5 Colo. Code Regs. § 1002-34.38
The provisions of C.R S. 25-8-202(1)(a), (b) and (2); 25-8-203; 25-8-204; and 25-8-402; provide the specific statutory authority for adoption of these regulatory amendments. The Commission also adopted in compliance with 24-4-103(4) C.R.S. the following statement of basis and purpose.
BASIS AND PURPOSE:
The Commission split lakes and reservoirs from segments that also contained streams, so that new temperature standards could be adopted. Lakes and reservoirs were deleted from the following segments that previously encompassed streams and lakes and reservoirs:
San Juan River segments: 1a, 3, 4, 5, 6a, 9a, 9b, 11a, 11b, 12a
Piedra River segments: 1, 5, 6a, 6b
Los Pinos River segments: 1, 4a, 6a, 6b
Animas and Florida River segments: 1, 3c, 6, 7, 8, 12a, 13b, 13c
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 1, 3a, 3b, 4a, 6a,
6b, 7a, 8a, 8b, 10a, 10b
Upper Dolores River segments: 1, 5a, 11
The following segments were created for lakes and reservoirs:
San Juan River segments: 13, 14, 15a, 15b, 16, 17, 18a, 18b, 19
Piedra River segments: 8, 9, 10, 11a, 11b
Los Pinos River segments: 8, 9, 10, 11a, 11b
Animas and Florida River segments: 16, 17, 18, 19, 20, 21, 22, 23, 24
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 12, 13, 14, 15, 16,
17, 18, 19, 20, 21, 22
Upper Dolores River segments: 12, 13, 14, 15
The following segment was deleted when the constituent water bodies were merged with other segments:
San Juan River segment: 12b
Some existing stream segments were divided into two or more segments at the point where a change in temperature tiers occurred. The following segments were created or revised to facilitate adoption of the new temperature standards into individual segments:
San Juan River segments: 1a, 1b, 7, 8, 9a
Piedra River segments: 2a, 2b
Animas and Florida River segments: 10a, 10b, 14a, 14b
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 3a, 3c, 4a, 4c, 6a
The following segments were created or revised based upon water quality and/or aquatic life data which showed that streams should be resegmented or grouped with another segment for which there was similar water quality and designated uses:
San Juan River segments: 11b
Animas and Florida River segments: 12a, 12d, 13b, 13d, 14a
Dolores River segments 5a, 5b
The following segment descriptions were edited to improve clarity, fix typographical errors, update numbering and correct spelling:
San Juan River segments: 2, 5, 6a, 9a, 10, 11a, 11b, 12a
Piedra River segments: 4a, 5, 6a
Los Pinos River segments: 7a, 7b, 8
Animas and Florida River segments: 6, 12a, 13a, 13b, 15
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 4b, 7b, 10a, 10b
Upper Dolores River segment: 1
The Commission reviewed information regarding the existing aquatic communities. Class 2 segments with exceptionally high MMI scores, or fish data showing the presence of a wide variety of species, were upgraded from Class 2 to Class 1.
The following segments were upgraded from Warm 2 to Warm 1:
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 2b, 5a, 5b San Juan River segment: 11b (revised to include water bodies from the former segment 12b)
The following segments were upgraded from Cold 2 to Cold 1:
La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 2a Animas and Florida River segments: 12a, 12d
Fish Ingestion qualifiers were added to the following segments, based upon review of available data:
Piedra River segment 11a
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 14
Fish Ingestion qualifiers were deleted for the following segment that was upgraded from Class 2 to Class 1, since fish ingestion is presumed for all Class 1 waters:
La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 2a
The following segment was upgraded from Warm 2 to Cold 1 based on biological data showing that the segments have cold-water species, or cold-water species are expected to be present:
La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 3c
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:
San Juan River segments: 3, 12, 19
Los Pinos River segments: 6a, 6b, 11a, 11b
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 10a, 10b
Some new lake segments were split from stream segments with no Aquatic Life Use. These new lake segments were designated as Aquatic Life Cold 2, because the Aquatic Life UAAs did not include data from these lakes. The full suite of standards protective of aquatic life was added to the following segments:
Animas and Florida River segments: 19, 20
A Use Attainability Analysis was prepared to downgrade the following segment from Cold 1 to Warm 1:
San Juan River segment: 8 A
Use Attainability Analysis was prepared to remove the Aquatic Life Use and standards:
Animas and Florida River segment: 13d
Newly created segments were given the same Recreation Use classification as the segment from which they were split, unless there was insufficient evidence to support keeping that classification, or evidence to show that the use classification was inappropriate or that recreation use had changed.
