E. coli Total Maximum Daily Loads - Bitter and Killpecker Creeks, Wyoming
March 14, 2018
E. coli Total Maximum Daily Loads - Bitter and Killpecker Creeks, Wyoming January 29, 2018
PREPARED BY PREPARED FOR
Tetra Tech, Inc. Wyoming Department of Environmental P.O. Box 11895 Quality Jackson, WY 83002 Water Quality Division 200 West 17th Street Cheyenne, WY 82002
ACKNOWLEDGEMENTS
DEQ would like to acknowledge the Sweetwater County Conservation District, the Bitter Creek- Killpecker Creek Watershed Advisory Group (BKWAG), and Environmental Design Engineering (EDE) for their contributions to the development of the TMDLs contained in this document.
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CONTENTS
1.0 INTRODUCTION AND PROBLEM IDENTIFICATION ...... 1 2.0 WATERSHED DESCRIPTION ...... 3 3.0 WATERSHED HYDROLOGY ...... 7 4.0 WATER QUALITY STANDARDS AND TARGETS ...... 14 4.1 Applicable Water Quality Standards ...... 14 4.2 TMDL targets ...... 15 5.0 WATER QUALITY ...... 16 5.1 Bitter Creek ...... 16 5.1.1 Primary Contact Recreation ...... 16 5.1.2 Secondary Contact Recreation ...... 20 5.2 Killpecker Creek ...... 21 5.2.1 Primary Contact Recreation ...... 21 5.2.2 Secondary Contact Recreation ...... 24 6.0 SOURCE ASSESSMENT ...... 25 6.1 Pathways ...... 25 6.2 Potentially Significant Sources of Bacteria ...... 27 6.3 Point Sources ...... 28 6.3.1 Superior Wastewater Lagoon (WY0021806) ...... 30 6.3.2 B & R Mobile Home Village (WY0022128) ...... 31 6.3.3 Rock Springs Water Reclamation Facility (WY0022357) ...... 32 6.3.4 Stansbury Mine (WY0023825) ...... 33 6.3.5 Leucite Hills Mine (WY0028886) ...... 33 6.3.6 Black Butte Mine (WY0030261) ...... 33 6.3.7 Jim Bridger Mine (WY0030350) ...... 33 6.3.8 BLM Rock Springs Wild Horse Facility (WY0094528) ...... 33 6.3.9 Point of Rocks Lagoons (No Permit) ...... 34 6.3.10 Reliance Facultative Lagoons (No Permit) ...... 34 6.3.11 Summary ...... 35 6.4 Nonpoint Sources ...... 37 6.4.1 Septic Systems ...... 37 6.4.2 Livestock ...... 38 6.4.3 Wild Horses ...... 40
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6.4.4 Wildlife ...... 42 6.4.5 Pets ...... 49 7.0 TMDL CALCULATIONS AND ALLOCATIONS TO SOURCES ...... 50 7.1 Total Maximum Daily Load...... 50 7.2 Loading Capacity ...... 51 7.3 Load Allocations ...... 52 7.4 Wasteload Allocations ...... 52 7.5 Margin of Safety ...... 52 7.6 Seasonality ...... 52 8.0 MONITORING STRATEGY ...... 53 8.1 Trend Monitoring ...... 53 8.2 Flow Monitoring ...... 53 8.3 Source Sampling ...... 54 8.4 Point Sources ...... 54 8.5 BMP Tracking and Effectiveness Monitoring ...... 54 9.0 RESTORATION STRATEGY ...... 55 9.1 Point Sources ...... 55 9.2 Septic Systems ...... 55 9.3 Pets ...... 55 9.4 Livestock ...... 55 9.5 Wild Horse ...... 56 9.6 Wildlife ...... 56 9.7 Coordination with the Rock Springs Beautification Committee...... 56 10.0 PUBLIC PARTICIPATION SUMMARY ...... 56 11.0 REFERENCES ...... 58
APPENDICES
Appendix A. Summary of Available Hydrology Data Appendix B. Water Quality Data and Analysis Appendix C. Wild Horse Census and Flight Paths Appendix D. Response to Public Comments
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TABLES
Table 1. Bacteria Impaired waters in the Bitter Creek Sub-basin (HUC 14040105) ...... 1 Table 2. Summary of temperature and precipitation data at Rock Springs, Wyoming ...... 6 Table 3. Instantaneous streamflow measurements in Killpecker Creek ...... 12 Table 4. PCR geometric means for sites on Bitter Creek...... 18 Table 5. Summary of post-2011 E. coli data collected from Bitter Creek during the summer ...... 19 Table 6. SCR geometric means for sites on Bitter Creek...... 20 Table 7. PCR geometric means for sites on Killpecker Creek ...... 23 Table 8. Summary of post-2011 E. coli data collected from Killpecker Creek during the summer ...... 23 Table 9. SCR geometric means for sites on Bitter Creek...... 24 Table 10. Permitted point source dischargers with E. coli limits in the Bitter Creek watershed...... 28 Table 11. Flow and E. coli daily maximum data for the Superior Wastewater Lagoon (2009-2015) ...... 30 Table 12. Flow and E. coli daily maximum data summary for the B & R Mobile Home Village (2012-2015) ...... 31 Table 13. Flow and E. coli daily maximum data summary for the Rock Springs Water Reclamation Facility (2012-2015) ...... 32 Table 14. BLM grazing allotments in the Bitter Creek watershed ...... 40 Table 15. Wild horse HMAs ...... 41 Table 16. Estimated total number of elk in the Bitter Creek watershed ...... 42 Table 17. Estimated total number of mule deer in the Bitter Creek watershed ...... 45 Table 18. Estimated total number of pronghorn in the Bitter Creek watershed ...... 47 Table 19. Estimated big game density and population in the Bitter Creek watershed ...... 49 Table 20. Summer E. coli TMDL for Bitter Creek above highway 373 (at monitoring site BC-2)...... 51 Table 21. Summer E. coli TMDL for Killpecker Creek at Western Wyoming Community College (at monitoring site KC-1) ...... 51 Table 22. Key monitoring locations along Bitter and Killpecker Creeks ...... 53
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FIGURES
Figure 1. Bacteria-impaired stream reaches in the Bitter Creek watershed...... 3 Figure 2. Land ownership in and around the Bitter Creek watershed...... 4 Figure 3. Land cover in the Bitter Creek watershed...... 5 Figure 4. Continuous flow monitoring sites...... 8 Figure 5. Instantaneous flow and E. coli monitoring sites...... 9 Figure 6. Instantaneous flow and E. coli monitoring sites in Rock Springs (zoomed in from Figure 5)...... 10 Figure 7. Historic average daily discharge in Bitter Creek...... 11 Figure 8. 2011 daily average discharge in Bitter Creek ...... 11 Figure 9. Median of instantaneous discharge for the PCR season at sites with greater than 15 discharge measurements...... 12 Figure 10. 2011 daily average discharge in Killpecker Creek...... 13 Figure 11. Primary contact recreational use designations in the Bitter Creek watershed...... 15 Figure 12. Summary of E. coli concentrations during the summer along Bitter Creek...... 17 Figure 13. Summary of E. coli loads during the summer along Bitter Creek...... 17 Figure 14. Summary of E. coli concentrations during the winter along Bitter Creek...... 20 Figure 15. Summary of E. coli concentrations during the summer along Killpecker Creek...... 21 Figure 16. Summary of E. coli loads during the summer along Killpecker Creek...... 22 Figure 17. Summary of E. coli concentrations during the winter along Killpecker Creek...... 24 Figure 18. City of Rock Springs storm water conveyance pipes...... 26 Figure 19. Bacteria transport pathways ...... 27 Figure 20. Permitted point source dischargers and outfall locations within the Bitter Creek watershed...... 29 Figure 21. Flow and E. coli daily maximum data for the B & R Mobile Home Village (2004-2016)...... 31 Figure 22. Flow and E. coli daily maximum data for the Rock Springs Water Reclamation Facility (2004-2017)...... 32 Figure 23. Location of septic systems, municipalities, and water and sewer districts...... 38 Figure 24. BLM grazing allotments in the Bitter Creek watershed...... 39 Figure 25. Wild horse HMAs within the Bitter Creek watershed...... 41 Figure 26. Elk HUs within the Bitter Creek watershed...... 43 Figure 27. Elk seasonal ranges in the Bitter Creek watershed...... 44 Figure 28. Mule deer HUs within the Bitter Creek watershed...... 45 Figure 29. Mule deer seasonal ranges...... 46 Figure 30. Pronghorn HUs within the Bitter Creek watershed...... 47 Figure 31. Pronghorn seasonal ranges...... 48 Figure 32. Pet waste brochure developed by SWCCD ...... 55
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ACRONYMS/ABBREVIATIONS
Acronyms/Abbreviations Definition AML Abandoned Mine Lands Division (WDEQ) BMP best management practice E. coli Escherichia coli HMA herd management area HU herd unit HUC hydrologic unit code LDC load duration curve LQD Land Quality Division (WDEQ) OSLI Office of State Lands and Investment (Wyoming) SCEHD Sweetwater County Environmental Health Department SWCCD Sweetwater County Conservation District TMDL total maximum daily load EPA U.S. Environmental Protection Agency USDA U.S. Department of Agriculture WDEQ Wyoming Department of Environmental Quality WQD Water Quality Division (WDEQ) WQS water quality standards WWTF wastewater treatment facility WYPDES Wyoming Pollutant Discharge Elimination System
Units of Measure Definition cfs cubic feet per second mgd million gallons per day mL milliliter
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EXECUTIVE SUMMARY
Much of the main body of this document is organized and was written to satisfy the regulatory requirement of Section 303(d) of the Clean Water Act and the U.S. Environmental Protection Agency’s implementing regulations for total maximum daily loads (TMDL) at 40 CFR Part 130. In contrast, this executive summary is provided to present a non-regulatory, non-technical summary of the water quality problem, its sources, and potential future actions that may be taken to correct the problem.
