5 Colo. Code Regs. § 1002-33.52
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 deleted, renumbered, and/or created new segments to facilitate appropriate organization of waterbodies in this regulation. The following changes were made:
Upper Colorado River Segment 5: This segment was deleted and the lakes and reservoirs in this segment were moved to a new Segment 13 at the end of the subbasin to be consistent with the organization of lakes and reservoirs segments in other basins.
Blue River Segment 1: Based on the information presented by the Upper Blue Sanitation District (UBSD), the mainstem of the Blue River from the confluence with the Swan River to Dillon Reservoir was moved to new Segment 2c to simplify the segmentation of the Upper Blue River and to facilitate the adoption of appropriate nutrient standards.
Blue River Segment 3: This segment was deleted and the lakes and reservoirs in this segment were moved to a new Segment 22 at the end of the subbasin to be consistent with the organization of lakes and reservoirs segments in other basins. The waters previously in Segment 22 were renumbered to Segment 23 as a result.
Eagle River Segments 9a and 9b: The lower portion of Eagle River Segment 9a, the mainstem of the Eagle River from a point immediately below Squaw Creek to a point immediately below Rube Creek, was moved to a new Segment 9b to facilitate the adoption of appropriate temperature standards. Segment 9b was renumbered to 9c to facilitate this change.
Roaring Fork River Segment 3d: The following waters were moved from existing Segment 3a to a new Segment 3d: Cattle Creek, including all tributaries and wetlands, from the source to the most downstream White River National Forest boundary (39.467850, -107.065410). These waters were split into different segments to facilitate the adoption of an Outstanding Waters designation for Segment 3d.
Roaring Fork River Segment 10a and 10b: The following waters were moved from existing Segment 10 to a new Segment 10b: Mainstem of North Thompson Creek, including all tributaries and wetlands, from the source to the White River National Forest boundary (39.316522,-107.305749). Mainstem of Middle Thompson Creek, including all tributaries and wetlands, from the source to a point immediately below the confluence with the South Branch of Middle Thompson Creek (39.295749, -107.308788). These waters were split into different segments to facilitate the adoption of an Outstanding Waters designation for Segment 10b.
Yampa River Segment 1b: The lakes and reservoirs in this segment were moved to a new Segment 21 at the end of the subbasin to be consistent with the organization of lakes and reservoirs segments in other basins. Segment 1a was also changed to Segment 1 as a result.
Yampa River Segment 2b: The lakes and reservoirs in this segment were moved to a new Segment 22 at the end of the subbasin to be consistent with the organization of lakes and reservoirs segments in other basins. Segment 2c was also changed to Segment 2b as a result.
Yampa River Segments 6 and 7: The boundary of these two segments did not change, but the description was altered as it is not the Commission's practice to use the location of an outfall as a segment boundary. The boundary is now described as "a point 0.25 mile below County Road 27" instead of "the point of discharge of the Oak Creek wastewater treatment plant."
Yampa River Segments 13b, 13d, 13e, 13g, 13h, 13i, 13j: The Commission created new segments for a number of segments in the Yampa River sub-basin. Seneca Coal, Peabody Sage Creek Mining LLC, and Twentymile Coal, LLC collected seasonal water quality and biomonitoring data over two years from multiple drainages within Yampa River segments 13b, 13d, 13e. The upper reaches of segments 13b, 13d, and 13e (i.e., Cow Camp Creek, Bond Creek, Little Grassy Creek, Grassy Creek, Sage Creek, and Dry Creek) only flow seasonally, largely in response to spring snowmelt (March - July); the remainder of the year flow is greatly limited. The lower reaches of these segments have limited flow as well; spring flows are consistent, but summer and fall streamflow is primarily restricted to small sections of flowing water and/or isolated pools, likely freezing over in the winter months. The only exceptions to this flow regime are the mainstems of Fish, Foidel, and Middle Creeks, which normally maintain flow year-round, and select locations within lower Dry and Grassy Creeks which maintain sufficient pools to support holdover populations of fish. The reaches of the steams with ephemeral flows have been included in segments 13d, 13e, 13g, 13h, 13i. The streams with perennial flows have been included in segments 13b and 13j.
Yampa River Segments 22 and 23: Elkhead Reservoir was moved to a new Segment 23. These waters were split into different segments to facilitate a revision of the Aquatic Life use from Cold 1 to Warm 1.