The following segments with year-round or seasonal Recreation N standards were upgraded to Recreation E:
La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 3c La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 14
The following segments with year-round or seasonal Recreation P standards were upgraded to Recreation E:
Piedra River segment: 11a
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 1, 12
The following segment with year-round or seasonal Recreation N standards was upgraded to Recreation P:
La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 13
Based on review of information regarding the location of alluvial wells, where the evidence demonstrates a reasonable potential for a hydrological connection between the surface water and the wells, the Water Supply Use classification and standards were added to the following segments:
San Juan River segments: 10, 11a
Animas and Florida River segments: 9, 13a
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 2a, 2b, 3b, 4c, 5a, 8a
Upper Dolores River segment: 3
A Use Attainability Analysis was prepared to remove the Water Supply Use and standards from the following segment:
Animas and Florida River segment: 13d
A review of the standards associated with the Agriculture Use classification showed that many segments were missing a chronic chromium III standard to protect the use. The chronic chromium III standard to protect the Aquatic Life Use classification may be not be protective of the Agriculture Use in some high hardness situations. A chromium III standard of CrIII(ch)=100(Trec), was added to the following segments classified for Agriculture Use, but not for Water Supply, which has a more restrictive chromium III standard:
San Juan River segments: 11b, 18b
Los Pinos River segments: 7a, 7b
Animas and Florida River segment: 3a
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 6a, 6b, 6c, 7a, 7b, 8b, 8c, 9, 13, 14, 16, 17, 18, 19
Several segments with the Agriculture Use classification were missing a standard for nitrate. A nitrate standard of 100 mg/l was added to the following segments:
Los Pinos River segments: 7a, 7b
Animas and Florida River segments: 3a, 3c, 4a, 17, 19, 20
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 3a, 5b, 6a, 6b, 6c, 7a, 7b, 8b, 8c, 9, 13, 14, 16, 17, 18, 19, 20
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 ug/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 region is common, but is not universal. Therefore, copper supplementation assumption was removed from the equation, which yields a standard of 160 ug/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 view of EPA disapproval of the 300 ug/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 Use 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 of 160 ug/l was adopted for all segments in Regulation 34 with an Agriculture Use classification; except for La Plata segment 6c, because grazing is not allowed within Mesa Verde National Park. No molybdenum standard was applied to Animas and Florida River segment 3b, because it does not have an Agriculture Use classification.
Outstanding Waters: Based on evidence that shows the water quality meets the requirements of section 31.8 , and on the presence of conservation populations of native cutthroat trout in all three streams, the Outstanding Waters designation was added to Rio Lado, Little Taylor Creek and Spring Creek (Dolores River segment 5b). The Commission has determined that the evidence demonstrates that the three criteria for an Outstanding Waters designation set forth in section 31.8 are met for this proposal. The Commission also notes that the outreach undertaken by Trout Unlimited as proponent of this designation helps to demonstrate broad support for the conclusion that these waters constitute an outstanding natural resource and that the additional protection provided by this designation is appropriate.
The Commission understands that there are existing land uses, including grazing permits, in place in the watershed. The evidence demonstrates that these existing land uses are compatible with the Outstanding Waters 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 Outstanding Waters designation should not be the basis upon which federal, state or local agencies place more onerous or costly conditions upon permits or approvals existing at the time of the designation, or upon any renewals thereof.
