# WATER QUALITY STANDARDS (2025) > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/tribal%3Asouthern_ute%3Afabb1108f85f959e ## Record - **Collection:** Tribal code - **Document type:** Tribal code ## Text WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 4/24/2025 SOUTHERN UTE INDIAN TRIBE ENVIRONMENTAL PROGRAMS DEPARTMENT These water quality standards establish water quality goals for water bodies on the Southern Ute Indian Reservation and provide the legal basis for regulatory pollution controls. WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION CONTENTS 1 PURPOSE, AUTHORITY, AND APPLICABILITY ................................................................. 1 1.1 Purpose ........................................................................................................................................... 1 1.2 Authority.......................................................................................................................................... 2 1.3 Severability .................................................................................................................................... 2 1.4 Applicability................................................................................................................................... 2 1.5 Clean Water Act Program Implementation in Cooperation with EPA ................................ 3 1.6 Inquiries, Correspondence, and Notifications to the Tribe .................................................... 3 1.7 Definitions ....................................................................................................................................... 3 2 IMPLEMENTATION OF STANDARDS ................................................................................ 7 2.1 Critical Conditions ......................................................................................................................... 8 2.2 Water Rights .................................................................................................................................. 8 3 TRIENNIAL REVIEW ........................................................................................................... 8 4 MIXING ZONES AND DILUTION POLICY ......................................................................... 9 4.1 Purpose ........................................................................................................................................... 9 4.2 Implementation .............................................................................................................................. 9 5 DESIGNATED USES .......................................................................................................... 10 5.1 Designated Use Codes .............................................................................................................. 11 5.2 Designated Uses Definitions ..................................................................................................... 11 5.3 Stream Segmentation Criteria ................................................................................................. 12 5.4 Assigning Designated Uses ....................................................................................................... 12 5.5 Use Attainability Analyses........................................................................................................ 13 5.6 Changing Use Designations ...................................................................................................... 14 5.7 Surface Water Use Designations for Tribal waters ............................................................ 14 5.8 Intermittent AND EPHEMERAL Waters ................................................................................... 22 5.9 Tribal waters Subject to Use Attainability Analyses ........................................................... 22 6 NARRATIVE WATER QUALITY CRITERIA ....................................................................... 22 6.1 Criteria ......................................................................................................................................... 23 6.2 Implementation ........................................................................................................................... 23 7 NARRATIVE BIOLOGICAL CRITERIA .............................................................................. 24 7.1 Criteria ......................................................................................................................................... 24 7.2 Implementation ........................................................................................................................... 24 8 NUMERIC CRITERIA......................................................................................................... 25 8.1 Establishing Numeric Criteria ................................................................................................... 25 8.2 Potable and Industrial Water Supply.................................................................................... 26 8.3 Primary Contact Recreation ..................................................................................................... 26 8.4 Secondary Contact Recreation ................................................................................................ 27 8.5 Aquatic Life ................................................................................................................................. 27 Page ii WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 8.6 Hardness-Dependent Criteria for Metals .............................................................................. 27 8.7 Ammonia Numerical Criteria for All Segments Designated for Aquatic Use ................. 29 8.8 Selenium Aquatic Life Criteria for Fresh Waters ................................................................. 30 9 NUMERIC CRITERIA TABLES ........................................................................................... 30 9.1 Numeric Criteria for Aquatic Life............................................................................................ 31 9.2 Numeric Criteria for Human Health ........................................................................................ 33 10 WATER QUALITY STANDARDS FOR WETLANDS ........................................................ 40 11 OUTSTANDING TRIBAL RESOURCE WATERS .............................................................. 40 12 ANALYTICAL METHODS ............................................................................................... 42 13 ANTIDEGRADATION REVIEW POLICIES AND PROCEDURES ..................................... 42 13.1 Antidegradation Policy .......................................................................................................... 42 13.2 Antidegradation Implementation Procedures .................................................................... 43 14 VARIANCES FROM WATER QUALITY STANDARDS ................................................... 43 14.1 Application ............................................................................................................................... 43 14.2 Requirements for a Variance ................................................................................................ 44 Tables Table 1. Designated Use Codes ......................................................................................................................................... 11 Table 2. Designated Uses for the Pine River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries.......................................................................................................... 15 Table 3. Designated Uses for the Animas River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. ...................................................................................................... 16 Table 4. Designated Uses for the Florida River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. ....................................................................................................... 17 Table 5. Designated Uses for the La Plata River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. ....................................................................................................... 17 Table 6. Designated Uses for Cherry Creek, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. ...................................................................................................... 18 Table 7. Designated Uses for the Piedra River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. ...................................................................................................... 19 Table 8. Designated Uses for Sambrito Creek, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. ....................................................................................................... 19 Table 9. Designated Uses for Stollsteimer Creek Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries.......................................................................................................... 20 Table 10. Designated Uses for the San Juan River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries.......................................................................................................... 20 Table 11. Designated Uses for the Navajo River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries.......................................................................................................... 21 Table 12. Designated Uses for the Rio Blanco River, Wetlands sustained through Hydrologic and Hydraulic Connections . ........................................................................................................................................................................... 21 Table 13. Designated Uses for Capote Reservoir and Scotts Pond. ........................................................................... 22 Page iii WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Table 14. Designated Uses for Ephemeral Waters. ...................................................................................................... 22 Table 15 Aquatic Life Temperature Designations (Class 1 and 2) ................................................................................ 27 Table 16. Hardness Dependent Parameters for Calculating Freshwater Dissolved Metals Acute and Chronic Criteria ................................................................................................................................... Error! Bookmark not defined. Table 17. Selected Values of Calculated Acute and Chronic Criteria (µg/L). ......................................................... 28 Table 18. Equation Used for Numerical Criteria of Total Ammonia Nitrogen (“TAN”). .......................................... 29 Table 19. Selenium Numerical Criteria. ............................................................................................................................ 30 Table 20 Numeric Criteria for the Protection of Aquatic Life in Surface Water. .................................................... 31 Table 21 Numeric Criteria for the Protection of Human Health in Surface Water.................................................. 33 Table 22. These water quality requirements apply to all Outstanding Tribal Resource Waters. ........................ 41 Appendix A – Antidegradation Implementation Procedures Appendix B – Antidegradation Review Worksheet Page iv WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION SOUTHERN UTE INDIAN TRIBE E N V I RON M E N TA L P ROG R A M S D E PA R T M E N T 1 PURPOSE, AUTHORITY, AND APPLICABILITY 1.1 PURPOSE The Southern Ute Indian Tribe (“Tribe”) adopted these water quality standards to protect public health and welfare, enhance the quality of water, and serve the purposes of the Clean Water Act (CWA), 33 U.S.C. Section 1251, et seq.1 These water quality standards are comprised of: 0F • • • • designated uses for tribal waters; numeric and narrative water quality criteria designed to support each designated use; anti-degradation policies and procedures to ensure attainment and maintenance of those uses; and general policies to protect water quality These water quality standards serve the primary functions of establishing water quality goals for water bodies on the Southern Ute Indian Reservation over which the Tribe has authority for purposes of setting water quality standards and providing the legal basis for regulatory pollution controls. Establishing criteria and designated uses that provide for protection of aquatic and wildlife species, recreational, potable water and agricultural uses is also an important objective of these standards. More specifically, these standards are intended to serve, and shall be implemented to achieve, the following purposes: 1. Assessment. Provide a point of reference for the assessment of surface water quality. These standards represent the water quality goals of the Tribe for surface waters and will be used in assessing potential impacts to that quality. 2. Regulatory Controls. Both point and nonpoint source regulatory pollution controls to be established by the Tribe or the United States will be developed to ensure a level of water quality that will satisfy these water quality standards. Regulatory pollution controls established for point source discharges shall also be consistent with applicable sections of the CWA. Tribal programs to control nonpoint sources, whether regulatory or voluntary, shall be designed to meet these water quality standards. “Serve the purposes of the Clean Water Act” means that these water quality standards are intended, wherever attainable, to provide water quality for the protection and propagation of fish, shellfish and wildlife and for recreation in and on the water and take into consideration their use and value of public water supplies, propagation of fish, shellfish, and wildlife, recreation in and on the water, and agricultural, industrial, and other purposes including navigation. 