Bacteria levels in Bitter Creek and Killpecker Creek exceed Wyoming’s water quality standards. According to the Wyoming Department of Environmental Quality’s (WDEQ) list of impaired waters (i.e., Wyoming’s 303(d) list) and based on samples collected over the last 13 years by the Sweetwater County Conservation District (SWCCD), high E. coli bacteria levels in Bitter Creek and Killpecker Creek impair the recreational uses of these waterbodies. E. coli bacteria are indicator species for pathogens that are harmful to human health. The E. coli bacteria and pathogens come from the digestive tracks of warm-blooded animals.
Wyoming’s water quality standards protect waterbodies for recreational use by maintaining a level of water quality that is safe for human contact. Since SWCCD began collecting samples in 2004, 66 percent of the samples collected at sites along Bitter Creek have exceeded these standards and 58 percent of the samples collected in Killpecker Creek exceeded the standards.
Potential sources of bacteria in the Bitter Creek watershed include livestock, wildlife, pets, and humans. Bacteria in animal and human waste can become a significant problem when the waste is transported to streams and rivers. For example, most human waste is either discharged into and treated by a municipal waste water treatment facility (WWTF), or discharged into a septic system where it is treated. Properly functioning WWTFs and properly sited and functioning septic systems are not generally considered significant sources of bacteria. However, failing septic systems and/or septic leach fields that either become flooded or are in contact with shallow groundwater can be a source of bacteria, as can WWTFs that fail to meet their permit limits. The largest point source in the Bitter Creek watershed, Rock Springs Water Reclamation Facility, contributes E. coli loads to Bitter Creek but does not appear to be a significant cause of impairment because the facility discharges below its E. coli permit limits. Some of the other WWTFs in the watershed, however, are not always meeting their E. coli permit limits.
Similarly, well managed livestock are not necessarily a significant source of bacteria. However, when livestock, such as cattle or sheep, are allowed uncontrolled and long-term access to streams, and manure containing bacteria is deposited near the stream bank or directly in the stream, livestock can become a significant source of bacteria loading. Livestock are often at low densities in the Bitter Creek watershed, but, occasionally congregate in the stream valleys where they can become a significant contributor of bacteria.
There are three primary pathways by which bacteria can reach surface waters in the Bitter Creek watershed from the various sources discussed above: direct deposition, surface water runoff, or leaching into the shallow groundwater and ultimately into Bitter Creek (Figure ES-1).
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Figure ES-1. Bacteria transport pathways.
All sources that have the potential to deliver bacteria to Bitter Creek and Killpecker Creek need to be considered to solve this problem. As described in the main body of this document, Section 303(d) of the Clean Water Act requires that bacteria load reductions be allocated to each of the potentially significant sources. In this case, the allocation approach broadly applies an overall load reduction goal to achieve water quality standards. Bacteria load reduction targets unique to each source type were not specified. Since implementation of this water quality improvement plan is voluntary for nonpoint sources and dependent upon the actions of watershed stakeholders, flexibility is provided with this approach to allow watershed stakeholders to determine how and where to reduce bacteria loads from each of the sources.
TMDLs were prepared and are presented in the main body of this document for two impaired stream reaches in the Bitter Creek watershed: a 58.1-mile reach of the main stem of Bitter Creek (from the confluence with the Green River upstream to the town of Point of Rocks) and a 6.3-mile reach of Killpecker Creek (from the confluence with Bitter Creek upstream to the town of Reliance). Given insufficient data collected during the winter season, TMDLs were only developed for the summer. Although the TMDLs were prepared to address specific water body reaches, the geographic scope of the analysis and sources of the water quality problem extend over the entire Bitter Creek watershed. Summaries of the TMDLs are provided in Table ES-1 and Table ES-2.
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Table ES-1. Bitter Creek near Highway 373 TMDL summary
Total Maximum Daily Load Summary Waterbody Name/Description Bitter Creek from confluence with the Green River upstream to Point of Rocks TMDL Compliance Point Bitter Creek near Highway 373 (BC-2) Assessment Unit I.D. WYGR140401050506_01 Length of Impaired Waterbody 58.1 miles Size of Watershed 2,229 square miles Location Hydrologic unit code 14040105 05 06 Impaired Designated Use(s) Recreation 303(d) Listing Parameter Fecal coliform Cycle Most Recently Listed 2014 TMDL Priority Ranking 2014 Applicable Water Quality Criteria/Targets From May 1 through September 30, concentrations of E. coli bacteria shall not exceed a geometric mean of 126 organisms per 100 milliliters during any consecutive 60-day period. Threshold Values Daily not to exceed 126 organisms per 100 milliliters from May through September Analytical Approach Arithmetic mean of summer flows and loads
TMDL component Allocation (billion organisms per day) TMDL 63.9 LA 43.4 WLA (sum) 20.5 Existing load 153.6 Necessary reduction 58% Notes LA = load allocation; TMDL = total maximum daily load; WLA (sum) = summation of wasteload allocations. Refer to Table 21 in Section 7.1 for the discussion of this TMDL, including the allocation table with explanatory notes.
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Table ES-2. Killpecker Creek at Western Wyoming Community College TMDL summary
Total Maximum Daily Load Summary Waterbody Name/Description Killpecker Creek from confluence with Bitter Creek upstream to Reliance TMDL Compliance Point Killpecker Creek at Western Wyoming Community College (KC-1) Assessment Unit I.D. WYGR140401050808_01 Length of Impaired Waterbody 6.3 miles Size of Watershed 317 square miles Location Hydrologic unit code 14040105 08 08 Impaired Designated Use(s) Recreation 303(d) Listing Parameter Fecal coliform Cycle Most Recently Listed 2014 TMDL Priority Ranking 2014 Applicable Water Quality Criteria/Targets From May 1 through September 30, concentrations of E. coli bacteria shall not exceed a geometric mean of 126 organisms per 100 milliliters during any consecutive 60-day period. Threshold Values Daily not to exceed 126 organisms per 100 milliliters from May through September Analytical Approach Arithmetic mean of summer flows and loads
TMDL component Allocation (billion organisms per day) TMDL 10.3 LA 10.0 WLA (sum) 0.3 Existing load 85.6 Necessary reduction 88% Notes LA = load allocation; TMDL = total maximum daily load; WLA (sum) = summation of wasteload allocations. Refer to Table 22 in Section 7.1 for the discussion of this TMDL, including the allocation table with explanatory notes.
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1.0 INTRODUCTION AND PROBLEM IDENTIFICATION
The recreational uses in Bitter Creek and one of its tributaries, Killpecker Creek, were originally listed as impaired due to excessive levels of fecal coliform bacteria in 2000 (Table 1). Although Wyoming’s bacteria standards are now based on Escherichia coli (E. coli), both streams are still listed as impaired on the most recent approved 303(d) list (i.e., 2014).
Table 1. Bacteria Impaired waters in the Bitter Creek Sub-basin (HUC 14040105)
Waterbody 305(b) Class Location Miles Impaired Cause Original Identifier use list year Bitter Creek WYGR140401 2C From the 58.1 Recreation Fecal 2000 050506_01 confluence with coliform the Green River upstream to Point of Rocks Killpecker WYGR140401 3B From the 6.3 Recreation Fecal 2000 Creek 050808_01 confluence with coliform Bitter Creek upstream to Reliance Source: Wyoming Department of Environmental Quality 2016.
The Clean Water Act and U.S. Environmental Protection Agency (EPA) regulations require that states develop Total Maximum Daily Loads (TMDLs) for waters that do not support their designated uses. In simple terms, a TMDL is a plan to attain and maintain water quality standards in waters that are not currently meeting them (i.e., a “Water Quality Improvement Plan”).
All of the required components of a TMDL are summarized within this document. Additional technical details are contained in the appendices. In addition to this introductory section, this document includes:
Section 2.0 - Watershed Description: Provides a summary description of the Bitter Creek watershed focusing on those characteristics that may have an influence on water quality.
Section 3.0 – Watershed Hydrology. Provides a summary of the hydrology of Bitter Creek and its tributaries based on the available data. Detailed hydrologic data summaries are provided in Appendix A.
Section 4.0 - Water Standards and Targets: Describes the applicable water quality standards and water quality goals (i.e., targets).
Section 5.0 – Water Quality: Presents a summary of the available water quality data and compares these data to the target water quality conditions. Detailed water quality data summaries are provided in Appendix B.
Section 6.0 – Source Assessment: Identifies the potentially significant sources of bacteria and pathways for delivery to Bitter Creek and Killpecker Creek.
Section 7.0 – TMDL Calculations and Allocations to Sources: Presents the TMDLs, allocations, margin of safety, and a discussion of uncertainty.
Section 8.0 - Monitoring Strategy: Presents a framework strategy for collection of water quality data in the future to assess future trends, address uncertainties, and track implementation progress.
Section 9.0 Restoration Strategy: Provides a brief summary of the restoration strategy.
Section 10.0 – Public Participation Summary: Describes other agencies and stakeholder groups who were involved with the development of the plan and the public participation process used to review the draft document. Addresses comments received during the public review period.
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Section 11.0 – References: Presents citations for all of the technical documents, reports, literature, and secondary data used to support the conclusions in this document.
