Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-33 - REGULATION NO. 33 - CLASSIFICATIONS AND NUMERIC STANDARDS FOR UPPER COLORADO RIVER BASIN AND NORTH PLATTE RIVER (PLANNING REGION 12)
Section 5 CCR 1002-33.32 - STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE; AUGUST, 1999 RULEMAKING

A. Resegmentation

Some renumbering and/or creation of new segments was made in the basin due to information which showed that:

B. Wetlands

In March 1993, the Commission amended the Basic Standards and Methodologies for Surface Water, Regulation #31 (5 CCR 1002-31) to include wetlands in the stream classification and standards' system for the state. Due to that action, it became necessary to revise the segment description for all segments of the "all tributary" type to clarify that wetlands are also part of the tributary system for a given mainstem segment. All tributary wetlands now clearly carry the same classifications and standards as the stream to which they are tributary as provided for in 3.1.13(1)(e)(iv).

C. Manganese

The aquatic life manganese criterion was changed in 1997 revisions to the Basic Standards (5 CCR 1002-31) from a single chronic dissolved criterion to acute and chronic hardness-based equations, i.e., Acute=e(0.7693[ln (hardness)]+ 4.4995) and Chronic=e(.5434[ln(hardness)]+ 4.7850). These manganese equations were added as table value standards in 33.6(3). As a result of the adoption of these new TVS, all segments classified for aquatic life use that had a chronic dissolved manganese standard of 1,000 ug/l had the 1,000 standard stricken and replaced with Mn(ac/ch)=TVS.

D. Selenium

The regulation in 33.6 (3) listed the table value standards for selenium as Acute=135 ug/L and Chronic=17ug/L. This was updated to reflect the existing acute and chronic criteria for selenium listed in the Basic Standards as Acute=20 ug/L and Chronic=5 ug/L which was adopted in 1995 by the Commission. This change means that all segments with standards for selenium given as TVS now have these lower acute and chronic standards. Because of this change, on all segments classified for a water supply use, the chronic total recoverable selenium of 10 ug/L was stricken and replaced with Se(ac/ch)=TVS.

E. Outstanding Waters Designations

Several segments or waterbodies were designated outstanding waters (OW) due to their meeting certain criterion pursuant to section 31.8 . Other segments that already had the OW designation but whose classifications and/or standards were inconsistent with the those prescribed by the Commission for OW waters in other basins in Colorado were corrected. These changes are discussed below for each segment.

F. Temporary Modifications

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

Upper Colorado segment 6c - Mainstem of un-named tributary to Willow Creek from the Willow Creek Reservoir Rd to the confluence Willow Creek.

This segment had 5-year temporary modification for un-ionized ammonia that will expire in 12/30/2000, but under the terms of a stipulation entered into at the 1995 rulemaking the temporary modification is "subject to review at approximately a three-year interval into the modification". The Commission determined that after review of information submitted by the Division and Three Lakes Water and Sanitation District that the present expiration date provided sufficient time for Three Lakes to develop and implement its plan for meeting the unionized ammonia standard in this segment.

Upper Colorado segment 8 - Mainstem of the Williams Fork River.

The Commission reviewed the need for the existing temporary modifications to the manganese and iron water supply standards and determined that their removal would not pose a significant hardship to Climax's ability to meet its permit limits and manage the water in its facility provided that a point of compliance is adopted. As noted in the Basis and Purpose for the October 1997 rulemaking, Climax, with the participation of Grand County and the Northwest Colorado Council of Governments, identified a well as a potential point of compliance. Climax monitored the iron and manganese levels in a well at the Aspen Canyon Ranch. The data from March 1998 through February 1999 showed that the existing water quality was well below the water supply standards for iron and manganese. In view of the above, the temporary modifications for iron and manganese are deleted and a point of compliance at the Aspen Canyon Ranch well is adopted.