Further, acknowledging that the adoption of the Outstanding Waters designation for identified segments is a discretionary undertaking by the Commission, with such designations not being subject to federal approval or disapproval, the Commission may, in the future, remove the Outstanding Waters designation from any such segment in accordance with the state substantive and procedural rules then in effect.
The Commission has not adopted the Outstanding Waters designations proposed by WildEarth Guardians for multiple segments. The Commission is not persuaded that the fact of being located within an area identified as a "roadless area" is sufficient to demonstrate that the waters in question constitute an outstanding natural resource. Moreover, the proponents did not provide adequate data to persuasively demonstrate the current quality of the waters in question. Finally, the Commission notes that the proponents did not demonstrate a substantial level of public outreach that might have helped to demonstrate a consensus that the criteria in section 31.8(2)(a) are met.
Decoupling Cold 2 and UP: As part of the Basic Standards hearing of 2005, the Commission eliminated the direct linkage between Cold-Water Aquatic Life Class 2 and the Use-Protected designation. The Commission reviewed available water quality data for all Cold 2 segments that were Use-Protected to determine if that designation was still warranted. The following segment(s) are now Reviewable:
Animas and Florida River segments: 17, 19, 20
Decoupling Aquatic Life Warm 2 and UP: As part of the Basic Standards hearing of 2005, the Commission decided that the presence of a Warm Water Class 2 classification would still be a presumptive basis for applying a Use-Protected designation; however, that presumption can be overcome if there is data showing that the water is of high quality. The Commission reviewed available water quality data for all Warm 2 segments to determine if the Use-Protected designation is still warranted. The following segment(s) are now Reviewable:
San Juan River segments: 11b (revised to include water bodies from the former segment 12b), 12
Other Changes to Antidegradation: The following segment was upgraded from "Warm 2"to "Warm 1"and the Antidegradation designation is now Reviewable:
La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 2b
The following segment was upgraded from "Warm 2"to "Cold 1"and the antidegradation designation is now Reviewable:
La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 3c
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. The following segments have ambient-based or other site-specific standards:
Animas and Florida River segments: 2, 3a, 3b, 4a, 7, 8, 9
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 7a, 9
No changes were made to the ambient quality-based standards for these segments.
A site-specific manganese standard of 255 ug/L was added to Dolores Segment 3. This value was calculated as the 85th percentile of available data from 1/1/1995 - 12/31/2012, and is expected to be representative of conditions on January 1, 2000, consistent with 31.11(6)).
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 34.6(3) were modified to conform to Regulation No. 31.
Site-Specific Zinc Standards for Mottled Sculpin: 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. The Commission did not add a sculpin-specific zinc equation to any segment in Regulation 34.