The following segment descriptions were edited to improve clarity, correct typographical errors, and correct spelling errors:
Upper Colorado River Segment: 6c and 13
Blue River Segment: 8 and 6b
Eagle River Segments: 2, 5a and 11
Yampa River Segments: 8, 14, 15 and 18
Yampa River Segment 23: Based on a Use Attainability Analysis (UAA) prepared by Colorado Parks and Wildlife and the Colorado River Water Conservation District, the Commission adopted a change in the Aquatic Life use classification and standard from Cold 1 to Warm 1 and a new Yampa River Segment 23 for Elkhead Reservoir. Available temperature and fish data identify that the original classification of Elkhead Reservoir as a cold water lake was in error and that only warm water species are expected to occur due to natural and man-induced irreversible conditions.
Yampa River Segments 13b, 13g: Based on fish species expected to be present, temperature data, and other available evidence in a Use Attainability Analysis submitted by Seneca Coal, Inc., the Commission changed the aquatic life use classification for Yampa River segment 13b from Cold 1 to Warm 1. For Segment 13g the Commission maintained the aquatic life use classification of Warm 1. The Commission found that this was necessary to protect the fish collected in tributaries to Fish Creek in segment 13g, which included a round tail chub, a species that has been designated by Colorado Parks and Wildlife as a species of special concern. It is likely that the chub and other species use the streams in 13g when flow and habitat are present. Segments 13h, 13i, and 13j inherited their aquatic life use classifications as a result of re-segmentation.
A review of the segments with an existing Recreation use classification showed that one segment had an incorrect E. coli standard to protect that use. The E. coli standard was corrected for the following segment:
Upper Colorado River Segment: 6a
The Commission added a Water Supply use classification and standards where the evidence demonstrated 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:
Roaring Fork River Segment: 4
North Platte River Segment: 6
Yampa River Segment: 7
Numerous segments were missing the "(dis)" notation for the manganese water supply standard. These errors were corrected to "Mn(ch)=WS(dis)".
A molybdenum standard of 210 ug/l was applied to the following segments to protect the Water Supply use classification:
Blue River Segments: 14 and 15
Blue River Segment 13: The Commission adopted a narrative standard for segment 13 to protect water supply uses in downstream waters. It is the Commission's intent that permit effluent limits for sources in segment 13 are written to protect downstream uses.
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 the 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 light of EPA's 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 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 the following segments in Regulation 33 that have an Agriculture use classification, and where livestock or irrigated forage are present or expected to be present.
Upper Colorado River Segments: 1, 2, 3, 4, 6a, 6b, 6c, 7a, 7b, 7c, 8, 9, 10a, 10b, 10c, 11, 12 and
13
Blue River Segments: 1, 2a, 2b, 2c, 4a, 4b, 5, 6a, 6b, 8, 9, 10, 11, 12, 16, 17, 18, 19, 20, 21, 22
and 23
Eagle River Segments: 1, 2, 3, 4, 5a, 5b, 5c, 6, 7a, 7b, 8, 9a, 9b, 9c, 10a, 10b, 11, 12, 13 and 14
Roaring Fork River Segments: 1, 2, 3a, 3b, 3c, 3d, 4, 5, 6, 7, 8, 9, 10a, 10b, 11 and 12
North Platte River Segments: 1, 2, 3, 4a, 4b, 5a, 5b, 6, 7a, 7b, 8 and 9
Yampa River Segments: 1, 2a, 2b, 3, 4, 5, 6, 7, 8, 11, 12, 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, 13i, 13j, 14, 15, 18, 19, 20a, 20b, 21, 22, and 23
The following segments have an Agriculture use classification, but livestock or irrigated forage are not expected to be present. A molybdenum standard of 160 ug/l was not applied to these segments to protect the Agriculture use classification:
Blue River Segments: 13, 14 and 15
Upper Colorado Segment 8: A site-specific molybdenum standard of 190 ug/l was adopted for this segment, which has an Agriculture use classification, and livestock and irrigated forage are present or expected to be present. This site-specific molybdenum standard is based on protection of a lactating cow (409 kg), which is the animal and life stage that is most sensitive to molybdenum, and site-specific factors appropriate for the Williams Fork area. The equation above and in the Regulation #31 Statement of Basis (2010, 31.48 H) was used with the following dietary and water intake values : [Cu] forage = 7 mg/kg, [Mo] forage = 0.5 mg/kg, forage intake = 10.2 kg/day (OSU, 2004), [Cu] water = 0.008 mg/L, [Mo] water = 0.375 mg/L, Cu supplementation = 0 mg/day, Mo supplementation = 0 mg/day. Water intake = 67.8 L/day (NRC, 2000), based on an ambient temperature of 80°C (ave. daily max. at Kremmling, CO).