Blue River segment 2 - Mainstem of the Blue River from the confluence with French Gulch to a point one mile above the confluence with Swan River.

The temporary modifications were reviewed and revised to reflect data collected from the segment in 1996-98. It was determined that an expiration date of 12/31/2002 would provide sufficient time for the French Gulch Opportunity Group (FROG) to determine the appropriate steps to address the source of the high metals in this segment which derive from French Gulch (Blue River segment 11) and complete a use attainability analysis on segment 2 which should determine the proper classifications and standards for the segment.

Blue River segment 6 - Snake River

The Commission has adopted underlying TVS with temporary modifications that reflect the existing ambient conditions to expire 12/31/02, with the understanding that at the future triennial reviews, additional changes may be necessary. Based on information in the record, the Commission suspects that ambient standards may be appropriate in the upper basin. The local stakeholders and the NWCCOG, with assistance by the WQCD, have agreed to gather data over the next few years to determine the sources of metals in the watershed and the remediation potential for those sources. This information will be used to determine if ambient standards and/or resegmentation is appropriate. In addition, a TMDL is planned for segment 7 (Peru Creek) and the lower portion of segment 6. This will help determine what degree of cleanup is possible for the lower Snake River.

Blue River segment 7 - Peru Creek.

The temporary modifications were reviewed and revised to reflect data collected from the segment in 1996-98 and they and the underlying standards were adjusted to reflect dissolved metals standards rather than the total recoverable that have been in place since 1980.

Eagle River segment 5 - Mainstem of the Eagle River from the compressor house bridge at Belden to the confluence with Gore Creek.

Several ambient standards for metals and a temporary modification for manganese were in place on segment 5 since 1980. The ambient standards and temporary modification were based on limited data and the metal standards were based on the total recoverable form which the Commission had specified for standards prior to 1987. In 1987, Colorado's Basic Standards prescribed dissolved metals as the standard of choice for all metals standards that are based on toxicity to aquatic life. Also, since the adoption of the standards in 1980, the Eagle Mine and mill area has been declared a Superfund site with remediation begun in 1988. Viacom International, Inc., the responsible party for the remediation, has collected an extensive record of water quality data throughout segment 5 that documents the improvements in quality to date.

The purpose of adopting new underlying standards and temporary modifications is to reflect the existing water quality, establish underlying standards (goals) based on ARARs established for the Eagle Superfund site, and make the standards consistent with the dissolve' criteria established in the 1987 Basic Standards. The underlying numeric standards for cadmium and zinc of 1.1 ug/L and 106 ug/L, respectively, are the ARAR's established by the U. S. Environmental Protection Agency. The underlying manganese standard of 50 ug/L was the existing standard which was adopted in 1980 to protect the water supply classification. The temporary modifications are adopted for two seasons, May 1 through November 30 and December 1 through April 30, because of the extreme seasonal variation shown by the data. The temporary modifications for chronic cadmium, zinc and manganese are based on the 85th percentile values of the water quality data collected in segment 5 from 1996 through 1998.

It is anticipated that at the next triennial rulemaking for the Upper Colorado River Basin the temporary modifications will be reviewed and adjusted, if necessary, to reflect the most recent instream quality of segment 5. At the time of completion of the remediation (estimated to be 10 years) or achievement of an agreed upon acceptable level of recovery of the aquatic biota, should that happen sooner, the water quality data for the segment should be reviewed to ascertain what the levels of instream metals are at that time. Based on those findings, the Commission may determine that ambient standards are appropriate for segment 5 for any metals still exceeding the underlying standards.

The previous use-protected designation for this segment has been removed, since there are now only two parameters (cadmium and zinc) which exceed table values for all or part of the year.

Eagle River Segment 7 - Mainstem of Cross Creek from the source to the confluence with the Eagle River.