1 PURPOSE, AUTHORITY, AND APPLICABILITY Page 1 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 3. Protection of Aquatic and Wildlife Species. It is the intention of the Tribe that the designated uses and criteria assigned to tribal waters will provide a level of water quality that will be fully protective of the aquatic and wildlife species that depend on it, including threatened or endangered species listed under the Endangered Species Act. 1.2 AUTHORITY Authority is both inherent to the Tribe and legally vested in the Southern Ute Indian Tribal Council by the Constitution of the Southern Ute Indian Tribe of the Southern Ute Indian Reservation, Article VII, Section 1(n), to protect and preserve the property, wildlife, and natural resources of the Tribe and Article VII, Section 1(e), to protect the property, health, and general welfare of the members of the Southern Ute Indian Tribe. Under Resolution No. 2015-16, adopted on February 17, 2015, the Southern Ute Indian Tribal Council delegated authority to the Tribe's Environmental Programs Division (now known as Environmental Programs Department (EPD) to exercise the Tribe’s Clean Water Act authority. In 2018, the U.S. Environmental Protection Agency (EPA) approved the Tribe’s application for Treatment as a State (TAS) to administer the Clean Water Act (Section 518, for purposes of the CWA Section 303(c) Water Quality Standards) for water bodies on tribal trust land on the Southern Ute Indian Reservation (Reservation). EPD developed Tribal Water Quality Standards (WQS) which were first adopted by the Southern Ute Indian Tribal Council on February 8, 2022, and approved by Environmental Protection Agency (EPA) on April 15, 2022. In 2023, EPD formed its Water Quality and Remediation Division (WQRD) to administer Tribal WQS as well as their triennial review. The purpose of these water quality standards is to protect public health and welfare, enhance the quality of water, and serve the purposes of the Clean Water Act. 1.3 SEVERABILITY If any word, phrase, clause, sentence, paragraph, section, or other part of these water quality standards is held invalid by any court of competent jurisdiction, such judgment shall affect only that portion held invalid. 1.4 APPLICABILITY These water quality standards apply to all waters within the exterior boundary of the Southern Ute Indian Reservation over which the Tribe has authority for establishing water quality standards (i.e., “tribal waters”). Some of the water bodies within the exterior boundaries of the Southern Ute Indian Reservation are located upon fee land that is owned by non-Tribal members. The Tribe has included water quality standards for all water bodies located within the Reservation’s exterior boundaries to avoid a gap or “checkerboard” in the standards adopted for the Reservation. The State of Colorado has claimed authority to set water quality standards for some water bodies located within the Reservation’s exterior boundaries. This claim is disputed by the Tribe. The Tribe intends that the standards that it is adopting apply to the water bodies in question only to the extent that the Tribe has jurisdiction and is not attempting to resolve that jurisdictional issue here. PURPOSE, AUTHORITY, AND APPLICABILITY Page 2 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 1.5 CLEAN WATER ACT PROGRAM IMPLEMENTATION IN COOPERATION WITH EPA On March 28, 2018, the EPA determined the Tribe was eligible to be treated in the same manner as a state under CWA Section 518(e) and 40 C.F.R. Section 131.8 for purposes of the CWA’s water quality standards and certification programs. The Tribe anticipates that EPA will continue to exercise authority under Section 402 to issue National Pollutant Discharge Elimination System (“NPDES”) permits to facilities discharging to tribal waters with terms consistent with these water quality standards. Any applicants for federal permits or licenses potentially affecting tribal waters, including NPDES permits, will need to obtain a water quality certification from the Tribe pursuant to the Tribe’s CWA Section 401 Certification Procedures. The Tribe may also seek to enter into a Direct Implementation Tribal Cooperative Agreement with EPA under which the Tribe will perform certain additional CWA activities (e.g., inspection of NPDES permit facilities) in cooperation with the EPA. 1.6 INQUIRIES, CORRESPONDENCE, AND NOTIFICATIONS TO THE TRIBE All inquiries, correspondence, and notifications to the Tribe with regard to these water quality standards are to be directed to the Water Quality and Remediation Division Head, Environmental Programs Department (“Department”), Southern Ute Indian Tribe, P.O. Box 737 #81, 71 Mike Frost Way, Ignacio, Colorado 81137. Email: wqs@southernute-nsn.gov 1.7 DEFINITIONS In this document, the terms listed below have the meanings indicated. For any terms in this document for which a definition is not provided or for which the definition is deemed incomplete, any definitions found in the CWA and any federal implementing regulations, guidance, or policy shall apply to the extent not inconsistent with the intent and policies evident in this document. Acute Toxicity is a stimulus severe enough to induce an adverse response within 96 hours of exposure or less. Acute toxicity is not always measured in terms of lethality but may include other toxic effects that occur within a short time period. Antidegradation is a policy and procedure of the Tribe’s water quality standards that protects existing uses and waters where the quality is better than necessary to support CWA Section 101 (a)(2) goal uses, as required by federal regulations at 40 C.F.R. Section 131.12. Assemblage is an association of aquatic organisms of similar taxonomic classification living in the same area. Examples of assemblages include, but are not limited to fish, macroinvertebrates, algae, and vascular plants. Aquatic Organism is any plant or animal which lives at least part of its life cycle in water. Attainment of a goal or standard means that the water body is of sufficient quality chemically, biologically and physically, to support the uses for which it is designated and to otherwise achieve applicable water quality standards. Best Management Practices (“BMPs”) are methods that have been determined to be the most effective, practical means of preventing or reducing pollution from nonpoint sources. PURPOSE, AUTHORITY, AND APPLICABILITY Page 3 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Bioaccumulative Substances are ones that increase in concentration in living organisms and/or are found to be in higher concentrations within an organism as they move up the food chain. Biological Condition is the taxonomic composition, richness, and functional organization of an assemblage of aquatic organisms at a site or within a water body. Biological Criteria, also known as biocriteria, are narrative expressions or numeric values of the biological characteristics of aquatic communities based on appropriate reference conditions. Biological criteria are intended to serve as an index of aquatic community health. Chronic Toxicity is a toxicity involving a stimulus that lingers or continues for a relatively long period relative to the life span of an organism. Chronic toxicity effects include, but are not limited to, lethality, growth impairment, behavioral modifications, disease and reduced reproduction. Cold Water Biota are organisms that are generally adapted to cold water environments (i.e. max temperature of 20oC), including the expected associated diverse aquatic community, functions, and sensitive species. Cool Water Biota are organisms that are generally adapted to transitional zones between cold and warm water segments (i.e., max temperature of 24oC) of a stream segment, including the expected associated diverse aquatic community, functions, and sensitive species. Constructed Wetlands are those wetlands intentionally designed, constructed, and operated on upland, nonwetland sites for the primary purpose of wastewater, agricultural runoff, environmental enhancement, stormwater treatment, or environmental remediation. Constructed wetlands are not waters over which the Tribe has authority for setting water quality standards under the CWA. Criterion Continuous Concentration (“CCC”) is an estimate of the highest concentration of a pollutant in freshwater, to which an aquatic community can be exposed for long periods (chronic limit) without resulting in an unacceptable effect. The multi-day average concentration of a pollutant in ambient water should not exceed the CCC more than once every three years on the average. Criterion Maximum Concentration (“CMC”) is an estimate of the highest concentration of a pollutant in freshwater, to which an aquatic community can be exposed for short periods (acute limit) without resulting in an unacceptable effect. The one-hour average concentration in the ambient water should not exceed the CMC more than once every three years. Critical Condition concept is that if an effluent is controlled such that it does not cause water quality criteria to be exceeded in the receiving water at the critical flow condition, then the effluent controls will likely be protective (i.e., ensuring that water quality criteria are attained at all flows). Criteria are elements of water quality standards, expressed as a desired condition, constituent concentration, level, or narrative statement, representing a quality of water that supports a particular use. CWA is an acronym for the Clean Water Act, 33 U.S.C. Section 1251, et seq., the common name for the Federal Water Pollution Control Act. PURPOSE, AUTHORITY, AND APPLICABILITY Page 4 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Designated Use is a use that is specified in these water quality standards as a goal for the water body segment, whether or not it is currently being attained. Dissolved refers to the fraction of a constituent of a water sample that passes through a 0.45 micrometer pore-size filter. The “dissolved” fraction is also termed “filterable residue.” Effluent is wastewater, treated or untreated, that flows out of a treatment plant, sewer, or industrial outfall. Generally, effluent refers to wastes discharged into surface waters. Environment is the sum of all external conditions affecting the life, development and survival of an organism. Ephemeral Waters are water bodies that flow or contain water only in direct response to precipitation in the immediate watershed. The stream channel of such a water body is generally above the adjacent water table. Eutrophication is when a body of water becomes overly enriched with minerals and nutrients which can induce excessive growth of algae. This process may result in oxygen depletion of the water body. Existing Use is a use that is attained in the water body on or after November 28, 1975, whether or not it is designated in the water quality standards. Groundwater means all subsurface waters (in a zone of saturation) that are or can be brought to the surface of the ground or to surface waters through wells, springs, seeps, or other discharge areas. Impaired is a physical, biological or chemical condition in which a water body is not attaining the applicable water quality standards, including the uses for which it is designated. Intermittent Waters are water bodies that do not typically have a perennial flow or contain water perennially and that flow or contain water in response to surface run-off and groundwater discharge. Mixing Zones are areas surrounding or downstream of a point source discharge where the effluent plume is progressively diluted by the receiving water and certain numerical water quality criteria otherwise applicable to the water body segment may be exceeded. NPDES is an acronym for National Pollutant Discharge Elimination System, the national program for issuing, modifying, revoking and reissuing, terminating, monitoring and enforcing pretreatment requirements, under Sections 307, 402, and 405 of the CWA. Nonpoint Source of pollution means any source of pollutants to surface waters that is not from a single attributable location. Nonpoint source pollution is typically associated with water moving over or through the ground and can originate from many types of diffuse sources (e.g. agricultural, ranch and forest lands, construction sites, development, urban runoff, atmospheric deposition, etc.). Nutrients mean the chemical elements, primarily nitrogen and phosphorus, which are essential to the growth of aquatic plants. Outstanding Tribal Resource Water (“OTRW”) means a segment that has been classified as an OTRW by the Tribe and is subject to more stringent antidegradation protection and review. OTRW segments may include, but are not limited to, waters that have outstanding water quality, unique aquatic ecology, or recreational, cultural, ceremonial, or aesthetic characteristics that qualify them for such classification by the Tribe. PURPOSE, AUTHORITY, AND APPLICABILITY Page 5 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Perennial Waters have flowing water year-round during a typical year. Permit means a National Pollutant Discharge Elimination System permit or other tribal or federal water quality permit. pH is a measure of hydrogen ion concentration, a measure of the acidity or alkalinity of a solution. Point Source is any discernible, confined and discrete conveyance including, but not limited to, any pipe, ditch, channel, sewer, tunnel, conduit, well, discrete fissure, container, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. Pollutant includes, but is not limited to dredged soil, solid waste, incinerator residue, filter backwash, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials (except those regulated under the Atomic Energy Act of 1954 as amended, 42 U.S.C. Section 2011, et seq.), heat, wrecked or discarded equipment, oil, mine tailings, rock, sand, cellar dirt and industrial, municipal, and agricultural waste discharged into water. Pollution includes such contamination, or other alteration of the physical, chemical, or biological properties of any waters of the tribe, including change in temperature, taste, color, turbidity, or odor of the waters, or such discharge of any liquid, gaseous, solid, radioactive, or other substance, or any exotic biota into any waters of the Tribe that will or is likely to create a nuisance to or impair any beneficial use of such waters. Receiving Water is any water course or water body that receives a treated or untreated discharge of a pollutant or pollution from a point source or nonpoint source. Regulated Activity is any activity that requires a permit or a water quality certification pursuant to CWA Section 401 or any other federal law (e.g., without limitation, Section 402 NPDES permits, Section 404 dredge and fill permits, and Federal Energy Regulatory Commission licenses) and any other activities where tribal law or regulation specifies that an antidegradation review is required. Summer is the period from April 15th to October 14th as it relates to temperature classifications (Section 8.5). Total Recoverable Metals is that portion of a water and suspended sediment sample measured by the total recoverable analytical procedure described in “Methods for Chemical Analysis of Water and Wastes,” U.S. Environmental Protection Agency, March 1979, or its equivalent. Toxics are those pollutants that have a harmful effect on living organisms. The CWA Section 307(a) priority toxic pollutants are a subset of this group of pollutants. Toxicity is the degree to which a chemical substance or pollutant can be harmful or cause damage to an organism. Toxicity is typically expressed as either acute or chronic toxicity. Tribal Waters are waters over which the Tribe has authority for establishing water quality standards. Tribe refers to the Southern Ute Indian Tribe. Use Attainability Analysis (“UAA”) is a structured scientific assessment of the factors affecting the attainment of aquatic life uses or other designated uses, which may include physical, chemical, biological, and economic factors. PURPOSE, AUTHORITY, AND APPLICABILITY Page 6 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Warm Water Biota are organisms that are generally adapted to warm water environments (i.e. max temperature of 30oC), including the expected associated diverse aquatic community, functions, and sensitive species. Water Quality Standards (“WQS” or “Standards”) consist of a designated use or uses, numeric and narrative criteria, an antidegradation policy, and other policies adopted to protect, maintain, and enhance water quality. Wetlands are those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs and similar areas. Winter is the period from October 15th to April 14th as it relates to temperature classifications (Section 8.5). 