/31/06 to coincide with the next triennial review.

Lower Gunnison, Segment 9: Fruitgrowers Reservoir: This segment has temporary modifications for fecal coliform and unionized ammonia. The Division and other agencies are studying the reservoir. Data indicates that the underlying standards are attained. The temporary modifications were deleted. A temporary modification for dissolved oxygen was adopted with an expiration date of 12/31/06.

San Miguel, Segment 3a: San Miguel River, Upper portion to Marshall Creek: This segment has a temporary modification for zinc. Remedial work is currently conducted in the upper part of the basin. The expiration date of the temporary modification was extended from 6/30/02 to 12/31/06 to coincide with the next triennial review.

San Miguel, Segment 3b: San Miguel River, Marshall Creek to South Fork: This segment has temporary modifications for zinc, cadmium and manganese. Data indicates that the underlying standards are attained for cadmium and manganese. The temporary modifications for cadmium and manganese were deleted. The zinc temporary modification value was changed to reflect current conditions and the expiration date was extended from 6/30/02 to 12/31/06 to coincide with the next triennial review.

San Miguel, Segment 4, San Miguel River, South Fork to Naturita Creek : This segment has a temporary modification of the temperature standard from the Power Plant Bridge to Naturita Creek, of 28° C for July, August and September, which is set to expire 12/31/2006. The temporary modification is provided to allow time for Tri-State Generation and Transmission Association to participate in a work group to address the statewide implementation of the narrative and numeric temperature standards.

There were several segments where temporary modifications that reflect current ambient conditions were adopted. Temporary modifications were set to expire on 12/31/06 to coincide with the next triennial review. The segments and the constituents are:

Upper Gunnison, Segment 10: cadmium, copper, and zinc

Upper Gunnison, Segment 11: cadmium and zinc

Upper Gunnison, Segment 12: zinc

North Fork, Segment 6: selenium

Uncompahgre, Segment 12: selenium

Lower Gunnison, Segment 4: selenium

Lower Gunnison, Segment 7: selenium and iron

San Miguel, Segments 6a and 6b: zinc

San Miguel Segment 7b: lead

I. Organic Chemical Standards

The organic chemical standards were updated to include changes adopted by the Commission in the 2000 revisions to the Basic Standards (see 31.11 in Regulation No. 31). "Water + Fish" organic chemical standards are presumptively applied to all Aquatic Life Class 1 streams which also have a Water Supply classification, and are applied to Aquatic Life Class 2 streams which also have a Water Supply classification, on a case-by-case basis. The "Fish Ingestion" organic chemical standards are presumptively applied to all Aquatic Life Class 1 streams which do not have a Water Supply classification, and are applied to aquatic life class 2 streams which do not have a Water Supply classification, on a case-by-case basis. Existing site-specific applications of additional organics (as noted in the Qualifier column of Table 35.7) were modified to conform to this change.

Information was reviewed regarding Aquatic Life Class 2 segments that have fish that are presently being taken for human consumption or have fisheries that would indicate the potential for human consumption. That information showed that four additional segments had the potential for consumption offish. These waterbodies were designated to receive the full protection of numeric Water + Fish or Fish Ingestion organic standards:

Fish Ingestion: Upper Gunnison Segment 13

Water + Fish: Upper Gunnison Segment 17,

North Fork Segment 6, and Uncompahgre Segment 10

J. Water Suppiy Ciassification

These segments had the Water Supply classification added to them. The associated water supply standards will now apply to segments:

Upper Gunnison, Segments: 13a, 13bUncompahgre, Segment: lOLower Gunnison, Segment: 4San Miguel, Segment: 12

The Commission rejected a proposal by the High Country Citizens Alliance that a water supply classification be added to Upper Gunnison segment 12, based on the presence of a private water well near this segment of the stream. The Commission does not believe that adequate evidence was provided that the quality of water in segment 12 influences the quality of water in this well.

K. Modification of Water Suppiy Standards

Water supply standards were modified to conform to the changes made by the Commission in the 2000 revisions to the Basic Standards (see Regulation No. 31 at section 31.11). The Commission modified the water supply standards for iron, manganese, and sulfate that are based on secondary drinking water standards (based on aesthetics as opposed to human-health risks). The numeric values in the tables were changed to Fe(ch) = WS (dis), Mn(ch) = WS (dis), and SO4 = WS. These abbreviations mean that for all surface waters with an actual water supply use, the less restrictive of the following two options shall apply as numerical standards, as discussed in the Basic Standards and Methodologies at section 31.11 : either (i) existing quality as of January 1 2000; or (ii) Iron = 300 µg/L (dissolved); Manganese = 50 µg/L (dissolved); Sulfate = 250 mg/L (dissolved). For all surface waters with a "Water Supply" classification that are not in actual use as a water supply, no water supply standards are applied for iron, manganese or sulfate, unless the Commission determined as the result of a site-specific rulemaking hearing that such standards are appropriate.

L. Agriculture Classifications

There is one segment in the Gunnison River Basin that was not correctly classified for Agricultural use. The Agricultural use classification was adopted for San Miguel, Segment 3b.

M. Agriculture Standards

Numeric Standards to protect Agricultural Uses were adopted for the following segments:

Upper Gunnison, Segments: 6a, 31 Lower Gunnison, Segment 12 Lower Dolores, Segment 3

N. Other Site-Specific Revisions

The Commission corrected several typographical and spelling errors, and clarified segment descriptions.

The following aquatic life classifications were upgraded from class 2 to class 1 based on information presented that showed diverse aquatic communities in these segments.

Lower Gunnison, Segment 8

Lower Gunnison, Segment 6 was changed from aquatic life class 2 warm to class 1 cold, based on information received about the aquatic community that includes trout species.

Aquatic life cold 2 use classifications were added to Upper Gunnison Segment 13 and Uncompahgre Segments 6a and 6b, based on information that an aquatic community is in place in these segments.

PARTIES TO THE RULEMAKING HEARING