Roaring Fork Segment 3d: The Commission adopted an Outstanding Waters (OW) designation for this segment based on evidence presented by WildEarth Guardians showing that water quality meets the requirements of 31.8(2)(a). 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.
Roaring Fork Segment 10b: The Commission adopted an Outstanding Waters (OW) designation for this segment based on evidence presented by Trout Unlimited showing that the criteria of 31.8(2)a has been met for these waters. In addition to meeting the water quality requirements of 31.8(2)a, these waters support Colorado River cutthroat trout, including key conservation populations in North and Middle Thompson Creek. The Colorado River cutthroat trout is listed as a species of concern in Colorado and is subject to a conservation agreement to prevent potential federal Endangered Species Act listing. The Commission 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 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.
Yampa River Segments 13d, 13e, 13h, 13i, and 13j: The Commission retained use protected designation for segments 13d and 13e, and segments 13h, 13i, and 13j inherited their use protected designations as a result of re-segmentation.
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 that were revised:
Upper Colorado River Segments: 12 (Lake Granby) and 13 (Wolford Mountain)
North Platte River Segment: 9 (Lake John)
Yampa River Segments: 13b (Middle Creek) and 22 (Stagecoach Reservoir)
New ambient based standards were adopted for the following segments:
North Platte River Segment: 9 (South Delaney Lake)
Yampa River Segment: 2b (Pearl Lake)
Yampa River Segment 13b: Foidel Creek is achieving the table value standard for total recoverable iron which is 1000 ug/L with assessment locations specified in 33.6(4)(c), which the Commission adopted due to spatial variability in iron concentrations throughout the stream reach. Accordingly the Commission retained the 1000 ug/L total recoverable iron standard for Foidel Creek. The Commission updated the annual ambient-based standard on Middle Creek to a seasonal ambient-based standard for March-June of 2090 ug/L, based on the most recent five years of data. TVS applies for the remainder of the year for Middle Creek.
Yampa River Segments 13h and 13j: While the Commission did not adopt ambient based selenium standards proposed in this hearing on these segments, parties are encouraged to collect additional data to further evaluate the appropriateness of an ambient based selenium standard in the future.
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 33.6(3) were modified to conform to Regulation 31. The footnotes to the table values in 33.6(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. A review of existing hardness and fishery data showed numerous segments with low average hardness (<102 CaCO3 mg/l) and where the Colorado Division of Parks and Wildlife expects sculpin to be present. A sculpin-specific zinc equation was added to the following segments:
Blue River Segments: 13 and 18
Eagle River Segment: 3
Roaring Fork River Segment: 7
Yampa River Segment: 1
For the following segments where hardness could exceed 102 mg/l, both the zinc sculpin standard and the chronic zinc table value standard were adopted:
Upper Colorado River Segments: 1, 2, 3, 7b, 8, 10a, 10b and 10c
Blue River Segments: 1, 4a, 4b, 8, 14 and 17
Eagle River Segments: 1, 2, 4, 6, 7a and 8
Roaring Fork River Segments: 2, 5, 6, 10a and 10b
Yampa River Segments: 2a, 2b, 3, 8, 13a, 18 and 19
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 33.5(3)(c) to reflect the change to the basin-wide standard. A new section 33.5 was added to explain the hyphenated standard. Subsection 33.5 was deleted because it was redundant with 33.5(3)(c).
To remain consistent with the Commission's decisions regarding arsenic at 33.50, 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 ug/l and a permitted discharger with a predicted water quality-based effluent limit compliance problem:
Upper Colorado River Segment: 10c
Roaring Fork River Segment: 4
Yampa River Segment: 7
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.