2 IMPLEMENTATION OF STANDARDS All discharges from point sources, all instream activities, and all activities that generate nonpoint source pollution are to be conducted so as to achieve these water quality standards. The Tribe anticipates that both regulatory and voluntary pollution control programs will be needed to protect and enhance water quality on the Reservation. All activities which require a federal license or permit on the Reservation are subject to certification by the Tribe consistent with CWA Section 401 (see “Southern Ute Indian Tribe CWA Section 401 Certification Procedures”). All federal licenses and permits, such as permit for wastewater discharges issued under the NPDES, should be conditioned in such a manner as to authorize only activities that will not cause violations of these water quality standards. For new standards, revised standards that have become more stringent, or new interpretations of existing standards, the Tribe has the authority to allow schedules of compliance which may be included in such permits, where appropriate, considering guidance issued by EPA. Schedules of compliance may be authorized by the Tribe on a case-by-case basis. Unless the Tribe receives eligibility to implement CWA Section 402, discharge permits for discharges to tribal waters will be issued by the EPA. All discharge permit applications will be reviewed by the Tribe pursuant to its Section 401 certification authority. In accordance with the Tribe’s antidegradation review procedures, the Tribe may deny certification of any discharge into tribal waters, if the Tribe determines that the proposed discharge would cause a violation of these water quality standards. These water quality standards should serve as a basis for the Tribe's (or EPA's, as applicable) review of proposed discharges from upstream sources under the Clean Water Act Section 401 water quality certification process. This review will ensure that any proposed upstream discharge, regardless of its origin, is consistent with the Tribe's established water quality goals and objectives as outlined in these standards. The Tribe retains the authority to specify, within a water quality certification, particular methods for implementing water quality standards when establishing pollution control measures for both point and nonpoint sources. All controls shall be developed using technically defensible methods such as those described in EPA guidance documents. IMPLEMENTATION OF STANDARDS Page 7 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION These water quality standards should serve as the basis for any Section 303(d) total maximum daily loads (TMDLs) developed for tribal waters. These water quality standards apply to all Tribal waters affected by point sources of pollution. For nonpoint sources of pollution, the primary means for implementing the standards shall be through the application of all known and reasonable methods of prevention, control, and treatment, including BMPs, which shall be required in water quality certifications issued by the Tribe. At this time, the Tribe intends to rely on voluntary compliance for activities which result in nonpoint sources of pollution but are not regulated activities. 2.1 CRITICAL CONDITIONS For purposes of determining water quality-based control requirements for point source discharges, critical conditions shall be determined consistent with the policy and procedure described below where a steady state modeling approach is used. Where seasonal controls are appropriate, critical conditions shall be determined based on seasonal characteristics of the receiving water and pollution source. Other exceptions may be granted where a technically sound reason to use an alternative method is developed and approved by the Tribe (e.g., where a dynamic or continuous simulation modeling method is used). Critical conditions shall be representative of conditions upstream from the point where the discharge exists. The following critical flows may be assumed to dilute the effluent: Stream Flows Chronic Aquatic Life 4-day, 3-year flow (biologically based) Acute Aquatic Life 1-day, 3-year flow (biologically based) Human Health (carcinogens) harmonic mean flow Human Health (non- carcinogens) 4-day, 3-year flow (biologically based), or 1-day, 3-year flow (biologically based) Effluent Flows Chronic Aquatic Life Mean daily flow Acute Aquatic Life Maximum daily flow Human Health (all) Mean daily flow Assessment of attainment of designated uses and compliance with water quality criteria shall be in accordance with available guidance and procedures published by EPA. 2.2 WATER RIGHTS Implementation of these water quality standards shall not interfere with the lawful diversion of water pursuant to decreed water rights. However, the Tribe encourages individuals and entities to manage and administer water diversions in a manner that supports the attainment and enhancement of designated uses whenever practicable. 3 TRIENNIAL REVIEW The Tribe shall hold a hearing to review these water quality standards at least once every three years for the purpose of determining whether revisions are necessary or warranted to comply with applicable federal TRIENNIAL REVIEW Page 8 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION regulations or to meet tribal water quality goals. For example, any water body segment with designated uses that do not include the goal uses specified in CWA Section 101(a)(2) shall be re-examined every three years to determine if any new information has become available. If such new information indicates the CWA goal uses are attainable, the Tribe shall revise its standards accordingly. The procedures for a triennial review or any other revisions to these water quality standards shall meet the requirements of CWA Section 303(c) and tribal administrative procedures. Public hearings shall be held in accordance with tribal laws and EPA requirements. Any proposed water quality standards revisions and supporting analyses shall be made available to the public before the hearing. The Tribe shall submit the revised standards and any supporting analyses to the EPA Region 8 Regional Administrator for review and approval within 30 days following the final action to adopt revised standards. The Tribe’s submission shall be consistent with EPA requirements found in 40 C.F.R. Section 131.6. 4 MIXING ZONES AND DILUTION POLICY 4.1 PURPOSE Mixing zones are regions surrounding or downstream of a point source discharge in which the discharge is progressively diluted by the receiving water and some numerical water quality criteria may not apply. This policy establishes how mixing and dilution of point source discharges with receiving waters will be addressed in developing chemical-specific and whole effluent toxicity discharge limitations. Depending on site-specific mixing patterns and environmental concerns, some pollutants may be allowed a mixing zone for dilution and others may not. In all cases, mixing zone and dilution allowances shall be limited as necessary to protect designated uses and the integrity of the receiving water ecosystem as a whole. This policy shall be implemented consistent with the most recent EPA guidance and procedures. 4.2 IMPLEMENTATION Where dilution is available at critical conditions and the discharge does not completely mix at a near instantaneous rate, on a case-by-case basis an appropriate mixing zone may be designated if: 1. meeting numeric criteria at the end-of-pipe is not practicable; 2. allowing a mixing zone will not pose unacceptable risks to designated uses in the receiving water as a whole, considering factors such as: a. bioaccumulation in fish tissues or wildlife; b. biologically important areas such as fish spawning or nursery areas; c. presence of listed or proposed threatened or endangered species or of species of concern; d. low acute to chronic ratio; e. potential human exposure to pollutants via drinking water or recreational activities; f. attraction of aquatic species to effluent plume; g. toxicity or persistence of the substance discharged; h. zone of passage for migrating fish or other species (including access to tributaries); and i. cumulative effects of multiple discharges and mixing zones. 3. narrative criteria will be achieved within the mixing zone. Effluent limits will be assigned consistent with mixing zone size limits determined by field study, an appropriate mixing model, or other defensible method. Mixing zone size shall generally be limited as follows, MIXING ZONES AND DILUTION POLICY Page 9 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION provided that individual chronic mixing zones may be further limited or denied as needed to protect designated and existing uses based on the factors listed above: 1. No acute mixing zone shall be allowed; 2. The size of chronic mixing zones for streams and rivers shall not exceed one-half the cross-sectional area or a length 10 times the stream width at critical low flow, whichever is more limiting; and 3. Each mixing zone will be developed on a case-by-case basis to protect the most sensitive designated use, consistent with applicable EPA guidance. Where the discharge is to a river or stream, dilution is available at critical conditions, and available information is sufficient to reasonably conclude that the discharge exhibits near instantaneous and complete mixing, an appropriate dilution allowance equal to or less than the critical low flows identified in Section 3 may be provided for purposes of establishing acute and chronic chemical-specific and whole effluent toxicity effluent limitations. Near instantaneous and complete mixing may be assumed where the mean daily flow of the discharge exceeds the critical low flow of the receiving water, or where an effluent diffuser has been installed. In all other cases where instantaneous and complete mixing is assumed, a defensible basis should be included in the statement of basis for the permit. For purposes of field mixing studies, near instantaneous and complete mixing is defined as no more than 10% difference in bank-to-bank concentrations within a longitudinal distance not greater than two stream widths. Where dilution flow is not available at critical conditions, the discharge limits will be based on achieving water quality criteria at the end-of-pipe. In addition, discharge limits for all point source discharges to a wetland will be based on achieving water quality criteria at the end-of-pipe. All mixing zone-dilution assumptions are subject to review and revision as information on the nature and impacts of the discharge becomes available (e.g., chemical or biological monitoring in the mixing zone boundary). At a minimum, mixing zone and dilution decisions are subject to review and revision along with all other aspects of the discharge permit upon expiration of the permit. Where warranted, the discharger may be required to complete monitoring to verify that mixing zone restrictions are being achieved. For certain pollutants (e.g., ammonia, dissolved oxygen, metals, etc.) that may exhibit increased toxicity or other effects on water quality after dilution and complete mixing with receiving waters is achieved, permit terms should address such toxicity or other effects on water quality as necessary to fully protect designated uses (i.e., the point of compliance may be something other than the mixing zone boundary or the point where complete mixing is achieved). 