Although this plan is officially developed to address the two 303(d) listed segments, it has been prepared at the scale of the entire Bitter Creek watershed, and addresses sources at the watershed scale.
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2.0 WATERSHED DESCRIPTION
Bitter Creek is an 80 mile long stream in south central Wyoming. It rises near the Delaney Rim on the western side of Wyoming's Red Desert in Sweetwater County. For most of its course, Bitter Creek parallels the path of Interstate 80. It flows through the cities of Rock Springs and Green River before emptying into the Green River (Figure 1).
The Bitter Creek sub-basin lies within the Green River Basin, a headwaters tributary to the Colorado River. The assessment area for this project is the entire sub-basin hydrologic unit that is identified with the eight digit Hydrologic Unit Code (8-digit HUC) 14040105. The Bitter Creek watershed totals approximately 2,229 square miles.
Figure 1. Bacteria-impaired stream reaches in the Bitter Creek watershed.
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Most of Bitter Creek is in Sweetwater County. Sweetwater County’s population is 43,806 people or 4.2 people per square mile (U.S. Census Bureau, 2010). Land ownership is a mix of private and public (Figure 2). The majority of the public land is managed by the U.S. Bureau of Land Management (BLM). The Bitter Creek watershed is located in the Cool Central Desertic Basins and Plateaus Major Land Resource Area (USDA 2016). This area is characterized by sagebrush steppe (i.e., area shown as scrub/shrub in Figure 3). The representative vegetation includes Wyoming big sagebrush, early sagebrush, antelope bitterbrush, bluebunch wheatgrass, western wheatgrass, prairie junegrass, needleandthread, and Indian ricegrass. Cottonwood and willows grow in riparian zones along the major perennial streams and rivers.
Figure 2. Land ownership in and around the Bitter Creek watershed.
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Figure 3. Land cover in the Bitter Creek watershed.
The Western Regional Climate Center classifies the climate as semi-arid. The average total monthly precipitation ranges between 0.5 and 1.2 inches, with the lowest precipitation in the winter months and the highest in the spring and summer (Table 2). Average annual precipitation is 8.61 inches. The average monthly maximum temperature ranges from 29 degrees Fahrenheit in January to 84 degrees Fahrenheit in August.
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Table 2. Summary of temperature and precipitation data at Rock Springs, Wyoming
Weather Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg. max. 29 33 42 53 64 75 84 81 71 57 41 31 temperature Avg. min. 11 14 21 29 37 46 53 52 42 32 21 13 temperature Avg. total 0.5 0.5 0.7 1 1.2 0.9 0.7 0.6 0.8 0.8 0.6 0.5 precipitation Avg. total 6.9 5.7 6.8 5.8 2 0.1 0 0 0.7 4 5.6 6.1 snowfall Source: Western Regional Climate Center Note: Temperatures are in degrees Fahrenheit and precipitation and snowfall are in inches.
Bitter Creek has the potential to provide important habitat for a variety of aquatic species (personal communication with Rob Keith, Green River Fisheries Supervisor, Wyoming Game and Fish Department. June 14, 2017). There is a small population of the rare flannelmouth sucker in the headwaters of Bitter Creek and the creek supports an assemblage of native non-game species as well as the occasional brown trout and kokanee salmon, thought to migrate up into Bitter Creek from the Green River.
The Bitter Creek watershed has a rich history. According to WWC Engineering (2015), coal mining in the area began in the 1860s, with the advent of the Union Pacific Railroad, and continued until the late 1950s. Coal was extensively extracted beneath the City of Rock Springs, the result of which is a large underground network of mine tunnels/rooms. Minimal historical groundwater level data exist prior to or during mining activities. However, considerable volumes of groundwater were pumped from the mines during the years of operation. Due to the pumping, groundwater heads in the mines were artificially maintained below the extent of mining. It is estimated that groundwater heads were lowered approximately 600 feet. Since pumping was discontinued in 1945, groundwater heads have been recovering, re-saturating the coal seams and mine voids, associated inter-burden and overlying alluvium. Rising groundwater levels are a manifestation of the heads returning to a pre-mine configuration. Groundwater inflows from historic mining are now common in the vicinity of Rock Springs (see Section 3.0 for additional hydrology discussion).
Bitter Creek was rerouted in the vicinity of Rock Springs (WWC 2015). As Bitter Creek was rerouted, the abandoned channel was backfilled with random material. This random material has a significantly higher permeability than the native soils, establishing a preferential pathway for groundwater flow, complicating the groundwater/surface water interactions in Bitter Creek.
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3.0 WATERSHED HYDROLOGY
Instantaneous and continuous flow data have been collected throughout the Bitter Creek watershed; however, the flow record for Bitter Creek is discontinuous and presents an incomplete picture of watershed hydrology. Most flow data were collected on Bitter Creek and Killpecker Creek, with a few monitoring locations on various tributaries. Monitoring locations are shown in Figure 4 through Figure 6. Tabular summaries of the available streamflow data are presented and described in Appendix A.
The available data present only snapshots in time at a variety of locations. A hydrological evaluation of all the data from multiple locations and time periods suggest a flashy system, with a spring peak between March and June associated with snowmelt, and numerous short-duration, storm-event driven peaks throughout the summer and early fall (Figure 7 and Figure 8). Bitter Creek is perennial in the headwaters, but occasionally goes dry between approximately monitoring sites BC-6 and BC-5, and becomes perennial again in the vicinity of the City of Rock Springs (Figure 5).
To facilitate development of E. coli TMDLs, median discharge during the summer recreation season (; May 1 – September 30) when primary contact recreation (PCR) occurs was evaluated at monitoring locations with greater than 15 measurements (Figure 9). The natural hydrology of Bitter Creek is modified by irrigation withdrawals, inflows from wastewater treatment facilities (WWTFs), and groundwater inflows from historic mining. These anthropogenic influences are likely greatest during low flow periods. The Pierotto Ditch (the only known irrigation diversion in the watershed) is permitted to withdrawal up to 0.57 cubic feet per second (cfs) between monitoring sites BC-6 and BC-10 (Figure 9 and Figure 5). Measured median mine inflow totals 0.61 cfs in the City of Rock Springs between monitoring sites BC-4 and BC-3. However, given the increase in median discharge between monitoring sites BC-4 and BC-3 (Figure 9), mine inflows may be larger. Just downstream of that segment, the Rock Springs WWTF discharges 3.73 cfs (median of monthly average discharge) between monitoring sites BC-3 and BC-2 (Figure 9 and Figure 5).
Median streamflows in Killpecker Creek are less than one cubic feet per second and Killpecker Creek appears to be intermittent upstream of monitoring site KC-4 (Table 3). However, based on the available data flow was continuous in lower Killpecker Creek in 2011 (Figure 10).
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Figure 4. Continuous flow monitoring sites.
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Figure 5. Instantaneous flow and E. coli monitoring sites.
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Figure 6. Instantaneous flow and E. coli monitoring sites in Rock Springs (zoomed in from Figure 5).
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Note: Bitter Creek near Bitter Creek, Wyoming (gage 09216545; water years 1975 through 1981) and Bitter Creek above Salt Wells Creek near Salt Wells Creek, Wyoming (gage 09216562; water years 1976 through 1981).
Figure 7. Historic average daily discharge in Bitter Creek.
Figure 8. 2011 daily average discharge in Bitter Creek Page 11 of 59
Note: Sites are organized from upstream (left) to downstream (right).
Figure 9. Median of instantaneous discharge for the PCR season at sites with greater than 15 discharge measurements.
Table 3. Instantaneous streamflow measurements in Killpecker Creek
Monitoring site No. of records Minimum Median Maximum KC-3 17 0 0 7.58 KC-7 2 0 0 0 KC-2 34 0 0.08 6.38 KC-1H 1 0.33 0.33 0.33 KC-1G 1 0.70 0.70 0.70 KC-13 3 0.00 0.01 0.02 KC-5 11 0.00 0.13 46.35 KC-4 5 0.02 0.06 0.34 KC-1D 1 0.01 0.01 0.01 KC-14 3 0.03 0.04 0.15 KC-1C 1 0.05 0.05 0.05 KC-1B 4 0.03 0.15 0.38 KC-1A 1 0.06 0.06 0.06 KC-1 50 0.03 0.62 55.26 KC-15 3 0.09 0.11 0.43 Source: SWCCD, collected from 2004 through 2016. Note: Instantaneous streamflow is reported in cubic feet per second.
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Figure 10. 2011 daily average discharge in Killpecker Creek.
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4.0 WATER QUALITY STANDARDS AND TARGETS
The applicable water quality standards and water quality goals (i.e., targets) established for the TMDLs presented herein are described in this section. 4.1 APPLICABLE WATER QUALITY STANDARDS
Bitter Creek is classified as 2C according to Wyoming’s Surface Water Classification List (WDEQ 2013a) and Killpecker Creek is classified as 3B. Class 2C waters are designated for non-game fish, fish consumption, other aquatic life, recreation, wildlife, agriculture, industry and scenic value. Class 3B waters are designated for other aquatic life, recreation, wildlife, agriculture, industry and scenic value; these waters are intermittent or ephemeral, where fish populations and drinking water supplies are not attainable (WDEQ 2013a)
WDEQ further classifies all surface waters in Wyoming as having either a primary contact (ingestion or full body immersion) or secondary contact (incidental or accidental exposure not resulting in ingestion or immersion) recreational use category (WDEQ 2013a). The majority of Bitter Creek and Killpecker Creek stream segments and tributaries are classified as secondary contact recreational (SCR) use waters. However, portions of both streams have been classified as primary contact recreational (PCR) waters where they pass through urban areas, areas with ease of access, or are within specially developed federal, state, or local recreational use areas (WDEQ 2016). PCR use areas within the Bitter Creek watershed are shown in Figure 11.