Iron
Yampa River Segments 13d and 13i: The Commission adopted a narrative temporary modification for iron on the former segment 13e in the 2008 basin hearing and the temporary modification has remained in place. Since that time Peabody has been working on resolving the uncertainty surrounding the appropriate underlying standard. The Commission adopted a current conditions narrative temporary modifications on segments 13d and 13i (13i is a new segment that was formerly a part of 13e) until December 31, 2016. The Commission expects that Peabody will work with the Division and other interested stakeholders to develop a definitive plan to resolve the uncertainty for these segments for the December 2014 temporary modification hearing.
Selenium
Yampa River Segments 13b, 13d, 13e, 13g, 13i: Seneca Coal, Peabody, and Twentymile originally proposed numeric fish tissue-based site-specific standards for selenium for Yampa River segments 13b, 13d, 13e, 13g and 13i. In support of their proposal they provided data including in-stream selenium concentration and fish-tissue selenium concentrations along with proposed implementation methodologies. However, during the rulemaking process EPA issued new draft selenium criteria. In response to EPA's May 2014 draft selenium criteria, Seneca Coal, Peabody, and Twentymile withdrew their site-specific standard proposal and revised their proposal to a narrative "current conditions" temporary modification for selenium for these segments.
The Commission adopted a current conditions temporary modification for selenium for these segments. Peabody presented information that shows a demonstrated or predicted compliance problem for each of these segments. Additionally, the Commission found there was significant uncertainty regarding the water quality standard necessary to protect current and/or future uses, and that there is substantial uncertainty about the extent to which existing quality is the result of natural or irreversible human-induced conditions.
Molybdenum
Blue River Segment 14: The Commission adopted a temporary modification of the molybdenum standard for this segment of Mo(ch)="current conditions" (Exp. 12/31/16). The Commission recognizes that there is new toxicological information that should be included in recalculation of a human health-based criterion. Parties do not agree on the uncertainty factors that need to be included in the calculations. Since this issue is larger than a segment-specific issue, it is more appropriate to address this situation in the review of the Basic Standards and the expiration date was set to accommodate that schedule. There is also uncertainty regarding the extent to which existing quality in Blue River Segment 14 is the result of irreversible human-induced conditions due to forthcoming new treatment facilities at the Climax Mine. Climax also presented information that shows a predicted compliance problem and has submitted an adequate plan for eliminating the need for the temporary modification.
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:
Upper Colorado River Segment: 12 (Shadow Mountain and Lake Granby)
Upper Colorado River Segment: 13 (Wolford Mountain and Williams Fork Reservoirs)
Roaring Fork River Segment: 12 (Ruedi Reservoir)
Yampa River Segment: 22 (Pearl Lake, Stagecoach and Steamboat Reservoirs)
Eagle River Segments 8, 9a, 9b and 9c: In the 2008 hearing, the Commission adopted temperature standards for Eagle River Segments 8 and 9a. Due to the limited temperature and biological information available at the time, the Commission recognized that there was uncertainty regarding the appropriate temperature standards adopted in that hearing. Since 2008, Eagle River Water and Sanitation District (ERWSD) has collected temperature data in Segments 8 and 9a and has worked with Colorado Parks and Wildlife (CPW) to determine the aquatic species expected to occur in Gore Creek and the Eagle River.
In this hearing, based on information presented by ERWSD and CPW, the Commission adopted site-specific temperature standards for Eagle River segments 8, 9a, and 9b to protect the aquatic life use (31.7(1)(b)(iii)) and re-segmentation where appropriate (Section A). The spring shoulder season standards were adjusted to protect cutthroat trout spawning and incubation. The fall shoulder season standards were adjusted to protect brook and brown trout migration and spawning. The basis for these temperature standards is specific to the temperature and biological conditions in the Eagle River Segments 8, 9a, and 9b, and accounts for the seasonal temperature requirements for the various life stages of the aquatic species expected to occur in this area while recognizing that these segments include a transitional zone between Cold Stream Tier I and Tier II. This action is not intended to revise the biological goals for the Eagle River established by the Commission in 2008, regarding the Eagle Mine Superfund Site.
The Commission recognizes the high quality fishery that exists in these segments is economically important, yet is currently stressed and in recovery. Local stakeholders are actively working to protect and improve water quality including projects associated with urban runoff, stream and riparian restoration, hydrologic conditions, and the Eagle Mine Superfund Site. Future refinements of temperature standards for these segments may be warranted as more information becomes available regarding their natural and existing thermal regimes, and the temperatures needed to protect the aquatic species expected to occur.
