UPPER GRANDE RONDE RIVER SUB BASIN TOTAL MAXIMUM DAILY LOAD ( TMDL)

Oregon Department of Environmental Quality April, 2000 Page Left Blank Intentionally We descend a very steep hill in coming into Grande Ronde, at the foot of which is a beautiful cluster of pitch and spruce pine trees, but no white pine like that I have been accustomed to see at home. Grande Ronde is indeed a beautiful place. It is a circular plain, surrounded by lofty mountains, and has a beautiful stream coursing through it, skirted with quite large timber. The scenery while passing through it is quite delightful in some places. We nooned upon Grande Ronde river.

 The Letters and Journals of Narcissa Whitman August 28th, 1836 Page Left Blank Intentionally Date: April 24, 2000 To: Interested Parties Subject: Upper Grande Ronde River Sub Basin Total Maximum Daily Load ( TMDL) & Water Quality Management Plan ( WQMP)

The Upper Grande Ronde River Sub Basin includes all lands draining to the Grande Ronde River upstream of its confluence with the Wallowa River. Many of these streams do not meet state water quality standards. As a result, a Total Maximum Daily Load ( TMDL) and a Water Quality Management Plan ( WQMP) have been developed and submitted to EPA. The TMDL sets targets for attaining water quality standards and the WQMP outlines the management steps necessary to attain TMDL targets. To be properly understood, the documents should be reviewed together.

Total Maximum Daily Load ( TMDL)

The TMDL analyzes the factors affecting water quality and identifies the amount of pollution that can be present without causing state water quality standards to be violated. The standards of concern include stream temperature, dissolved oxygen, and pH. The pollutants responsible for these water quality problems include excess heat, nutrients and sediments that enter the streams as a result of human induced changes to streamside vegetation and stream channel changes. The TMDL establishes targets ( allocations) for reducing these pollutants so that water quality standards can be achieved. DEQ scientists, with the assistance of technical specialists from a variety of agencies produced the TMDL as required by the federal Clean Water Act.

Water Quality Management Plan ( WQMP)

The WQMP report describes the actions that will be taken to reduce the pollutant loads identified in the TMDL. A local group, the Grande Ronde Water Quality Committee, produced the WQMP. This committee included representatives of " stakeholder" groups from within the Upper Grande Ronde Sub Basin. Representation included forestry, agriculture, local government, transportation, environmental interests, business, and tribal. The committee, appointed jointly by DEQ and The Grande Ronde Model Watershed Program, identified priorities for management categories that will be implemented to improve water quality. The highest priorities included improving riparian vegetation, in stream flow, and stream channel characteristics. Management measures are identified for point sources and for four categories of nonpoint sources: transportation, municipal, forestry and agriculture. Implementation of the plan, including periodic reviews and revisions, is expected to lead to attainment of the water quality standards. The DEQ would like to thank the committee for two years of precedent setting cooperation in developing the WQMP.

Public Review A formal public comment period on the draft TMDL and WQMP was opened on December 10, 1999. There was considerable press coverage throughout the development of the TMDL and WQMP as well as during the comment period. A public information open house was held on January 13, 2000. A formal public hearing was held on February 2, 2000. The close of the public comment period was March 3, 2000. The Department received written and oral comments from 37 individuals or organizations. The Department carefully considered all comments and questions and made appropriate revisions to the draft TMDL and WQMP prior to finalizing the documents. The Response to Comment document is available from DEQ. Page Left Blank Intentionally UPPER GRANDE RONDE RIVER SUB BASIN TOTAL MAXIMUM DAILY LOAD ( TMDL)

Prepared by:

Oregon Department of Environmental Quality April 2000 Page Left Blank Intentionally Upper Grande Ronde Sub Basin Total Maximum Daily Load ( TMDL)

Table of Contents INTRODUCTION.................................................................................................. 1 Existing Water Quality Programs 1 Implementation and Adaptive Management Issues 3 Scope 4 Beneficial Uses 6 Water Quality Impairments and Target Identification  CWA 303( d)( 1) 7 TOTAL MAXIMUM DAILY LOADS ( TMDLS).................................................... 16 Temperature 16 Dissolved Oxygen and pH 30 Sedimentation 40 Bacteria 43 Ammonia Toxicity 45 Habitat Modification and Flow Modification 47 Reasonable Assurance of Implementation 48 GLOSSARY OF TERMS.................................................................................... 51 General Terminology 51 Statistical Terminology 56 REFERENCES................................................................................................... 59 APPENDIX A   TEMPERATURE ANALYSIS APPENDIX B   PERIPHYTON ANALYSIS APPENDIX C   PERMITTED WATER RIGHT WITHDRAWALS APPENDIX D   APPLICABLE WATER QUALITY STANDARDS APPENDIX E   ODEQ POINT SOURCE TECHNICAL MEMORANDUMS Table 1. Upper Grande Ronde Sub Basin TMDL Components State/ Tribe: Oregon Waterbody Name( s): Perennial streams within the 4th field HUC ( hydrologic unit code) 17060104. Point Source TMDL: X Nonpoint Source TMDL: X ( check one or both) Date: 11/ 22/ 99 Component Comments Pollutant Identification Pollutants: Radiant Heat Energy ( Temperature) and Nutrients ( DO/ pH) Anthropogenic Contribution: Increased Radiant Energy and Nutrient Input Target Identification CWA 303( d)( 1) 40 CFR 130.2( f) Applicable Water Quality Standards: see Appendix D Loading Capacities Temperature: No increases in radiant energy above site potentials and maximum discharge temperatures listed in Table 15. Nutrient/ pH/ Dissolved Oxygen: Instream nutrient concentrations listed in Tables 18, 19, 20, and 21. Existing Sources CWA 303( d)( 1) Forestry, Agriculture, Transportation, Rural Residential, Urban, Industrial Discharge, Waste Water Treatment Facilities Seasonal Variation CWA 303( d)( 1) Temperature: Peak temperatures occur throughout June to October pH: Peak pH values occur during July, August and September Dissolved Oxygen: Lowest dissolved oxygen values occur during July, August and September TMDL Allocations 40 CFR 130.2( g) 40 CFR 130.2( h) Temperature Waste Load Allocations ( Point Sources): No measurable increase over site potential water temperatures. Load Allocations ( Background/ Non Point Sources): 100% of Loading Capacity allocated to natural sources. Nutrient/ pH/ Dissolved Oxygen Waste Load Allocations ( Point Sources): Listed orthophosphate and dissolved inorganic nitrogen reductions ( see Wasteload Allocations for Point Sources, pages 28 31) Load Allocations ( Background/ Non Point Sources): Percent reduction in instream nutrient concentrations listed in Tables 19, 20, 21 and 22.

Margins of Safety CWA 303( d)( 1) Temperature: Margins of Safety demonstrated in critical condition assumptions. Nutrient/ pH/ Dissolved Oxygen: 1. Modeling pH in addition to dissolved oxygen. Since pH was found to control the load allocations, this approach resulted in more stringent load allocations, 2. Applying 8.7 as a maximum pH standard rather than 9.0, and, 3. Ignoring potential benefits of width reductions expected for site potential conditions when establishing load allocations.

Water Quality Standard Attainment Analysis CWA 303( d)( 1)   Analytical modeling demonstrates that allocated loads will attain water quality standards   In areas where numeric criteria are not met, analytical assessments demonstrate that allocated loads represent a pollutant loading condition where anthropogenic contributions are minimized to the extent possible.   A Water Quality Management Plan ( WQMP) is developed to implement measures that attain load/ wasteload allocations. Public Notice 40 CFR 25 Completed by Oregon Department of Environmental Quality UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 1 APRIL, 2000 Introduction The Upper Grande Ronde sub basin is home to productive forested and agriculture lands and has the distinction of containing streams with historically viable salmonid populations. Interactions between multiple land uses ( i. e., agriculture, forestry, transportation, rural residential and urban) and imperiled salmonid fisheries in the Upper Grande Ronde sub basin have prompted extensive data collection and study of the interaction between land use and water quality. The knowledge derived from these data collection efforts and academic study, some of which is presented in this document, will be used to design protective and enhancement strategies that address water quality issues.

This document presents a Total Maximum Daily Load ( TMDL) that addresses salmonid fisheries concerns for all streams in the Upper Grande Ronde sub basin ( see Table 1). Water quality impairments in tributaries and mainstem reaches throughout the Upper Grande Ronde sub basin have reduced the extent of spawning and rearing habitat for chinook salmon, steelhead trout and bull trout. Primary watershed disturbance activities contributing to increased surface water temperatures and other water quality impairments include forest disturbances within and outside the riparian zone, agricultural riparian and upland disturbances, road construction and maintenance, and rural residential and urban development near streams and rivers. As a result of water quality standards ( WQS) violations, waters in the Upper Grande Ronde sub basin are included on Oregon's 1998 § 303( d) list. Load allocations associated with this TMDL are designed to reduce the input of pollutants into streams.

Several agencies have developed management strategies for the Upper Grande Ronde subbasin Water quality management plans ( WQMPs) have been developed for forested, agricultural and urban lands that address both non point and point sources of pollution. This TMDL builds upon the current land management programs in the Upper Grande Ronde sub basin, and will be the basis for the development and/ or alteration of water quality management efforts, including:

 Oregon's Forest Practices Act ( state and private forest lands),

 Senate Bill 1010 ( agricultural lands), and  Oregon Plan ( all lands).

This TMDL should be used to evaluate long term improvements in water quality, in stream physical parameters and landscape conditions that occur over time as WQMPs are implemented. Planned management practices should be evaluated in terms of their adequacy in improving water quality, meeting in stream targets ( i. e. load allocations), and protecting beneficial uses.

Existing Water Quality Programs Oregon's Total Maximum Daily Load Program Section 303( d) of the Federal Clean Water Act requires that a list be developed of all impaired or threatened waters within the State ( § 303( d) List). The principal agency responsible for monitoring the quality of Oregon's streams, lakes, estuaries and groundwater is the Department of Environmental Quality ( ODEQ). The information collected by ODEQ, as well as other agencies, is used to determine whether water quality standards are being violated and, consequently, whether the beneficial uses of the waters are being threatened. Beneficial uses include fisheries, aquatic life, drinking water, recreation and irrigation. Applicable State and Federal laws and regulations that protect beneficial uses include the Clean Water Act and its applicable regulations ( 40 Codified Federal Regulations 131, 40 CFR 131), and Oregon's Administrative Rules ( OAR Chapter 340) and Oregon's Revised Statutes ( ORS Chapter 468). UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 2 APRIL, 2000 The State must establish a Total Maximum Daily Load ( TMDL) for any waterbody designated as water quality limited ( with a few exceptions, such as in cases where violations are due to natural causes). The term water quality limited is applied to streams and lakes where violations of State water quality standards occur. TMDLs are written plans and analyses established to ensure that waterbodies will attain and maintain water quality standards. TMDLs must contain the following elements: ( 1) identification of the pollutant and quantification of the pollutant load that may be present in the waterbody and still allow attainment and maintenance of water quality standards; ( 2) identification of the amount or degree by which the pollutant load in the waterbody deviates from the target representing attainment or maintenance of water quality standards; ( 3) identification of source categories, source subcategories or individual sources of the pollutant for which wasteload and load allocations are being established; ( 4) wasteload allocations for pollutants from point sources; ( 5) load allocations for pollutants from non point sources; ( 6) a margin of safety; ( 7) consideration of seasonal variation; ( 8) an allowance for future growth which accounts for reasonably foreseeable increases in pollutant loads; and ( 9) an implementation plan.

The total allowable pollutant load is allocated to point, non point, background, and future sources of pollution. Wasteload Allocations are portions of the total allowable pollutant load that are allocated to point sources of pollution, such as wastewater treatment plants or industries. They are used to establish effluent limits in discharge permits. Load allocations are portions of the total allowable pollutant load that are allocated to non point sources, such as agriculture or forestry activities, and natural background sources. Allocations can also be set aside in reserve for future uses. Simply stated, allocations are quantified measures that assure water quality standard compliance. The TMDL is the integration of all developed allocations.

Oregon's Forest Practices Act The Oregon Forest Practices Act ( FPA, 1994) contains regulatory provisions that include the following objectives: classify and protect water resources, reduce the impacts of clearcut harvesting, maintain soil and site productivity, ensure successful reforestation, reduce forest management impacts to anadromous fish, conserve and protect water quality and maintain fish and wildlife habitat, develop cooperative monitoring agreements, foster public participation, identify stream restoration projects, recognize the value of biodiversity and monitor/ regulate the application of chemicals. Oregon's Department of Forestry ( ODF) has adopted Forest Practice Administrative Rules ( 1997) that clearly define allowable actions on State, County and private forestlands. Forest Practice Administrative Rules allow revisions and adjustments to the regulatory parameters it contains. Several revisions have been made in previous years and it is expected that the ODF, in conjunction with DEQ, will continue to monitor the success of the Forest Practice Administrative Rules and make appropriate revisions when necessary to address water quality concerns.