Wyoming’s recreation use attainment is based upon Escherichia coli (E. coli), which is an indicator of pathogenic organisms that are harmful to humans. The PCR standard for E. coli is exceeded when concentrations of E. coli from not less than five samples taken in a period of not more than 60 days are greater than a geometric mean of 126 organisms per 100 milliliters (WDEQ 2013a). The primary contact standard applies during the summer recreation season (hereafter referred to as “summer”) defined as May 1 through September 30. For the remainder of the year (the winter recreation season, hereafter referred to as “winter”), the SCR standard applies to waters designated for PCR use. The SCR standard is exceeded when the geometric mean of not less than five samples taken in a period of not more than 60 days is greater than 630 organisms per 100 milliliters (WDEQ 2013a).
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Figure 11. Primary contact recreational use designations in the Bitter Creek watershed.
4.2 TMDL TARGETS
TMDL water quality targets (i.e., water quality goals) are a translation of the applicable numeric or narrative water quality standard(s) for each pollutant. For pollutants with established numeric water quality standards, the numeric value(s) are used as the TMDL targets. As described above, Wyoming has numeric water quality criteria for E. coli and these criteria are used as the TMDL targets for the bacteria-impaired streams (i.e., 126 and 630 organisms per 100 mL for summer and winter, respectively). The overall goal of the TMDL process for the Bitter Creek watershed is to achieve these standards in Bitter Creek and Killpecker Creek.
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5.0 WATER QUALITY
SWCCD has sampled sites throughout the Bitter Creek watershed since 2004. Monitoring sites include streams, wells (i.e., groundwater), and source areas (e.g., runoff from a business). Tabular summaries of these data are provided in Appendix B.
As only Bitter Creek and Killpecker Creek are listed as impaired for their recreation use, data analysis focused upon these two streams. The available data collected along each stream and comparisons with water quality standards are presented in the following subsections. The following five conclusions were drawn:
Individual results at many monitoring sites along Bitter Creek and Killpecker Creek exceed 126 organisms per 100 mL during the summer, while a few sites on each stream exceed 630 organisms per 100 mL in the winter. Note, however, that few data are available for the winter season. Geometric means calculated during the summer from 2004 through 2011 regularly exceed the PCR criterion at most sites along Bitter Creek and some sites along Killpecker Creek. Geometric means calculated from samples collected in the winter in 2004 and 2005 never exceed the SCR criterion. Temporal trends were examined at the monitoring sites with the most data and E. coli concentrations were slightly higher during the summer. Insufficient data at most sites prevents further temporal trend analysis. No spatial trends were identified. No relationships between E. coli concentration and stream flow are evident (Appendix B). 5.1 BITTER CREEK
SWCCD sampled 19 monitoring sites along Bitter Creek during the summer (Appendix B); seven of those sites were sampled in the winter. Samples collected during the summer (and thus subject to the PCR criteria) and winter (and thus subject to the SCR criteria) are discussed separately in the following two subsections. 5.1.1 Primary Contact Recreation During the summer, measured E. coli concentrations in Bitter Creek ranged from 1 to 24,200 organisms per 100 mL (Figure 12). The highest values were observed at monitoring site BC-8 within the city limits of Rock Springs. Single sample exceedances of the 126 organisms per 100 mL criterion1 were observed at all sites where more than two samples were collected. There do not appear to be any spatial trends in observed concentrations, with the exception of monitoring site BC-8 where observed concentrations were up to an order of magnitude higher than many of the other sites along Bitter Creek.
1 The 126 organism per 100 mL criterion are used in this context only as a point of reference. Page 16 of 59
Figure 12. Summary of E. coli concentrations during the summer along Bitter Creek.
With regards to E. coli loads, a slight increasing trend from upstream to downstream in Bitter Creek is apparent, but this is likely attributable to increased flows in the downstream segment.
Figure 13. Summary of E. coli loads during the summer along Bitter Creek.
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Finally, sufficient data are available to calculate E. coli geometric means during the PCR period for eight months between 2004 and 2011 (Table 4). Since 2011, samples have been collected and evaluated for E. coli, but never have 5 samples been collected within a 60-day period during the summer.
Exceedances of the 126 organisms per 100 milliliter E. coli criterion have been observed at all samples sites, from the headwaters to the mouth in Bitter Creek except monitoring site BC-5, which has been infrequently sampled. Data from 2004, 2005, and 2009 regularly exceeded the PCR criterion at several locations, especially in lower Bitter Creek.
Although insufficient samples have been collected since that time to meet the minimum of 5 samples within 60- day criterion, numerous discrete samples have been collected and suggest that E. coli impairment persists through 20162 (Table 5).
Table 4. PCR geometric means for sites on Bitter Creek
Monitoring Aug May Sep May Sep May Sep Jun site 2004 2005 2005 2009 2009 2010 2010 2011 BC-7 101 65 821 ------BC-6 --a 32 271 165 79 83 -- 110 BC-12 ------91 843 ------BC-10 ------616 ------5 BC-5 -- 59 -- --a ------BC-8 ------1,634 1,045 ------BC-4 195 58 1,548 1,740 448 95 -- 271 BC-16 ------248 458 ------BC-3 143 333 1,348 170 556 ------BC-2 180 264 657 70 147 112 55 144 BC-1 714 238 745 ------Notes Geometric means were only calculated at sites with at least 5 samples in the specified month. Bolded values exceed the geometric mean criterion of 126 organisms per 100 milliliters. a. Geometric means were not calculated for these sites during these months because corresponding flow records indicated Bitter Creek was dry.
2 The geometric mean values presented in Table 4 do not meet the 5 sample within a 60 day period criterion and should be viewed as informational only. Page 18 of 59
Table 5. Summary of post-2011 E. coli data collected from Bitter Creek during the summer
Monitoring site No. of samples Relative no. of samples greater Informational geometric than 126 organisms per 100 mL mean (organisms per 100 mL) BC-7 3 67% 137 BC-6 8 25% 25 BC-12 3 33% 138 BC-10 4 25% 71 BC-5 0 -- -- BC-8 3 67% 387 BC-4 9 56% 83 BC-16 3 100% 826 BC-3 5 60% 131 BC-2 9 33% 44 BC-1 2 0% 1 Note: The geometric mean values presented in Table 5 do not meet the 5 sample within a 60 day period criterion and should be viewed as informational only.
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5.1.2 Secondary Contact Recreation Fewer samples were collected during the winter. Measured E. coli concentrations in Bitter Creek during this period ranged from 1 to 3,395 organisms per 100 mL (Figure 14). The highest values were observed at monitoring site BC-4 within the city limits of Rock Springs. Single sample exceedances of the 630 organisms per 100 mL criterion were observed only at monitoring site BC-4. Insufficient data are available to detect meaningful spatial trends, however, it appears that concentrations may be higher within and downstream from Rock Springs during the SCR season. Insufficient loads were available to evaluate trends during the winter.
Figure 14. Summary of E. coli concentrations during the winter along Bitter Creek.
Sufficient data are available to calculate E. coli geometric means during the winter for only two months between 2004 and 2011 (Table 6). No exceedances were observed.
Table 6. SCR geometric means for sites on Bitter Creek
Monitoring site Aug May 2004 2005 BC-7 3 -- BC-6 3 41 BC-10 -- 9 BC-5 6 -- BC-4 13 250 BC-3 62 -- BC-2 26 104 BC-1 25 -- Notes Geometric means were only calculated at sites with at least 5 samples in the specified month. Bolded values exceed the geometric mean criterion of 630 organisms per 100 milliliters.
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5.2 KILLPECKER CREEK
SWCCD sampled 9 monitoring sites along Killpecker Creek during the summer (Appendix B); three of those sites were also sampled in the winter. Samples collected during the summer (and thus subject to the PCR criteria) and in winter (and thus subject to the SCR criteria) are discussed separately in the following two subsections. 5.2.1 Primary Contact Recreation Similar to Bitter Creek, measured E. coli concentrations in Killpecker Creek during the summer ranged from 0.5 organism/mL to 24,200 organisms/mL (Figure 15). The highest values were observed at monitoring site KC-2 upstream from the city limits of Rock Springs. Single sample exceedances of the 126 organisms per 100 mL criteria were observed at all monitoring sites except KC-13 and KC-15, where only a limited number of samples were collected (Figure 15). As with Bitter Creek, there do not appear to be any spatial trends.
Figure 15. Summary of E. coli concentrations during the summer along Killpecker Creek.
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Given the limited amount of data, it is difficult to ascertain spatial trends across all the monitoring locations along Killpecker Creek. Loads are similar in magnitude at the two monitoring locations with a relative large number of samples (i.e., KC-2 above the City of Rock Springs and KC-1 within the City).
Figure 16. Summary of E. coli loads during the summer along Killpecker Creek.
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Sufficient data are available to calculate E. coli geometric means during the PCR period for eight months between 2004 and 2011 (Table 7). Since 2011, samples have been collected and evaluated for E. coli, but never have 5 samples been collected within a 60-day period during the summer recreation season.
Exceedances of the 126 organisms per 100 milliliter E. coli criterion have been observed at monitoring sites KC-1 and KC-2. Although insufficient samples have been collected since that time to meet the minimum of 5 samples within 60-day criterion, numerous discrete samples have been collected and suggest that E. coli impairment persists through 20163 (Table 8).
