Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-37 - REGULATION NO. 37 - CLASSIFICATIONS AND NUMERIC STANDARDS FOR LOWER COLORADO RIVER BASIN
Section 5 CCR 1002-37.33 - STATEMENT OF BASIS SPECIFIC STATUTORY AUTHORITY AND PURPOSE JUNE 9, 2014 RULEMAKING; FINAL ACTION AUGUST 11, 2014 EFFECTIVE DATE DECEMBER 31, 2014

A. Waterbody Segmentation

Some water bodies were moved from one segment to anotlner segment to improve organization and/or to facilitate changes in classified uses or standards. Some new segments were created to facilitate changes that applied only to a portion of an existing segment. The following changes were made:

Lower Yampa/Green River Segments 3b and 31: Lower Johnson Gulch from the confluence with Pyeatt Gulch at CO 107 to the confluence with the Yampa River was moved from Segment 3b to a new Segment 31 to facilitate a change in the antidegradation designation.

Lower Yampa/Green River Segments 3d and 3h: Lay Creek was moved from Segment 3d to a new Segment 3h to facilitate the adoption of a water supply use classification and standards.

Lower Yampa/Green River Segments 3c and 3e: Wilson Creek was moved from segment 3e to segment 3c to upgrade the aquatic life use from Warm 2 to Warm 1.

Lower Yampa/Green River Segment 6a was renumbered as segment 6.

Lower Yampa/Green River Segments 9 and 12c: Beaver Creek was moved from Segment 9 to a a new Segment 12c to facilitate the adoption of the Outstanding Waters designation.

Lower Yampa/Green River Segments 17b and 17c: Scandinavian Gulch was moved from Segment 17b to a new Segment 17c to facilitate adoption of standards for the protection of the aquatic life use.

Lower Yampa/Green River Segments 20 and 22d: Conway Draw was moved from Segment 20 to a new Segment 22d to facilitate the adoption of a water supply use classification and standards.

White River Segments 4a and 4b: Lost Creek and Snell Creek were moved from Segment 4a to Segment 4b to facilitate the adoption of the Outstanding Waters designation.

White River Segments 16a and 16b: Some of the tributaries to Piceance Creek were moved from Segment 16a to a new Segmenti 6b to facilitate the adoption of a water supply use classification and standards on Segement 16a.

White River Segements 18a and 18b: Some tributaries to Piceance Creek were moved from Segment 18a to a new Segment 18b to facilitate the adoption of a water supply use classification and standards on Segment 18b.

Lower Colorado River Segments 11b and 11c: The water bodies in these segments were combined into one segment because the designation, uses and standards are the same.

Lower Colorado Segments 13a and 13f: Asbury Creek was moved from Segment 13a to a new Segment 13f to facilitate the adoption of a water supply use classification and standards.

Lower Colorado River Segments 19 and 21: All lakes and reservoirs tributary to Plateau Creek and within Grand Mesa National Forest were moved from Segment 19 to Segment 21 to upgrade the aquatic life use from Warm 1 to Cold 1 and to facilitate the adoption of water supply standards.

Lower Colorado Segments 15a - 15d and 16: Plateau Creek and its tributaries (Segment 15) were divided into 4 segments to facilitate changing the temperature tier on the new Segment 15b and the adoption of site-specific ambient temperature standards on the new Segments 15c and 15d. The upstream boundary of Segment 16 was changed to facilitate a change in the aquatic life use and adoption of ambient temperature standards for the lower portion of Plateu Creek.

The following segment descriptions were edited to improve clarity, correct typographical errors, and correct spelling errors:

Lower Yampa/Green River Segments: 10, 19a

White River Segments: 9a, 9b,10b, 13b

Lower Colorado River Segments: 11g, 12b, 13d

B. Revised Aquatic-Life Use Classifications

The Commission reviewed information regarding the existing aquatic communities. Class 2 segments with exceptionally high MMI scores, or a wide variety offish species were upgraded from Class 2 to Class 1. Segments that supported Colorado State Species of Special Concern such as mountain sucker or native cutthroat trout were also upgraded from Class 2 to Class 1.