Senate Bill 1010 Senate Bill 1010 allows the Oregon Department of Agriculture ( ODA) to develop Water Quality Management Plans for agricultural lands where such actions are required by State or Federal Law, such as TMDL requirements. The Water Quality Management Plan should be crafted in such a way that landowners in the local area can prevent and control water pollution resulting from agricultural activities. Local stakeholders will be asked to take corrective action against identified problems such as soil erosion, nutrient transport to waterways and degraded riparian areas. It is the ODA's intent to establish Water Quality Management Plans on a voluntary basis. Senate Bill 1010 allows the ODA to use civil penalties when necessary to enforce against agriculture activity that is found to transgress parameters of an approved Water Quality Management Plan. The ODA has expressed a desire to work with the local stakeholders and other State and Federal agencies to formulate and enforce approved Water Quality Management Plans. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 3 APRIL, 2000 Oregon Plan The State of Oregon has formed a partnership between Federal and State agencies, local groups and grassroots organizations, that recognizes the attributes of aquatic health and their connection to the health of salmon populations. The Oregon Plan considers the condition of salmon as a critical indicator of ecosystems ( CSRI, 1997). The decline of salmon populations has been linked to impoverished ecosystem form and function. The Oregon Plan has committed the State of Oregon to the following obligations: an ecosystem approach that requires consideration of the full range of attributes of aquatic health, focuses on reversing factors for decline by meeting objectives that address these factors, develops adaptive management and a comprehensive monitoring strategy, and relies on citizens and constituent groups in all parts of the restoration process.

The intent of the Oregon Plan is to conserve and restore functional elements of the ecosystem that supports fish, wildlife and people. Specifically, the Oregon Plan is designed to build on existing State and Federal water quality programs, namely: Coastal Zone Non point Pollution Control Programs, the Northwest Forest Plan, Oregon's Forest Practices Act, Oregon's Senate Bill 1010 and Oregon's Total Maximum Daily Load Program.

Implementation and Adaptive Management Issues a) The goal of the Clean Water Act and associated Oregon Administrative Rules is that water quality standards shall be met or that all feasible steps will be taken towards achieving the highest quality water attainable. This is a long term goal in many watersheds, particularly where nonpoint sources are the main concern, but implementation must commence as soon as possible.

b) Total Maximum Daily Loads ( TMDLs) are numerical loading that are set to limit pollutant levels such that in stream water quality standards are met. The Department recognizes that TMDLs are values calculated from mathematical models and other analytical techniques designed to simulate and/ or predict very complex physical, chemical and biological processes. Models and techniques are simplifications of these complex processes and, as such, are unlikely to produce an exact and accurate prediction of how streams and other waterbodies will respond to the application of various management measures. It is for this reason that the TMDL has been established with a margin of safety.

c) Water Quality Management Plans ( WQMPs) are plans designed to reduce pollutant loads from nonpoint sources to meet TMDLs. The Department recognizes that it may take some period of time   from several years to several decades after full implementation before management practices in a WQMP become fully effective in reducing and controlling non point source pollution. In addition, the Department recognizes that technology for controlling nonpoint source pollution is, in many cases, in the development stages and that it may take one or more iterations before effective techniques are found. It is possible that after application of all reasonable best management practices, some TMDLs or their associated surrogates cannot be achieved as originally established.

d) The Department also recognizes that, despite the best and most sincere of efforts, natural events beyond the control of humans may interfere with or delay attainment of the TMDL and/ or its associated surrogates. Such events could be, but are not limited to, floods, fire, insect infestations, and drought.

e) In some cases in this TMDL, pollutant surrogates have been defined as alternative targets for meeting the TMDL. The purpose of the surrogates is not to bar or eliminate human access or activity in the basin or its riparian areas. It is the expectation, however, that WQMPs will address how human activities will be managed to achieve the surrogates. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 4 APRIL, 2000 f) If a nonpoint source that is covered by this TMDL complies with its WQMP or applicable forest practice rules, it will be considered in compliance with the TMDL.

g) The Department intends to regularly review progress of WQMPs to achieve TMDLs. If and when the Department determines that WQMP have been fully implemented, that all feasible management practices have reached maximum expected effectiveness and a TMDL or its interim targets have not been achieved, the Department shall reopen the TMDL and adjust it or its interim targets and its associated water quality standard( s) as necessary.

h) The implementation of TMDLs and the associated management plans is generally enforceable by the Department, other state agencies and local government. However, it is envisioned that sufficient initiative exists to achieve water quality goals with minimal enforcement. Should the need for additional effort emerge, it is expected that the responsible agency will work with land managers to overcome impediments to progress through education, technical support or enforcement. Enforcement may be necessary in instances of insufficient action towards progress. This could occur first through direct intervention from land management agencies ( e. g. ODF, ODA, counties and cities), and secondarily through DEQ. The latter may be based in departmental orders to implement management goals leading to water quality standards.

i) In employing an adaptive management approach to this TMDL and WQMP, DEQ has the following expectations and intentions:

1. Subject to available resources, on a five year basis, the Department intends to review the progress of the TMDL and the WQMP.

2. In conducting this review, the Department will evaluate the progress towards achieving the TMDL ( and water quality standards) and the success of implementing the WQMP.

3. The Department expects that each management agency will also monitor and document its progress in implementing the provisions of its component of the WQMP. This information will be provided to DEQ for its use in reviewing the TMDL.

4. As implementation of the WQMP proceeds, DEQ expects that management agencies will develop bench marks for attainment of TMDL surrogates which can then be used to measure progress.

5. Where implementation of the WQMP or effectiveness of management techniques are found to be inadequate, DEQ expects management agencies to revise the components of the WQMP to address these deficiencies.

6. When DEQ, in consultation with the management agencies, concludes that all feasible steps have been taken to meet the TMDL and its associated surrogates and attainment of water quality standards, the TMDL, or the associated surrogates is not practicable, it will reopen the TMDL and revise it as appropriate. DEQ would also consider reopening the TMDL should new information become available indicating that the TMDL or its associated surrogates should be modified.

Scope The area covered by the Upper Grande Ronde sub basin TMDL corresponds to hydrologic unit code ( HUC) 17060104, which includes all lands that drain to Grande Ronde River upstream of the confluence with the Wallowa River at Rondowa. The Upper Grande Ronde River sub basin is approximately 1,640 square miles, bordered by the Blue Mountains to the west/ northwest, the Elkhorn Range to the southwest and the Wallowa Mountains to the east/ southeast. Elevations vary from 2,300 feet to 7,800 feet. Lower elevations generally receive 12 to 25 of rainfall equivalent precipitation annually. Higher elevations commonly receive up to 50 inches of annual rainfall equivalent precipitation, most of which is received as snowfall. Highest flows are UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 5 APRIL, 2000 associated with rain on snowpack events. Low stream flows are generally associated with a long summertime drought and complete melt of the winter received snowpack.

Land ownership in the Upper Grande Ronde sub basin is equally divided between private and federal land, with small tracts of land owned/ managed by the State of Oregon and the Confederated Tribes of the Umatilla Indian Reservation ( CTUIR). Total distributions of ownership/ management are displayed in Figure 1, while spatial distributions of land ownership is displayed in Image 1. This TMDL does not apply to Confederated Tribes of the Umatilla Indian Reservation ( CTUIR) lands. Figure 1. Land Ownership/ Management Distribution Private 53.26% USFS 45.81% CTUIR 0.33% State 0.19% BLM 0.41%

Image 1. Land Ownership/ Management Spatial Distribution Gr ande Ronde Riv er Fly Creek Beaver Creek Catherine Creek Meadow Creek Indian Creek Phil lips Creek McCoy Creek Jarboe Creek Lookingglass Creek Five Points Creek Sheep Creek Jordan Creek Dark Canyon Spring Creek Gekeler Slough Mottet Creek Clark Creek B ear Creek Little Rock Creek Pelican Creek Sta te Ditch Mill Creek Burnt Corral Creek Ch icken Creek Lick Creek Clear Creek Tanner Gulch Pedro Cre ek M t Em ily Cree k Grande Ronde River Mill Cree k Union La Grande Elgin Cove Imbler Summerville USFS BLM State Lands Indian Reservation Private Lands Land Ownership UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 6 APRIL, 2000 Beneficial Uses Oregon Administrative Rules ( OAR Chapter 340, Division 41, Table 13) lists the designated beneficial uses for which water is to be protected in the Upper Grande Ronde sub basin. Designated beneficial uses are presented in Table 2. ( Temperature, dissolved oxygen, and pH sensitive beneficial uses are marked in gray.) Numeric and narrative water quality standards are designed to protect the most sensitive beneficial uses. In the Upper Grande Ronde sub basin, resident fish and aquatic life, salmonid spawning, rearing and migration ( i. e., anadromous fish passage) are designated the most sensitive beneficial uses ( Image 2).

Table 2. Designated Beneficial Uses Occurring in the Upper Grande Ronde Sub Basin ( OAR 340 41 722)

Temperature, dissolved oxygen and pH sensitive beneficial uses are marked in gray Beneficial Use Occurring Beneficial Use Occurring Public Domestic Water Supply  Anadromous Fish Passage  Private Domestic Water Supply  Salmonid Fish Spawning  Industrial Water Supply  Salmonid Fish Rearing  Irrigation  Resident Fish and Aquatic Life  Livestock Watering  Wildlife and Hunting  Boating  Fishing  Aesthetic Quality  Water Contact Recreation  Commercial Navigation & Trans. Hydro Power Image 2. Sensitive Beneficial Uses   Salmonid Migration, Spawning and Rearing Grande Ronde River Fly Creek Beaver Creek Catherine Creek Meadow Creek Indian Cree k Phillips Creek McCoy Creek Jarboe Creek Lookingglass Creek Five Points Creek Sheep Creek Jordan C reek Dark Can yon Spring Creek Gekele r Slough Mottet Creek Clark Creek Bear Cree k Little Roc k Creek Pelican Creek State Ditch Mill Creek Burnt Corral Creek Chicken Creek Lick Creek Clear Creek Tanner Gulch Pedro Creek Mt Emily Creek Grande Ronde River Mill Creek Union La Grande Elgin Cove Imbler Summerville Chinook Salmon and Steelhead Trout Bull Trout Salmonid Fish Distributions UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 7 APRIL, 2000 Water Quality Impairments and Target Identification  CWA 303( d)( 1) Monitoring shows that water quality in the Upper Grande Ronde sub basin frequently violates numeric criteria contained in State water quality standards ( WQS) 1. Applicable water quality standards for the Grande Ronde Sub Basin are presented in Appendix D. Section 303( d) of the Federal Clean Water Act requires that water bodies that violate water quality standards, and thereby fail to fully protect beneficial uses, be identified and placed on the § 303( d) list of impaired or threatened waters. Following further assessment, the Act requires that Total Maximum Daily Loads ( TMDL) and Water Quality Management Plans ( WQMP) be developed and implemented to restore water quality. WQMPs must include long term monitoring plans and adaptive management strategies to insure that water quality standards are achieved ( DEQ WQMP guidance 1997). Grande Ronde sub basin water quality parameters included in the 1998 § 303( d) list are presented below.

Temperature Aquatic life is sensitive to water temperature. Salmonid fishes, often referred to as cold water fish, and some amphibians are sensitive to temperature. In particular, Chinook salmon ( Oncorhynchus tshawytscha) and bull trout ( Salvelinus confluentus) are among the most temperature sensitive of the cold water fish species. Oregon's water temperature standard employs logic that relies on using these indicator species, which are the most sensitive. If temperatures are protective of these indicator species, other species will share in this level of protection.

The two indicator species, Chinook salmon and bull trout, that are referenced in Oregon's water temperature standard have, coincidentally, been allotted protection ( listed) under the Endangered Species Act ( ESA, 1972) in the Upper Grande Ronde sub basin. Further, Snake River steelhead trout ( Oncorhynchus mykiss) are listed as threatened in the Upper Grande Ronde sub basin. Snake River fall and spring Chinook salmon are designated under ESA as threatened species.

If stream temperatures become too hot, fish die almost instantaneously due to denaturing of critical enzyme systems in their bodies ( Posser, 1967; Hogan, 1970). The ultimate instantaneous lethal limit occurs in high temperature ranges ( upper 90 ° F).

More common and widespread, is the occurrence of temperatures in the mid to high 70 ° F range ( mid to high 20 ° C range). These temperatures cause death of cold water fish species during exposure times lasting a few hours to a day. The exact temperature at which a cold water fish succumbs to such a thermal stress depends on the temperature that the fish is acclimated and on particular development life stages. This cause of mortality, termed the incipient lethal limit, results from breakdown of physiological regulation of vital processes such as respiration and circulation ( Heath and Hughes, 1973). Brett ( 1952) reported an incipient lethal limit of 77 ° F ( 25 ° C) for spring Chinook salmon. Similarly, Bell ( 1986) reported an incipient lethal limit for Chinook salmon of 77 ° F ( 25 ° C). The Environmental Protection Agency ( EPA) and National Marine Fisheries Service ( NMFS) reported 50% mortality to adult salmon and steelhead trout with a constant water temperature of 70 ° F ( 21 ° C).

The most common and widespread cause of thermally induced fish mortality is attributed to interactive effects of decreased or lack of metabolic energy for feeding, growth or reproductive behavior, increased exposure to pathogens ( viruses, bacteria and fungi), decreased food supply ( impaired macroinvertebrate populations) and increased competition from warm water tolerant species. This mode of thermally induced mortality, termed indirect or sub lethal, is more delayed, and occurs weeks to months after the onset of elevated temperatures ( mid 60 ° F to low 70 ° F). Table 3 summarizes the modes of cold water fish mortality.