5 DESIGNATED USES 40 C.F.R. Section 131.10 requires that the Tribe specify appropriate water uses to be achieved and protected. The designation of uses for tribal waters must take into consideration the use and value of water for public water supplies, protection and propagation of fish, shellfish and wildlife, recreation in and on the water, agricultural, industrial, and other purposes including navigation. In no case can waste transport or waste assimilation be adopted as a designated use. In designating uses and the appropriate criteria for those uses, the Tribe must take into consideration the water quality classifications and standards of downstream waters and ensure that as implemented through its policies, the water quality classifications and standards of downstream waters will be attained and maintained. The Tribe has elected to consider the following designated uses for tribal waters. DESIGNATED USES Page 10 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 5.1 DESIGNATED USE CODES Table 1. Designated Use Codes CODE COLD1 COLD2 COOL1 COOL2 WARM1 WARM2 REC1 REC2 PWS IND AGR USE High Quality Cold Water Aquatic Life (Class 1) Low Quality Cold Water Aquatic Life (Class 2) High Quality Cool Water Aquatic Life (Class 1) Low Quality Cool Water Aquatic Life (Class 2) High Quality Warm Water Aquatic Life (Class 1) Low Quality Warm Water Aquatic Life (Class 2) Primary Contact Recreation (Class 1) Secondary Contact Recreation (Class 2) Potable Water Supply Industrial Water Supply Agricultural Water Supply 5.2 DESIGNATED USES DEFINITIONS The following designated uses may be applied to tribal waters: Potable Water Supply - Waters suitable or intended to become suitable, after appropriate pretreatment, for human consumption. Primary Contact Recreation (Class 1) – Waters suitable for recreational activities where full body immersion and/or the ingestion of small quantities of water is likely to occur. Such activities include but are not limited to swimming, rafting, kayaking, tubing, windsurfing, water-skiing, and water play by children. Secondary Contact Recreation (Class 2) – Water suitable for recreational activities where a person’s water contact is likely to be limited (e.g., wading or fishing) such that exposure of the eyes, ears, respiratory, or digestive systems or urogenital areas would normally be avoided. Aquatic Life (Class 1) – High quality waters that support or are intended to become supportive of a typical diversity and abundance of cold, cool, or warm water aquatic biota that are generally able to function at intermediate or transitional zones between temperatures representative of a stream segment, including the expected diverse aquatic community, functions, and sensitive species. Aquatic Life (Class 2) – Low quality waters that are not capable of sustaining a typical diversity or abundance of cold, cool, or warm water aquatic biota, respectively, due to physical habitat, water flows or levels, or uncorrectable water quality conditions that result in substantially limited abundance or diversity of species. Industrial Water Supply - Waters that are suitable for industrial processes and cooling water. Agricultural Water Supply - Waters suitable or intended to become suitable for irrigating crops and for use as drinking water for livestock. DESIGNATED USES Page 11 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 5.3 STREAM SEGMENTATION CRITERIA For purposes of adopting designated uses and water quality criteria, streams and other surface water bodies were identified according to river basin or sub-basin and specific segments. Segments may constitute a specific reach of a stream mainstem, a specific tributary, a specific lake or reservoir, or a generally defined grouping of waters within a basin (e.g., a specific mainstem segment and another segment consisting of all tributaries flowing into that mainstem segment). Segments were delineated to create consistency in the designation of uses by determining segment boundaries according to where physical or water quality characteristics of a watercourse change significantly enough to require a change in use classifications or water quality criteria. In many cases, boundaries between segments were identified directly using water quality data. In other cases, data were only available upstream or downstream of a segment boundary and the delineation of segments was inferred using best professional judgment of where instream changes in uses, physical characteristics, or water quality occur. The Tribe’s adopted water quality standards define wetlands as “…those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions.” Section 5.8 of the Tribe’s water quality standards state: “Intermittent and ephemeral waters shall support existing and designated uses when there is surface water present from any source, however minimal. The numeric and narrative criteria for connected perennial segments shall apply to intermittent and ephemeral water bodies when there is surface water present from any source, however minimal.” Water aggregates within and discharges from wetland areas as part of the hydrologic cycle on time scales that are perennial, intermittent, or ephemeral in nature. The waters that sustain wetlands connect (i.e., make physical contact with or contribute in quantity or quality) to other bodies of surface water that are relatively permanent, standing or continuously flowing - regardless of the degree to which that hydrologic or hydraulic connection is navigable. The Tribe’s water quality standards therefore define “wetlands sustained through hydrologic and hydraulic connections” as any areas that: 1. Are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence (i.e., 50% cover or greater, as estimated within 1 square meter (1 m2) of land area) of vegetation typically adapted for life in saturated soil conditions, and 2. Contain a prevalence of the aforementioned vegetation that encompasses 1/10 (.10%) of an acre or greater in area, regardless of its degree of physical proximity, adjacency, and surface connection (or lack thereof) to navigable or non-navigable waterways. 5.4 ASSIGNING DESIGNATED USES Designated uses for tribal waters have been assigned by the Tribe in accordance with Sections 101(a)(2) and 303 of the CWA and the implementing federal regulation at 40 C.F.R. Section 131.10. All segments have been assigned the highest attainable uses that the Tribe reasonably believes the segment can support. The DESIGNATED USES Page 12 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION designated uses may be revised for a segment as part of the triennial review process or if new information or data indicates that a revision is warranted, subject to the policies and limitations discussed below. Section 101(a) (2) requires that waters be designated as “fishable and swimmable” (i.e., supporting protection and propagation of fish, shellfish, and wildlife, and providing for recreation in and on the water) unless a use attainability analysis (UAA) demonstrates that a less stringent use designation is appropriate. Accordingly, those waters that do not fully support, and it is believed cannot reasonably support, fishable and swimmable uses must be evaluated in a UAA to determine their potential and possible downgraded uses. On the other hand, some uses may be designated that are not currently attained, but for which there is a reasonable expectation that those uses can be attained using point and nonpoint source controls of pollutants. The following specific policies and limitations apply to assigning and revising designated uses for tribal waters: 1. The Tribe will not remove a designated use specified in CWA Section 101(a)(2) (i.e., “fishable and swimmable” uses) or adopt subcategories of a Section 101(a)(2) use requiring less stringent criteria unless a UAA demonstrates that attaining the use is not feasible because of a factor listed in 40 C.F.R. Section 131.10(g). 2. An existing designated use for a segment will not be removed unless a use requiring more stringent criteria is designated. 3. Assigning designated uses will be guided by the objective of realizing the water quality goals set forth in the CWA. 4. Designated uses must be protective of water quality for all current and future uses consistent with the Tribe’s Antidegradation Policy. 5. Designated uses will be set for the highest water quality reasonably attainable. Attainability is to be judged through preparing a UAA and whether the use designation can be attained in a timeframe approximating twenty years by reasonable control techniques that are determined during public hearing. At a minimum, uses are deemed attainable if they can be achieved by the imposition of effluent limits required under the CWA for point sources and cost-effective and reasonable best management practices for nonpoint source control. 6. Designated uses set for upstream segments should not jeopardize attainable downstream designated uses. 7. Relevant physical, chemical, and biological characteristics are valid water quality concerns that may be taken into account in the use designation process. 5.5 USE ATTAINABILITY ANALYSES A UAA is a structured scientific assessment completed to evaluate the factors affecting the attainability of a use. Whenever a UAA is prepared, it shall be subject to the requirements and limitations set forth in 40 C.F.R. Part 131, including subsections 131.3(g), 131.10(g), 131.10(h) and 131.10(j). The Tribe completed UAAs to support its initial use designations for certain segments. All UAAs, Aquatic Life UAAs and/or Recreation UAAs, shall be revised and supplemented as new information and data become available. In addition to the Tribe, third parties may petition for and complete a UAA to support a proposed revision to the designated uses for one or more segments. The petitioner shall submit notice to the Tribe stating its intent to conduct a UAA for tribal waters. The petitioner shall develop a work plan to conduct the UAA and shall submit the work plan to the Tribe for review and comment. The work plan shall identify the scope of data DESIGNATED USES Page 13 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION currently available and the scope of data to be gathered, the factors affecting use attainment that will be analyzed, and provisions for public notice and consultation with appropriate tribal and federal agencies. The Tribe may consult with EPA in its review of the work plan. Upon approval of the work plan by the Tribe, and subject to any required amendments thereto, the petitioner shall conduct the UAA in accordance with the approved work plan. All costs of such analysis shall be the responsibility of the petitioner. Upon completion of the UAA, the petitioner shall submit the data, findings, conclusions, and proposed use revision(s) to the Tribe. Proposed third party use revisions will be evaluated by the Tribe, and may be proposed to the public during the next water quality standards rulemaking opportunity. Revisions to designated uses are final only after adoption by the Tribe and CWA review and approval by EPA. 5.6 CHANGING USE DESIGNATIONS The Tribe may assign a new designated use or change a currently designated use based upon the requirements in this document, public testimony, and any other information considered at a public hearing concerning the proposed change. Any interested person shall have the right to petition the Tribe to assign or change a use designation. Action on such petition shall be within the discretion of the Tribe subject to the following policies: 1. Adding Designations – The Tribe shall maintain those water quality use designations which are currently being attained. Where current designations specify fewer designated water uses than those which are presently being attained, the Tribe will add the designated use(s) to reflect the uses actually being attained or for which there is a reasonable expectation that those uses can be attained. 2. Removing or Reducing Designations – If the Tribe or a petitioning party can scientifically demonstrate that a designated use is not being attained; that the designated use cannot reasonably be attained due to a factor listed in 40 C.F.R. Section 131.10(g); and the use is not an existing use; then the designation may be downgraded (e.g., from “High Quality Class 1” to “Low Quality Class 2”) or removed by the Tribe. When a petitioner wishes to remove or downgrade an aquatic life or recreation classification or recommends adopting a less stringent criterion for a water body designated for these uses, the Tribe shall require the petitioner to conduct a UAA to justify the proposed change. Where changing circumstances, such as improvements in technology or management practices or the cessation of a discharge, may allow the reasonable attainment of the current uses within a reasonable time, the Tribe shall instead favor granting a variance as provided in Section 14 and maintaining the current uses as a goal. 3. Where the use designations of a water body segment include a use designation with less stringent criteria, or do not include an aquatic life and/or recreation class 1 designation, as part of the triennial review of the segment, the Tribe shall review any prior UAA or other basis for omission of one or more of the above designated uses. If the justification for the omission is determined not to be consistent with current data and information or accepted use attainability policies, the Tribe shall perform a supplemental analysis to provide a basis for a determination by the Tribe whether such uses are attainable. 