The Commission deleted the zinc scuplin standards from the following new and revised lake segments, where mottled sculpin are not expected to be present:
San Juan River segments: 8, 17
Piedra River segments: 8, 10
Los Pinos River segment: 10
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 12, 13
Upper Dolores River segments: 12, 13, 14, 15
Chromium III Standards: A review of chromium III standards showed that the standard associated with the Water Supply Use classification is not protective of aquatic life where the average hardness is low (less than 61 mg/l). A chromium III standard, CrIII(ch)=TVS was added to following segments with Aquatic Life and Water Supply Use classifications that did not previously include this standard:
San Juan River segments: 1a, 1b, 2, 3, 4, 5, 6a, 6b, 7, 8, 9a, 9b, 10, 11a, 11b, 12, 13, 14, 15a, 15b, 16, 17, 18a, 18b, 19
Piedra River segments: 1, 2a, 2b, 3, 4a, 4b, 5, 6a, 6b, 7, 8 , 9, 10, 11a, 11b
Los Pinos River segments: 1, 2a, 2b, 3, 4a, 4b, 5, 8, 9, 10
Animas and Florida River segments: 1, 5a, 5b, 6, 10a, 10b, 11a, 11b, 12a, 12c, 12d, 13b, 13c, 14a, 15, 16, 21, 22, 23, 24
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 1, 3b, 4a, 4b, 11, 12, 15
Upper Dolores River segments: 1, 2, 3, 4a, 4b, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
The acute chromium III standard, CrIII(ac)=TVS was deleted from the following segments with Aquatic Life and Water Supply Use classifications that have the CrIII(ac)=50 ug/l standard:
San Juan River segment: 11a
Animas and Florida River segment: 4b
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 2a, 2b, 3b
Arsenic Standards: A review of arsenic standards showed that the acute standard for the protection of aquatic life was missing in some segments. An Acute Arsenic standard of 340 ug/l was added to the following segments:
Los Pinos River segments: 6a, 6b, 7a, 7b, 11a, 11b
At the 2010 Basic Standards rulemaking hearing, the Commission changed the Water Supply table value for uranium from 30 ug/L to a hyphenated standard of 16.8-30 ug/L. The Commission revised the language in 34.5(3)(c) to reflect the change to the basin-wide standard. A new section 34.5 was added to explain the hyphenated standard. Subsection 34.5 was deleted because it was redundant with 34.5(3)(c).
All existing Temporary Modifications were re-examined to determine if they should be allowed to expire or to extend them. Temporary Modifications were not automatically extended if non-attainment persisted due to revisions made to the Temporary Modification provisions in 2005 and 2010.
The following segments had Temporary Modifications that were not extended:
San Juan River segment: 11a
Animas and Florida River segments: 2, 3a, 3b, 3c, 4a, 4b, 7, 8, 9
La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 8a
The following segments have new or extended "Type A"Temporary Modifications for ammonia:
Animas and Florida River segment: 13b
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 7a, 8c
Temporary Modifications were added or extended for existing discharges to these segments, based upon evidence that the dischargers could not meet water quality based effluent limits for ammonia. The Commission's intent is to preserve the status quo during the term of the Temporary Modification. Existing discharges to these segments shall continue to be authorized to discharge ammonia at their current permitted concentration and flow levels, including a "report only" value. The Division will work with the existing dischargers to determine whether the table value standard for ammonia is necessary to protect the Aquatic Life Uses of these segments. The uncertainty in the standard for each segment may be resolved through a site-specific standard or a discharger specific variance. The Commission does not intend that Temporary Modifications set at "current condition" will apply to new or expanded facilities. The progress on resolving the uncertainty with the ammonia standards will be reviewed in the annual Temporary Modification hearing in December 2013.
The following segment has a new "Type B" Temporary Modification:
Animas and Florida River segment: 3b
For Animas River Segment 3b, the Commission adopted a Type B Temporary Modification for copper, cadmium and zinc with a narrative value of "current condition", and an expiration date of December 31, 2017. The Commission's intent is to preserve the status quo during the term of the Temporary Modification. Existing discharges to Animas River Segment 3b shall continue to be authorized to discharge copper, cadmium and zinc at their current permitted concentration and flow levels, including a "report only" value. Historic mining impacts upstream from Silverton indicate that elevated levels of copper, cadmium and zinc in the Animas River may be due to irreversible human-induced conditions. Since remediation options are still be evaluated, and some improvement in water quality may be gained, it is not yet feasible to quantify the extent of irreversible impacts. The Commission does not intend that Temporary Modifications set at "current condition" will apply to new or expanded facilities. The progress on resolving the uncertainty with the cadmium, copper and zinc standards will be reviewed in the annual Temporary Modification hearing in December 2015.
New table values were adopted for temperature in the 2007 Basic Standards hearing, and revised in the 2010 Basic Standards hearing. Temperature standards were applied to individual segments based upon the fish species expected to be present as provided by Parks and Wildlife, temperature data, and other available evidence.