The following segments or portions of segments were upgraded from Warm 2 to Warm 1:

Lower Yampa/Green River Segments: 3e (Wilson Creek moved to 3c), 22b, 22c

The following segments were upgraded from Cold 2 to Cold 1:

White River Segment: 19

Lower Colorado River Segments: 11b, 11h

Based upon evidence that the waters are expected to support cold water fisheries, portions of the following segment were upgraded from Warm 1 to Cold 1:

Lower Colorado River Segment: 21

Based upon the results of a Use Attainability Analysis that demonstrated the Cold Aquatic Life Use is not attainable, the following segment was downgraded from Cold 1 to Warm 1:

Lower Colorado River Segment: 16

C. Recreation Classifications and Standards

Based upon evidence that portions of these segments support recreational fishing and are publicly accessible and/or accessible to families who live in the area, it was determined that there is the potential for primary contact recreation. The following segments with year-round Recreation N standards were upgraded to Recreation P:

White River Segments: 13b, 13c, 17, 18b, 20 Lower Colorado River Segment: 8

The use classification for the following segment was inadvertently changed to Recreation P in 2007, and the Recreation N use classification was restored in this rulemaking hearing:

White River Segment: 16

D. Water Supply Use Classification and Standards

The Commission added a Water Supply use classification and standards on segments where there is a drinking water intake or where the evidence demonstrates a reasonable potential for a hydrological connection between surface water and alluvial wells used for drinking water. The Water Supply use classification and standards were added to the following segments:

Lower Yampa/Green River Segments: 3h, 5, 6, 12a, 16, 22d

White River Segments: 13b, 14a, 16a, 18b, 20

Lower Colorado River Segments: 11h, 13f

A review of the segments with an existing Water Supply use classification showed that some segments were missing one or more standards to protect that use. The full suite of Water Supply standards were added to the following segment:

Lower Colorado River segments: 11e

E. Agriculture Standards

Molybdenum: In 2010, the Commission adopted a new standard for molybdenum to protect cattle from the effects of molybdenosis. The table value adopted at that time was 300 µg/l, but included an assumption of 48 mg/day of copper supplementation to ameliorate the effects of molybdenosis. State and local experts on cattle nutrition indicated that copper supplementation in the region is common, but is not universal. Therefore, copper supplementation assumption was removed from the equation, which yields a standard of 160 µg/l. The Commission expects that this value may be revised when data on the copper and molybdenum content of local forage becomes available. The Commission also notes that in light of EPAs disapproval of the 300 µg/l table value in the Basic Standards and Methodologies for Surface Water, the Commission intends to review this value during the next Basic Standards triennial review.

The Agriculture table value assumes that the safe copper:molybdenum ratio is 4:1. Food and water intake is based on a 273 kg (600 lb) feeder steer consuming 6.8 kg/day of dry matter and 20% of its body weight in water per day. Total copper and molybdenum intakes are calculated from the following equations:

Cu intake mg/day = [([Cu] forage, mg/kg) x (forage intake, kg/day)] + [([Cu] water, mg/l) x (water intake, L/day)] + (Cu supplementation, mg/day)

Mo intake mg/day = [([Mo] forage, mg/kg) x (forage intake, kg/day)] + [([Mo] water, mg/l) x (water intake, L/day)] + (Mo supplementation, mg/day)

The assumed values for these equations are as follows:

[Cu] forage = 7 mg/kg, [Mo] forage = 0.5 mg/kg, forage intake = 6.8 kg/day, [Cu] water = 0.008 mg/L, [Mo] water = 0.375 mg/L, water intake = 54.6 L/day, Cu supplementation = 0 mg/day. Mo supplementation = 0 mg/day.

A molybdenum standard of160 µg/l was adopted for the following segments in Regulation 37 that have an Agriculture use classification, and where livestock or irrigated forage are present or expected to be present:

Lower Yampa/Green River Segments: 2, 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 31, 4, 5, 6, 7, 8, 9, 10, 12a, 12b, 12c, 13a, 13b, 15, 16, 17a, 17c, 18, 19a, 19b, 20, 21, 22a, 22b, 22c, 22d, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33

White River Segments: 1, 3, 4a, 4b, 6, 7, 8, 9a, 9b, 9c, 9d, 10a, 10b, 11, 12, 13a, 13b, 13c, 13d, 14a, 14b, 15, 16a, 16b, 17, 18a, 18b, 19, 20, 21, 22, 23, 24, 25, 26, 27

Lower Colorado River Segments: 1, 2a, 2b, 3, 4a, 4c, 4d, 4e, 4f, 5, 6, 7a, 7b, 8, 9a, 9b, 9c, 10, 11a, lib, lid, 11e, 11f, 11g, 11h, 12a, 12b, 13a, 13b, 13c, 13d, 13e, 13f, 14a, 14b, 14c, 15a, 15b, 15c, 15d, 16, 17a, 17b, 18, 19, 20, 21

The following segment does not have an Agriculture use classification or a Water Supply use classification, and a molybdenum standard was not applied:

Lower Yampa/Green River Segment: 17b

Lower Colorado River Segment: 4b

F. Changes to Antidegradation Designation

The Commission reviewed all Cold 2 segments that were Use-Protected to determine if that designation was still warranted. No segments were changed to Reviewable.