5.7 SURFACE WATER USE DESIGNATIONS FOR TRIBAL WATERS Use designations adopted for all surface water segments, tributaries and lakes that are tribal waters are listed in the following tables. In cases where the upper end of a stream segment is defined by a tributary, that DESIGNATED USES Page 14 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION tributary is included in that segment unless specified otherwise. Latitude and longitude coordinates (WGS 1984) are provided for segment boundaries. All Segments on the Reservation are designated Seasonal COLD1 in the Winter: October 15- April 15. Temperature designations for Summer: April 16- October 14 are identified in the tables below. Table 2. Designated Uses for the Pine River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment and Description Pine River Segment1 (Reservation boundary to Pine Ditch Diversion and all perennial streams, small ponds and wetlands tributary to this segment) Pine River Segment2 (Pine Ditch Diversion to confluence with Dry Creek and all perennial streams, small ponds and wetlands tributary to this segment, excluding Dry Creek,) Pine River Segment3 (Dry Creek to New Mexico state line, including Dry Creek, and all perennial streams, small ponds and wetlands tributary to this segment) DESIGNATED USES Designated Uses Segment Boundaries COOL1 REC1 PWS AGR Northern Boundary Pine Ditch Diversion River Mile 19.5 River Mile 17.5 N 37.214814 N 37.190642 W -107.595264 W -107.587775 COOL1 REC1 PWS AGR Pine Ditch Diversion Dry Creek Confluence River Mile 17.5 River Mile 12 N 37.190642 N 37.139717 W -107.587775 W -107.620411 WARM1 REC1 PWS AGR Dry Creek Confluence River Mile 12 N 37.139717 W -107.620411 Southern Boundary River Mile 0 N 36.999978 W -107.601111 Page 15 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Table 3. Designated Uses for the Animas River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment and Description Designated Uses Animas River Segment1 COOL1 REC1 PWS AGR Northern Boundary Basin Creek River Mile 19 River Mile 15 N 37.214794 N 37.18606944 W -107.854722 W --107.878889 COOL1 REC1 PWS AGR Basin Creek River Mile 15 N 37.18606944 W -107.878889 Florida River River Mile 3.8 N 37.048706 W -107.872933 COOL1 REC1 PWS AGR Florida River River Mile 3.8 W 107.872933 N 37.048706 Southern Boundary River Mile 0 N 36.999739 W -107.866181 (Reservation boundary to Basin Creek and all perennial streams, small ponds and wetlands tributary to this segment, excluding Basin Creek,) Animas River Segment2 (Basin Creek to confluence with Florida River, excluding the Florida River including Basin Creek, and all perennial streams, small ponds and wetlands tributary to this segment, excluding the Florida River) Animas River Segment3 (Florida River to New Mexico state line and all perennial streams (excluding the Florida River), small ponds and wetlands tributary to this segment) DESIGNATED USES Segment Boundaries Page 16 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Table 4. Designated Uses for the Florida River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment and Description Designated Uses Florida River (Reservation boundary to Animas River and all perennial streams, small ponds and wetlands tributary to this segment) WARM1 REC1 PWS AGR Segment Boundaries Northern Boundary River Mile 22.9 N 37.21497222 W -107.72916667 Confluence with Animas River Mile 0 N 37.048706 W -107.872933 Table 5. Designated Uses for the La Plata River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment and Description Designated Uses La Plata River Segment1 (Northern Reservation boundary to the confluence of Cherry Creek and all perennial streams, small ponds and wetlands tributary to this segment, excluding Cherry Creek,) La Plata River Segment2 (Cherry Creek to Long Hollow Creek and all perennial streams, small ponds and wetlands tributary to this segment, excluding Segment Boundaries COOL1 REC2 PWS AGR Northern Boundary River Mile 21.4 N 37.214814 W -108.061594 Cherry Creek River Mile 9.7 N 37.11562778 W -108.198333 WARM1 REC2 PWS AGR Cherry Creek River Mile 9.7 N 37.11562778 W -108.198333 Long Hollow Confluence River Mile 4.4 N 37.05325 W -108.182108 DESIGNATED USES Page 17 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Long Hollow and Cherry Creek) La Plata River Segment3 (Long Hollow Creek to southern end of the Reservation, including Long Hollow Creek, and all perennial streams, small ponds and wetlands tributary to this segment) COOL1 REC2 PWS AGR Long Hollow Confluence River Mile 4.4 N 37.05325 W -108.182108 Southern Boundary River Mile 0 N 36.999719 W -108.188558 Table 6. Designated Uses for Cherry Creek, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment and Description Designated Uses Cherry Creek WARM1 REC2 PWS AGR (Northern Reservation boundary to the confluence of the La Plata River and all perennial streams, small ponds and wetlands tributary to this segment) DESIGNATED USES Segment Boundaries Northern Boundary River Mile 7.9 N 37.215056 W -108.223667 Confluence with the La Plata River River Mile 10.2 N 37.115661 W -108.198542 Page 18 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Table 7. Designated Uses for the Piedra River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment Description Piedra River Segment1 Designated Uses Segment Boundaries COOL1 REC1 PWS AGR Northern Boundary River Mile 15.8 N 37.214789 W -107.348381 Confluence with Stollsteimer Creek River Mile 5.3 N 37.1388361 W -107.355000 Piedra River Segment2 WARM1 (Confluence with Stollsteimer Creek to Navajo Reservoir and all perennial streams, small ponds and wetlands tributary to this segment, excluding Stollsteimer Creek) REC1 PWS AGR Confluence with Stollsteimer Creek River Mile 5.3 N 37.1388361 W -107.355000 High Water Elevation of Navajo Reservoir River Mile 0 N 37.054994 W -107.410683 (Reservation boundary to confluence with Stollsteimer Creek and all perennial streams, small ponds and wetlands tributary to this segment, excluding Stollsteimer Creek) Table 8. Designated Uses for Sambrito Creek, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment and Description Sambrito Creek (Headwaters to confluence with Navajo Reservoir and all perennial streams, small ponds and wetlands tributary to this segment) DESIGNATED USES Designated Uses WARM1 REC1 PWS AGR Segment Boundaries Headwaters River Mile 12 N 37.139181 W -107.464247 Confluence with Navajo Reservoir River Mile 0 N 37.006569 W -107.457364 Page 19 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Table 9. Designated Uses for Stollsteimer Creek Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment and Description Stollsteimer Creek (Reservation boundary to confluence with Piedra River and all perennial streams, small ponds and wetlands tributary to this segment) Designated Uses WARM1 REC1 PWS AGR Segment Boundaries Reservation Boundary River Mile 14.2 N 37.21484167 W -107.220278 Confluence with Piedra River River Mile 0 N 37.138947 W -107.355278 Table 10. Designated Uses for the San Juan River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment San Juan River Segment1 (Northern Reservation boundary to Rio Blanco and all perennial streams, small ponds and wetlands tributary to this segment, excluding Rio Blanco) San Juan River Segment2 Rio Blanco to confluence with Navajo River and all perennial streams, small ponds and wetlands tributary to this segment, excluding Rio Blanco and Navajo River) San Juan River Segment3 (Confluence with Navajo River to Navajo Reservoir and all perennial streams, small ponds and wetlands DESIGNATED USES Designated Uses Segment Description and Location WARM1 REC1 PWS AGR Northern Boundary River Mile 36.1 N 37.218325 W -107.018056 Confluence with Rio Blanco River Mile 28.4 N 37.120727 W -107.043497 WARM1 REC1 PWS AGR Confluence with Rio Blanco River Mile 28.4 N 37.120727 W -107.043497 Confluence with Navajo River River Mile 15.1 N 37.024364 W -107.158656 WARM1 REC1 PWS AGR Confluence with Navajo River River Mile 15.1 N 37.024364 W -107.158656 Navajo Reservoir River Mile 0 N 37.019003 W -107.344558 Page 20 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION tributary to this segment, excluding Navajo River) Table 11. Designated Uses for the Navajo River, Wetlands sustained through Hydrologic and Hydraulic Connections and Associated Perennial Tributaries. Segment Navajo River (Southern Boundary to confluence with the San Juan River and all perennial streams, small ponds and wetlands tributary to this segment) Designated Uses WARM1 REC1 PWS AGR Segment Description and Location Reservation Boundary River Mile 4.7 N 37.000069 W -107.108752 Confluence with San Juan River River Mile 0 N 37.024364 W -107.158656 Table 12. Designated Uses for the Rio Blanco River, Wetlands sustained through Hydrologic and Hydraulic Connections. Designated Uses Segment Rio Blanco River (Southern Boundary to confluence with the San Juan River and all perennial streams, small ponds and wetlands tributary to this segment) DESIGNATED USES WARM1 REC1 PWS AGR Segment Description and Location Reservation Boundary River Mile 3.2 N 37.135 W -107.001 Confluence with San Juan River River Mile 0.0 N 37.120727 W -107.043497 Page 21 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Table 13. Designated Uses for Capote Reservoir and Scotts Pond. Water body Capote Reservoir Scott’s Pond Designated Uses Location WARM1 REC1 WARM1 REC1 N 37.199403 W -107.257744 N 37.135747 W -107.623406 Table 14. Designated Uses for Ephemeral Waters. Segment All Ephemeral Waters Designated Uses WARM1 REC2 AGR PWS Segment Description and Location Reservation wide 5.8 INTERMITTENT AND EPHEMERAL WATERS Intermittent and ephemeral waters shall support existing and designated uses when there is surface water present from any source, however minimal. The numeric and narrative criteria for connected perennial segments shall apply to intermittent and ephemeral water bodies when there is surface water present from any source, however minimal. 5.9 TRIBAL WATERS SUBJECT TO USE ATTAINABILITY ANALYSES CWA Section 101(a)(2) requires that waters be designated as “fishable and swimmable” (supporting protection and propagation of fish, shellfish, and wildlife, and providing for recreation in and on the water) unless a Use Attainment Analysis (UAA) demonstrates that a less stringent use designation and criteria are appropriate. The segments listed below have Secondary Contact Recreation (Rec 2 or Class 2) use designations. These waters are protected by Primary Contact Recreation (Rec 1 or Class 1) criteria (see section 8.4 below) so do not require supporting UAAs. A UAA will be prepared for each segment that does not fully support a Class 1 Aquatic Life or Class 1 Recreation use designation and is assigned criteria less stringent than Class 1. • • • La Plata River Segments 1, 2 and 3, Recreation only Cherry Creek, Recreation only All Ephemeral Waters, Recreation only 6 NARRATIVE WATER QUALITY CRITERIA All tribal waters are subject to the narrative water quality criteria below. The goal of the narrative water quality criteria is to be able to assess and protect water quality using parameters that humans and biota can directly perceive and in situations where numeric standards for individual pollutants or parameters may not be sufficient. NARRATIVE WATER QUALITY CRITERIA Page 22 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 6.1 CRITERIA Surface waters shall be free from substances attributable to human-caused point or nonpoint sources in amounts, concentrations, or combinations which may: 1. settle to form deposits beneath the water surface or upon adjoining shorelines that have a deleterious effect on biota or that significantly alter the physical or chemical properties of the water or the bottom sediments; 2. form objectionable floating debris, scum, film, grease, oil, or other surface materials, including “floatable material” as defined by the CWA; 3. produce color, turbidity, odor, or other conditions in such a degree as to impair photosynthesis, reduce water clarity, or create a nuisance; 4. cause eutrophication resulting in the objectionable growth of aquatic vegetation or algae or other impairments from excessive nutrients to the extent that it threatens public health or welfare or impairs present or future beneficial uses. 5. impart any undesirable taste to edible aquatic or terrestrial species or to the water; 6. cause injury to or are toxic to humans or aquatic or terrestrial animals or plants; 7. produce undesirable or nuisance aquatic or terrestrial animals or plants; or 8. impair the capability of a water body to support a designated use. 6.2 IMPLEMENTATION The narrative water quality criteria shall be implemented taking into consideration appropriate EPA technical guidance concerning the development of water quality-based controls. To implement these criteria for substances that lack numeric criteria for public water supply use, drinking water standards or health advisories issued by EPA under the Safe Drinking Water Act will be considered. For point source discharges, criteria 6.1(5) and (6) should be implemented by including appropriate acute and chronic chemical-specific and Whole Effluent Toxicity effluent quality limitations in the NPDES permit, as specified in the latest EPA NPDES Whole Effluent Toxicity Program guidance. For substances that lack numeric water quality criteria or for which numeric criteria are not protective or representative of water quality goals, these narrative water quality criteria shall be implemented considering appropriate information, including any criteria guidance issued by EPA under CWA Section 304(a) or information in EPA or other toxicity databases, and the Tribe’s best professional judgement. Although the Tribe does not envision that it will always be necessary to establish effluent limits for point source discharges based on narrative criteria, the Tribe intends that the narrative criteria are to be used as required by CWA Section 301(b)(1)(C) and 40 C.F.R. Section 122.44(d) in determining appropriate effluent limits for point source discharges. For example, where the narrative criteria are not attained, that information can be used by the permitting authority to reevaluate any NPDES permits for upstream discharges to determine if all appropriate chemical-specific and whole effluent toxicity limits are included in the permits. This may involve examining whether such permits contain limits for all substances present in the discharge and for any pollutants or parameters that are or may be discharged that cause, have the reasonable potential to cause, or contribute to any failure to attain the narrative water quality criteria. The Tribe adopted narrative water quality criteria to provide additional benchmarks for protecting water quality and an additional assessment method for identifying impaired waters. The Tribe recognizes an inherent difference between narrative criteria and numeric, chemical-specific criteria. A major difference is the NARRATIVE WATER QUALITY CRITERIA Page 23 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION manner in which the two types of criteria can be applied effectively in determining water quality-based effluent limits for point source discharges. Chemical-specific criteria typically are expressed as a concentration of a given parameter, with provisions that describe an averaging period and an allowable frequency of exceedance. Narrative criteria describe a desired physical, chemical, or biological condition, and are expressed and interpreted using information that is generally detectable by the senses and aquatic organisms. Narrative criteria, therefore, may require additional steps and interpretations when calculating effluent limits for point source discharges. Nevertheless, incorporating narrative criteria into assessments and permits is vital because there can be impacts to water bodies and designated uses that are unrelated to chemical constituents for which numeric criteria have been established. 7 NARRATIVE BIOLOGICAL CRITERIA All tribal waters are subject to the narrative biological criteria below. The goal of the biological criteria is to ensure the maintenance and protection of the structure and function of aquatic communities. 