1 For detailed analytical information pertaining to Upper Grande Ronde sub basin water temperatures, see Appendix A. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 8 APRIL, 2000 Table 3. Modes of Thermally Induced Cold Water Fish Mortality ( Brett, 1952; Bell, 1986; Hokanson et al., 1977)

Modes of Thermally Induced Fish Mortality Temperature Range Time to Death Instantaneous Lethal Limit   Denaturing of bodily enzyme systems > 90oF > 32oC Instantaneous Incipient Lethal Limit   Breakdown of physiological regulation of vital bodily processes, namely: respiration and circulation 70oF to 77oF 21oC to 25oC Hours to Days Sub Lethal Limit   Conditions that cause decreased or lack of metabolic energy for feeding, growth or reproductive behavior, encourage increased exposure to pathogens, decreased food supply and increased competition from warm water tolerant species 64oF to 74oF 20oC to 23oC Weeks to Months A seven day moving average of daily maximums ( 7 day statistic) was adopted as the statistical measure of the stream temperature standard. Absolute numeric criteria are deemed action levels and indication of water quality standard compliance. Unless specifically allowed under a Department approved surface water temperature management plan as required under ( OAR 340 041 0026( 3)( a)( D)), no measurable surface water temperature increase resulting from anthropogenic activities is allowed in State of Oregon Waters determined out of compliance with the temperature standard ( see Appendix D). The numeric criteria adopted in Oregon's water temperature standard rely on the biological temperature limitations considering sensitive indicator species is presented in Table 3. A much more extensive analysis of water temperature related to aquatic life and supporting documentation for the temperature standard can be found in the 1992 1994 Water Quality Standards Review Final Issue Papers ( ODEQ, 1995).

It is important to understand the State of Oregon's temperature standard and that there is more to it than just a 64oF standard. Specifically for the Grande Ronde Basin OAR states at 340 041 0725:

( A) To accomplish the goals identified in OAR 340 041 0120( 11), unless specifically allowed under a Department approved surface water temperature management plan as required under OAR 340 041 0026( 3)( a)( D), no measurable surface water temperature increase resulting from anthropogenic activities is allowed:

( i) In a basin for which salmonid fish rearing is a designated beneficial use, and in which surface water temperatures exceed 64.0 ° F ( 17.8 ° C);

( ii) In waters and periods of the year determined by the Department to support native salmonid spawning, egg incubation, and fry emergence from the egg and from the gravels in a basin which exceeds 55.0 ° F ( 12.8 ° C);

( iii) In waters determined by the Department to support or to be necessary to maintain the viability of native Oregon bull trout, when surface water temperatures exceed 50.0 ° F ( 10.0 ° C);

( iv) In waters determined by the Department to be ecologically significant coldwater refugia;

( v) In stream segments containing federally listed Threatened and Endangered species if the increase would impair the biological integrity of the Threatened and Endangered population;

( vi) In Oregon waters when the dissolved oxygen ( DO) levels are within 0.5 mg/ l or 10 percent saturation of the water column or intergravel DO criterion for a given stream reach or subbasin;

( vii) In natural lakes. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 9 APRIL, 2000 As a result of water quality standards ( WQS) exceedances for temperature, thirty eight stream segments in the Upper Grande Ronde sub basin are included on Oregon's 1998 § 303( d) list. Image 3 displays 1998 § 303( d) listed stream segments for temperature violations, while Table 4 lists the reaches § 303( d) listed for temperature and the applicable criterion that is exceeded. In addition, this TMDL addresses potential water quality impairment for streams within the Upper Grande Ronde River sub basin that are not currently on Oregon's 1998 § 303( d) list.

Image 3. 1998 § 303( d) Listings for Temperature Grande Ronde River Fly Creek Beaver Creek Catherine Creek Meado w Creek In di an Creek Phillips Creek McCoy Creek Jarboe Creek Lookingglass Creek Five Points Creek Sheep Creek Jordan Creek Dark Canyon Spring Creek Gekeler Sloug h Mottet Creek Clark Creek Bear Cree k Lit tle Rock Cre ek Pelican Cr eek State Ditch Mill Cree k Burn t Corr al Cr eek Chick en Cree k Li ck Cre ek Clear Creek Tanner Gul ch Pedro C reek Mt Emily Creek Grande Ronde River Mill Creek Union La Grande Elgin Cove Imbler Summerville 1998 303( d) Temperature Limited UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 10 APRIL, 2000 Table 4. 1998 § 303( d) Listed Segments and Applicable Numeric Criterion OAR 340 41 725( 2)( b)( A)

Time Period:   Rearing: July 1 through September 30   Spawning Through Fry Emergence: October 1 through June 30 or waterbody specified as identified by ODFW biologist. Supporting Data:   ODEQ ( 1991   1998)   USFS ( 1992   1998) Stream Segment Criterion Bear Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) Beaver Cr. Mouth to La Grande Reservoir Rearing 64oF ( 17.8oC) Burnt Corral Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) Catherine Cr. Mouth to Union Dam Rearing 64oF ( 17.8oC) Catherine Cr. Union Dam to N. F./ S. F. Catherine Cr. Oregon Bull Trout 50oF ( 10oC) Catherine Cr., M. F. Mouth to Squaw Cr. Oregon Bull Trout 50oF ( 10oC) Catherine Cr., N. F. Mouth to M. F. Catherine Cr. Oregon Bull Trout 50oF ( 10oC) Catherine Cr., S. F. Pole Cr. to S. Catherine Ditch Diversion Oregon Bull Trout 50oF ( 10oC) Chicken Cr. Mouth to West Chicken Cr. Rearing 64oF ( 17.8oC) Chicken Cr., West Mouth to end of meadow in Section 15 Rearing 64oF ( 17.8oC) Clark Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) Dark Canyon Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) Fivepoints Cr. Mouth to Tie Cr. Rearing 64oF ( 17.8oC) Fly Cr. Mouth to Umapine Cr. Rearing 64oF ( 17.8oC) Fly Cr., Little Mouth to Headwater Rearing 64oF ( 17.8oC) Grande Ronde R. Limber Jim Cr. To Clear Cr. Oregon Bull Trout 50oF ( 10oC) Grande Ronde R. Wallowa R to Five Points Cr. Rearing 64oF ( 17.8oC) Grande Ronde R. Five Points Cr. to Limber Jim Cr. Rearing 64oF ( 17.8oC) Indian Cr. Mouth to Little Indian Cr. Rearing 64oF ( 17.8oC) Indiana Cr. Mouth to Headwaters Oregon Bull Trout 50oF ( 10oC) Jarboe Cr. Mouth to FSR 6413 Rearing 64oF ( 17.8oC) Lick Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) Limber Jim Cr. Mouth to Marion Cr. Rearing 64oF ( 17.8oC) Limber Jim Cr. Marion Cr. to Headwaters Oregon Bull Trout 50oF ( 10oC) Limber Jim Cr., S. F. Mouth to Headwaters Rearing 64oF ( 17.8oC) Lookingglass Cr. Mouth to Luger Springs ( RM 7) Oregon Bull Trout 50oF ( 10oC) Lookingglass Cr., Little Mouth to Headwaters Oregon Bull Trout 50oF ( 10oC) Lookout Cr. Mouth to Forest Boundary at Section 35 Rearing 64oF ( 17.8oC) McCoy Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) Meadow Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) Mill Cr. ( La Grande) Mouth to La Grande City Limits Rearing 64oF ( 17.8oC) Pelican Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) Rock Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) Sheep Cr. Mouth to Warm Mineral Springs Rearing 64oF ( 17.8oC) Sheep Cr., E. F. Mouth to headwaters Rearing 64oF ( 17.8oC) Spring Cr. Mouth to South Fork Rearing 64oF ( 17.8oC) State Ditch Mouth to Headwaters Rearing 64oF ( 17.8oC) Waucup Cr. Mouth to Headwaters Rearing 64oF ( 17.8oC) UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 11 APRIL, 2000 Dissolved Oxygen and pH The Grande Ronde River and Catherine and Meadow Creeks experience dissolved oxygen and pH water quality standards violations related to excessive periphyton growth. The excessive growth is due to a number of factors including elevated nutrient concentrations, high water temperatures, excessive solar radiation, high width to depth ratios, and inadequate stream flow rates. This excessive periphyton activity causes large diel dissolved oxygen and pH fluctuations which result in dissolved oxygen standards violations at night and pH standards violations during the day.

For dissolved oxygen, the applicable standard depends on whether the most sensitive species present are cold water ( salmonid) or cool water ( non salmonid) species and on whether salmonid spawning and egg incubation occurs. Waterbodies identified as providing for cold water aquatic life are those in which salmon, trout, cold water invertebrates, and other native cold water species exist throughout all or most of the year ( OAR 340 41 455 Table 21) and in which juvenile anadromous salmonids may rear throughout the year. All reaches in the upper Grande Ronde sub basin have been identified as providing for cold water aquatic life at all times of the year and for salmonid spawning and egg incubation during the fall, winter and spring months from October 1 through June 30.

For time periods identified as providing for salmonid spawning and egg incubation, the applicable water column standard is 95% of saturation. For a 3000 ft. elevation, which is roughly the average elevation of the reaches modeled, 95% saturation at 10oC ( bull trout temperature criteria) is 9.7 mg/ L and at 12.8oC ( salmonid spawning temperature criteria) is 9.1 mg/ L.

For reaches and time periods identified as providing for cold water aquatic life, including salmonids ( other than during spawning and egg incubation), two sets of standards are specified:

1) 8.0 mg/ L as an absolute minimum. Where conditions of barometric pressure, altitude, and temperature preclude attainment of 8.0 mg/ L, dissolved oxygen shall not be less than 90% of saturation. This set of standards applies when only limited data is available.

2) 8.0 mg/ L as a minimum 30 day average, 6.5 mg/ L as a minimum 7 day average of the daily minimums, and 6.0 mg/ L as an absolute minimum. This set of standards applies at the discretion of the Department when the Department determines that adequate information exists.

Due to the large amount of continuous monitoring data available in the Upper Grande Ronde subbasin the second set of standards has been applied.

For pH, Oregon Administrative Rule specifies that the pH ( log10{ H+} ) shall not fall outside of the range 6.5 to 9.0. The OAR further requires that when greater than 25% of ambient measurements taken between June and September are greater than pH 8.7, and as resources are available according to priorities set by the Department, the Department shall determine whether the values higher than 8.7 are anthropogenic or natural in origin.

In order to provide for additional margins of safety when establishing load allocations, targets for dissolved oxygen and pH have been set to levels more stringent than the standards require. For dissolved oxygen, targets for non salmonid spawning periods have been set to 6.5 mg/ L as an absolute minimum ( rather than as a 7 day average of the daily minimums) and 8.0 mg/ L as a minimum 30 day average. For spawning periods, the 95% of saturation criterion has been applied. For pH, targets have been set to 8.7 as an absolute maximum, and 6.5 as an absolute minimum.

Tables 5 through 12 and Images 4 through 11 display reaches in the sub basin included in the 1998 § 303( d) list for violating water quality standards. Stream segments included in the § 303( d) list for dissolved oxygen violations are displayed in Image 6 and Table 7. Those listed for pH violations are displayed in Image 10 and Table 11. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 12 APRIL, 2000 Aquatic Weeds or Algae Table 5. Segments on the 1998 § 303( d) List for Aquatic Weeds or Algae Waterbody Name Boundaries Catherine Creek Mouth to Union Dam Grande Ronde River Wallowa R to Five Points Cr State Ditch Mouth to Headwaters Bacteria Table 6. Segments on the 1998 § 303( d) List for Bacteria Waterbody Name Boundaries Grande Ronde River Wallowa R to Five Points Cr Dissolved Oxygen ( DO)

Table 7. Segments on the 1998 § 303( d) List for Dissolved Oxygen ( DO) Waterbody Name Boundaries Catherine Creek Mouth to Union Dam Grande Ronde River Wallowa R to Five Points Cr Flow Modification Table 8. Segments on the 1998 § 303( d) List for Flow Modification Waterbody Name Boundaries Catherine Creek Mouth to Union Dam Grande Ronde River Wallowa R to Five Points Cr State Ditch Mouth to Headwaters Habitat Modification Table 9. Segments on the 1998 § 303( d) List for Habitat Modification Waterbody Name Boundaries Catherine Creek Mouth to Union Dam Chicken Creek Mouth to West Chicken Creek Dark Canyon Creek Mouth to Headwaters Fly Creek Mouth to Umapine Creek Grande Ronde River Wallowa R to Five Points Cr Grande Ronde River Five Points Cr to Tanner Gulch Grande Ronde River Tanner Gulch to Headwaters Jordan Creek Mouth to National Forest Boundary Limber Jim Creek Mouth to North Fork Little Fly Creek Mouth to Headwater Little Lookingglass Creek Mouth to Headwaters Lookingglass Creek Mouth to Headwaters McCoy Creek Mouth to Headwaters McIntyre Creek Mouth to Headwaters Meadow Creek Mouth to Headwaters Rock Creek Mouth to Headwaters Sheep Creek Mouth to Warm Mineral Springs Sheep Creek Warm Mineral Springs to Headwaters State Ditch Mouth to Headwaters UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 13 APRIL, 2000 Nutrients Table 10. Segments on the 1998 § 303( d) List for Nutrients Waterbody Name Boundaries Catherine Creek Mouth to Union Dam Grande Ronde River Wallowa R to Five Points Cr State Ditch Mouth to Headwaters pH Table 11. Segments on the 1998 § 303( d) List for pH Waterbody Name Boundaries Catherine Creek Mouth to Union Dam Grande Ronde River Five Points Cr to Tanner Gulch Grande Ronde River Wallowa R to Five Points Cr Meadow Creek Mouth to Headwaters State Ditch Mouth to Headwaters Sedimentation Table 12. Segments on the 1998 § 303( d) List for Sedimentation Waterbody Name Boundaries Beaver Creek Mouth to La Grande Reservoir Catherine Creek, North Fork Mouth to Middle Fork Catherine Creek, South Fork Mouth to South Catherine Ditch Diversion Chicken Creek Mouth to West Chicken Creek Clear Creek Mouth to Headwaters Dark Canyon Creek Mouth to Headwaters Fly Creek Mouth to Umapine Creek Grande Ronde River Wallowa R to Five Points Cr Grande Ronde River Five Points Cr to Tanner Gulch Grande Ronde River Tanner Gulch to Headwaters Jordan Creek Mouth to National Forest Boundary Limber Jim Creek Mouth to North Fork Little Catherine Creek Mouth to Headwaters Little Fly Creek Mouth to Headwater Lookingglass Creek Mouth to Headwaters Lookout Creek Mouth to Forest Boundary at Section 35 McCoy Creek Mouth to Headwaters McIntyre Creek Mouth to Headwaters Meadow Creek Mouth to Headwaters Mottet Creek Mouth to Headwaters Sheep Creek Mouth to Warm Mineral Springs Sheep Creek Warm Mineral Springs to Headwaters UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 14 APRIL, 2000 Image 4. Segments on the 1998 § 303( d) List for Aquatic Weeds or Algae Image 5. Segments on the 1998 § 303( d) List for Bacteria Image 6. Segments on the 1998 § 303( d) List for Dissolved Oxygen ( DO) Image 7. Segments on the 1998 § 303( d) List for Flow Modification UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 15 APRIL, 2000 Image 8. Segments on the 1998 § 303( d) List for Habitat Modification Image 9. Segments on the 1998 § 303( d) List for Nutrients Image 10. Segments on the 1998 § 303( d) List for pH Image 11. Segments on the 1998 § 303( d) List for Sedimentation UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 16 APRIL, 2000 Total Maximum Daily Loads ( TMDLs)

Temperature Pollutant Identification Human caused increases solar radiation loading, and warm water discharge to surface waters.