The Commission reviewed all Warm 2 segments to determine if the Use-Protected designation is still warranted. Based upon available water quality data that meet the criteria of 31.8(2), the Use-Protection designation was removed from the following segments:

Lower Yampa/Green River Segments: 3g, 3i, 6

The Commission adopted an Outstanding Waters (OW) designation for the following segments based on evidence presented by WildEarth Guardians showing that water quality meets the requirements of 31.8(2)(a):

Lower Yampa/Green River Segment: 12c

White River Segment: 4b

The presence of designated Critical Cutthroat Trout Habitat by the State of Colorado proves the exceptional recreational or ecological significance of the waters. Outreach conducted by WildEarth Guardians demonstrated support for the change in designation, the outstanding nature of these waters and the need for the additional protection of the outstanding waters designation. The Commission understands that existing land uses, including grazing, are in place in these watersheds. The evidence demonstrates that these existing land uses are compatible with the OW designation since the current high level of water quality has been attained with these uses in place. It is the Commission's intent that this OW designation should not be used to establish additional permit requirements for existing uses within this area.

G. Ambient Standards

Ambient standards are adopted where natural or irreversible man-induced conditions result in exceedances of table value standards. The Commission reviewed 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. In some cases, new ambient standards were adopted. The following segments have ambient-based standards for metals that were revised:

Lower Yampa/Green River Segment: 16

White River Segments: 13b, 13c

New assessment locations were adopted for White River segments 13b and 13c, because additional data was available to develop individual site-specific selenium standards for Corral Gulch, Duck Creek, Greasewood Creek and Yellow Creek. The assessment locations are listed at 37.6(4).

H. Aquatic Life Ammonia and Metals Standards

New Table Value Standards: The zinc, zinc sculpin, and aluminum table values were revised in the 2010 Basic Standards hearing. The acute and chronic zinc, zinc sculpin, and aluminum equations in 37.6(3) were modified to conform to Regulation 31. The footnotes to the table values in 37.6(3) were renumbered to match the appropriate references. Footnote (4 old) was deleted and a new footnote 4 was added.

Zinc sculpin standards: In low-hardness situations (hardness below 102 mg/L), the zinc equation is not protective of mottled sculpin (Cottus bairdi), a native west-slope fish species. For the following segments where sculpin are expected to occur and hardness could be low, both the zinc sculpin standard and the chronic zinc table value standard were adopted:

Lower Yampa/Green River Segments: 4, 7, 10, 15, 18

White River Segments: 1, 3, 6

Based upon a review of existing hardness and fishery data, the sculpin-specific zinc equation was deleted from the following segments where hardness is consistently higher than 102 mg/L:

Lower Yampa/Green River Segments: 2, 12a, 13b

Lower Colorado River Segments: 7a, 15a

The following segments were designated as Aquatic Life Warm 2 or Cold 2, but lacked standards to fully support the Aquatic Life Use. Available data indicates that the Aquatic Life Use is attainable, and therefore the full suite of standards protective of aquatic life was added to the following segments, with a delayed effective data of December 31, 2019 on Lower Yampa segment 3b:

Lower Yampa/Green River Segments: 3b, 31, 6, 17c

Lower Colorado River Segments: 11b, 13a

The goal qualifier for selenium was deleted on Lower Yampa/Green River segment 3b, based upon data that indicate the table value standard for selenium is attained.

I. Uranium Standards

At the 2010 Basic Standards rulemaking hearing, the Commission changed the Water Supply table value for uranium from 30 µg/l to a hyphenated standard of 16.8-30 µg/l. The Commission revised the language in 37.5(3)(c) to reflect the change to the basin-wide standard. A new section 37.5 was added to explain the hyphenated standard. Subsection 37.5 was deleted because it was redundant with 37.5(3)(c).

J. Temporary Modifications

All existing Temporary Modifications were examined to determine if they should be allowed to expire or be extended. Temporary Modifications were not automatically extended if non-attainment persisted due to revisions made to the Temporary Modification provisions in 2005 and 2010.