7.1 CRITERIA Surface waters shall be free from substances attributable to human-caused point or nonpoint sources in amounts, concentrations, or combinations which adversely impact the structure or function of all life stages of aquatic or terrestrial communities. This shall include protecting, in addition to aquatic life, all life stages of resident and migratory wildlife that use surface waters for feeding, drinking, habitat, or propagation. 7.2 IMPLEMENTATION Assessment of biological conditions will include monitoring of the benthic macroinvertebrates, fish, and plant communities, as appropriate. Community metrics will be determined by the Tribe relative to reference sites. A reference condition may be assigned as a goal for the biological community if there is an insufficient number of reference sites or if those sites become impaired. Data for a reference condition will be treated in the same manner as if it were a reference site. The intent of the Tribe in adopting a narrative biological criterion is to provide an additional assessment method for the identification of impaired waters based on impacts to the structure and function of communities and to provide protection for impacts that may not otherwise be addressed, such as from the bioaccumulation of toxins in aquatic or terrestrial food webs. Biological criteria describe a desired biological condition and are expressed and interpreted using information about organisms and communities of organisms. Although the Tribe does not envision that it will always be necessary to establish effluent limits for point source discharges based on biological criteria, the Tribe intends that the biological criteria are to be used as required by CWA Section 301(b)(1)(C) and 40 C.F.R. Section 122.44(d) in determining appropriate effluent limits for point source discharges. For example, where the biological criteria are not met, that information can be used by the permitting authority to reevaluate any NPDES permits for upstream discharges to determine if all appropriate chemical-specific and whole effluent toxicity limits are included in the permits. This may involve examining whether such permits contain limits for all substances present in the discharge and for whatever pollutants or parameters are or may be discharged that cause, have the reasonable potential to cause, or contribute to any failure to meet the narrative biological criteria. NARRATIVE BIOLOGICAL CRITERIA Page 24 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 8 NUMERIC CRITERIA This section describes the numeric criteria applicable to tribal waters. Unless noted otherwise, the Tribe adopted the National Recommended Water Quality Criteria for priority and non-priority pollutants published by the EPA pursuant to CWA Section 304(a). They include water quality criteria for the protection of aquatic life and human health in surface waters for approximately 150 pollutants. The 304(a) aquatic life criteria are intended to be protective of the vast majority of the aquatic communities in the United States and Indian reservations located therein. Where the analytical detection limit of a particular substance is greater than the adopted numeric criterion, the applicability of the numeric criterion for regulatory purposes will be unaffected, but enforcement decisions such as the identification of compliance thresholds to be included in NPDES permits may be influenced. 8.1 ESTABLISHING NUMERIC CRITERIA The Tribe establishes numeric criteria for tribal waters as follows: 1. Default numeric criteria presented in Table 20 are adopted for all segments that have been assigned an Aquatic Life use, regardless of sub-category, unless the Tribe, following a public hearing, adopts an alternative criterion on a site-specific basis consistent with one of the approaches described in this section. Both acute and chronic criteria apply. Hardness-dependent criteria for metals will be calculated as necessary using site-specific hardness information identified in Section 8.6. 2. Default numeric criteria presented in Table 21 are adopted for all segments that have been assigned the Potable Water Supply use, unless the Tribe, following a public hearing, adopts an alternative criterion on a site-specific basis consistent with one of the approaches described in this section. 3. For tribal waters where ambient water quality levels of one or more pollutants are higher than applicable numeric criteria but designated uses are nevertheless supported, the Tribe may adopt sitespecific or seasonal ambient criteria. Ambient chronic criteria shall be set at the 90th percentile of the available representative data. Ambient acute criteria shall be based on the default values in this document. In no case may an ambient chronic criterion be less stringent than the acute criterion. 4. The Tribe may adopt site-specific numeric criteria applicable to all or part of a segment. A sitespecific criterion is intended to come closer than the national criterion to provide the intended level of protection to the aquatic life at the site, usually by taking into account the biological or chemical conditions (i.e., the species composition or water quality characteristics) at the site. Accordingly, any site-specific criteria shall be developed based on relevant site-specific conditions such as: a. actual species at a site are more or less sensitive than those used in the national criteria data set; b. physical or chemical characteristics at a site such as pH, temperature or hardness alter the biological availability or toxicity of the pollutant; c. physical, biological or chemical factors alter the bioaccumulation potential of a pollutant; d. the concentration resulting from natural background exceeds numeric criteria for aquatic life or other uses; or e. other factors or combination of factors that may warrant modification of the default criteria, subject to EPA review and approval. Site-specific criteria must fully protect the designated use to which they apply. In the case of human health-organism only criteria, site-specific criteria must fully protect human health when organisms are NUMERIC CRITERIA Page 25 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION consumed from waters containing pollutants. In special cases where protection of designated uses requires criteria not provided by the normal water quality requirements above, site-specific criteria may be assigned after public notice and hearing. Examples where special protection may be necessary include but are not limited to wildlife preserves, water bodies endangered by eutrophication, and waters of special cultural significance to the Tribe. Any party may petition the Tribe to adopt site-specific criteria by submitting a petition with the following information: a. identify the specific waters to which the site-specific criteria would apply; b. explain the rationale for proposing the site-specific criteria; c. describe the methods used to notify and solicit input from potential stakeholders and from the general public in the affected area, and present and respond to the public input received; and d. present and justify the derivation of the proposed criteria. A derivation of site-specific criteria shall rely on a scientifically defensible method such as one of the following: a. the “Resident Species Procedure,” as described in the Water Quality Standards Handbook: Second Edition (EPA-823-B-94-005a; August 1994); b. the “Recalculation Procedure,” or the “Water-Effect Ratio Procedure,” as updated in the Water Quality Standards Handbook: Third Edition (EPA-823-B-17-001; 2017); c. the Biotic Ligand Model as described in Aquatic Life Ambient Freshwater Quality Criteria – Copper 2007 Revision (EPA-822-R-07-001; February 2007); and d. the Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health (EPA-822-B-00-004; October 2000) and associated Technical Support Documents. Proposed third party revisions for site-specific criteria will be evaluated by the Tribe and may be proposed to the public during the next water quality standards rulemaking opportunity. Site-specific criteria revisions are final and applicable for use only after adoption by the Tribe and CWA review and approval by EPA. 8.2 POTABLE AND INDUSTRIAL WATER SUPPLY The numeric criteria for the protection of human health in surface water (Table 21) apply to all waters designated for Potable Water Supply use. The policy of the Tribe is that tribal waters designated for use as a potable water supply shall not contain substances in concentrations that create a lifetime cancer risk of more than one cancer occurrence per 1,000,000 exposed persons based on a fish consumption rate of 22 grams/day. Numeric criteria for such segments shall at minimum meet that cancer risk threshold. No unique numeric criteria apply to Industrial Water Supply (IND) uses at this time. 8.3 PRIMARY CONTACT RECREATION The monthly maximum geometric mean of E. coli bacteria of 126 cfu/100 mL and statistical threshold value maximum of 410 cfu/100 mL and pH within the range of 6.5 to 9.0 apply to segments designated as Primary Contact Recreation (REC1). NUMERIC CRITERIA Page 26 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION The maximum Water + Organism measurement of Microcystins of 8 (µg/L) and maximum Water + Organism measurement of Cylindrospermopsin of 15 (µg/L) apply to primary contact recreation waters. 8.4 SECONDARY CONTACT RECREATION The monthly maximum geometric mean of E. coli bacteria of 126 cfu/100 mL and statistical threshold value maximum of 410 cfu/100 mL apply to segments designated as Secondary Contact Recreation (REC2). The maximum Water + Organism measurement of Microcystins of 8 (µg/L) and maximum Water + Organism measurement of Cylindrospermopsin of 15 (µg/L) apply to secondary contact recreation waters. 8.5 AQUATIC LIFE In addition to the narrative water quality criteria and narrative biological criteria, the acute and chronic aquatic life criteria identified in Table 20 apply to all segments designated for Aquatic Life use. In addition, the specific criteria for aquatic life subcategories in the following paragraphs apply to waters classified under the respective designations. Table 15. Aquatic Life Temperature Designations (Class 1 and 2) Temperature Class Max Daily Temp Cold Water Dissolved Oxygen (Min Value) 6 mg/L (6.5)*** pH Specific Conductance 20°C (68°F)* Maximum Weekly Average Temp 17°C (63°F)** 6.5 - 9.0 200--1,600 µS/cm Cool Water 6 mg/L (6.0)*** 24°C (75°F)* 21°C (70°F)** 6.5 - 9.0 200--1,600 µS/cm Warm Water 5 mg/L (6.0)*** 30°C (86°F)* 27°C (81°F)** 6.5 - 9.0 200--1,600 µS/cm * Acute Temperature - Duration: 2 hours. Frequency: not to exceed more than once in 3 years. ** Chronic Temperature – Duration: 7-day mean of multiple, equally spaced, daily temperatures. Frequency: not to exceed more than once in 3 years. *** (Min Value) are instantaneous concentrations to be achieved at all times. Values in parenthesis represents the 7-day mean value. *** These values represent the intergravel dissolved oxygen concentrations for proper development of embryonic and larval stages for aquatic species. See table 20, Footnote “L” for further clarification. In some circumstances, aquatic life uses may be supported even where, occasionally, these criteria are not met. An appropriate assessment procedure shall be used to identify when such excursions are or may be impairing aquatic life. The objective of the specific conductance criterion, provided as a range, is to prevent excessive increases in dissolved solids that could result in changes in community structure. The criterion applied to a particular water body will depend on its estimated natural background concentration and meeting that objective. 8.6 HARDNESS-DEPENDENT CRITERIA FOR METALS Hardness-dependent acute and chronic criteria for selected metals apply to all segments designated for Aquatic Life use. The criteria, which are a function of dissolved hardness (as mg CaCO3/L) measured in the water body, are calculated using the equations specified in this section and the coefficient values listed in Table 18. Unless noted otherwise, they are equivalent to the National Recommended Water Quality Criteria published by EPA pursuant to CWA Section 304(a). NUMERIC CRITERIA Page 27 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 1. Acute aquatic life criteria for metals in µg/L of dissolved metal: CMC = (exp(mA[ln(hardness)] + bA))CF 2. Chronic aquatic life criteria for metals in ug/L of dissolved metal: CCC = (exp(mC[ln(hardness)] + bC))CF Where CMC refers to Acute Criteria and CCC refers to Chronic Criteria, CF is the conversion factor used for converting a metal criterion expressed as the total recoverable fraction in the water column to a criterion expressed as the dissolved fraction in the water column, and mA, bA, mC, and bC are metal-specific coefficients listed in Table 16 . Table 17 provides examples of the criteria for each metal at various levels of hardness. The equations are valid only for dissolved hardness concentrations of 0-400 mg/L. For dissolved hardness concentrations above 400 mg/L, the criteria for 400 mg/L apply. Table 16. Hardness Dependent Parameters for Calculating Freshwater Dissolved Metals Acute and Chronic Criteria Metal mA bA mC bC Conversion factor (CF) CMC Conversion factor (CF) CCC 1.136672 - 1.101672 - Cadmium (Cd) 0.9789 -3.866 0.7977 -3.909 [(ln hardness) * (0.041838)] [(ln hardness) * (0.041838)] Chromium (Cr) III 0.8190 3.7256 0.8190 0.6848 0.316 0.860 1.46203 - 1.46203 - Lead (Pb) 1.273 -1.460 1.273 -4.705 [(ln hardness) * (0.145712)] [(ln hardness) * (0.145712)] Nickel (Ni) 0.8460 2.255 0.8460 0.0584 0.998 0.997 Silver (Ag) 1.72 -6.59 - - 0.85 - Zinc (Zn) 0.8473 0.884 0.8473 0.884 0.978 0.986 Table 17. Selected Values of Calculated Acute and Chronic Criteria (µg/L). Hardness (mg/L CaCO3) 25 50 75 100 150 200 250 300 350 400 Acute 0.52 1.03 1.52 2.01 2.99 3.95 4.90 5.85 6.80 7.74 Chronic 0.09 0.15 0.20 0.25 0.33 0.40 0.46 0.53 0.59 0.64 Cadmium NUMERIC CRITERIA Page 28 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Chromium III Acute 183 323 450 570 794 1005 1207 1401 1590 1773 Chronic 24 42 59 74 103 131 157 182 207 231 Acute 14 30 47 65 100 136 172 209 245 281 Chronic 0.5 1.2 1.8 2.5 3.9 5.3 6.7 8.1 9.5 10.9 Acute 145 260 367 468 660 842 1017 1186 1351 1513 Chronic 16 29 41 52 73 93 113 132 150 168 Acute 0.30 0.98 1.96 3.22 6.46 10.60 15.56 21.28 27.75 34.91 Acute 36 65 92 117 165 211 255 297 339 379 Chronic 36 66 93 118 167 213 257 300 341 382 Lead Nickel Silver Zinc 8.7 AMMONIA NUMERICAL CRITERIA FOR ALL SEGMENTS DESIGNATED FOR AQUATIC USE Table 18. Equation Used for Numerical Criteria of Total Ammonia Nitrogen (“TAN”). mg TAN/L Acute (CMC) equation (1 hour average) Chronic (CCC) equation (30-day rolling average)* Note: Ammonia criteria are a function of pH and temperature. At the standard normalized pH of 7.0 and temperature of 20 oC, the acute criterion would be 17 mg TAN/L and the chronic criterion would be 1.9 mg TAN/L. Criteria duration: the acute criterion is a one-hour average and the chronic criterion is a thirty-day rolling average. Criteria frequency: Not to be exceeded more than once in 3 years. * Not to exceed 2.5 times the CCC as a 4-day average within the 30-days, i.e. 4.8 mg TAN/L at pH 7 and 20 oC more than once in 3 years on average. NUMERIC CRITERIA Page 29 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Note to Ammonia Numerical Criteria: Acute (CMC) and chronic (CCC) freshwater ammonia criteria were developed using EPA’s 2013 Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater (EPA– 822–R–13–001), which is hereby incorporated by reference. Illustrations, tables, and formulae used in the development of these equations can be found on pages 40-52 of the criteria document. Alternative equations for the presence or absence of Oncorhynchus sp. (rainbow trout) can be found on pages 41-42 of the document. 