The lower reach of Cross Creek, like segment 5 of the Eagle River, is part of the Eagle Mine Superfund site. It is still undergoing remediation and at one time the Creek was the receiving stream for the treated wastes from the Eagle Mine. The standards in place were, as in segment 5, based on outdated data, information and criteria in place in the early 80's. As a result of this hearing, temporary modifications to underlying table value standards were adopted for zinc and manganese to reflect the current instream water quality based on samples collected from 1996 through 1998. Because of the seasonality shown by the data, the temporary modifications were adopted for two periods, May 1 through October 31 for manganese (165 ug/L) and November 1 through April 30 for zinc (170 ug/L) and manganese (840 ug/L).

Eagle River segment 9 - The existing temporary modification for manganese was reviewed and renewed for three years. Review of the most recent data from this segment indicated that there had not been a significant lowering of the manganese from the existing temporary modification of 85 ug/l. Since the manganese levels in this segment may be related to the remediation underway at the Eagle Mine Superfund site modification it was felt that the temporary modification date should track those established for Eagle River segment 5.

G. Recreation Classifications/Fecal Coliform 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 a Recreation Class 1, with the 200/100 ml fecal coliform standard (assigned wherever swimming, rafting, kayaking, etc. are in place or have the potential to occur). In some river basins, the Commission has adopted a Recreation Class 2 classification, with 200/100 ml standard, where only secondary contact recreation is practiced, and the existing quality supports a Class 1 Recreation use and little or no impact to dischargers will result. However, the current Basic Standards and Methodologies for Surface Water do not address this option. To maintain the existing Recreation Class 2, with the 2000/100 ml standard on a segment, it must be shown that there is minimal chance that a Recreation Class 1 activity could exist (e.g. intermittent or small streams that have insufficient depth to support any type of Recreation Class 1 use or very restricted access).

Based on the information received that showed Recreation Class 1 uses are in place, the Commission upgraded the following Recreation Class 2 segments to Class 1 with a 200/100 ml standard:

Upper Colorado segment 10.

Blue River segments 1, 2, and 14.

Eagle River segment 4, 5, and 8.

Yampa River segments 2a (was already Class 1 but had 2,000/100ml standard) and 8.

Upper Colorado segment 9, Blue River segment 16, and Eagle River segment 1 were also upgraded to Recreation Class 1, but because of their being designated outstanding waters.

The following segments retained their Recreation Class 2 and 2,000 fecal coliform standard based on the evidence submitted in this rulemaking hearing, including the segment-specific information in the Division's Rationale and testimony from the parties. No evidence was submitted indicating that these segments have a reasonable potential to support Recreation Class 1 uses.

Upper Colorado segments 6a, 6b, 6c and 7c.

Blue River segments 5, 7, 8, 11, 12, 13 and 20.

Eagle River segment 11.

North Platte River segments 2, 5, 6 and 7.

Roaring Fork segments 4, and 10.

Yampa River segments 4, 5, 7, 8, 12, 13d and 19.

The recreation classifications and standards for each of these segments will be reviewed by the Commission in each future triennial review. The Commission encourages all interested persons to submit any available information regarding the potential uses of these segments. In addition, the Commission notes that the system for adopting recreation use classifications and standards will be reviewed in the upcoming triennial review of the Basic Standards and Methodologies for Surface Water.

H. Full Standards Not Applied to Aquatic Life Segments

The Commission reviewed information regarding Aquatic Life Class 2 segments where the full set of inorganic aquatic life protection standards have not been applied. EPA is concerned that this be done on those segments that are receiving waters for wastewater treatment plant discharges. 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. The segments which were reviewed in this hearing and for which sufficient evidence was received for them to retain their present classifications and standards are:

Upper Colorado segment 6b

Blue River segment 20.

Eagle River segment 11.

North Platte River segment 7.

Yampa River segments 4b and 12.