To remain consistent with the Commission's decisions regarding arsenic at 37.31, all existing temporary modifications for arsenic of "As(ch)=hybrid" (expiration date of 12/31/21) were retained. An arsenic temporary modification was added to the following segments, which had an existing or newly added chronic arsenic standard of 0.02 µg/l and a permitted discharger with a predicted water quality-based effluent limit compliance problem:

Lower Yampa/Green River Segments: 5, 17a,

Lower Colorado River Segments: 4c, 11 h, 15b, 15c, 15d, 17b

New or modified Temporary Modifications were adopted for the following segments.

Lower Colorado Segment 4e: The Commission extended the Type A Temporary Modification for copper from December 31, 2015 to June 30, 2017. The extension of the Temporary Modification of the underlying copper standards recognizes that Tri-State Generation and Transmission Association, Inc. (Tri-State) provided water quality data predicting a compliance issue associated with its permitted discharge on Lower Colorado Segment 4e and there remains uncertainty as to the appropriate standards for that segment. Tri-State submitted a plan to collect additional data and to evaluate the bioavailability of copper in this segment. The progress on resolving the uncertainty with the copper standards will be reviewed in the annual Temporary Modification hearing in December 2015.

The Commission shortened the Type A Temporary Modification for iron from December 31, 2015 to June 30, 2015. This will allow time for Tri-State to develop a more definitive plan to resolve the uncertainty with the iron standards. Tri-State provided water quality data predicting a compliance issue associated with its permitted discharge on Lower Colorado Segment 4e and there remains uncertainty as to the appropriate standards for that segment. Tri-State may request an extension of the temporary modification at the annual Temporary Modification hearing in December 2014.

Where the Commission has adopted a narrative temporary modification of "current condition", the Commission intends that, when implementing the temporary modification in a CDPS permit, the permit conditions will reflect the current effluent quality, recognizing that it changes over time due to seasonal variability, change in the influent flow and the concentration over time.

K. Temperature

Ambient temperature standards for lakes

In the 2008 triennial review, the WAT standard was found to be unattainable for a number of cold large lakes and reservoirs with apparently healthy cold-water fish populations. Because summertime temperature in the mixed layer for large lakes and reservoirs is very well correlated to the waterbody's elevation, the Commission adopted ambient temperature standards for large lakes wherever data were available to characterize a WAT and the thermal characteristics of the lakes and reservoirs were determined to be the result of natural conditions. As a result of setting ambient temperature standards, the adequate refuge defined in Regulation 31, Table 1, footnote 5(c)(iii) was assessed using the site-specific temperature standard, and many lakes with obvious dissolved oxygen issues were considered to have adequate refuge.

Footnote 5(c)(iii) states:

When a lake or reservoir is stratified, the mixed layer may exceed the criteria in Table 1 provided that an adequate refuge exists in water below the mixed layer. Adequate refuge depends on concurrent attainment of applicable dissolved oxygen standards. If the refuge is not adequate because of dissolved oxygen levels, the lake or reservoir may be included on the 303(d) List as "impaired" for dissolved oxygen, rather than for temperature.

To ensure that adequate refuge is defined in a way that protects the Aquatic Life use, the Commission adopted Footnote D which was applied to the temperature standard for deep stratified lakes. Footnote D states "Assessment of adequate refuge shall rely on the Cold Large Lake table value temperature criterion and applicable dissolved oxygen standard rather than the site-specific temperature standard", and was applied to the following lake segments:

White River segment: 25 (Lake Avery)

Lower Colorado River segment: 20 (Rifle Gap, Harvey Gap and Vega Reservoirs)

Based upon a Use Attainability Analysis that demonstrates the table value standards for temperature are not attainable, ambient-based temperature standards were adopted for the following segments:

Lower Colorado River Segments: 15c, 15d, 16

Based upon a Use Attainability Analysis that determined Cold Stream Tier I species were not expected to occur, the temperature standard was changed from CS-I to CS-II on the following segment:

Lower Colorado Segment: 15b

L. Nutrients

In March 2012, the Commission adopted interim nutrient values in the Basic Standards (Regulation 31) and created a new statewide control regulation (Regulation 85) to address nutrients in Colorado. Regulation 31.17 includes interim nutrient values for total phosphorus, total nitrogen, and chlorophyll a for both lakes and reservoirs, and rivers and streams. Due to the phased implementation approach adopted with these criteria (31.17(e)), the Commission adopted only total phosphorus and chlorophyll a standards at this time. Nitrogen standards were not considered as part of this rulemaking hearing, but will be considered in the next triennial review, currently scheduled for June, 2019.