Table 7. PCR geometric means for sites on Killpecker Creek
Monitoring Aug May Sep May Sep May Sep Jun site 2004 2005 2005 2009 2009 2010 2010 2011 KC-3 -- 39 ------KC-2 --a -- a 3,773 4,801 982 ------KC-1 238 154 275 71 35 13 4 431 Notes Geometric means were only calculated at sites with at least 5 samples in the specified month. Bolded values exceed the geometric mean criterion of 126 organisms per 100 milliliters. a. Geometric means were not calculated for these sites during these months because corresponding flow records indicated Killpecker Creek was dry.
Table 8. Summary of post-2011 E. coli data collected from Killpecker Creek during the summer
Monitoring site No. of samples Relative no. of samples greater Informational geometric than 126 organisms per 100 mL mean (organisms per 100 mL) KC-3 0 -- -- KC-2 6 50% 245 KC-1 8 38% 78
3 The geometric mean values presented in Table 7 do not meet the 5 sample within a 60 day period criterion and should be viewed as informational only. Page 23 of 59
5.2.2 Secondary Contact Recreation Measured E. coli concentrations in Killpecker Creek during the winter ranged from 0.5 to 2,247 organisms per 100 mL (Figure 17). The highest values were observed at monitoring site KC-2 upstream from the city limits of Rock Springs. Single sample exceedances of the 630 organisms per 100 mL criterion were observed only at monitoring site KC-2. As with Bitter Creek, insufficient data are available to detect spatial trends during the winter season in Killpecker Creek.
Figure 17. Summary of E. coli concentrations during the winter along Killpecker Creek.
Sufficient data are available to calculate E. coli geometric means during the SCR period for two months between 2004 and 2011 (Table 9). No exceedances were observed.
Table 9. SCR geometric means for sites on Bitter Creek
Monitoring site Aug May 2004 2005 KC-3 1 -- KC-2 65 -- KC-1 46 13 Note: Geometric means were only calculated at sites with at least 5 samples in the specified month.
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6.0 SOURCE ASSESSMENT
E. coli bacteria are found in the excreta of warm-blooded animals such as humans, livestock, pets, and wildlife. A weight-of-evidence approach was used to assess the sources that contribute bacteria loads to the impaired segments in the Bitter Creek watershed. Potential transport pathways from these sources to Bitter Creek are described below, followed by a discussion of each of the potential sources.
6.1 PATHWAYS
There are three primary pathways by which bacteria can reach surface waters in the Bitter Creek watershed: direct deposition, surface water runoff, or leaching into the shallow groundwater and ultimately into Bitter Creek or its tributaries (Figure 19). Direct deposition occurs when livestock, pets, or wildlife defecate or urinate directly into surface water or when bacteria are discharged directly through a point source4. Illicit discharges5 could also result in direct deposition. Unlike the other pathways, there is no reduction between the bacteria source and the stream; the entire load is delivered.
Bacteria transport in surface runoff refers to water flowing over the ground surface including rainwater, snowmelt, or irrigation water that does not infiltrate the soil. The City of Rock Springs stormwater conveyance system is an important example of this pathway in the Bitter Creek watershed. As shown in Figure 18, much of the stormwater conveyance system discharges directly to Bitter and Killpecker Creeks. Bacteria in runoff waters may be associated with both direct entrainment of organisms in overland flow and transport of sediments onto which bacteria have been attached. Factors such as proximity to streams and length of overland flow can have a strong influence on bacteria mobilization and delivery via the surface water pathway. Photo 1 provides an example of a stormwater outlet that discharges directly to Bitter Creek.
Leaching is the process whereby bacteria are carried Photo 1. Stormwater outlet to Bitter Creek in downward and/or through the soil profile by snowmelt, rain or the vicinity of monitoring site BC-3. irrigation water. While soils can be effective filters for microorganisms, the existence of macropores (relatively large channels in soil resulting from worm-holes, voids left by decayed plant roots, etc.) can allow bacteria to bypass soil filtration. Significant movement of bacteria through macropores and into groundwater and eventually into surface waterbodies has been documented in cropland receiving manure and from grazing land (Jamieson et al., 2002). Leaching is not likely an important pathway in much of the Bitter Creek watershed.
4 The term "point source" means any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. 5 The discharge of untreated domestic sanitary waste to a stream, without treatment in a septic system or a centralized waste water treatment system, is an illicit discharge. This includes illicit connections of sanitary sewers to storm sewers that eventually discharge to streams. Page 25 of 59
Figure 18. City of Rock Springs storm water conveyance pipes.
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Figure 19. Bacteria transport pathways
6.2 POTENTIALLY SIGNIFICANT SOURCES OF BACTERIA
Bacteria sources in the Bitter Creek watershed may be derived from both point source and nonpoint source pollution. Pollution originating from a single, identifiable source, such as a discharge pipe from a wastewater treatment plant, is called point source pollution. Pollution that does not originate from a single source, or point, is called nonpoint source pollution. Nonpoint source pollution is caused by rainfall or snowmelt moving over and through the ground; direct deposition is also a nonpoint source as discussed in Section 6.1. As the runoff moves, it picks up and carries away natural and human-made pollutants, depositing them into rivers and streams. The point and nonpoint sources of bacteria in the Bitter Creek watershed are described below.
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6.3 POINT SOURCES
WDEQ identified eight facilities with Wyoming Pollutant Discharge Elimination System (WYPDES) permits to discharge within the Bitter Creek watershed6 (Table 10 and Figure 20). As described below, only four of the facilities appear to be potential sources of bacteria: the Superior Wastewater Lagoon, B&R Mobile Home Village, Rock Springs Water Reclamation Facility, and BLM Rock Springs Wild Horse Facility.
In addition to the permitted facilities, the towns of Reliance and Point of Rocks are served by lagoon systems that are not permitted to discharge.
Table 10. Permitted point source dischargers with E. coli limits in the Bitter Creek watershed
Permit Permitee Facility Type Design Summer limits Winter limits flow Monthly Daily Monthly Daily (mgd) Avg. Max. Avg. Max. WY0021806 Superior, Superior Sanitary 0.05 126 576 630 630 Town of Wastewater Lagoon WY0022128 Regency of B & R Mobile Sanitary 0.06 126 236 630 630 Wyoming, Inc. Home Village WY0022357 City of Rock Rock Springs Sanitary 4.2 126 236 630 630 Springs Water Reclamation Facility WY0023825 Rocky Stansbury Mine Coal ------Mountain Coal Mine Company, LLC WY0028886 Black Butte Leucite Hills Coal ------Coal Mine Mine Company WY0030261 Black Butte Black Butte Coal ------Coal Mine Mine Company WY0030350 Bridger Coal Jim Bridger Coal ------Company Mine Mine WY0094528 BLM BLM Rock CAFO This facility may only discharge under limited Springs Wild conditions following certain precipitation events Horse Facility specified in the discharge permit. (none) (unknown) Point of Rocks Sanitary 0 This facility is not permitted to lagoons discharge. (none) North Reliance Sanitary 0 The facility is not permitted to Sweetwater facultative discharge. Water & lagoons Sewer District Note: Avg. = average (mean); BLM = Bureau of Lange Management; CAFO = concentrated animal feeding operation; Max. = maximum; mgd = million gallons per day; ND = no discharge.
6 Sol Brich, TMDL Coordinator, WDEQ WQD, electronic communications, February 2, 2017. Page 28 of 59
Figure 20. Permitted point source dischargers and outfall locations within the Bitter Creek watershed.
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6.3.1 Superior Wastewater Lagoon (WY0021806) The city of Superior operates a wastewater treatment facility (WWTF) where wastewater flows to a three-cell stabilization pond system. Wastewater enters cells one and two in parallel and then enters cell three. The stabilization ponds were constructed to flow in series or individual cells to allow for maintenance. The WWTF has a total storage volume of 0.05 million gallons (MG). This system receives wastewater from a population of 244 (2000 Census). Past monitoring data indicates this facility rarely discharges. The treated water is immediately discharged to Horsethief Canyon Creek, a tributary to Bitter Creek (Figure 20). The permit establishes E. coli effluent limits for the end of pipe (Table 10).
Daily maximum and monthly average DMR data were provided by WDEQ for January 2009 through September 2014. During this timeframe, 13 discharges were reported; however, some of the DMR data are clearly erroneous and have been excluded from this analysis (e.g., 108 million gallons per day [mgd] discharge in May and June 2009). During most months from January 2009 through September 2014, the Superior Wastewater Lagoon reported that no discharges occurred. Daily maximum flow and E. coli data for when the lagoon discharged are summarized in Table 11. Much of the E. coli concentration data exceed the daily maximum permit limit.
Table 11. Flow and E. coli daily maximum data for the Superior Wastewater Lagoon (2009-2015)
Period Flow Flow E. coli E. coli load Exceed E. coli (cfs) (mgd) (colonies / 100 mL) (billion colonies / day) permit limit? January 2009 0.185 0.12 121,000 550 Yes May 2009 -- a -- a 3,080 -- Yes June 2009 -- a -- a 2,420 -- Yes February 2010 0.263 0.17 137,000 882 Yes September 2010 -- b -- b 2,420 -- Yes June 2011 0.033 0.0216 840 0.69 Yes October 2012 0.077 0.05 1,466 2.78 Yes November 2012 0.124 0.08 24,192 73 Yes July 2013 0.009 0.006 48 0.011 No August 2013 -- c -- c 27.8 -- No July 2014 0.045 0.029 27.5 0.030 No August 2014 0.056 0.036 68.3 0.093 No September 2014 0.067 0.043 648 1.1 Yes Notes a. A flow of 108 mgd (167 cfs) was reported, which is assumed to be erroneous. b. A flow of 1.7 mgd (2.6 cfs) was reported, which is assumed to be erroneous. b. A flow of 6.0 mgd (9.3 cfs) was reported, which is assumed to be erroneous.