With a few exceptions, such as in cases where violations are due to natural causes, the State must establish a Total Maximum Daily Load or TMDL for any waterbody designated on the 303( d) list as violating water quality standards. A TMDL is the total amount of a pollutant ( from all sources) that can enter a specific waterbody without violating the water quality standards Water temperature change is an expression of heat energy exchange per unit volume:

Volume Energy Heat e Temperatur       .

Anthropogenic increase in heat energy is derived from solar radiation as increased levels of sunlight reach the stream surface and raise water temperature. The pollutants targeted in this TMDL are ( 1) human caused increases in solar radiation loading to the stream network and ( 2) warm water point source discharges.

Existing Sources  CWA § 303( d)( 1)

Non Point Sources Elevated summertime stream temperatures attributed to sources in the Upper Grande Ronde River sub basin result primarily from riparian vegetation disturbance. Reduction in stream surface shading ( via decreased riparian vegetation height, width and/ or density and increased channel width) increases the amount of solar radiation reaching the stream surface. Non point source contributions to pollutant loading are discussed in detail within Appendix A.

Riparian vegetation, stream morphology, hydrology, climate, and geographic location influence stream temperature. While climate and geographic location are outside of human control, riparian condition, channel morphology and hydrology are affected by land use activities. Specifically, the elevated summertime stream temperatures attributed to anthropogenic sources in the Upper Grande Ronde sub basin result from the following:

1. Riparian vegetation disturbance reduces stream surface shading via decreased riparian vegetation height, width and/ or density, thus increasing the amount of solar radiation reaching the stream surface,

2. Channel widening ( increased width to depth ratios) increases the stream surface area exposed to energy processes, namely solar radiation,

3. Reduced summertime saturated riparian soils that reduce the overall watershed ability to capture and slowly release stored water, and 4. Reduced summertime base flows may result from instream withdrawals.

Human activities that contribute to the factors that degrade water quality conditions ( listed above # 1 to # 4) in the Upper Grande Ronde sub basin include timber harvest, as well as road, agriculture and rural and urban residential related riparian disturbances. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 17 APRIL, 2000 Point Sources Three NPDES permitted facilities discharge surface water to the Grande Ronde River and tributaries during the critical summertime temperature period.

The locations of the NPDES cooling water and general NPDES permitted discharge points are mapped in Figure 2. There are five permitted facilities within the Upper Grande Ronde subbasin three of which discharge during critical summertime periods. Facilities that discharge are listed in Table 13. Discharge temperatures are as high as 73oF. Discharge rates are generally very low.

Figure 2. NPDES Permitted Point Sources # S # S # S # S % U NPDES Permit General Permit Table 13. NPDES Permitted Facilities Facility Name City Receiving Water River Mile Permit Type Ave. August Temp. ( oF)

Elgin STP Elgin Grande Ronde R. 198.0 NPDES *

La Grande STP La Grande Grande Ronde R. 158.0 NPDES 73.2 Union STP Union Catherine Cr. 18.0 NPDES No Data Boise Cascade  Elgin Complex Elgin Phillips Cr. 1.0 NPDES *

Island City Particleboard Island City Grande Ronde R. 158.5 GEN01 No Data * Currently does not discharge during critical summertime period. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 18 APRIL, 2000 Seasonal Variation  CWA 303( d)( 1)

Critical temperature period spans June, July, August, September and October.

Section 303( d)( 1) requires this TMDL to be " established at a level necessary to implement the applicable water quality standard with seasonal variations." Both stream temperature and flow vary seasonally from year to year. Water temperatures are coolest in winter and early spring months. Stream temperatures exceed State water quality standards in summer and early fall months ( June, July, August, September and October) ( Figure 3). Warmest stream temperatures correspond to prolonged solar radiation exposure, warm air temperature, low flow conditions and decreased groundwater contribution. These conditions occur during summer and early fall. The analysis presented in this TMDL is concerned with summertime periods in which stream temperatures are most critical.

Figure 3. Critical Period Summertime 7 Day Temperature Statistic ( ODEQ data, 1999)

45 50 55 60 65 70 75 80 85 21 Jul 99 26 Jul 99 31 Jul 99 05 Aug 99 10 Aug 99 15 Aug 99 20 Aug 99 25 Aug 99 30 Aug 99 04 Sep 99 09 Sep 99 7 Day Temperature Statistic ( oF) Above Wallow R Confluence At Pierce Lane Upstream Meadow Creek Downstream Vey Meadows Upstream Clear Creek Loading Capacities  40 CFR 130.2( f)

The Water Quality Standard mandates a Loading Capacity based on the condition that meets the no measurable surface water temperature increase resulting from anthropogenic activities. This condition is termed Site Potential and is achieved when ( 1) non point source solar radiation loading is representative of a riparian vegetation condition without human disturbance and ( 2) point source discharges cause no measurable increases in surface waters.

The loading capacity provides a reference for calculating the amount of pollutant reduction needed to bring water into compliance with standards. EPA's current regulation defines loading capacity as " the greatest amount of loading that a water can receive without violating water quality standards." ( 40 CFR § 130.2( f)). UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 19 APRIL, 2000   The water quality standard as identified states that no measurable surface water temperature increase resulting from anthropogenic activities is allowed in the Grande Ronde River and tributaries ( OAR 340 41 722( 2)( b)( A)).

  The pollutants as identified are human increases in solar radiation loading ( non point sources) and warm water discharge ( point sources).

Loading capacities in the Upper Grande Ronde sub basin consist of ( 1) solar radiation loading profiles for the mainstem Grande Ronde River ( expressed as Langleys per day) based on potential near stream vegetation characteristics without anthropogenic disturbance and ( 2) NPDES permitted point source effluent discharge temperature limits. Appendix A describes the modeling results that lead to the loading capacities.

Under the current regulatory framework for development of TMDLs, identification of the loading capacity is an important first step. The loading capacity provides a reference for calculating the amount of pollutant reduction needed to bring water into compliance with standards. Figure 4 contrasts the longitudinal profile of the current radiant energy load with the longitudinal profile of the site potential radiant energy load. The site potential radiant energy load is the loading capacity.

Non Point Sources Analysis/ simulation of heat transfer processes indicate that water temperatures increase above natural daily fluctuations when the heat load from solar radiation is above those allowed by site potential riparian vegetation conditions. Further, peer reviewed stream temperature research specifically pertaining to Grande Ronde River temperature has implicated solar radiation loading as the primary source of pollutant delivery ( Bohle, 1994 and Chen, 1996).

Figure 4. Loading Capacity for Non Point Sources  Solar Radiation Load2 Forest Land Agriculture Land Mixed Land City Elgin Vey Meadows La Grande WWTP State Ditch 0 50 100 150 200 250 300 350 400 450 500 550 600 650 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 Longitudinal Distance from Mouth ( Miles) Radiant Energy Loading ( ly/ day) Site Potential Current Condition 3 Mile Average 3 Mile Average 2 See Appendix A for information regarding derivation of loading capacities and Site Potential. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 20 APRIL, 2000 Point Sources System potential temperatures during the critical condition in August result when the non point source loading capacity is achieved throughout the Upper Grande Ronde sub basin. These system potential temperatures were developed using computer modeling ( see Appendix A) and used to assign the wasteload allocations to the point sources. System potential temperatures and waste load allocations were derived by DEQ for all point sources.

Table 14. Loading Capacity for Point Sources ( NPDES Permitted Facilities)

Facility Name, City Receiving Water River Mile Current Condition August Dishcharge Temp. ( oF) Wasteload Allocation Max. Dishcarge Temp. ( oF) Percent Reduction Elgin STP, Elgin Grande Ronde R. 198.0 * 65.7 *

La Grande STP, La Grande Grande Ronde R. 158.0 73.2 68.0 7.6%

Union STP, Union Catherine Cr. 18.0 No Data 64.0 Boise Cascade  Elgin Complex, Elgin Phillips Cr. 1.0 * 64.0 *

Island City Particleboard, Island City Grande Ronde R. 158.5 No Data 67.5 * Currently does not discharge during critical period.

Load Allocations/ Wasteload Allocations   40 CFR 130.2( g), 40 CFR 130.2( h)

Load Allocations ( Non Point Sources)  Since the Loading Capacity targets system potential ( i. e. no measurable temperature increases from anthropogenic sources), 100% of the Loading Capacity is allocated to natural sources.

Wasteload Allocations ( Point Sources)  Surface water discharges into Grande Ronde River sub basin receiving waters must not exceed the system potential temperatures listed in Table 15.

By definition, TMDLs are the sum of the allocations [ 40 CFR 130.2( i)]. Allocations are defined as the portion of a receiving water loading capacity that is allocated to point or non point sources and natural background. EPA's current regulation defines loading capacity as " the greatest amount of loading that a water can receive without violating water quality standards." ( 40 CFR § 130.2( f)) Please recall that unless specifically allowed under a Department approved surface water temperature management plan as required under ( OAR 340 041 0026( 3)( a)( D)), no measurable surface water temperature increase resulting from anthropogenic activities is allowed in Oregon waters determined out of compliance with the temperature standard.

A Load Allocation ( LA) is the amount of pollutant that non point sources can contribute to the stream without exceeding state water quality standards. A Waste Load Allocation ( WLA) is the amount of pollutant that a point source can contribute to the stream without violating water quality criteria. Table 15 lists load allocations and wasteload allocations for the Upper Grande Ronde sub basin according to land use. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 21 APRIL, 2000 Table 15. Allocations Load Allocations ( Non point Sources)

Non Point Source Load Allocation ( Distributed Radiant Energy Load Capacity)

Natural Sources 100%

Agriculture 0%

Forestry 0%

Urban 0%

Future Sources 0%

Waste Load Allocations ( Non point Sources)

Point Source Waste Load Allocation ( Maximum Discharge Temperature)

All Point Sources No measurable increase over site potential water temperatures during the critical temperature period ( June to October). Table 15 lists specific waste load allocations for each NPDES permitted facility Surrogate Measures  40 CFR 130.2( i)

The Upper Grande Ronde sub basin TMDL incorporates measures other than " daily loads" to fulfill requirements of § 303( d). Although a loading capacity for heat energy is derived [ e. g. Langleys per day], it is of limited value in guiding management activities needed to solve identified water quality problems. In addition to heat energy loads, the Upper Grande Ronde subbasin TMDL allocates " other appropriate measures" ( or surrogates measures) as provided under EPA regulations [ 40 CFR 130.2( i)].

The Report of Federal Advisory Committee on the Total Maximum Daily Load ( TMDL) Program" ( FACA Report, July 1998) offers a discussion on the use of surrogate measures for TMDL development. The FACA Report indicates:

" When the impairment is tied to a pollutant for which a numeric criterion is not possible, or where the impairment is identified but cannot be attributed to a single traditional " pollutant," the state should try to identify another ( surrogate) environmental indicator that can be used to develop a quantified TMDL, using numeric analytical techniques where they are available, and best professional judgment ( BPJ) where they are not. The criterion must be designed to meet water quality standards, including the waterbody's designated uses. The use of BPJ does not imply lack of rigor; it should make use of the " best" scientific information available, and should be conducted by " professionals." When BPJ is used, care should be taken to document all assumptions, and BPJ based decisions should be clearly explained to the public at the earliest possible stage.

If they are used, surrogate environmental indicators should be clearly related to the water quality standard that the TMDL is designed to achieve. Use of a surrogate environmental parameter should require additional post implementation verification that attainment of the surrogate parameter results in elimination of the impairment. If not, a procedure should be in place to modify the surrogate parameter or to select a different or additional surrogate parameter and to impose additional remedial measures to eliminate the impairment." UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 22 APRIL, 2000 As mentioned above, a loading capacity of Langleys per day is not very useful in guiding nonpoint source management practices. Percent effective shade is a surrogate measure that can be calculated directly from the loading capacity. Additionally, percent effective shade is simple to quantify in the field or through mathematical calculations. Figure 5 displays the percent effective shade values that correspond to the current condition and the loading capacity ( i. e., site potential).