Total phosphorus and chlorophyll a standards were adopted for waters upstream of all permitted domestic wastewater treatment facilities discharging prior to May 31, 2012 or with preliminary effluent limits requested prior to May 31, 2012, and any non-domestic facilities subject to Regulation 85 effluent limits and discharging prior to May 31, 2012. A new section (4) was added at 37.5 describing implementation of the interim nutrient values into the tables at 37.6, and includes a table which lists these facilities and the segment to which they discharge.

* For segments located entirely above these facilities, nutrient standards apply to the entire segment.

* For segments with portions downstream of these facilities, nutrient standards only apply above these facilities. A footnote "C" was added to the total phosphorus and chlorophyll a standards in these segments. The footnote references the table of qualified facilities at 37.5(4).

* For segments located entirely below these facilities, nutrient standards do not apply.

* For rivers and streams segments, total phosphorus standards were adopted above the dischargers listed at 37.5(4) for segments with an Aquatic Life Use. Chlorophyll a standards were adopted above the dischargers listed at 37.5(4) for segments with either an E, P, or U Recreation use classification.

* For lakes and reservoirs segments above the dischargers listed at 37.5(4), total phosphorus and chlorophyll standards were adopted with a footnote "B" as these standards only apply to waterbodies larger than 25 acres surface area.

31.17(e)(ii) also allows the Commission to adopt numeric nutrient standards for Direct Use Water Supply (DUWS) lakes and reservoirs. No proposals were made by the Division to adopt standards based on this provision in this rulemaking.

31.17(e)(iii) also allows the Commission to adopt numeric nutrient standards for circumstances where the provisions of Regulation 85 are not adequate to protect waters from existing or potential nutrient pollution. No proposals were made to adopt standards based on this provision in this rulemaking.

Chlorophyll a standards were adopted for the following segments:

Lower Yampa/Green River Segments: 3b, 3c, 3e, 3f, 3g, 31, 4, 5, 6, 7, 8, 9, 10, 12a, 12b, 12c, 13a, 13b, 15, 16, 17a, 18, 19a, 19b, 20, 22c, 22d, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33 White River Segments: 1,3, 4a, 4b, 6,7,8, 9c, 9d, 10a, 10b, 11, 13b, 13c, 13d, 14a, 14b, 15, 16a, 16b, 17, 18b, 19, 20, 22, 23, 24, 25, 26, 27

Lower Colorado River Segments: 4b, 4c, 5, 6, 7a, 7b, 8, 9a, 9b, 9c, 10, 11 h, 12b, 13a, 13b, 13c, 13d, 13e, 13f, 14a, 14b, 14c, 15a, 15b, 15c, 15d, 16, 17a, 17b, 18, 19, 20, 21

Total Phosphorus standards were adopted for the following segments:

Lower Yampa/Green River Segments: 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 31, 4, 5, 6, 7, 8, 9, 10, 12a, 12b, 12c, 13a, 13b, 15, 16, 17a, 17b, 17c, 18, 19a, 19b, 20, 21, 22a, 22b, 22c, 22d, 23, 24, 25, 26,27,28,29,30,31,32,33

White River Segments: 1, 3, 4a, 4b, 6, 7, 8, 9a, 9b, 9c, 9d, 10a, 10b, 11, 13a, 13b, 13c, 13d, 14a, 14b, 15, 16a, 16b, 17, 18a, 18b, 19, 20, 22, 23, 24, 25, 26, 27

Lower Colorado River Segments: 4a, 4b, 4c, 4d, 4e, 4f, 5, 6, 7a, 7b, 8, 9a, 9b, 9c, 10, 11a, 11b, 11d, 11e, 11f, 11g, 11h, 12a, 12b, 13a, 13b, 13c, 13d, 13e, 13f, 14a, 14b, 14c, 15a, 15b, 15c, 15d, 16, 17a, 17b, 18, 19, 20, 21

Lower Colorado Segment 4e: A footnote C was added to the total phosphorus standard on this segment and on Lower Colorado Segment 4f. Tri-State Generation and Transmission Association, Inc was added to the list of facilities at 37.5(4). Tri-State submitted effluent data that demonstrated a compliance problem with the total phosphorus standard. At the time when Regulation 31.17(e) was adopted, it was not apparent that cooling tower discharges were a significant source of phosphorus or that these facilies would be impacted by nutrient standards. The Commission decided to include Tri-State in the list of exempt dischargers at 37.5(4) as a matter of policy on the basis that the overall intention of the phased implementation of nutrient criteria was to control existing discharges through Regulation 85, rather than through water-quality based effluent limits.