The following segments have a Cold Stream Tier I temperature standard (CS-I):
San Juan River segments: 1a, 4, 5, 7
Piedra River segments: 1, 2a, 3, 5
Los Pinos River segments: 1, 4a, 5
Animas and Florida River segments: 1, 3a, 3c, 4a, 4b, 6, 9, 10a, 12a, 12c, 12d, 13b, 14a, 15
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 1, 4a
Upper Dolores River segments: 1, 2, 3, 5a, 5b, 6, 7, 8, 9, 10, 11
The following segments have a Cold Stream Tier II temperature standard (CS-II):
San Juan River segments: 1b, 2, 6a, 6b, 9a, 9b, 10
Piedra River segments: 2b, 4a, 4b
Los Pinos River segments: 2a, 2b, 4b, 6a, 6b, 7a, 7b
Animas and Florida River segments: 5a, 5b, 10b, 11a, 11b, 13a, 13c, 14b
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 2a, 3c, 4c
Upper Dolores River segment: 4a
The following segments have a Warm Stream Tier II temperature standard (WS-II):
San Juan River segments: 3, 11a, 11b
Piedra River segment: 6a
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 2b, 3a, 3b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9
The following segments have a Warm Stream Tier III temperature standard (WS-III):
San Juan River segment: 12a
Piedra River segment: 6b
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 6c, 8c, 10a, 10b
The following segments have a Cold Lakes temperature standard (CL):
San Juan River segments: 13, 15a, 15b, 16, 17
Piedra River segments: 9, 10
Los Pinos River segments: 8, 10, 11a, 11b
Animas and Florida River segments: 16, 17, 18, 19, 20, 21, 23, 24
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 12, 15
Upper Dolores River segments: 12, 14, 15
The following segments have a Large Cold Lakes (greater than 100 acres surface area) temperature standard (CLL):
Piedra River segment: 8
Los Pinos River segments: 3, 9
Animas and Florida River segments: 12b, 22
La Plata River, Mancos, River, McElmo Creek and San Juan River segment: 4b
Upper Dolores River segments: 4b, 13
The following segments have a Warm Lakes temperature standard (WL):
San Juan River segments: 8, 14, 18a, 18b, 19
Piedra River segments: 7, 11a, 11b
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 11,13, 14, 16, 17, 18, 19, 20, 21, 22
A temperature standard was not adopted for several segments which do not have a designated Aquatic Life Use:
Animas and Florida River segments: 2, 3b, 7, 8, 13d
The Commission recognizes that in some cases there is uncertainty about the temperature standards adopted in this hearing. The uncertainty stems from a lack of data about temperature or the aquatic community or where there is a conflict between the lines of evidence. In particular, there was very limited data available for segments within the Southern Ute and Ute Mountain Indian Reservations. It is the Commission's intent that the Division and interested parties work to resolve the uncertainty for the following segments:
San Juan River segments: 2, 6b, 9b, 11b, 15b, 18b
Piedra River segments: 4b, 6b, 11b
Los Pinos River segments: 2b, 4b, 6b, 7b, 11b
Animas and Florida River segments: 5b, 11b, 13c, 24
La Plata River, Mancos, River, McElmo Creek and San Juan River segments: 2b, 3b, 5b, 6b, 7b, 8b, 9, 10b, 14, 17, 20, 22
La Plata River, Mancos, River, McElmo Creek and San Juan River 2b: The discrepancy between the Recreation Use season and the E. coli standard season was corrected. The fecal coliform standard was also deleted.
Upper Dolores River segment 11: The typographical error in the Agriculture designated use was corrected.
The Southern Ute Indian Tribe raised an issue with the wording of section 34.5 . The Commission deleted the phrase "in agreement with the Southern Ute and Ute Mountain Ute Indian Tribes". This section was added in 2001 and referred to a verbal staff level agreement at that time.
PARTIES TO THE RULEMAKING HEARING
5 CCR 1002-34.38