Segment 8: The lower portion of this segment is currently designated a Gold Medal Fishery. Cutthroat, brook, brown and rainbow trout are all expected to occur in this segment. The Commission adopted site-specific chronic temperature standards based on a modification of Cold Stream Tier I table values
Segment 9a: This segment is impacted by metals contributions from historic mining. Cutthroat, brook, rainbow, and brown trout could occur in this segment. The Commission adopted site-specific chronic temperature standards based on a modification of Cold Stream Tier I table values.
Segment 9b: This segment is also impacted by metals contributions from historic mining. Rainbow and brown trout are expected to occur in this segment, and this area is a transition zone. Cutthroat and brook trout may use this segment seasonally, and when hydrologic conditions are favorable. The Commission adopted site-specific acute and chronic temperature standards based on a modification of Cold Stream Tier II table values.
Segment 9c: Segment 9b was renumbered to segment 9c, and retained its use classifications and Cold Stream Tier II temperature standards.
Yampa River Segments 13b, 13d, 13e, 13g, 13h, 13i, and 13j: Based on fish species expected to be present, temperature data, and other available evidence submitted by Peabody, Warm Stream Tier II temperature standards were retained for segments 13d and 13e, and were adopted for segments 13b and 13g. Segments 13h, 13i, and 13j inherited their Warm Stream Tier II temperature standards as a result of re-segmentation.
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 33.5 describing implementation of the interim nutrient values into the tables at 33.6, 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 33.5(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 33.5(4) for segments with an Aquatic Life use. Chlorophyll a standards were adopted above the dischargers listed at 33.5(4) for segments with either an E, P, or U Recreation use classification.
* For lakes and reservoirs segments, 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:
Upper Colorado River Segments: 1, 2, 3, 4, 6a, 7b, 8, 9, 10a, 11, 12 and 13
Blue River Segments: 1, 2a, 4a, 4b, 5, 6a, 6b, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 21, 22 and 23
Eagle River Segments: 1, 2, 3, 4, 6, 7a, 7b, 8, 10a, 10b, 11, 12, 13 and 14
Roaring Fork River Segments: 1, 2, 3a, 3c, 3d, 4, 5, 6, 7, 8, 9, 10a, 10b, 11 and 12
North Platte River Segments: 1, 2, 3, 4a, 4b, 5a, 8 and 9
Yampa River Segments: 1, 2a, 3, 5, 6, 7, 8, 13a, 13b, 13c, 13d, 13f, 13g, 13h, 14, 15, 18, 19, 20a, 21, 22 and 23
Total Phosphorus standards were adopted for the following segments:
Upper Colorado River Segments: 1, 2, 3, 4, 6a, 6b, 7a, 7b, 7c, 8, 9, 10a, 11, 12 and 13
Blue River Segments: 1, 2a, 4a, 4b, 5, 6a, 6b, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22 and 23
Eagle River Segments: 1, 2, 3, 4, 6, 7a, 7b, 8, 10a, 10b, 11, 12, 13 and 14
Roaring Fork River Segments: 1, 2, 3a, 3b, 3c, 3d, 4, 5, 6, 7, 8, 9, 10a, 10b, 11 and 12
North Platte River Segments: 1, 2, 3, 4a, 4b, 5a, 5b, 6, 7a, 7b, 8 and 9
Yampa River Segments: 1, 2a, 3, 4, 5, 6, 7, 8, 11, 12, 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, 13i, 13j, 14, 15, 18, 19, 20a, 20b, 21, 22 and 23
Blue River Segments 1, 2a, 2b and 2c: Nutrient standards were adopted for Blue River Segment 1, as this segment is located entirely above qualified dischargers. Nutrient standards were adopted with a footnote "C" for Segment 2a, as the Upper Blue Sanitation District's (UBSD) Iowa Hill Water Reclamation Facility is a qualified discharger listed at 33.5(4) and is located within this segment. Nutrient standards were not adopted for Blue River Segment 2b and new Segment 2c, as these segments are located entirely below the Iowa Hill Water Reclamation Facility and nutrient standards do not apply.
The UBSD's South Blue River wastewater treatment facility is located within Blue River Segment 1. However, this facility discharges to groundwater and it is not subject to Regulation 85 nutrient limitations for surface water discharges. It is therefore not a qualified discharger listed at 33.5(4). If the nature of the discharge from UBSD's South Blue River wastewater treatment facility changes to include a discharge to surface water, this issue will be revisited to reflect such a change.