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6.3.2 B & R Mobile Home Village (WY0022128) The B & R Mobile Home Village provides wastewater treatment for approximately 160 mobile homes in the park and for 9 commercial users (WDEQ 2016d). This facility is located just west of Reliance and north of Rock Springs. It is a package plant that consists of course screening, and an extended air aeration tank, followed by clarifers, chlorination, and dechlorination (WDEQ 2010, 2016d). There is a final polishing pond. At this time, the polishing pond is used in effluent quantity or quality emergencies. Sludge is handled through an aerated digester. The typical daily flow for this facility is 0.05 mgd with peak flows of 0.06 mgd (WDEQ 2016d), and discharges to Killpecker Creek (Figure 21). The permit establishes E. coli effluent limits for the end of pipe (Table 10). Daily maximum and monthly average DMR data were provided by WDEQ for January 2004 through December 2016. E. coli data were only available from 2012 onward. Of the 150 discharges, only 109 were evaluated herein (Figure 21) because 41 discharges from late 2006 through early 2011 appeared to be erroneous (e.g., 33 mgd discharge in January through March 2009). Daily maximum flow and E. coli data are summarized in Figure 21. Flow, concentration, and calculated loads are summarized in Table 12. About a third of summer and about a quarter of winter E. coli concentration records exceed the daily maximum permit limit7.
Notes Suspiciously high flow data from late 2006 through early 2011 are not presented. Figure 21. Flow and E. coli daily maximum data for the B & R Mobile Home Village (2004-2016).
Table 12. Flow and E. coli daily maximum data summary for the B & R Mobile Home Village (2012-2015)
Period No. of Flow Flow E. coli E. coli load Exceed records (cfs) (mgd) (colonies / 100 (million E. coli mL) colonies / day) permit limit May 1 - Sep 30 25 0.077 - 0.093 0.05 - 0.06 1 - 2,419 1.9 - 4,578 32% Oct 1 - Apr 30 31 0.062 - 0.093 0.04 - 0.06 1 - 24,192 1.9 - 54,946 23%
7 Ten samples collected from the pond (monitoring site KC-6) by SWCCD in May and September 2009 ranged from 209 to 24,200 counts per 100 milliliter (median of 1,745 counts per 100 milliliter); nine samples were greater than 236 count per 100 milliliter. Page 31 of 59
6.3.3 Rock Springs Water Reclamation Facility (WY0022357) The water reclamation facility serving the City of Rock Springs consists of course screening and grit removal; influent flow monitoring; the influent then flows to two oxidation ditches operated in parallel; followed by two covered final clarifiers operated in parallel (WDEQ 2014b). The final effluent is then disinfected with UV disinfection, is metered for quantity, and then directly discharged to Bitter Creek (Figure 20). This sanitary wastewater treatment facility serves a population of approximately 23,036 citizens (2010 census). It has a design flow of 4.2 MGD, and is currently reclaiming approximately 2.15 MGD of wastewater. The permit (WDEQ 2014b) establishes E. coli effluent limits for the end of pipe (Table 10).
Daily maximum and monthly average DMR data were provided by WDEQ for April 2004 through May 2017. E. coli data were only available from 2011 onward. During this timeframe, 155 discharges were reported; one record was likely erroneous (e.g., 262 mgd discharge in February 2014) and excluded from analysis. Daily maximum flow and E. coli data are summarized in Figure 22. Flow, concentration, and calculated loads are summarized in Table 13.
None of the E. coli concentrations exceed the daily maximum permit limit.
Figure 22. Flow and E. coli daily maximum data for the Rock Springs Water Reclamation Facility (2004- 2017).
Table 13. Flow and E. coli daily maximum data summary for the Rock Springs Water Reclamation Facility (2012-2015)
Period No. of Flow Flow E. coli E. coli load Exceed records (cfs) (mgd) (colonies / 100 (billion E. coli mL) colonies / day) permit limit May 1 - Sep 30 30 3.7 - 7.4 2.39 - 4.78 6 - 223 0.54 - 33 0% Oct 1 - Apr 30 43 3.7 - 6.8 2.39 - 4.40 3 - 150 0.27 - 16 0%
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6.3.4 Stansbury Mine (WY0023825) Rocky Mountain Coal Company, LLC is the owner and operator of the Stansbury Underground coal mine that is located near the Town of Reliance in Sweetwater County. The permit authorizes the discharge from four separate outfalls. The wastewater that contributes to these outfalls are: pumped groundwater, surface area runoff, facilities wash down water, overflow from a water storage tank, and wastewater from dewatering wells (WDEQ 2013b). This facility rarely discharges. There has only been a single reported discharge since 1998 (0.003 mgd). The discharges from this facility are not considered a source of bacteria and therefore are not considered further as a component of this TMDL. 6.3.5 Leucite Hills Mine (WY0028886) The Black Butte Coal Company is the owner and operator of an open pit coal mine located approximately three miles west of the Jim Bridger Power Plant in Sweetwater County. Pit water and runoff from disturbed areas, plant yards, and stockpile areas can be discharged from 9 different outfalls. The discharges from these will drain to the OK Draw, Mac Creek, B Draw, Humphrey Draw, Coon Draw, Nine Mile Creek via an unnamed drainage, the PP & L evaporation pond via an unnamed drainage and Deadman Wash via an unnamed drainage (all Class 3B waters). Discharges also flow to Pit 21 and Pit 22 (class 4A waters8). The discharges9 from this facility are not considered a source of bacteria and therefore are not considered further as a component of this TMDL. 6.3.6 Black Butte Mine (WY0030261) The Black Butte Coal Company is the owner and operator of an open pit coal mine located approximately thirty miles east of the City of Rock Springs. Pit water, coal crusher wash down water, and runoff from disturbed areas, coal piles, and the office/shop areas can be discharged from 49 different outfalls. The discharges from these outfalls will flow to various draws (class 3B waters) that are tributary to Bitter Creek (class 2C water). This facility discharges infrequently10. The discharges from this facility are not considered a source of bacteria and therefore are not considered further as a component of this TMDL. 6.3.7 Jim Bridger Mine (WY0030350) The Bridger Coal Company is the owner and operator of the Jim Bridger Coal Mine. The mine, which is located east of Rock Springs, provides coal for the Jim Bridger Power Plant. The permit authorizes the discharge of wastewater from sixteen sedimentation ponds which receive pit water, disturbed area runoff, coal pile runoff, and truck dump station runoff. The discharges11 from this facility are not considered a source of bacteria and therefore are not considered further as a component of this TMDL. 6.3.8 BLM Rock Springs Wild Horse Facility (WY0094528) The BLM owns and manages a wild horse facility located 1.5 miles north of Rock Springs, WY (Figure 20). They are permitted for 800 horses being held for up to 365 days per year. Runoff control is with berms along the edges of Lionkol Draw and two retention ponds. Pond 1, on the north side of Lionkol Draw has the capacity to hold 2.6 acre feet of water and pond 2, on the south side of Lionkol Draw, is designed to hold 0.7 acre feet of water. There are two potential outfalls for this facility; one outfall per retention pond, all discharging to Lionkol Draw, a tributary to Killpecker Creek.
Manure from this facility is pen-held and removed to stockpile two times annually. It is either transported to the Rock Springs Landfill at the time of collection, or stored and moved to the landfill as soon as possible. Manure is not land applied.
The permit requires immediate compliance with Best Practical Control Technology (BPT) and Best Available Technology (BAT) Limits that are defined in the EPA Effluent Guidelines and Standards for Feedlots (all
8 Class 4A waters are designated for recreation, wildlife, agriculture, industry and scenic value; they are artificial canals and ditches that are not known to support fish populations. 9 No discharges were reported from October 2002 through June 2017 at any of the 18 outfalls. 10 From October 2002 through June 2017, discharges were reported for 14 of the 58 outfalls. Between one and four discharges were reported for 12 outfalls across a span of 15 years. Seven discharges were reported at outfall 017 and 19 discharges are reported for outfall 031. 11 From May 2000 through June 2017, discharges were reported for 14 of the 26 outfalls. Page 33 of 59
subcategories except ducks), 40 CFR PART 412, and Chapter 2, Wyoming Water Quality Rules and Regulations, Appendix G. According to these standards, there shall be no discharge of process wastewater to navigable waters except in the case of a chronic or catastrophic storm event which causes an overflow from the runoff and/or wastewater control structures. These facilities are to be designed, constructed and operated to contain all process generated wastewaters plus the runoff from a 25-year/24 hour storm event (1.9 inches)12. 6.3.9 Point of Rocks Lagoons (No Permit) A multi-cell lagoon system is operated in the town of Point of Rocks. The lagoons are along Black Butte Road to the south of the railroad right-of-way and Instate 80 (the Lincoln Highway). The southern two lagoon cells are about 100 feet north of Bitter Creek, which meanders along the town. A review of USGS and Farm Service Agency aerial imagery in GoogleEarthTM indicates that several cells have been in operation since at least June 1994.