8.8 SELENIUM AQUATIC LIFE CRITERIA FOR FRESH WATERS Table 19. Selenium Numerical Criteria. Criterion Element Fish Tissuea (Egg-Ovary)b Magnitude 15.1 mg/kg dw Fish Tissuea (Whole Body or Muscle)d 8.5 mg/kg dw or 11.3 mg/kg dw muscle (skinless, boneless filet) 1.5 µg/L in lentic aquatic systems Water Columne (Monthly Average Exposure) Water Columne (Intermittent Exposure)f 3.1 µg/L in lotic aquatic systems WQCint = WQC30-day – Cbkgrnd(1 – fint) fint Duration Instantaneous measurementc Instantaneous measurementc Frequency Not to be exceeded Not to be exceeded 30 days Not more than once in three years on average Number of days/month with an elevated concentration Not more than once in three years on average a Fish tissue elements are expressed as steady-state. Egg/ovary supersedes any whole-body, muscle, or water column element when fish egg/ovary concentrations are measured. c Fish tissue data provide point measurements that reflect integrative accumulation of selenium over time and space in fish population(s) at a given site. d Fish whole-body or muscle tissue supersedes water column element when both fish tissue and water concentrations are measured. e Water column values are based on dissolved total selenium in water and are derived from fish tissue values via bioaccumulation modeling. Water column values are the applicable criterion element in the absence of steady-state condition fish tissue data. f Where WQC30-day is the water column monthly element, for either lentic or lotic waters; Cbkgrnd is the average background selenium concentration, and fint is the fraction of any 30-day period during which elevated selenium concentrations occur, with fint assigned a value ≥0.033 (corresponding to 1 day). g Fish tissue studies and implementation decisions will be based on EPA’s Final Criterion: Aquatic Life Ambient Water Quality Criterion for Selenium- Freshwater (June 30, 2016, 822-R-16-006). b 9 NUMERIC CRITERIA TABLES The Tribe has adopted the National Recommended Water Quality Criteria for freshwater pollutants published by EPA pursuant to CWA Section 304(a). NUMERIC CRITERIA TABLES Page 30 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 9.1 NUMERIC CRITERIA FOR AQUATIC LIFE Table 20 below lists acute (CMC) and chronic (CCC) criteria for the protection of aquatic life. They apply to all water designated for aquatic life use, regardless of sub-category. Hardness-dependent criteria for certain metals are discussed in Subsection 8.6 above. All criteria are expressed in dissolved fractions unless otherwise noted. Table 20. Numeric Criteria for the Protection of Aquatic Life in Surface Water. Pollutant Acrolein AldrinA AlkalinityB alpha-EndosulfanA,C AluminumD Ammonia ArsenicE,F beta-EndosulfanA,C CadmiumF Carbaryl ChlordaneA Chloride Chlorine Chlorpyrifos Chromium (III)F Chromium (VI)F CopperG Cyanide H Demeton Diazinon DieldrinA EndrinI gamma-BHC (Lindane) Guthion Heptachlor A Heptachlor Epoxide A,J Iron LeadF Malathion MercuryF,K Methoxychlor Mirex NickelF Nonylphenol Oxygen, Dissolved L Parathion PentachlorophenolM CAS Number 107028 309002 959988 7429905 7664417 7440382 33213659 7440439 63252 57749 16887006 7782505 2921882 16065831 18540299 7440508 57125 8065483 333415 60571 72208 58899 86500 76448 1024573 7439896 7439921 121755 22967926 or 7439976 72435 2385855 7440020 84852153 7782447 56382 87865 NUMERIC CRITERIA TABLES CMC (acute) - µg/L N 3 3.0 0.22 CCC (chronic) - µg/L N 3 20000 0.056 See Table 18 340 0.22 150 0.056 See Table 16 2.1 2.4 860000 19 0.083 2.1 0.0043 230000 11 0.041 See Table 16 16 11 22 0.17 0.24 0.086 0.95 0.52 0.52 - 5.2 0.1 0.17 0.056 0.036 0.01 0.0038 0.0038 1000 See Table 16 1.4 - 0.1 0.03 0.001 See Table 16 28 6.6 See Table 15 0.065 19 0.013 15 Page 31 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Pollutant pH Selenium SilverA,F Sulfide-Hydrogen Sulfide Temperature Toxaphene Tributyltin (TBT) ZincF 4,4'-DDTA CAS Number 7782492 7440224 7783064 CMC (acute) - µg/L N CCC (chronic) - µg/L N 6.5 – 9 See Table 19 See Table 16 - Cold, Cool, and Warm Water Matrix – See Section 8.5 0.73 0.0002 0.46 0.072 See Table 16 1.1 0.001 8001352 7440666 50293 - 2 Aquatic Life Table – Footnotes A. These criteria are based on the 1980 criteria, which used different Minimum Data Requirements and derivation procedures from the 1985 Guidelines. If evaluation is to be done using an averaging period, the acute criteria values given are not to be exceeded and should be divided by 2 to obtain a value that is more comparable to a CMC derived using the 1985 Guidelines. B. The CCC of 20mg/L is a minimum value except where alkalinity is naturally lower, in which case the criterion cannot be lower than 25% of the natural level. C. This value was derived from data for endosulfan and is most appropriately applied to the sum of alpha-endosulfan and beta-endosulfan. D. Freshwater criteria for aluminum shall be developed using EPA’s 2018 Final Aquatic Life Ambient Water Quality Criteria for Aluminum (December 2018, EPA 822-R-18-001). E. This recommended water quality criterion was derived from data for arsenic (III) but is applied here to total arsenic. F. Freshwater and saltwater criteria for metals are expressed in terms of the dissolved metal in the water column. See Office of Water Policy and Technical Guidance on Interpretation and Implementation of Aquatic Life Metals Criteria. See Table 1a for conversion factors. G. Acute (CMC) and chronic (CCC) freshwater copper criteria shall be developed using EPA’s 2007 Aquatic Life Ambient Freshwater Quality Criteria—Copper (EPA–822–R–07–001), which incorporates use of the copper biotic ligand model (BLM). Where sufficiently representative ambient data for DOC, calcium, magnesium, sodium, potassium, sulfate, chloride, or alkalinity are not available, the Tribe shall use the values from the Draft Technical Support Document: Recommended Estimates for Missing Water Quality Parameters for Application in EPA’s Biotic Ligand Model, March 2016, EPA 820-E-15-106, which is hereby incorporated by reference. If taking stream order into account, the Tribe will use Tables 8, 9, and 10 of the document; for estimates irrespective of stream order, the state or tribe will refer to Table 4. H. These recommended water quality criteria are expressed as µg free cyanide (CN/L). I. The derivation of the CCC for this pollutant did not consider exposure through the diet, which evidence suggests is important for aquatic life occupying upper trophic levels. J. This value was derived from data for heptachlor and there was insufficient data to determine relative toxicities of heptachlor and heptachlor epoxide. K. This recommended water quality criterion was derived from data for inorganic mercury (II), but is applied here to total dissolved mercury. If a substantial portion of the mercury in the water column is methylmercury, this criterion will probably be under protective. In addition, even though inorganic NUMERIC CRITERIA TABLES Page 32 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION mercury is converted to methylmercury and methylmercury bioaccumulates to a great extent, this criterion does not account for uptake via the food chain because sufficient data were not available when the criterion was derived. L. For fresh waters, see Quality Criteria for Water, 1986 ("Gold Book"), for protection of early live stages. M. Freshwater aquatic life values for pentachlorophenol are expressed as a function of pH and values displayed in table correspond to a pH of 7.8. CCC = e 1.005(pH) – 5.134, CMC = e 1.005 (pH) – 4.869 N. Criteria duration: the acute criterion is instantaneous, and the chronic criterion is a thirty-day rolling average. Criteria frequency: Not to be exceeded more than once in 3 years. 9.2 NUMERIC CRITERIA FOR HUMAN HEALTH Table 21 lists numeric criteria for surface water to protect human health from ingesting water and resident organisms and for ingesting resident organisms only. The calculated human health criteria are based on a fish consumption rate of 22 grams/day and cancer risk level of 1 in 1,000,000 people (10-6) and applies to all waters designated for Potable Water Supply use. Table 21. Numeric Criteria for the Protection of Human Health in Surface Water. Pollutant CAS Number Water + Organism (µg/L) J Organism Only (µg/L) J 1,1,1-Trichloroethane A 71556 10000 200000 1,1,2,2-Tetrachloroethane 79345 0.2 3 1,1,2-Trichloroethane A 79005 0.55 8.9 1,1-Dichloroethylene A 75354 300 20000 1,2,4,5-Tetrachlorobenzene 95943 0.03 0.03 1,2,4-Trichlorobenzene A 120821 0.071 0.076 1,2-Dichlorobenzene A 95501 1000 3000 1,2-Dichloroethane A 107062 9.9 650 1,2-Dichloropropane 78875 0.90 31 1,2-Diphenylhydrazine 122667 0.03 0.2 1,2-Trans-Dichloroethylene A 156605 100 4000 1,3-Dichlorobenzene 541731 7 10 NUMERIC CRITERIA TABLES Page 33 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Pollutant CAS Number Water + Organism (µg/L) J Organism Only (µg/L) J 1,3-Dichloropropene 542756 0.27 12 1,4-Dichlorobenzene A 106467 300 900 2,3,7,8-TCDD (Dioxin) 1746016 5.0e-9 5.1e-9 2,4,5-Trichlorophenol B 95954 300 600 2,4,6-Trichlorophenol B 88062 1.5 2.8 2,4-Dichlorophenol B 120832 10 60 2,4-Dimethylphenol B 105679 100 3000 2,4-Dinitrophenol 51285 10 300 2,4-Dinitrotoluene 121142 0.049 1.7 2-Chloronaphthalene 91587 800 1000 2-Chlorophenol B 95578 30 800 2-Methyl-4,6-Dinitrophenol 534521 2 30 3,3'-Dichlorobenzidine 91941 0.049 0.15 3-Methyl-4-Chlorophenol B 59507 500 2000 4,4'-DDD 72548 0.00012 0.00012 4,4'-DDE 72559 0.000018 0.000018 4,4'-DDT 50293 0.000030 0.000030 Acenaphthene B 83329 70 90 Acrolein 107028 3 400 Acrylonitrile 107131 0.061 7.0 Aldrin 309002 7.7e-7 7.7e-7 NUMERIC CRITERIA TABLES Page 34 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Pollutant CAS Number Water + Organism (µg/L) J Organism Only (µg/L) J alpha-BHC 319-84-6 0.00036 0.00039 alpha-Endosulfan 959988 20 30 Anthracene 120127 300 400 Antimony A,C,D 7440360 5.6 640 Arsenic 7440382 0.018 0.14 Asbestos A,C,E 1332214 7 million fibers/L -- Barium A,C,E,F 7440393 1000 -- Benzene A 71432 0.58 16 Benzidine 92875 0.00014 0.011 Benzo(a) Anthracene 56553 0.0012 0.0013 Benzo(a) Pyrene A 50328 0.00012 0.00013 Benzo(b) Fluoranthene 205992 0.0012 0.0013 Benzo(k) Fluoranthene 207089 0.012 0.013 beta-BHC (beta-HCH) 319857 0.0080 0.014 beta-Endosulfan 33213659 20 40 Bis(2-Chloro-1-Methylethyl) Ether 108601 200 4000 Bis(2-Chloroethyl) Ether 111444 0.030 2.2 Bis(2-Ethylhexyl) Phthalate A 117817 0.32 0.37 Bis(Chlormethyl) Ether 542881 0.00015 0.017 Bromoform A 75252 7.0 120 NUMERIC CRITERIA TABLES Page 35 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Pollutant CAS Number Water + Organism (µg/L) J Organism Only (µg/L) J Butylbenzyl Phthalate 85687 0.10 0.10 Carbon Tetrachloride A 56235 0.4 5 Chlordane A 57749 0.00031 0.00032 Chlorobenzene A,B 108907 100 800 Chlorodibromomethane A 124481 0.80 21 Chloroform A 67663 60 2000 Chlorophenoxy Herbicide (2,4,5-TP) [Silvex] A 93721 100 400 Chlorophenoxy Herbicide (2,4D) A 94757 1300 12000 Chrysene A 218019 0.12 0.13 Copper A, B, C, E 7440508 1300 -- 57125 4 400 Cylindrospermopsin K 143545-90-8 15 -- Di-n-Butyl Phthalate 84-74-2 20 30 Dibenzo(a,h) Anthracene 53703 0.00012 0.00013 Dichlorobromomethane A 75274 0.95 27 Dieldrin 60571 0.0000012 0.0000012 Diethyl Phthalate 84662 600 600 Dimethyl Phthalate 131113 2000 2000 Dinitrophenols 25550587 10 1000 Endosulfan Sulfate 1031078 20 40 Cyanide A NUMERIC CRITERIA TABLES Page 36 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Pollutant CAS Number Water + Organism (µg/L) J Organism Only (µg/L) J Endrin 72208 0.03 0.03 Endrin Aldehyde A 7421934 1 1 Ethylbenzene A 100414 68 130 Fluoranthene 206440 20 20 Fluorene 86737 50 70 Gamma-BHC (HCH); Lindane A 58899 4.2 4.4 Heptachlor A 76448 0.0000059 0.0000059 Heptachlor Epoxide A 1024573 0.000032 0.000032 Hexachlorobenzene A 118741 0.000079 0.000079 Hexachlorobutadiene A 87683 0.01 0.01 Hexachlorocyclohexane (HCH) Technical 608731 0.0066 0.010 Hexachlorocyclopentadiene A,B 77474 4 4 Hexachloroethane 67721 0.1 0.1 Indeno(1,2,3-cd) Pyrene 193395 0.0012 0.0013 Isophorone 78591 34 1800 Manganese B,C,G,E 7439965 50 100 Methoxychlor A 72435 0.02 0.02 Methyl Bromide 74839 100 10000 Methylene Chloride A 75092 20 1000 Methylmercury C,H 22967926 N/A 0.3 mg/Kg NUMERIC CRITERIA TABLES Page 37 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Pollutant CAS Number Water + Organism (µg/L) J Organism Only (µg/L) J Microcystin K 101043-37-2 8 -- N-Nitrosodi-n-Propylamine C 621647 0.0050 0.51 N-Nitrosodimethylamine C 62-75-9 0.00069 3.0 N-Nitrosodiphenylamine C 86306 3.3 6.0 Nickel C,D 7440020 610 4600 Nitrates A,C,E 14797558 10000 -- Nitrobenzene B 98953 10 600 Nitrosamines C 70-25-7 0.0008 1.24 Nitrosodibutylamine C 924-16-3 0.0063 0.22 Nitrosodiethylamine C 55-18-5 0.0008 1.24 Nitrosopyrrolidine C 930-55-2 0.016 34 Pentachlorobenzene 608935 0.1 0.1 Pentachlorophenol (PCP) A,B 87865 0.03 0.04 pH C,E - 5-9 -- Phenol B 108952 4000 300000 Polychlorinated Biphenyls (PCBs) 1336-36-3 0.000064 0.000064 A,C,I Pyrene 129000 20 30 Selenium A,C 7782492 170 4200 - 250000 -- 127184 10 29 Solids Dissolved and Salinity C,E Tetrachloroethylene A NUMERIC CRITERIA TABLES Page 38 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION Pollutant CAS Number Water + Organism (µg/L) J Organism Only (µg/L) J Thallium 7440280 0.24 0.47 Toluene A 108883 57 520 Toxaphene A 8001352 0.00070 0.00071 Trichloroethylene A 79016 0.6 7 Vinyl Chloride A 75014 0.022 1.6 Zinc B,C 7440666 7400 26000 Footnotes for Numerical Criteria for Human Health: A. Epa has issued a Maximum Contaminant Level (MCL) for this chemical which may be more stringent. See EPA's National Primary Drinking Water Regulations. B. The criterion for organoleptic (taste and odor) effects may be more stringent. See National Recommended Water Quality Criteria - Organoleptic Effects. C. EPA's National Recommended Human Health Water Quality Criteria for this pollutant were not updated in 2015. D. This criterion was revised to reflect EPA's q1* or RfD as contained in the Integrated Risk Information System (IRIS) as of May 17, 2002. The fish tissue bioconcentration factor (BCF) is from the 1980 Ambient Water Quality Criteria document. E. Criteria for these pollutants are from the National Recommended Water Quality Criteria - Human Health Criteria Table. They are not calculated based on this table's inputs for fish consumption rate and cancer risk level. F. This human health criterion is the same as originally published in the Quality Criteria for Water, 1976 ("Red Book") which predates the 1980 methodology and did not utilize the fish ingestion BCF approach. This same criterion value is published in the Quality Criteria for Water, 1986 ("Gold Book"). G. The Human Health for the consumption of Water + Organism criterion for manganese is not based on toxic effects, but rather is intended to minimize objectionable qualities such as laundry stains and objectionable tastes in beverages. H. This fish tissue residue criterion for methylmercury is based on the total fish consumption rate of 0.0175 kg/day. I. This criterion applies to total PCBs (e.g., the sum of all congener or all isomer or homolog or Aroclor analyses). J. Criteria duration: instantaneous. Criteria frequency: Not to be exceeded. K. This criterion is valid for implementation with a duration of ‘1 sampling event within any 10-day assessment period across a recreational season’ and an exceedance frequency not to exceed 3 excursions in a recreational season in more than one year. An excursion is defined as a 10-day assessment period with any toxin concentration higher than the recommended criteria magnitude. When more than three excursions occur within a recreational season and that pattern reoccurs in more than one year, it is an indication the water quality has been or is becoming degraded and is not supporting its recreational use. Methods for sampling, data management, and assessment are included NUMERIC CRITERIA TABLES Page 39 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION in an EPA-approved Quality Assurance Program Plan (QAPP). Should they be necessary, public advisories will be drafted by EPD, reviewed and approved by Tribal governance, and distributed via the Tribe’s electronic information services. 10 WATER QUALITY STANDARDS FOR WETLANDS All tribal waters that are wetlands, unless a constructed wetland, shall be subject to the level of protection as defined by the designated uses assigned to the river or stream segment to which they are hydraulically connected. Wetlands shall be presumed to provide habitat capable of supporting aquatic biota (e.g., fish, macroinvertebrates, amphibians, or hydrophytic vegetation) on a regular or periodic basis. It shall be a goal of the Tribe to maintain the water quality, functions, and values of wetlands at naturally occurring levels, within the natural range of variation for the individual wetland. The functions and values that shall be maintained include, but are not limited to, the following: 1. Storm and flood water storage and retention and the moderation of water level fluctuation extremes; 2. Filtration or storage of sediments, nutrients or toxic substances that would otherwise adversely impact the quality of other waters of the Tribe; 3. Shoreline protection against erosion through the dissipation of wave energy and water velocity and anchoring of sediments; 4. Habitat for aquatic organisms in the food web including, but not limited to, fish, crustaceans, mollusks, insects, annelids, planktonic organisms and the plants and animals upon which these aquatic organisms feed and depend upon for their development in all life stages; 5. Habitat for resident and transient wildlife species, including mammals, birds, reptiles and amphibians for breeding, resting, nesting, escape cover, travel corridors and food; and 6. Recreational, culturally significant wetland plant species, educational, scientific and natural scenic beauty values and uses. Wetlands shall be subject to narrative criteria, numeric criteria, and applicable antidegradation provisions. For substances that are not naturally occurring, water quality requirements shall be based on protecting designated uses of the wetland consistent with antidegradation requirements, the Tribe’s narrative water quality criteria, narrative biological criteria, criteria assigned to hydraulically-connected surface waters, or appropriate criteria guidance issued by EPA. The Tribe recognizes and expects that certain parameters may exceed applicable numeric criteria in wetlands due to natural forces and variability. Wetlands, except for constructed wetlands, shall not be permitted as repositories or treatment systems for wastes from human sources. 11 OUTSTANDING TRIBAL RESOURCE WATERS Outstanding Tribal Resource Water (OTRW) means a segment that has been classified as an OTRW pursuant to the provisions of these water quality standards and any procedures the Tribe adopts specific to OTRW. The intent of OTRW classification is to provide enhanced protection for certain waters. OTRW segments may include, but are not limited to, waters that have outstanding water quality, unique aquatic ecology, or recreational, cultural, ceremonial or aesthetic characteristics that qualify them for such classification by the Tribe. In addition to the numeric and narrative criteria for other applicable designated uses, waters classified as an OTRW shall be subject to the water quality requirements specified below and to tier 3 review under the Tribe’s antidegradation review policies and procedures. WATER QUALITY STANDARDS FOR WETLANDS Page 40 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 1. To qualify as an OTRW, following nomination from a member of the public or tribal personnel, the Tribal Council must make a finding that a tribal water is a unique tribal resource based upon one of the following criteria: a. The tribal water is of exceptional recreational or ecological significance because of its unique attributes including, but not limited to, those related to cultural values, geology, flora, water quality, aesthetic value, or its wilderness characteristics. b. Threatened or endangered species are known to be associated with the tribal water. The existing water quality is essential to the maintenance and propagation of a threatened or endangered species or provides critical habitat. Threatened and endangered species can be those identified under the Endangered Species Act, ones listed by the State of Colorado, or any additional species status designated by the Tribe. 2. The disclosure to the public of the existence and location of waters that qualify as an OTRW may result in visitation and impacts that are not consistent with the objectives of OTRW classification. Accordingly, the Tribe may, in the interest of protection of these waters, limit the public disclosure of any OTRW classification, the information supporting such classification, and the basis of the decision. The Tribe will develop procedures and policies to govern the confidential classification and administration of such waters, and the OTRW classifications will be made available to interested parties upon request in accordance with these procedures and policies. 3. The following water quality requirements apply to each OTRW, regardless of whether it is confidential. These water quality requirements are supplemental to the narrative and numeric water quality criteria associated with all other applicable designated uses for the water body. Table 22. These water quality requirements apply to all Outstanding Tribal Resource Waters. Constituent Standard Dissolved oxygen No observable change caused by discharge pH No observable change caused by discharge Temperature No observable change caused by discharge Total dissolved solids No observable change caused by discharge Total nitrogen No observable change caused by discharge Total phosphorus No observable change caused by discharge All numerical criteria No observable change caused by discharge The water quality requirement of “No observable change caused by discharge” will be implemented through the antidegradation review process and through incorporation into applicable NPDES permits for point source discharges and through required, enforceable BMPs for nonpoint sources. 4. The Tribe may adopt site-specific water quality standards to maintain and protect water quality in OTRWs. OUTSTANDING TRIBAL RESOURCE WATERS Page 41 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 12 ANALYTICAL METHODS All methods of analysis used to measure the water quality of surface waters for purposes of determining compliance with these standards shall be in accordance with procedures prescribed in the current 40 C.F.R. part 136. 13 ANTIDEGRADATION REVIEW POLICIES AND PROCEDURES 13.1 ANTIDEGRADATION POLICY Antidegradation refers to the mechanism to review the potential water quality impacts of existing or proposed activities; then to take actions that ensure that existing uses and water quality will be maintained or improved or ensure public notification and comment before allowing any degradation to occur. The Tribe’s Antidegradation Policy is based on the three-tiered federal antidegradation policy found in 40 C.F.R. Section 131.12. The antidegradation policy applicable to all tribal waters is as follows: Tier 1 - Existing uses and the level of water quality necessary to protect the existing uses shall be maintained and protected. Tier 2 - Where the quality of the waters exceeds a level of quality necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water, that quality shall be maintained and protected unless the Tribe finds, after appropriate intergovernmental coordination and public participation, that allowing lower water quality is necessary to accommodate important economic or social development in the area in which the waters are located. In allowing such degradation or lower water quality, the Tribe shall assure water quality adequate to protect existing uses fully. Further, the Tribe shall assure that there shall be achieved the highest statutory and regulatory requirements for all new and existing point sources and all cost-effective and reasonable best management practices for nonpoint source water pollution control. Before allowing any degradation of water quality, pursuant to 40 C.F.R. Section 131.12 (a)(2), the Tribe will find, after an analysis of alternatives, that such a lowering is necessary to accommodate important economic or social development in the area in which the waters are located. The analysis of alternatives will evaluate a range of practicable alternatives that would prevent or lessen the degradation associated with the proposed activity. When the analysis of alternatives identifies one or more practicable alternatives, the Tribe will only find that a lowering is necessary if one such alternative is selected for implementation. Tier 3 - Where a tribal water has been classified an OTRW, that water quality shall be maintained and protected. In those cases where potential water quality impairment associated with a thermal discharge is involved, the antidegradation policy and implementing method shall be consistent with CWA Section 316, 33 U.S.C. Section 1326. Among other things, Section 316 requires effluent limits for thermal discharges and any interacting pollutants that assure the protection and propagation of a balanced, indigenous population of fish and wildlife. ANALYTICAL METHODS Page 42 WATER QUALITY STANDARDS FOR SURFACE WATERS ON THE SOUTHERN UTE INDIAN RESERVATION 13.2 ANTIDEGRADATION IMPLEMENTATION PROCEDURES See Appendix A, Antidegradation Implementation Procedures, for specific procedures governing tribal review and approval of a proposed regulated activity that may have some effect on surface water quality and Antidegradation Review Worksheet for a worksheet intended to facilitate each antidegradation review. 14 VARIANCES FROM WATER QUALITY STANDARDS A variance is a short-term exemption from meeting certain otherwise applicable components of these water quality standards. EPA authorizes tribes to include variances in their water quality standards for CWA purposes. See 40 C.F.R. Section 131.13. The Tribe has adopted these variance policies and procedures to avoid the potential for unreasonable consequences where a water quality standard may not be attainable on a near-term basis, yet it represents an attainable goal. The Tribe’s intent is to encourage maintenance of adopted standards as goals as an alternative to removing or putting in place a standard that represents a lesser goal than can reasonably be attained should conditions change (e.g., technological improvements allow for improved treatment of a particular discharge at a reasonable cost). Therefore, the objective of this policy and procedure is (1) to provide for the proper issuance of variances when information demonstrates that such unreasonable consequences may arise, (2) to limit the possibility that a variance will be inappropriately relied upon when a current standard is reasonably achievable, and (3) to ensure the highest level of water quality achievable during the term of any variance that is granted. Because a variance is a revision to these water quali [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/tribal%3Asouthern_ute%3Afabb1108f85f959e. Public record. Not legal advice.