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 or 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.
Upper Colorado River Segment 12: | Grand Lake (YMCA) |
Upper Colorado River Segment 13: | Ute Creek Reservoir (Climax - Henderson Mill) |
Blue River Segment 22: | Goose Pasture Tarn (Town of Breckenridge) |
Roaring Fork River Segment 12: | Leonard Thomas Reservoir (City of Aspen) |
Roaring Fork River Segment 12: | Wildcat Reservoir (Wildcat Ranch) |
Yampa River Segment 22: | Steamboat Lake (Steamboat Lake State Park) |
Yampa River Segment 22: | Stagecoach Reservoir (Stagecoach State Park) |
Yampa River Segment 22: | Yampa River Holding Pond (PSCO OF CO - Hayden Station) |
31.17(e)(iii) 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.
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 CrIII(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 ug/l. For segments that have both Aquatic Life and Water Supply use classifications, a chronic chromium III standard of CrIII(ch)=TVS was added to all segments that did not previously have that standard. Changes were made to the following segments:
Upper Colorado River Segments: 3, 4, 6c, 7a, 7b, 7c, 9, 11, 12 and 13
Blue River Segments: 1, 6a, 6b, 11, 12, 13, 14, 16, 17, 19, 20, 21, 22 and 23
Eagle River Segments: 2, 3, 5a, 5b, 5c, 8, 9a, 9b, 9c, 10a, 10b, 12, 13 and 14
Roaring Fork River Segments: 1, 3a, 3b, 3c, 3d, 4, 6, 7, 8, 9, 10a, 10b, 11 and 12
North Platte River Segments: 3, 6, 7a, 7b, 8 and 9
Yampa River Segments: 2a, 2b, 5, 6, 7, 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, 13i, 13j, 14, 15, 19, 20a, 20b, 21, 22 and 23
Upper Colorado River Segment 12: The Commission determined in 2008 that the adoption of a 4 meter numerical standard with a delayed effective date was an appropriate policy choice to encourage cooperative efforts to improve Grand Lake clarity. At the same time, the Commission adopted the following narrative "The highest level of clarity attainable, consistent with the exercise of established water rights and the protection of aquatic life" as the effective standard. Efforts since 2008 have focused on data collection and understanding the factors controlling clarity.
In today's action, the Commission adopted a change to the narrative clarity standard that added "protection of water quality throughout the Three Lakes System" as another consideration for attainability in order to recognize the interdependence of water quality in the entire system. The Commission also decided that further delay in the effective date of the numerical standard was justified in view of the progress that has been made cooperatively by the parties and by the obstacles they have yet to overcome.
Sufficient effort has not yet been focused on determining an "attainable" level of clarity that is consistent with the constraints identified in the narrative standard. It is the Commission's hope that improvement in clarity can be achieved by a balanced approach that does not sacrifice water rights, the recreational fishery, or water quality. The Commission expects and anticipates a cooperative effort that will focus on identifying an attainable and protective Grand Lake clarity standard. The effort should address the following questions that consider the constraints imposed on attainability:
The Commission expects that the cooperative effort will also evaluate alternatives for describing the water transparency necessary to protect the assigned use classifications
Ultimately, the goal of the effort is to develop and propose by January 2016 an attainable and protective clarity standard for Grand Lake for consideration by the Commission. If this cooperative effort does not result in a proposal for an attainable and protective clarity standard by January 2016, the standard will be determined by a site specific clarity standard hearing to be scheduled for 2016.
Blue River Segment 5: The pH standard for Soda Creek was changed from 6.0-9.0 to the table value of 6.5-9.0, based on data demonstrating this value was currently being attained.
Eagle River Segment 11: The "(ac)" notation was deleted from the nitrite and nitrate standards for this segment.
Roaring Fork River Segment 3b: A footnote "A" was added to the chronic arsenic standard to explain the hyphenated standard.
Yampa River Segment 4: A footnote "A" was added to the chronic arsenic standard to explain the hyphenated standard.
Yampa River Segment 13d: A footnote "A" was added to the chronic arsenic standard to explain the hyphenated standard.
PARTIES TO THE RULEMAKING HEARING
5 CCR 1002-33.52