Figure 5. Percent Effective Shade Surrogate Measures3 Forest Land Agriculture Land Mixed Land City Elgin Vey Meadows La Grande WWTP State Ditch 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 Longitudinal Distance from Mouth ( Miles) Percent Effective Shade Site Potential Current Condition 3 Mile Average 3 Mile Average As discussed, water temperature warms as a result of increased solar radiation loads. A loading capacity for heat energy ( i. e., incoming solar radiation) can be used to define a reduction target that forms the basis for identifying a surrogate. The specific surrogate used is percent effective shade ( expressed as the percent reduction in potential solar radiation load delivered to the water surface). The solar radiation loading capacity is translated directly ( linearly) by effective solar loading. Decreased effective shade levels result from the lack of adequate riparian vegetation available to reduce sunlight ( i. e., incoming solar radiation). The definition of effective shade allows direct measurement of the solar loading capacity.

Because factors that affect water temperature are interrelated, the surrogate measure ( percent effective shade) relies on restoring/ protecting riparian vegetation to increase stream surface shade levels, reduce stream bank erosion, and stabilize channels. Likewise, narrower channels still require riparian vegetation to provide channel stability and shade, thus reducing heat loads ( unless confined by canyon walls or shaded by 3 See Appendix A for information regarding derivation of effective shade values. rise above natural conditions as a result of increased 1. WATER  Solar Radiation  due to reduced Effective Shade  UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 23 APRIL, 2000 topography). Effective shade screens the water's surface from direct rays of the sun. Highly shaded streams often experience cooler stream temperatures due to reduced input of solar energy ( Brown 1969, Beschta et al 1987, Holaday 1992, Li et al 1994).

Over the years, the term shade has been used in several contexts, including its components such as shade angle or shade density. For purposes of this TMDL, shade is defined as the percent reduction of potential solar radiation load delivered to the water surface. Thus, the role of effective shade in this TMDL is to prevent or reduce heating by solar radiation and serve as a linear translator to the solar loading capacities.

Site potential effective shade and solar radiation loading were simulated for various channel widths and channel aspects for different physiographic units. Site potential vegetation is assumed to correlate to the late seral/ staged indigenous riparian vegetation communities detailed in Appendix A. Potential effective shade and daily solar radiation loading for all channel width and stream orientation combinations were calculated based on these late seral/ staged indigenous riparian vegetation communities. Figures 7, 8, 9, and 10 illustrate the simulated percent effective shade and solar radiation loading that potentially may occur in the Upper Grande Ronde subbasin The effective shade curves are useful for determining the potential effective shade at a given channel width and channel aspect for each physiographic unit.

Surrogate Measure # 1: Along the Grande Ronde mainstem attain site potential effective shade levels specified in Figure 5 between Tanner Gulch ( i. e., Headwaters) and the Wallowa River confluence.

Surrogate Measure # 2: Along tributaries attain site potential effective shade levels provided in Figures 7, 8, 9, and 10 for the appropriate physiographic unit ( listed in Figure 6). Shade curves are provided.

Figure 6. Physiographic Units of the Upper Grande Ronde Sub Basin Blue Mountains Basin Continental Zone Mesic Forest Zone 1 Mesic Forest Zone 2 Upper Grande Ronde Subbasin Physiographic Units:

Grande Ronde River UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 24 APRIL, 2000 Figure 7. Continental Zone/ Blue Mountain Basin Zone Effective Shade Curves 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% 2 8 14 20 26 32 38 44 50 56 62 68 74 80 86 92 98 Channel Width ( feet) Effective Shade (%) 0.0 60.6 121.3 181.9 242.5 303.2 363.8 424.4 485.0 545.7 606.3 6.6 26.2 45.9 65.6 85.3 105.0 124.7 144.4 164.0 183.7 203.4 223.1 242.8 262.5 282.2 301.8 321.5 Channel Width ( meters)

Solar Radiation Load ( ly day 1) Average 0 or 180 degrees from North 45, 135, 225 or 315 degrees from North 90 or 270 degrees from North Figure 8. Mesic Forest Zone 1 ( Below 4,800 Feet) Effective Shade Curves 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% 2 8 14 20 26 32 38 44 50 56 62 68 74 80 86 92 98 Channel Width ( feet) Effective Shade (%) 0.0 60.6 121.3 181.9 242.5 303.2 363.8 424.4 485.0 545.7 606.3 6.6 26.2 45.9 65.6 85.3 105.0 124.7 144.4 164.0 183.7 203.4 223.1 242.8 262.5 282.2 301.8 321.5 Channel Width ( meters)

Solar Radiation Load ( ly day 1) Average 0 or 180 degrees from North 45, 135, 225 or 315 degrees from North 90 or 270 degrees from North UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 25 APRIL, 2000 Figure 9. Mesic Forest Zone 1 ( Above 4,800 Feet) Effective Shade Curves 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% 2 8 14 20 26 32 38 44 50 56 62 68 74 80 86 92 98 Channel Width ( feet) Effective Shade (%) 0.0 60.6 121.3 181.9 242.5 303.2 363.8 424.4 485.0 545.7 606.3 6.6 26.2 45.9 65.6 85.3 105.0 124.7 144.4 164.0 183.7 203.4 223.1 242.8 262.5 282.2 301.8 321.5 Channel Width ( meters)

Solar Radiation Load ( ly day 1) Average 0 or 180 degrees from North 45, 135, 225 or 315 degrees from North 90 or 270 degrees from North Figure 10. Mesic Forest Zone 2 ( Below 4,800 Feet) Effective Shade Curves 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% 2 8 14 20 26 32 38 44 50 56 62 68 74 80 86 92 98 Channel Width ( feet) Effective Shade (%) 0.0 60.6 121.3 181.9 242.5 303.2 363.8 424.4 485.0 545.7 606.3 6.6 26.2 45.9 65.6 85.3 105.0 124.7 144.4 164.0 183.7 203.4 223.1 242.8 262.5 282.2 301.8 321.5 Channel Width ( meters)

Solar Radiation Load ( ly day 1) Average 0 or 180 degrees from North 45, 135, 225 or 315 degrees from North 90 or 270 degrees from North UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 26 APRIL, 2000 Surrogate Measure # 3: Grande Ronde mainstem channel widths should be reduced to values listed in Table 16 when exceeding these values.

Table 16. Grande Ronde River Channel Width Reductions Grande Ronde Mainstem Reaches Maximum Channel Channel Width Tanner Gulch to Sheep Cr. Confluence 65 feet Sheep Cr. to Fly Cr. Confluence 82 feet Fly Cr. to Indian Cr. Confluence 98 feet Indian Cr. to Lookingglass Cr. Confluence 115 feet Lookingglass Cr. to Wallowa R. Confluence 131 feet Surrogate Measure # 4: Increase sinuosity in unconfined channels until either sinuosity equals 1.7 ( i. e., stream length/ valley length) or wetted width to depth ratio is 20 or less.

Table 17. Grande Ronde River Unconfined Channels ( McIntosh ( 1992) Grande Ronde Mainstem Reaches Distance from Mouth ( miles) Vey Meadow 169.2 to 163.8 Upstream Meadow Cr. 154.0 to 150.9 Downstream Beaver Cr. 149.3 to 146.7 Upstream Jordan Cr. 144.8 to 142.4 Downstream Jordan Cr. 140.6 to 140.0 Upstream Five Points Cr. 138.3 to 136.5 Grande Ronde Valley 130.8 to 104.4 Lower Valley 102.6 to 95.1 Surrogate Measure # 5: Where width to depth ratios are greater than 30, decrease wetted widths until width to depth ratios equal 30 or less.

Surrogate Measure # 6: Where feasible, maintain/ increase instream flows during the critical temperature periods ( July to September).

Surrogate Measures # 1 and # 2 primary and the main measure achieving the temperature standard. Surrogate Measures # 3, # 4, and # 5 are secondary and should only be applied when active channel restoration is occurring.

Margins of Safety  CWA § 303( d)( 1)

The Clean Water Act requires that each TMDL be established with a margin of safety ( MOS). The statutory requirement that TMDLs incorporate a margin of safety is intended to account for uncertainty in available data or in the actual effect controls will have on loading reductions and receiving water quality. A margin of safety is expressed as unallocated assimilative capacity or conservative analytical assumptions used in establishing the TMDL ( e. g., derivation of numeric targets, modeling assumptions or effectiveness of proposed management actions).

The margin of safety may be implicit, as in conservative assumptions used in calculating the loading capacity, WLAs, and LAs. The margin of safety may also be explicitly stated as an added, separate quantity in the TMDL calculation. In any case, assumptions should be stated and the basis behind the margin of safety documented. The margin of safety is not meant to compensate for a failure to consider known sources. Table 18 presents six approaches for incorporating a margin of safety into TMDLs. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 27 APRIL, 2000 Table 18. Approaches for Incorporating a Margin of Safety into a TMDL Type of Margin of Safety Available Approaches Explicit 1. Set numeric targets at more conservative levels than analytical results indicate. 2. Add a safety factor to pollutant loading estimates. 3. Do not allocate a portion of available loading capacity; reserve for MOS.

Implicit 4. Conservative assumptions in derivation of numeric targets. 5. Conservative assumptions when developing numeric model applications. 6. Conservative assumptions when analyzing prospective feasibility of practices and restoration activities.

The following factors may be considered in evaluating and deriving an appropriate margin of safety:

 The analysis and techniques used in evaluating the components of the TMDL process and deriving an allocation scheme.

 Characterization and estimates of source loading ( e. g., confidence regarding data limitation, analysis limitation or assumptions).

 Analysis of relationships between the source loading and instream impact.

 Prediction of response of receiving waters under various allocation scenarios ( e. g., the predictive capability of the analysis, simplifications in the selected techniques).

 The implications of the MOS on the overall load reductions identified in terms of reduction feasibility and implementation time frames.

A TMDL and associated margin of safety ( MOS), which results in an overall allocation, represents the best estimate of how standards can be achieved. The selection of the MOS should clarify the implications for monitoring and implementation planning in refining the estimate if necessary ( adaptive management). The TMDL process accommodates the ability to track and ultimately refine assumptions within the TMDL implementation planning component.

Implicit Margins of Safety Description of the margin of safety for the Upper Grande Ronde sub basin Temperature TMDL begins with a statement of assumptions. A margin of safety has been incorporated into the temperature assessment methodology. Conservative estimates for groundwater inflow and wind speed were used in the stream temperature simulations. Specifically, unless measured, groundwater inflow was assumed to be zero. Wind speed was also assumed to be at the lower end of recorded levels for the day of sampling. Recall that groundwater directly cools stream temperatures via mass transfer/ mixing. Wind speed is a controlling factor for evaporation, a cooling heat energy process. Further, cooler microclimates and channel morphology changes associated with late seral conifer riparian zones were not accounted for in the simulation methodology.

Calculating a numeric margin of safety is not easily performed with the methodology presented in this document. In fact, the basis for the loading capacities and allocations is the definition of site potential conditions. It is illogical to presume that anything more than site potential riparian conditions are possible, feasible or reasonable.

Adaptive Management The Upper Grande Ronde sub basin Temperature TMDL is intended to be adaptive in management implementation, allowing for future changes in loading capacities and surrogate UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 28 APRIL, 2000 measures ( load allocations) in the event that scientifically valid reasons demand alterations. It is important to recognize the continual study and progression of understanding of water quality parameter is addressed in this TMDL/ WQMP ( stream temperature). In the event that data collected in the future show that changes are warranted in the Upper Grande Ronde sub basin Temperature TMDL or WQMP, these changes will be made by Oregon DEQ.

Water Quality Standard Attainment Analysis  CWA § 303( d)( 1)

Maximum daily temperatures ( displayed in Figure 11) represent the system potential when no measurable surface water temperature increase resulting from anthropogenic activities is allowed.

Simulations were performed to calculate the temperatures that result with the allocated measures that form the basis for the factors that represent the system potential condition with no measurable surface water temperature increase resulting from anthropogenic activities. The resulting simulated temperatures represent attainment of system potential, and therefore, attainment of the temperature standard.

Approximately 95 river miles of the Grande Ronde River were analyzed and simulated during the critical period ( August 20, 1999). Figure 11 compares the current Grande Ronde River temperatures with the river temperatures that result at site potential conditions. The site potential river temperatures directly correlate to the loading capacity ( i. e., they are the temperatures that result when the loading capacity is met).

Generally speaking, the Grande Ronde River currently experiences critical condition maximum daily temperatures in the mid 70oF to mid 80oF range. Under the allocated system potential condition, maximum daily temperatures shifted to the mid 50oF to upper 60oF range. In 1999, 92% of the stream network had critical condition maximum daily temperatures greater than 64oF. Under the system potential, 48% of the stream network experience maximum daily temperatures greater than 64oF. The most noticeable difference between the current and allocated conditions is the complete removal of incipient lethal temperatures ( greater than 70oF). Under the allocated condition, 97% of the Grande Ronde River daily maximum temperature are below 68oF. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 29 APRIL, 2000 Figure 11. Grande Ronde River Temperatures at Current Conditions and Site Potential Forest Land Agriculture Land Mixed Land City Vey Meadows La Grande WWTP State Ditch Elgin 55 60 65 70 75 80 85 90 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 Longitudinal Distance from Mouth ( Miles) Water Temperature ( oF)  8/ 20/ 99 Site Potential + Maximum Potential Flow Site Potential Current Conditions Figure 12. Percent of River Temperatures Below Specified Temperature 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Current Conditions Bankfull Width Reductions Sinuosity/ Width to Depth Restoration Tributaries 64* F Maximum Potential Vegetation Potentail Vegation and Tributaries 64* F Maximum Potential Vegetation,

Tributaries 64* F Maximum, and Bankfull Width Reductions Site Potential Site Potential +

Maximum Potential Flow Proportion under 68* F Proportion under 64* F Proportion under 60* F UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 30 APRIL, 2000 Dissolved Oxygen and pH The Grande Ronde River, Catherine Creek, Meadow Creek, and the State Ditch experience dissolved oxygen and pH water quality standards violations related to excessive periphyton growth. Excessive growth is due to a number of factors including elevated nutrient concentrations, high water temperatures, excessive solar radiation, high width to depth ratios, and inadequate stream flow rates. Excessive periphyton activity causes large diel dissolved oxygen and pH fluctuations which result in dissolved oxygen standards violations at night and pH standards violations during the day.