The lagoon system is not covered by a WYPDES permit, and thus, it is not authorized to discharge to any surface waters of the state. WDEQ inspected the facility on May 13, 2015 and noted that the lagoons were well below maximum capacity at that time, there was no evidence of seeps into Bitter Creek, and several back-up berms where in place to prevent overtopping into Bitter Creek (Personal Communication. Andrea Summers. WYPDES Field Inspector, Wyoming Department of Environmental Quality, Rock Springs Field Office. December 18, 2017). Additionally, SWCCD investigated the area of the lagoons during routine monitoring and could not locate indications of discharge, though access was limited. SWCCD monitoring upstream at site BC-6 and downstream at site BC-18 during 2012, 2015, and 2016 showed no definitive evidence of increases in E. coli loading in Bitter Creek as it passes these lagoons. 6.3.10 Reliance Facultative Lagoons (No Permit) The North Sweetwater Water and Sewer Districts (NSWSD) owns and operates the Reliance lagoons that are just west of the town of Reliance. NSWSD assumed ownership of the lagoons and sanitary sewer lines in Reliance on March 1, 2011, following the dissolution of the Reliance Sewer District on February 12, 2009 (WDEQ 2014a).
The treatment works are composed of three facultative total containment lagoons (Office of State Lands and Investment [OSLI] 2014). Two lagoons were constructed in the 1960s (OSLI 2014). WDEQ (2014a) believes that the third lagoon was constructed in between September 1994 and January 200113. The third lagoon was built without a permit to construct and both the lagoon and its discharge outfall are unpermitted (WDEQ 2014a). WDEQ did not authorize the construction of any outfalls. Without a WYPDES permit, all discharges are illicit (WDEQ 2014a).
The system serves 125 residential connections in Reliance (OSLI 2014). The Reliance lagoons accept septage from septage haulers and WDEQ (2014) believes that such septage may cause or contribute to unpermitted discharges. As of 2014, NSWSD allowed the Reliance lagoons to continue to accept septage.
Several unpermitted discharges were documented since 1981 (WDEQ 2014a):
Date unknown in 1981 (letter of violation dated November 18, 1981) April 3, 1990 (letter of violation dated April 12, 1990) December 29, 2006 January 2, 2007 April 9, 2008
The lagoons are at capacity (OSLI 2014). WDEQ (2014a) has ordered NSWSD to apply for grants to construct a wastewater treatment system that complies with Wyoming’s water quality rules and regulations. NSWSD has
12 WDEQ has no DMR data for this facility. 13 OSLI (2014) indicates that a third cell was constructed in the 1980s. The agencies may be counting cells differently. A review of aerial imagery in GoogleEarthTM shows that two cells were present on September 3, 1994; however, the eastern cell is partially divided and may be considered two cells. The new third cell, north of the other two cells, is first apparent in aerial imagery from July 10, 2006. Page 34 of 59
sought state funding to connect the Reliance lagoons, and privately owned B & R mobile home village, to the city of Rock Springs wastewater reclamation facility (OSLI 2014). A population of over 700 people would be affected. State funding would be used to construct a lift station, to construct the necessary piping to connect to the Rock Springs wastewater reclamation facility, and to replace collection pipes in Reliance that are plagued by “recurring plugging issues, structural deficiencies,” and “do not meet current sizing standards” (OSLI 2014, p. 6). WDEQ (2017b) issued NSWSD a permit to construct (Permit NO. 17-034) to install a gravity sewage collection system, a lift station, and a force main; all permitted activities must be completed by December 31, 2019 when the permit expires.
In addition to the unpermitted lagoons and outfalls; breaches, leaks, and lagoon overflows; sewer leaks; and year- round odor from mounded sludge, NSWSD has trouble getting users to pay their sewer bills. NSWSD hosted a public meeting on March 8, 2016 to discuss potential solutions regarding users who are not paying their sewer bills (KQSW 96.5 2016). 6.3.11 Non-Discharging Wastewater Facilities A number of non-discharging wastewater facilities are also located within the watershed (Table 14). These facilities were constructed under WDEQ Permits to Construct, are not authorized to discharge, and are not expected to constitute significant source of bacteria loading in the watershed.
Table 14. Non-discharging wastewater facilities
Facility Permit to Construct West Side Water and Sewer District sewage lagoon 90-039 Wyoming Department of Transportation Bitter Creek 02-251 East and West Wyoming Department of Transportation Patrick Draw 04-107 Black Butte Coal 77-169 Bridger Coal 06-761 and 07-543 City of Rock Springs Land Application 07-313
6.3.12 Summary The following general conclusions were drawn regarding point source discharges in the Bitter Creek watershed:
Superior Wastewater Lagoon: The lagoons sometimes discharge at high E. coli concentrations, but the effluent flows are very small. No flows were observed in Horsethief Canyon where it crosses I-80 during routine SWCCD water quality monitoring from 2004 thru 2017 and anecdotal information indicates that the effluent does not reach Bitter Creek; therefore, these lagoons do not likely contribute substantially to the impairments on Bitter Creek.
B & R Mobile Home Village: These lagoons also sometimes discharge high E. coli concentrations, but the effluent flows are very small. Effluent loads may contribute to the impairments; however, a permit to construct a connection with the city of Rock Springs sewerage system and Water Reclamation Facility has been authorized. Connecting to Rock Springs will likely alleviate any issues with B & R Mobile Home Village.
Rock Springs Water Reclamation Facility: This WWTF contributes E. coli loads to Bitter Creek, but it discharges at or below permit limits and appears to have additional capacity.
Mines: Mines rarely discharge and do not contribute E. coli loads to the impaired segments.
CAFO: The Rock Springs Wild Horse Facility should not discharge, except under very limited conditions, and does not contribute E. coli loads to the impaired segments.
Point of Rocks Lagoons: The available information suggest that the Point of Rocks lagoonsare not likely a significant source of E. coli loading.
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Reliance Facultative Lagoons: A history of WDEQ compliance assistance and enforcement actions exist with this facility. However, as with B&R Mobile Home Village, a permit to construct a connection with the city of Rock Springs sewerage system and Water Reclamation Facility has been authorized. Connecting to Rock Springs will likely alleviate any issues with Reliance.
Non-Discharging Facilities: These facilities are not authorized to discharge and are not likely to be significant sources of bacteria loading.
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6.4 NONPOINT SOURCES
Potentially significant nonpoint sources of bacteria in the Bitter Creek watershed include septic systems, livestock, wild horses, wildlife, and pets. These nonpoint sources are described in the following subsections. 6.4.1 Septic Systems Septic systems in Sweetwater County are permitted through the Sweetwater County Environmental Health Department (SCEHD). However, Sweetwater County does not maintain a georeferenced database of septic systems.14 In other words, the septic systems in the SCEHD database have not been associated with locations in physical space.
As a result, the number and approximate location of septic systems in the watershed were determined using “household address points” obtained from the Sweetwater County Engineering Department (2017). The Department spatially located a point, in a Geographic Information System, for each physical address with an existing structure in the county (referred to as “household address points”). To estimate the number of septic systems in the Bitter Creek watershed, the household address points were summed, excluding those within areas currently served by wastewater treatment facilities15. The majority of households in the Bitter Creek watershed are served by wastewater treatment facilities (9,088 of 9,591). Only 503 septic systems are estimated to be located within the watershed.
The largest concentration of septic systems is in the vicinity of the City of Rock Springs within, or adjacent to Tenmile, North Sweetwater, and West Side Water and Sewer Districts (Figure 23). Households and associated septic systems are sparsely scattered throughout the remainder of the watershed, where they do not likely constitute a significant source of bacteria unless the systems are in close proximity and/or hydrologically connected to natural stream courses and are failing16.
Estimated Quantities and Locations
Septic systems within the Bitter Creek watershed were quantified and located using the best available information. However, the household address points may include some structures with addresses that do not have septic systems and some households may have been accidently excluded when Sweetwater County Engineering compiled the data. Further, many of the locations were based on the centroid of the parcel and do not necessarily represent the precise location of the septic system. As a result, both the reported quantity and location of septic systems are estimates. In spite of the uncertainties, the key conclusions are valid: With the exception of the areas adjacent to the City of Rock Springs where septic density is high, the density of septic systems in the watershed is very low. The higher the septic system density and the closer the systems are to natural waterways, the greater the potential for bacteria (and other pollutant) loading.
14 Sara Geffre. Environmental Health Specialist, SCEHD. Personal Communication. August 9, 2017. 15 There are three wastewater treatment facilities in the Bitter Creek watersheds (City of Rock Springs, Superior, and the B&R Mobile Home Village. Additionally, the White Mountain Water and Sewer District and Clearview Improvement District convey their waste water to the City of Rock Springs facility. Refer to Section 6.3 for a discussion of the wastewater treatment facilities in the watershed. 16 Septic systems are considered failing if they are not functioning properly or are functioning as designed but were improperly sized or sited. Page 37 of 59
Figure 23. Location of septic systems, municipalities, and water and sewer districts. 6.4.2 Livestock The Bureau of Land Management (BLM) manages rangelands throughout the west for the use of wildlife and livestock. The rangelands are divided into allotments and pastures for management purposes. Much of the landownership within the Bitter Creek watershed is in a “checkerboard” of private lands intermixed with BLM lands (refer to Figure 2). Fourteen grazing allotments are within the Bitter Creek watershed that include a combination of public and private lands (Figure 24 and Table 15). Only three are entirely within the watershed (Table 15). Many, such as the Rock Springs Allotment, extend well beyond the watershed boundaries.