M. Direct Use Water Supply Sub-classification

Also in the March 2012 rulemaking hearing, the Commission adopted a sub-classification of the Domestic Water Supply Use called "Direct Use Water Supply Lakes and Reservoirs Sub-classification (Regulation 31, at 31.13(1)(d)(i)). This sub-classification is for water supply lakes and reservoirs where there is a plant intake location in the lake or reservoir or a man-made conveyance from the lake of reservoir that is used regularly to provide raw water directly to a water treatment plant that treats and disinfects raw water. In this action today, the Commission has begun to apply this sub-classification and anticipates that it will take several basin reviews to evaluate all the reservoirs in the basin. The Commission adopted the DUWS sub-classification on the following reservoirs and added "DUWS" to the classification column in the standards tables. The public water systems are listed along with the reservoirs and segments.

White River segment 11: Kenney Reservoir (Western Fuels)

Lower Colorado River segment 21: Jerry Creek Reservoirs Number 1 and 2 (Ute Water Conservancy District) Lower Colorado River segment 21: Palisade Cabin Reservoir (Town of Palisade)

31.17(e)(ii) also allows the Commission to adopt numeric nutrient standards for Direct Use Water Supply ("DUWS") lakes and reservoirs. No standards were adopted based on this provision in this rulemaking.

N. Chromium III Standards

A review of the chromium III standards showed that standards to protect the Aquatic Life use classification may not be protective of the Agriculture use in some high-hardness situations. A chromium III standard of Crlll(ch)=100(Trec) was added to segments with Aquatic Life and Agriculture use classifications, but no Water Supply use. The acute chromium III standard associated with the Water Supply use is protective of the Agriculture use, but is not protective of the Aquatic Life use when hardness is less than 61 µg/l. For segments that have both Aquatic Life and Water Supply Use classifications, a chronic chromium III standard of Crlll(ch)=TVS was added to all segments that did not previously have that standard. Changes were made to the following segments:

Lower Yampa/Green River Segments: 2, 3b, 3c, 3d, 3e, 3h, 3i, 7, 9, 10, 12b, 12c, 13a, 13b, 17a, 19a, 19b, 21, 22a, 22b, 22c, 23, 25, 26, 27, 30, 32, 33

White River Segments: 1, 3, 4a, 6, 7, 8, 9a, 9b, 9c, 9d, 10a, 10b, 11, 12, 13c, 13d, 14b, 15, 16b, 17, 18a, 19,21,23,25,26,27

Lower Colorado River Segments: 1, 2a, 2b, 3, 4a, 4c, 4d, 4e, 4f, 5, 6, 7a, 7b, 8, 9a, 9b, 9c, 10, 11a, 11b, 11d, 11f, 12a, 12b, 13a, 13b, 13c, 13d, 13f, 14a, 14b, 14c, 15a, 15b, 15c, 15d, 16, 17a, 17b, 18, 19, 20, 21

O. Other Site-Specific Revisions

A footnote "A" was added to the chronic arsenic standard to explain the hyphenated standard on the following segments:

Lower Yampa/Green River Segments: 3e, 3h, 6, 13a, 13b, 16, 17c, 22d,

White River Segments: 9a, 9b, 9c, 9d, 13b, 16a, 18b

Lower Colorado River Segments: 4a, 4d, 6, 11e, 12b, 13f

PARTIES TO THE RULEMAKING HEARING

1. Grand County, Northwest Colorado Council of Governments and Northern Colorado Water Conservancy District

2. Eagle River Water and Sanitation District

3. Trout Unlimited

4. WildEarth Guardians

5. Tri-State Generation and Transmission Association

6. Seneca Coal Company, Peabody Sage Creek Mining, LLC, and Twentymile Coal Company

7. Western Resource Advocates

8. Colorado River Water Conservation District

9. Climax Molybdenum Company

10. Trapper Mining, Inc.

11. Upper Blue Sanitation District

12. Clinton Ditch & Reservoir Company

13. Vail Resorts, Inc. and Vail Summit Resorts, Inc.

14. Eagle Park Reservoir Company

15. Upper Eagle Regional Water Authority

16. Colorado Parks and Wildlife

17. Denver Water

18. Environmental Protection Agency

19. Powdr-Copper Mountain, LLC

20. Town of Frisco