Periphyton impact pH and dissolved oxygen levels as they grow and respire ( see Appendix B). During the day, when algae perform photosynthesis and grow, carbon dioxide is consumed and oxygen produced. At night respiration dominates and carbon dioxide is produced and oxygen consumed. Carbon dioxide affects pH because it combines with water to form carbonic acid. Therefore, during the day as algae consume carbon dioxide the pH increases, while at night as algae produce carbon dioxide the pH declines. Through this process algae can cause large diel fluctuations in dissolved oxygen and pH which may result in water quality standards violations. Low oxygen levels can suffocate aquatic organisms, while excessively high or low pH levels can cause toxic effects ranging from growth and reproduction limitations to death.

In order to address dissolved oxygen and pH standards violations and concerns regarding excessive nutrient concentrations and quantities of aquatic weeds and algae, Load Allocations are provided below for both nitrogen and phosphorus. The methodology employed to derive the allocations is described in detail in Appendix B.

Since not all nitrogen and phosphorus in a stream is available for algal growth, Nutrient Load Allocations are provided in terms of the reactive inorganic forms. For nitrogen this is the dissolved inorganic nitrogen ( DIN), which includes ammonia, nitrite and nitrate. For phosphorus it is the dissolved orthophosphate ( equivalent to soluble reactive phosphorus or SRP).

Nutrient Load Allocations have been provided for two sets of conditions:

( 1) existing riparian conditions with associated high stream temperatures and solar radiation, and ( 2) site potential riparian conditions of reduced stream temperatures and solar radiation.

Load allocations for both sets of conditions will be adequate to meet all applicable pH and dissolved oxygen standards and address concerns regarding excessive nutrient concentrations and quantities of aquatic weeds and algae. The first set of load allocations would apply if no efforts were made to control sources of stream heating. As described below, large nutrient load reductions will be needed if solar radiation loads and temperatures are not reduced. However, since the percent shade allocations proposed to meet the temperature standard will result in significant solar radiation and temperature reductions, the second set of nutrient load allocations is the nutrient TMDL for the system. As described below, nutrient load reductions needed to meet pH and dissolved oxygen standards for this second set of conditions are considerably more modest than for the first. However, if sufficient steps are not taken to reduce temperatures in the system, then the first set of load reductions will be needed for pH and dissolved oxygen standards to be met.

Sources of Nutrients in the Grande Ronde Sub Basin Nutrients enter the system from both point and non point sources, with the non point nutrient loads being functions of land use. Above Grande Ronde River MP 160, the basin is comprised mostly of forested public lands. In the Grande Ronde valley below MP 160, the basin is comprised mostly of privately owned agricultural and urban lands. While the valley constitutes less than seven percent of the land in the basin, it contains most of the human population ( more than 60 percent) and the vast majority of the crop agriculture in the basin. Forestry and grazing UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 31 APRIL, 2000 land uses predominate above the valley, while agriculture, urban and grazing land uses predominate within the valley. Significant point sources in the sub basin include the La Grande wastewater treatment plant, which discharges to the Grande Ronde River, and the City of Union WWTP, which discharges to Catherine Creek. The La Grande WWTP serves a population of approximately 12,900, including the cities of La Grande and Island City. It is the only point source in the sub basin classified as a " major" facility. The Union WWTP serves a population 1,915 and is classified as a " minor" facility. The City of Elgin has a wastewater treatment plant but it does not discharge during summer low flow months. There are three additional incorporated communities within the valley: Cove ( pop. 545), Imbler ( pop. 311), and Summerville ( pop. 145). None of these discharge wastewater during summer low flow months.

Figure 13 overlays land use information and modeling segments. As shown, reaches 4, 5 and 6 ( MP 166.9 and above) are mixed forest and rangeland. Therefore, all load reductions for these reaches will be allocated to these uses. Reach 7 ( MP 166.9 160.1) receives nutrient loads which enter from upstream that are associated with forest and range land uses and loads which enter within the reach that are associated with urban and agricultural land uses. Reach 8 ( 160.1 153.8) receives non point source ( NPS) loads which enter from upstream that are associated with all of the above and loads which enter within the reach that are primarily associated with agricultural land uses. Reach 9 ( 153.8 State Ditch) receives non point source loads from all the above, plus the point source load from the La Grande WWTP.

Figure 13. Land Use Relative to Modeled Grande Ronde Reaches Nutrient Loading Capacities and Load Allocations   Current Riparian Conditions The Grande Ronde River is listed for pH and dissolved oxygen ( DO) due to excessive periphyton activity. The allocations presented below are designed to achieve pH levels within the range 6.5 to 8.7 and dissolved oxygen concentrations greater than 6.5 mg/ L. The pH target of 8.7 is more UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 32 APRIL, 2000 stringent than the maximum pH of 9.0 allowed by the standard, thus providing for a margin of safety. The DO target of 6.5 mg/ L is more stringent than the minimum of 6.0 mg/ L allowed by the standard. This also provides a margin of safety. Water quality modeling using the periphyton model PCM ( Appendix B) indicates that the allocations are pH controlled ( i. e., the pH standard is more difficult to achieve in the Grande Ronde River than the DO standard). Because of this, allocations which result in the pH target of 8.7 being met are calculated by the model to result in DO concentrations significantly greater than 6.5 mg/ L. Such allocations will result in the 30 day average standard of 8.0 mg/ L being met in all reaches. Nutrient load allocations in terms of percent reductions from current levels are presented in Table 19, along with corresponding loading capacities. Nutrient load allocations apply to non point source ( NPS) pollution loads.

Table 19. Nutrient Allocations for Current Riparian Conditions  Grande Ronde River Loading Capacities ( Water Column Concentrations as Monthly Medians) Reaches Milepoints Nutrient Load Allocations (% Reductions) Dissolved Inorganic Nitrogen µ g/ L, as N Dissolved Orthophosphate µ g/ L, as P MS4 Headwaters   182.0 20% 16 8 MS5 182.0 173.0 50% 15 5 MS6 173.0 166.9 35% 23 7 MS7 166.9 160.1 20% 32 12 MS8 160.1 153.8 60% 26 6 MS9 153.8 State Ditch 60% ( 60% reduction in NPS loads plus summer point source removal) 26 6 State Ditch  Mouth 60% ( 60% reduction in NPS loads plus summer point source removal) 26 6 Table 19 presents nutrient load allocations and loading capacities for both nitrogen and phosphorus. However, only nitrogen concentrations directly impact the pH and dissolved oxygen concentrations calculated by the model. This is because the system is nitrogen limited and since the growth rate limitation due to nutrients in the model is controlled only by the nutrient in lowest supply relative to cellular requirements ( see Appendix B). However, to derive loading capacity concentrations for phosphorus, the same percent reductions required for nitrogen have been applied. This is because the same measures that reduce nitrogen are likely to provide similar reductions in phosphorus. In addition, in low nitrogen, high phosphorus aquatic environments nuisance bluegreen algae ( cyanobacteria) which can fix nitrogen may become established. Therefore, it is important to reduce both nitrogen and phosphorus concentrations.

Note that in some cases the above dissolved orthophosphate loading capacities may be less than natural background levels. However, it is unclear what the natural background concentrations are, since all reaches in the sub basin likely receive some degree of anthropogenic nutrient loading. However, it appears that natural background concentrations for dissolved orthophosphate are on the order of about 10 ug/ L as P. Therefore, dissolved orthophosphate concentrations less than 10 ug/ L as P may not be achievable. Due to uncertainty regarding natural background concentrations, the above loading capacities should be treated only as targets, not standards. Compliance should be based on whether existing standards for dissolved oxygen and pH are achieved, rather than on the above targets for dissolved orthophosphate and DIN. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 33 APRIL, 2000 Catherine Creek is listed for pH and DO due to excessive periphyton activity. Explicit modeling was not performed for Catherine Creek. However, the portion of Catherine Creek located within the Grande Ronde valley was determined to have similar characteristics as the Grande Ronde River within the Grande Ronde valley. Therefore, the nutrient load allocations developed for the Grande Ronde River within this area have been applied to Catherine Creek within the Grande Ronde valley. These are presented in Table 20. Meadow Creek is another stream listed for pH violations on the 1998 § 303( d) list. Meadow Creek is a tributary to the Grande Ronde River, with its confluence at Grande Ronde River MP 180. It has similar characteristics and nutrient loads as the Grande Ronde River in this area. Consequently, the nutrient load allocations that apply to Grande Ronde River MP 180 have been applied to Meadow Creek ( also shown in Table 19).

Table 20. Nutrient Allocations for Current Riparian Conditions  Catherine and Meadow Creeks Loading Capacities ( Water Column Concentrations as Monthly Medians) Reaches Milepoints Nutrient Load Allocations (% Reductions) Dissolved Inorganic Nitrogen µ g/ L as N Dissolved Orthophosphate µ g/ L as P Meadow Creek Mouth to Headwaters 50% 15 5 Catherine Creek Mouth to Union Dam 60% ( 60% reduction in NPS loads plus summer point source removal) 26 6 Nutrient Load Allocations and Loading Capacities   Site Potential Riparian Conditions A scenario was modeled using the site potential vegetative community ( potential natural community). For this site potential condition, the physiographic vegetative community for the Grande Ronde sub Basin ( from Crowe and Clausnitzer, 1997) was used to calculate the late sera/ staged indigenous riparian vegetation communities ( see Appendix A). Modeling was conducted at a climax riparian tree height. Outside of modifying the riparian community composition, the same model assumptions were used for both current condition and site potential modeling scenarios.

Water quality modeling indicates that shade levels produced at site potential conditions will result in significant dissolved oxygen and pH improvements. The modeling indicates that the DO target of 6.5 mg/ L will be met in all reaches without additional nutrient reductions. The pH target of 8.7 will be met in most reaches above MP 160, except for Reach MS5 ( MP 182.0 173.0). The modeling indicated that a 25% nutrient load reduction from current levels is needed in Reach MS5 to meet the pH target. Below MP 160, significant nutrient reductions are required. Nutrient load allocations for the site potential scenario are provided in Table 21. Nutrient load allocations and loading capacities for Meadow Creek and Catherine Creek for site potential riparian vegetation conditions are presented in Table 22. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 34 APRIL, 2000 Table 21. Nutrient Allocations for Site Potential Riparian Conditions  Grande Ronde River Loading Capacities ( Water Column Concentrations as Monthly Medians) Reaches Milepoints Nutrient Load Allocations (% Reductions) Dissolved Inorganic Nitrogen µ g/ L as N Dissolved Orthophosphate µ g/ L as P MS4 Headwaters   182.0 0 20 10 MS5 182.0 173.0 25% 23 7 MS6 173.0 166.9 0% 35 10 MS7 166.9 160.1 0% 40 15 MS8 160.1 153.8 50% 33 7 MS9 153.8 State Ditch 50% ( 50% reduction in NPS loads plus summer point source removal) 33 7 State Ditch   Mouth 50% ( 50% reduction in NPS loads plus summer point source removal) 33 7 Table 22. Nutrient Allocations for Site Potential Riparian Conditions ( Catherine Creek and Meadow Creek)

Loading Capacities ( Water Column Concentrations as Monthly Medians) Reaches Milepoints Nutrient Load Allocations (% Reductions) Dissolved Inorganic Nitrogen µ g/ L as N Dissolved Orthophosphate µ g/ L as P Meadow Creek Mouth to Headwaters 25% 23 7 Catherine Creek Mouth to Union Dam 50% ( 50% reduction in NPS loads plus summer point source removal) 33 7 Wasteload Allocations for Point Sources Permitted point sources in the Grande Ronde River Basin are regulated by either individual or general National Pollutant Discharge Elimination System ( NPDES) permits or by Water Pollution Control Facilities ( WPCF) permits. WPCF permits do not allow direct wastewater discharge to surface waters. The City of La Grande wastewater treatment plant is the only major NPDES permitted point source discharging to surface water in the Grande Ronde Valley. In addition, there are five minor point source permits: the City of Union wastewater treatment plant, Boise Cascade ( 2 plants), Fleetwood Travel Trailers, and Union Pacific Railroad. There are no permitted point sources discharging effluent upstream of the Grande Ronde Valley.

The wastewater treatment plants ( WWTPs) for the cities of La Grande and Union have been shown to be major contributors to nutrient loads in the Grande Ronde River and Catherine Creek, respectively. In the case of the La Grande plant, violations of water quality standards occur upstream of the effluent discharge, but violations are much more severe and frequent downstream of the outfall as a result of the nutrient load contributed by the plant. In the case of Union, violations of standards for dissolved oxygen and pH are generally not seen above the treatment plant discharge. Violations begin to occur immediately below the discharge and continue all the way to the confluence with the Grande Ronde River. The Boise Cascade UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 35 APRIL, 2000 particleboard plant has been shown to be a minor, but not insignificant, contributor of nutrients to the Grande Ronde River.