Yampa River segment 4b (Little White Snake River) had, in a 1987 hearing, been determined to not be suitable for an aquatic life class 1 or in need of the protection of aquatic life inorganic standards. The basis and purpose of this decision is detailed in 33.19 of this regulation. In this hearing, the Commission did review the numeric standards for metals on this segment which are based on water supply and agriculture criterion. These standards were revised as appropriate to reflect any amendments to the Basic Standards that occurred since the 1987 hearing.

One segment, Blue River segment 5 (Soda Creek), was found to support a sizeable population of brook trout and was given an Aquatic Life Cold 1 classification with a full set of numeric standards. Summit County's Snake River WWTF discharges at the mouth of this stream where it enters Dillon Reservoir and it is unlikely that they will be affected by the new standards. A site-specific pH standard of 6.0, which was established in 1990, was retained.

I. Ambient Quality-Based Standards

There are several segments in the Upper Colorado and North Platte River Basins that contained ambient standards. Ambient standards are adopted where natural or irreversible man-induced conditions result in water quality levels higher than table value standards. EPA had requested the Commission review the information that are 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 on the following segments:

Blue River segments 11, 12, and 14.

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:

Blue River segments 7, 9, and 13.

Eagle River segments 5 and 7.

J. Water + Fish Standards

One other issue that EPA has requested be addressed in the hearing was the justification for not having the water + fish organic basic standards applied to Aquatic Life Class 2 streams. Prior to the hearing, the Division contacted DOW fisheries personnel and other locals with extensive knowledge of sport fishing in the Upper Colorado and North Platte basins and requested information that would pinpoint any streams or lakes in 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. Information received indicated only two additional waterbodies that had the potential for consumption of fish. Blue River segment 5, was reclassified as Aquatic Life Class 1 and thus received the full protection of numeric and water + fish organic basic standards. The "water + fish organics" modifier was added to North Platte segment 7.

K. Other Site-Specific Revisions

Eagle River Ammonia Standards

Corrections were made to the formatting of the un-ionized ammonia standards for Eagle River segments 1 through 10. These corrections which do not alter the adopted standards on the segments merely correct typographical errors that occurred when routine revisions were made to the Upper Colorado basin standards in 1998.

Roaring Fork Segment 3a

At the request of the Spring Valley Sanitation District, the Commission reviewed the classifications and standards for Roaring Fork segment 3 and determined that reclassification of a portion of this segment is appropriate. The Commission has established a new segment 3a, consisting of the mainstem of Red Canyon and all tributaries, wetlands, lakes and reservoirs from the source to the confluence with the Roaring Fork River, except for Landis Creek from its source to the Hopkins Ditch Diversion. Based upon a use attainability analysis prepared by the Spring Valley District, the Commission has adopted an aquatic life cold water class 2 classification for this new segment. There was considerable debate in the testimony presented in this hearing as to whether this segment should be aquatic life class 1 or class 2. The dewatering effects of the Hopkins Ditch Diversion are a major consideration in the Commission's decision that class 2 is appropriate. The Commission does not intend this site-specific change to be viewed as a precedent for headwaters streams generally.

The usual set of numerical standards has been applied to this new segment, except for a 0.1 mg/l chronic unionized ammonia standard, which is based upon a site-specific recalculation procedure analysis submitted by Spring Valley. The evidence indicates that this ammonia standard should be protective of the aquatic life present in this segment.

In addition, in accordance with the stipulation between the Division and interested parties, the Commission adopted a recreation class 2 classification with a 200 per 100 ml fecal coliform standard for this new segment.

Roaring Fork Segment 4

The aquatic life classification for this segment has been changed from cold water class 2 to cold water class 1, based on biological data that supports this change. In addition, the testimony indicated that habitat issues are being addressed to improve channel stability. The Commission has retained the use-protected designation for this segment based on evidence that it is subject to significant point source discharges and the quality currently is maintained better than standards only because the treatment achieved by the existing discharger exceeds requirements of federal and state law and might not be maintained at that level in the future.

PARTIES/MAILING LIST TO THE RULEMAKING HEARING