City of La Grande Wastewater Treatment Plant Upstream of the La Grande Wastewater Treatment Plant, nutrient concentrations in the Grande Ronde River exceed recommended targets for orthophosphate and dissolved inorganic nitrogen. These concentrations are significantly increased by the La Grande discharge. Since target concentrations are already exceeded upstream of the discharge, the river has no capacity to assimilate loads from La Grande and the discharge exacerbates already excessive pH and DO fluctuations and standards violations.

Several options exist for mitigating the impact of the La Grande discharge on the Grande Ronde. One option is setting wasteload allocations equal to the lowest levels achievable by available municipal wastewater treatment technology. Concentrations achievable using advanced treatment are < 1 mg/ L (< 1000 µ g/ L) for orthophosphate and 3 5 mg/ L ( 3000 5000 µ g/ L) for dissolved inorganic nitrogen ( Metcalf & Eddy, 1991). Effluent concentrations of 1.0 mg/ L for orthophosphate and 5 mg/ L for DIN would result in the following in stream concentrations ( for the dry weather effluent flow of 4.2 cfs, the 7Q10 river flow of 14 cfs, and background river concentrations equal to 15 µ g/ L for orthophosphate and 33 µ g/ L for DIN):

Orthophosphate: 242 µ g/ L Dissolved Inorganic Nitrogen: 1,179 µ g/ L Clearly, even with advanced treatment, nutrient concentrations downstream of the discharge would far exceed target concentrations. Even with advanced treatment, nutrient loads due to the La Grande discharge could be 20 45 times greater than background loads.

A second option is to impose limits adequate to insure that the La Grande discharge does not increase nutrient concentrations in the river beyond the target concentrations. Wasteload allocations for this option would be set equal to river target concentrations of < 10 µ g/ L for orthophosphate and 26 33 µ g/ L DIN. Since such stringent limits could not be met using available municipal wastewater treatment technology, this is equivalent to a " no discharge" allocation. This is the most conservative option and is the only option that will insure that nutrient concentrations are not increased by the La Grande discharge and will result in an immediate improvement in downstream pH and dissolved oxygen concentrations.

In the Grande Ronde basin, viable options to river discharge exist for effluent disposal. Non river effluent disposal in this region is very cost competitive with advanced treatment. Therefore, since the no discharge option is cost competitive with advanced treatment and since it will result in the greatest improvement in water quality, no discharge during the critical summer time period is the recommended alternative being pursued by the city.

This no discharge option would remove the effluent during periods of extended low flow when algae are expected to significantly influence water quality. The removal of the point source would not influence the algae growth problems occurring upstream of the discharge nor would it address nutrients which enter the river from non point source contributions either upstream or downstream of the discharge. The no discharge option would, however, eliminate any further exacerbation of algae growth problems resulting from nutrient contributions of the La Grande waste water treatment plant.

In order to determine when the critical, no discharge time period occurs, water quality data was analyzed ( Schnurbusch 1996b, see Appendix). The analysis demonstrates that no discharge should be allowed during the months of July, August, and September. The months of June and October are transitional periods. It has been shown that in June there is a relationship between flow and pH. Standard violations begin to occur in June when the river flow falls below 150  200 UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 36 APRIL, 2000 CFS. Therefore, discharge would need to be discontinued in June when the average daily flow falls below 200 CFS.

During October there is a strong relationship between temperature and pH. Violations of the water quality standard for pH cease when maximum daily stream temperature falls below 15 C. Therefore the wastewater treatment plant would be allowed to resume discharge to the river in October when the maximum daily stream temperature has dropped to the point where it is consistently below 15 C. Alternatively, direct measurement of late afternoon pH could be used as the criteria for resumption of discharge. In October, when the late afternoon pH downstream of the discharge point has reached a level that would provide confidence that no violations of the pH standard would occur, discharge could be resumed. Therefore, it is recommended that discharge not occur in October unless the maximum daily stream temperature is less than 150C or the daily maximum pH is less than 8.7.

This " no discharge" option makes the establishment and adoption of WLA for the La Grande treatment plant irrelevant because the plant will contribute no nutrient load to the river during the critical low flow period.

Ammonia toxicity criteria are also exceeded in the Grande Ronde River during the summer months. This is related to the high pH and high water temperature that occurs in the river during these months. Ammonia toxicity will be eliminated following cessation of summer discharge. However, there is still potential for ammonia toxicity during other months of the year. As a result, the permit limitations for the La Grande wastewater treatment plant must include ammonia limitations that will prevent ammonia toxicity and meet DEQ standards for both chronic and acute toxicity ( Schnurbusch 1996a, see Appendix).

City of Union Wastewater Treatment Plant The City of Union wastewater treatment plant discharges to Catherine Creek and significantly increases in stream nutrient concentrations. The flow in Catherine Creek is greatly influenced by irrigation withdrawals. While minimum ( 7 day average) flows upstream of the irrigation withdrawal have varied from 10  35 cfs since 1930, flows at the Union discharge can be less than 1 cfs. Therefore, even though the Union discharge is only 0.47 cfs, which is small relative to many other treatment plants, it is the dominant source of nutrients to Catherine Creek.

In order to evaluate the impact of the Union discharge on Catherine Creek, a " mixing zone" analysis was performed ( Baumgartner, 1996). The focus of the analysis was the derivation of wasteload allocations that would minimize the impact of the Union discharge on the stream.

Two principle options are available for mitigating the impact of the Union discharge on Catherine Creek. The first option is to allow continued discharge during the summer but with stringent advanced treatment wasteload allocations. The second is no discharge. The mixing zone analysis indicated that the wasteload allocations described in the Table 23 would confine excessive periphyton impacts to a limited area and be sufficient to prevent ammonia toxicity.

Table 23. City of Union  Potential Waste Load Allocations ( WLA) for Dissolved Ortho Phosphate ( d ortho P) and Dissolved Inorganic Nitrogen ( DIN) Upstream Flow d Ortho P d Ortho P WLA DIN DIN WLA Cfs mg/ L as P lbs/ d as P mg/ L as N lbs/ d as N 1 0.27 0.68 1.8 4.6 5 0.94 2.4 6.6 16.9 10 1.79 4.6 12.7 32.2 15 2.64 6.7 18.7 47.6 UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 37 APRIL, 2000 These nutrient limits were estimated using the water quality model QUAL2E ( Baumgartner, 1996). The upstream dissolved orthophosphate concentration was assumed to be 20 µ g/ L, and the dissolved inorganic nitrogen concentration was assumed to be 30 µ g/ L. The in stream concentrations predicted downstream of the discharge were 100 µ g/ L of orthophosphate and 600 µ g/ L of dissolved inorganic nitrogen. Clearly, these nutrient concentrations are far in excess of algae growth requirements and would result in excessive periphyton growth immediately below the discharge. However, these impacts would be limited to a zone which would no longer extend into the area of currently observed highest periphyton growth, since the nutrients are expected to be incorporated into benthic algae prior to reaching this area. However, the analysis did not assess the effects of nutrient recycle. In addition, the effect of changes in production rates and stream flow on uptake rates was not assessed.

These wasteload allocations would be very difficult to meet with available municipal wastewater technology when stream flows are less than 5 cfs. Therefore, for such flows, they are essentially no discharge allocations.

As with La Grande, the no discharge option is cost competitive with the advanced treatment alternative. Therefore, since the no discharge option is cost competitive with advanced treatment and since it will result in the greatest improvement in water quality, no discharge during the critical summer time period is the recommended alternative being pursued by the city.

There is little information available to determine when the summer low flow period occurs. It is reasonable to assume that the change from spring to summer conditions occurs during nearly the same June  July period as the Grande Ronde River. This period would be coincident with the irrigation season, and may be related to irrigation. Although insufficient data is available to clearly define the stream flow below which discharge should cease, it is recommended that no discharge occur in June when the flow is less than 15 cfs and that no discharge occur in July, August, or September. The summer to fall transition is somewhat better defined by the limited October monitoring data. Assuming that available October water quality data is reasonably representative of typical fall conditions, the Union WWTP should be able to discharge at current mass loads in October once stream flow exceeds 15 cfs and maximum daily stream temperature does not exceed 12 ° C. Although little data is available for November, it is reasonable to assume that seasonal conditions are similar to the Grande Ronde and that discharge could occur at current loads without standards violations. The likelihood of standards being met will be improved by the implementation of a summer no discharge period, since there will be less periphyton biomass produced during the summer which will reduce the likelihood of excessive diurnal DO variation in the Fall.

Wasteload Allocations for Minor Permitted Industrial Point Sources In addition to the City of Union wastewater treatment plant, there are four minor industrial point sources in the basin. The only minor industrial source of potential concern is the Boise Cascade particleboard plant in Island City, which discharges to the Grande Ronde River.

Available data on the Boise Cascade Island City particleboard plant's permitted discharge effluent quality is very limited. Sampling performed during the 1993 survey showed that, although the discharge flow rate was low, the effluent contained high concentrations of total phosphorus ( 2.9  5.3 mg/ L) compared to in stream concentrations. Only one sample of the Island City effluent was analyzed for nitrogen. This had an inorganic nitrogen concentration of 0.21 mg/ L and a Kjeldahl nitrogen ( organic + ammonia) concentration of 2.1 mg/ L. The flow rate was estimated to be 0.3 cfs.

Observed nitrogen concentrations in the Grande Ronde River near the outfall varied between 60 and 100 µ g/ L during the summer low flow surveys. These exceed the target for DIN of 33 µ g/ L. If the background DIN concentration equaled 33 µ g/ L, a 0.3 cfs discharge with 0.21 mg/ L DIN would increase the in stream concentration about 3.7 µ g/ L. This is a relatively small increase. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 38 APRIL, 2000 While this increase in DIN would likely increase periphyton growth, it is unlikely that the increased periphyton growth or its impact on pH and DO would be measurable.

For phosphorus, based on an effluent flow rate of 0.3 cfs, an effluent concentration of 5.3 mg/ L, and a river flow rate of 14 cfs, the discharge would increase the in stream total phosphorus concentration over 100 µ g/ L. This is a significant increase. Because phosphorus concentrations in the vicinity of the Boise discharge currently exceed the loading capacity, there currently is no capacity available for assimilating the load. Since the system is generally nitrogen limited in the vicinity of the Boise discharge, it is possible that the facility could discharge some phosphorus without measurably increasing periphyton activity. The in stream dissolved orthophosphate ( as P) concentrations that would result from several potential effluent concentrations are as follows ( assuming an upstream concentration of 10 ug/ L):

Effluent dissolved orthophosphate concentration mg/ L as N Downstream dissolved orthophosphate concentration µ g/ L as P 1.0 30.8 0.5 20.3 0.1 11.9 It is likely that only an effluent dissolved orthophosphate concentration significantly less than 0.5 mg/ L as P would produce no measurable increase in periphyton activity. Such a low effluent concentration would likely be difficult to achieve on a consistent basis using available treatment technology. Unless it were demonstrated that such a low concentration could be consistently met and that it would have no measurable impact on periphyton growth, it is recommended that the facility cease discharge during the critical summer period. This is the alternative being pursued by the facility.

Spawning and Egg Incubation Periods The above allocations were designed to allow pH and DO standards to be met during critical summertime conditions. During fall, winter and spring ( October 1 through June 30), the most stringent beneficial use is salmonid spawning and egg incubation, and the applicable water column standard is 95% of saturation. For a 3000 ft. elevation, which is roughly the average elevation of the reaches modeled, 95% saturation at 10 ° C ( Bull Trout temperature std) is 9.7 mg/ L, at 12.8 ° C ( salmonid spawning temperature std) is 9.1 mg/ L, and at 17.8 ° C ( salmonid rearing std) is 8.1 mg/ L.

The non point source control measures needed to meet the above allocations will apply year round and should result in the 95% of saturation standard being met during all spawning and egg incubation periods. This is because the allocations were designed to meet the stringent pH standard of 8.7. DO is well above the DO standard whenever the pH standard is met. Therefore, the proposed allocation should result in applicable pH and DO standards being met year round.

After flows increase in October, the La Grande and Union WWTPs will be permitted to discharge at their current secondary permit limits through May 31. During this period flow rates are much higher than in the summer, and solar radiation and temperatures much lower. Therefore, periphyton activity is minimal during this period. In addition, dilution is quite high, which results in no significant impacts due to effluent BOD loads. Therefore, standards for pH and DO should be met during this period, even with the La Grande and Union WWTPs discharging at current permit limits.

Margin of Safety   Nutrient TMDLs A margin of safety has been provided for in the load allocations by: UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 39 APRIL, 2000 ( 1) Modeling both DO and pH, rather than taking the traditional approach of simply modeling DO. Since pH was found to control the load allocations, this approach resulted in more stringent load allocations;

( 2) Applying 8.7 as the pH standard rather than 9.0; and ( 3) Ignoring the benefits of width reductions in site potential riparian condition scenarios. Restoring the river to site potential conditions will likely result in reduced bank full and wetted widths, increased depths, increased shade, and reduced temperatures. These improvements will reduce diel pH and DO fluctuations beyond that predicted by modeling for the scenario and will provide additional margin of safety that standards will be met.

The combined margin of safety provided by the above will ensure that the load allocations proposed will result in the attainment of water quality standards for both pH and dissolved oxygen. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 40 APRIL, 2000 Sedimentation Fine sediments can adversely affect fish and other aquatic organisms by: 1) killing salmonids or reducing growth or reducing disease resistance; 2) interfering with the development of eggs and larvae; 3) modifying natural movements and migration of salmonids, and 4) reducing the abundance of food organisms ( Newcombe and McDonald 1991, see Appendix A). Sedimentation of redds has been shown to significantly impair the success of juvenile emergence. Numerous streams in the Upper Grande Ronde subbasin, including all reaches of the Grande Ronde River within the subbasin, are included on the § 303( d) list due to water quality concerns related to excessive sedimentation. Listed streams are presented in Table 13.

In the Grande Ronde River from the Wallowa River confluence ( River Mile 82.2) to the Five Points Creek confluence ( RM 156.7), cobble embeddedness and fine sediment have been identified in the § 303( d) list as limiting factors for salmonid rearing. In addition, fine sediment in the Grande Ronde River mainstem have been identified as being excessive from the Five Points Creek confluence ( RM 156.7) to the Headwaters.

Water Quality Standard Identification Oregon water quality standards related to sedimentation include:

Sedimentation ( OAR 340 41 722( 2)( j)  " The formation of appreciable bottom or sludge deposits or the formation of any organic or inorganic deposits deleterious to fish or other aquatic life or injurious to public health, recreation, or industry shall not be allowed."

Biological criteria ( OAR 340 41 027)  " Waters of the State shall be of sufficient quality to support aquatic species without detrimental changes in the resident biological communities."

Target Identification/ Loading Capacity The Environmental Protection Agency ( EPA) and the State of Oregon do not have numeric water quality standards for streambed fines. However, excessive fine sediment is addressed through application of state narrative criteria. For listing purposes, the PACFISH target of 20% streambed fines was utilized as an indicator of fine sediment impairment to salmonids ( the most sensitive " resident biological community"). Therefore, since a numeric target is needed to evaluate sediment for purposes of this TMDL, the target will be based on percent fine sediment which was used for 303( d) listing. Thus, the loading capacity for sedimentation will be defined as 20 percent streambed area fines. Long term monitoring and the adaptive management nature of this TMDL will be used to evaluate this goal over time.

Loading Capacity Identification of the instream sediment loading capacity is the first step for the development of TMDLs. The loading capacity is defined as the greatest amount of a pollutant that water can receive without exceeding water quality standards. As noted above, an instream streambed fines target of less than 20 percent streambed area fines has been established as an indicator of the amount of sediment loading which the waters in the Upper Grande Ronde sub basin can receive without exceeding the state's narrative sedimentation criteria. Thus, the sediment loading capacity for all streams listed for sedimentation in the Upper Grande Ronde sub basin is 20 percent streambed area fines.

Cobble embeddedness data collected by ocular assessment was also used as part of the § 303( d) listing criteria. The Department is not aware of any other cobble embeddedness data for use in determining the sedimentation TMDL. The focus of this TMDL will be on meeting the percent fines criteria. The assumption is made that reducing fine sediment will result in a corresponding UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 41 APRIL, 2000 reduction in cobble embeddedness. Future monitoring as part of the adaptive management component of this TMDL will help to determine the validity of this assumption.

Load Allocations/ Surrogate Measures A Load Allocation ( LA) is the amount of pollutant that nonpoint sources can contribute to a stream without exceeding state water quality standards. While load allocations are traditionally expressed as " mass per time", the TMDL regulation also provides for the expression of allocations in " other appropriate measures". It is not appropriate for streambed fines to be expressed as a load. Thus, another appropriate measure will be utilized in this TMDL.

As shown in Figure 14, percent streambed fines decreases with the increase in woody riparian vegetation. The observed data also indicate that when an established deciduous/ mixed/ conifer riparian community exists, the loading capacity of 20% streambed fines will be attained. Surrogate measures # 1 and # 2 developed in the temperature TMDL provide for the establishment of an established deciduous/ mixed/ conifer riparian community. Thus, these same surrogate measures can be utilized as load allocations for the sedimentation TMDL.

The load allocations for the mainstem Upper Grand Ronde River and for the tributaries to the Upper Grande Ronde River are those found in the temperature TMDL on page 23. The relationship between sediment and temperature is as follows:

Surrogate Measures # 1 and # 2 in the Temperature TMDL promote riparian conditions that will increase near stream ( stream bank) area resistance to erosive energy ( shear stress) and may reduce local shear stress levels. Specifically, the restoration/ protection of riparian areas called for in the temperature TMDL will serve to reduce stream bank erosion by increasing stream bank stability via rooting strength and near stream roughness.

Surrogate Measure # 3 in the Temperature TMDL targets a decrease in the near stream disturbance zone dimension that relies primarily on passive stream narrowing via decreased stream bank erosion and increased naturally occurring stream bank building processes.

Surrogate Measure # 4 in the Temperature TMDL targets an increase sinuosity in unconfined channels . Straighter river and creek channels ( lower sinuosity) have steeper gradients and hence higher flow velocities. Increased flow velocity exerts more force on the banks, accelerating erosion and stream widening.

Surrogate Measure # 5 in the Temperature TMDL targets decreased wetted width to depth ratio. Specifically, increased pool frequencies is an important component of instream habitat, healthy channel morphology and promotes reduced stream temperatures. And, reduced stream bank erosion and increased stream bank building processes are necessary to promote this condition. Further, reduced sedimentation ( the accumulation of sediments in the stream channel) will assist pool development and maintenance.

These allocations apply to all nonpoint sources ( agriculture, forestry, urban) in the watershed. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 42 APRIL, 2000 Figure 14. Stream Bed Percent Fines Related to Various Riparian Vegetation Types ( ODFW data, 1996)

Wasteload Allocations Wastewater treatment plants, and thus point sources in Upper Grande Ronde subbasin, are not considered a source of fine sediment and thus no wasteload allocations have been developed.

Seasonal Variation The goal of this TMDL is for year round achievement of the loading capacity. Due to the nature of the loading capacity and allocations assigned in this TMDL, a discussion of seasonal variations in sediment delivery and transport processes which may exist in the Upper Grande Ronde River subbasin was not necessary in developing the TMDL.

Margin of Safety The Clean Water Act requires that each TMDL be established with a margin of safety ( MOS) to account for uncertainty in available data or in the actual effect controls will have on loading reductions and receiving water quality. The TMDL also includes a long term monitoring and adaptive management plan which, among other things, will evaluate the effectiveness of this target and provides a MOS.

Calculating a numeric margin of safety is not easily performed with the methodology presented in this document. The basis for the load allocations ( surrogates) is the definition of site potential conditions. Thus, attainment of the load allocations will lead to the establishment of a mature riparian community and thus, sediment delivery rates which resemble those of the natural sources. It is illogical to presume that anything more than site potential riparian conditions are possible, feasible or reasonable. DEQ will utilize adaptive management to monitor whether the attainment of these surrogate measures are leading to the attainment of the applicable water quality standards. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 43 APRIL, 2000 Bacteria The Grande Ronde River from the Wallowa River to Five Points Creek ( River Mile 165.7, about 7 miles above the City of La Grande) is included in the § 303( d) list for bacteria standard violations. No other reaches in the Grande Ronde sub basin are listed for bacteria. The Grande Ronde River is included in the § 303( d) list due to observed violations of the former bacteria standard, which was based on fecal coliform. This standard is as follows:

" Organisms of the coliform group where associated with fecal sources ( MPN or equivalent MF using a representative number of samples.) A log mean of 200 fecal coliform per 100 milliliters based on a minimum of five samples in a 30 day period with no more than ten percent of the samples in the 30 day period exceeding 400 per 100 ml."

The Grande Ronde River was listed based on data from two stations ( Stations # 402396 and # 404200; River Mile 99.0 and 151.1, respectively). Twelve percent of observed values at River Mile 99.0 ( 3 of 25) and 11% at River Mile 151.1 ( 2 of 19) exceeded the 400 per 100 ml fecal coliform standard with a maximum value of 1600 between water years 1986 and 1995. These values only slightly exceeded the 10% violation criteria associated with the standard. Observed E. coli concentrations in the Grande Ronde River are presented in Figure 15.

In accordance with U. S. Environmental Protection Agency recommendations, the State of Oregon recently revised its bacteria standards to be based on Escherichia coli ( E. coli), rather than on fecal coliform. The applicable standard for bacteria ( i. e., E. coli) in the Upper Grande Ronde subbasin is now as follows:

" Numeric Criteria: Organisms of the coliform group commonly associated with fecal sources ( MPN or equivalent membrane filtration using a representative number of samples) shall not exceed the criteria described in subparagraphs ( i) and ( ii) of this paragraph. Freshwaters:

( i) A 30 day log mean of 126 E. coli organisms per 100 ml, based on a minimum of five samples;

( ii) No single sample shall exceed 406 E. coli organisms per 100 ml ( OAR 340 41 725( 2)( e)( A)).

Figure 15. Observed E. coli concentration in the Grande Ronde River.

10 UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 44 APRIL, 2000 As shown in Figure 15, only limited data is available on E. coli, and only from recent years. However, the available data does not show any violations of water quality standards. Observed median concentrations are well below the 30 day log mean standard of 126 E. coli organisms per 100 ml, and no observations exceeded the absolute maximum of 406, although one observation did come close. While no standards violations were observed, the data set is too limited to conclude that standards are being consistently met. It is possible that standards violations occur, particularly during rainfall events when accumulated surface organic matter is flushed into the streams.

As with sediment, it is quite likely that the load allocations provided to address temperature, pH and dissolved oxygen violations will also significantly reduce bacteria loads and reduce the likelihood of standard violations. Bacteria loads will be reduced by the filtering capability improvements that will result from the riparian vegetation improvements necessary to meet temperature surrogates. In addition, nutrient reductions resulting from the nutrient load allocations will result in bacteria load reductions, since much of the bacteria entering the streams is associated animal wastes, and animal wastes contain high levels of both nitrogen and phosphorus.

The OAR contains the following requirements intended to eliminate bacteria standard violations:

1) Raw Sewage Prohibition: No sewage shall be discharged into or in any other manner be allowed to enter the waters of the State unless such sewage has been treated in a manner approved by the Department or otherwise allowed by these rules. OAR 340 41 725 ( 2)( e)( B);

2) Animal Waste: Runoff contaminated with domesticated animal wastes shall be minimized and treated to the maximum extent practicable before it is allowed to enter waters of the State. OAR 340 41 725( 2)( e)( C);

3) Bacterial pollution or other conditions deleterious to waters used for domestic purposes, livestock watering, irrigation, bathing, or shellfish propagation, or otherwise injurious to public health shall not be allowed. OAR 340 41 725 ( 2)( f); and 4) In waterbodies designated by the Department as water quality limited for bacteria, and in accordance with priorities established by the Department, development and implementation of a bacteria management plan shall be required of those sources that the Department determines to be contributing to the problem. The Department may determine that a plan is not necessary for a particular stream segment or segments within a water quality limited basin based on the contribution of the segment( s) to the problem. The bacteria management plans will identify the technologies, BMPs and/ or measures and approaches to be implemented by point and nonpoint sources to limit bacterial contamination. For point sources, their National Pollutant Discharge Elimination System permit is their bacteria management plan. For nonpoint sources, the bacteria management plan will be developed by designated management agencies ( DMAs) which will identify the appropriate BMPs or measures and approaches. OAR 340 41 026 ( 3)( a)( I):

To insure that bacteria standards are met, monitoring for E. coli and fecal coliform will be continued in the basin. The adaptive management nature of the Plan will allow additional steps to be taken, as needed, to insure that standards are met and beneficial uses are protected. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 45 APRIL, 2000 Ammonia Toxicity Ammonia toxicity is a potential concern in the Upper Grande Ronde sub basin because of elevated pH and temperature levels. Ammonia is present in two states in natural waters: ammonium ion ( NH4 + ) and un ionized ammonia ( NH3). Un ionized ammonia is much more toxic to aquatic life than the ammonia ion state. Since the fraction of ammonia that is un ionized increases as pH increases, systems with high pH, such as the Grande Ronde River and Catherine Creek, are highly susceptible to ammonia toxicity. For a pH of 9.0 and a temperature of 25oC, the applicable total ammonia chronic standard ( NH4 + plus NH3) is 0.1 mg/ L ( 0.0822 mg/ L as nitrogen). The 4 day average ammonia concentration may not exceed this concentration more than once every 3 years on the average. For the same pH and temperature combination, the total ammonia acute standard is 0.72 mg/ L ( 0.59 mg/ L as nitrogen). The one hour average ammonia concentration may not exceed this concentration more than once every 3 years on the average.

Figures 16 and 17 present observed summer ammonia concentrations for the Grande Ronde River. Since ammonia toxicity is a function of pH and temperature, as pH and temperature is improved with implementation of the TMDL, the fraction un ionized will decrease and the loading capacity for total ammonia will increase. The lower dashed line on these figures is a standard appropriate for current conditions ( pH = 9.0, temperature= 25oC), while the upper dashed line is a standard appropriate for the site potential condition ( pH= 8.7, temperature = 20oC).

As shown in Figures 16 and 17, for current conditions of temperature and pH the ammonia standard ( lower dashed line) is occasionally exceeded, particularly downstream of the La Grande WWTP discharge which discharges at River Mile 153.8. For anticipated future temperature and pH conditions, the standard ( upper dashed line) should rarely be exceeded, particularly since the La Grande WWTP will not be discharging during low flow summer conditions.

Figure 16. Upper Grande Ronde River observed Ammonia concentrations during the summer. UPPER GRANDE RONDE SUB BASIN TMDL OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY PAGE 46 APRIL, 2000 Figure 17. Middle Grande Ronde River observed Ammonia concentrations during the summer.