Based on public records obtained from the BLM’s Rangeland Administration System Reports (BLM 2017), up to approximately 45,000 sheep and 7,500 cattle are grazed within the watershed17. This represents a density of approximately 12 sheep and 2 cattle per square mile if they were distributed uniformly throughout the watershed. However, they are not uniformly distributed. Rather, the spatial and temporal distribution of livestock is extremely variable throughout the year and numbers at any given location may be much higher or lower. Animals are moved based on grazing authorization requirements to minimize overgrazing and also move in response to forage quality and availability of water. According to the Rock Springs Grazing Association and based on WDEQ observations
17 Numbers were estimated by multiplying the maximum authorized number or cattle and sheep (at any point in time) by the percent of the grazing allotment within the Bitter Creek watershed. For the Rock Springs Allotment, the largest one in the watershed and the one with the majority of the AUMs, the livestock operators have used between 33 percent and 44 percent of their permitted AUMs. Thus, on average, they have been taking about 62 percent non-use. As a result, the estimates presented herein are conservative (Spencer Allred. Supervisory Rangeland Management Specialist. Bureau of Land Management – Rock Springs Field Office, electronic correspondence, October 2, 2017) Page 38 of 59
during water quality sampling in 2017, grazing along Bitter and Killpecker Creeks is minor and the majority of the grazing that does occur is winter grazing of sheep. However,in dry seasons/periods when water and forage are scarce, livestock may occasionally frequent the areas along stream courses where water is available and food sources may be greener. During more favorable conditions, they may be more widely distributed across the landscape.
Figure 24. BLM grazing allotments in the Bitter Creek watershed.
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Table 15. BLM grazing allotments in the Bitter Creek watershed
Allotment name Total area Area in Bitter Creek Relative area in Bitter (acres) watershed (acres) Creek watershed Circle Springs 22,012 22,012 100% Crookston Ranch 47 47 100% Fourth of July 21,810 1,133 5% Houghton 369 369 100% Mellor Mountain 69,644 57,192 82% Pacific Creek 197,608 109 <1% Pine Mountain 73,441 16,753 23% Red Creek 67,575 25 <1% Rife 33,559 1,092 3% Rock Springs 2,047,652 1,120,797 55% Salt Wells 52,352 28,570 55% Sands 110,297 61,741 56% Steamboat Mountain 36,951 492 1% Vermillion Creek 145,887 82,456 57% Totals 4,926,856 2,513,585 51%
6.4.3 Wild Horses Wild, free-roaming horses can be found on public lands across 10 western states. Pursuant to the Wild Free- Roaming Horses and Burros Act, the BLM and U.S. Forest Service manage wild horses on subsets of public lands where the animals were found upon passage of the Act in 1971. These areas are known as Herd Management Areas (HMA). There are four HMAs within the Bitter Creek watershed (Figure 25 and Table 16). None are entirely within the watershed (Table 16). A total of 3,152 wild horses were observed within these four HMAs during an aerial census conducted by BLM in May 2017 (Appendix C). Assuming uniform distribution across the HMAs, approximately 967 were within the Bitter Creek watershed18. That represents a wild horse density of approximately 0.6 wild horses per square mile. However, as with livestock, the spatial and temporal distribution of wild horses is extremely variable throughout the year and numbers at any given location may be much higher or lower. Appendix C provides a snapshot of the spatial distribution based on the above mentioned BLM aerial survey. At the time of the survey, the horses were fairly well distributed throughout the area, with the highest concentrations in the southern portion of the Salt Wells Creek HMA and northern portion of the Adobe Town HMA.
18 Numbers were estimated by multiplying the number of horses observed by the percent of the HMA within the Bitter Creek watershed. Page 40 of 59
Figure 25. Wild horse HMAs within the Bitter Creek watershed.
Table 16. Wild horse HMAs
Herd name Total area Area in Bitter Creek Relative area in Bitter (acres) watershed (acres) Creek watershed Divide Basin 778,949 112,680 14.5% White Mountain 393,073 33,600 8.5% Salt Wells Creek 1,172,660 944,509 80.5% Adobe Town 477,829 9,521 2.0% Total 2,822,511 1,100,311 39.0%
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6.4.4 Wildlife Wildlife in the Bitter Creek watershed are a natural background source of bacteria. Similar to livestock, wildlife, including big game species, waterfowl, and small mammals, contribute bacteria loads to Bitter Creek and tributaries: (1) directly by defecating while wading or swimming in the stream, and (2) indirectly by defecating on lands that are washed off during precipitation events.
The primary big game species in the Bitter Creek watershed include pronghorn antelope, mule deer, and elk. All three are potential sources of bacteria loading. This subsection presents population estimates and brief narratives regarding the distribution of each of these big game species in the Bitter Creek watershed. The Wyoming Game and Fish Department’s (WGFD) 2016 Big Game Job Completion Reports (WGFD 2016a,b,c) were relied upon as the primary source of data and information.
6.4.4.1 Elk The Bitter Creek watershed is located within three WGFD Herd Units (HUs; Figure 26). The total estimated population of elk within these three HUs is 2,788, but the Bitter Creek watershed comprises only 30 percent of the total area. Assuming uniform distribution of elk throughout the HUs (0.4 elk/square mile), the total estimated number of elk in the Bitter Creek watershed is approximately 1,034 (Table 17).
Clearly, however, elk distribution is not uniform. As shown in Notes: CRUWYL = crucial/winter/yearlong; OUT = out of range; SSF = spring, summer, fall; UND = undetermined; WYL = winter/yearlong; YRL = yearlong.
Figure 27, the primary elk habitat is along the periphery of the watershed, along the north, south, and east margins. A large portion of the watershed, including the majority of Killpecker Creek and the north side of Bitter Creek from the mouth upstream to the confluence with Ten Mile Draw, does not contain enough elk to be important habitat, or is of limited importance to elk (i.e., “Out” as shown in Notes: CRUWYL = crucial/winter/yearlong; OUT = out of range; SSF = spring, summer, fall; UND = undetermined; WYL = winter/yearlong; YRL = yearlong.
Figure 27). The central portion of the watershed includes a large area classified as Undetermined/Undocumented. This area is primarily within Herd Unit 430, where WGFD has not formally estimated the numbers of elk. WGFD estimates that roughly 175 elk may roam this area, but this is a small and highly mobile elk herd spread over a large area. A great deal of interchange occurs with Colorado to the south19 .
Table 17. Estimated total number of elk in the Bitter Creek watershed
Herd Unit Bitter Creek watershed HU ID No. of elk Total area Elk density Area Relative area Estimated (sq. mi.) (no. / sq. mi.) (sq. mi.) no. of elk a 424 688 658 1.0 571 87% 597 426 1,600 4,009 0.4 659 16% 263 430 b 500 2,868 0.2 998 35% 174 Totals 2,788 7,535 0.4 2,228 30% 1,034 Source: WGFD 2016a Notes a. Assumes uniform distribution of elk throughout the entire HU. Estimated by multiplying the number of elk in the HU by the relative area of the HU in the Bitter Creek watershed. b. The elk population in this HU has not been surveyed. WGFD estimates 300 to 500 elk roam the HU, but often migrate out of the HU into Colorado.
19 Mark Zornes, Senior Wildlife Biologist, WGFD Green River Region, personal communication, August 8, 2017. Page 42 of 59
Figure 26. Elk HUs within the Bitter Creek watershed.
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Notes: CRUWYL = crucial/winter/yearlong; OUT = out of range; SSF = spring, summer, fall; UND = undetermined; WYL = winter/yearlong; YRL = yearlong.
Figure 27. Elk seasonal ranges in the Bitter Creek watershed.
6.4.4.2 Mule Deer The Bitter Creek watershed is located within three WGFD mule deer HUs (Figure 28). The total estimated population of mule deer within these three HUs is greater than 50,000, but the Bitter Creek watershed comprises only 14 percent of the total area. Assuming uniform distribution throughout the HUs (3.3 mule deer/square mile), the total estimated number of mule deer in the Bitter Creek watershed is approximately 5,797 (Table 18). With the exception of an area along Killpecker Creek and near Rock Springs, mule deer regularly occupy the entire watershed (Notes: CRUWYL = crucial/winter/yearlong; OUT = out of range; SSF = spring, summer, fall; WYL = winter/yearlong; YRL = yearlong.
Figure 29).
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Table 18. Estimated total number of mule deer in the Bitter Creek watershed
Herd Unit Bitter Creek watershed HU ID No. of mule Total area Mule deer Area Relative area Estimated deer (sq. mi.) density (sq. mi.) no. of mule (no. / sq. mi.) deer a 104 b 28,509 10,093 2.8 659 7% 1,861 424 c 4,100 2,304 1.8 1,266 55% 2,253 427 18,600 3,350 5.6 303 9% 1,682 Totals 51,209 15,747 3.3 2,228 14% 5,797 Notes a. Assumes uniform distribution of mule deer throughout the entire HU. Estimated by multiplying the number of mule deer in the HU by the relative area of the HU in the Bitter Creek watershed. b. WGFD 2016a c. WGFD 2016c
Figure 28. Mule deer HUs within the Bitter Creek watershed.
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Notes: CRUWYL = crucial/winter/yearlong; OUT = out of range; SSF = spring, summer, fall; WYL = winter/yearlong; YRL = yearlong.
Figure 29. Mule deer seasonal ranges.
6.4.4.3 Pronghorn The Bitter Creek watershed is located within four WGFD pronghorn HUs (Figure 28). The total estimated population of pronghorn within these three HUs is greater than 18,000, but the Bitter Creek watershed comprises only 12 percent of the total area. Assuming uniform distribution throughout the HUs (3.9 pronghorn/square mile), the total estimated number of pronghorn in the Bitter Creek watershed is approximately 10,569 (Table 18). With the exception of a small area south of Rock Springs, pronghorn regularly occupy the entire watershed (Notes: CRUWYL = crucial/winter/yearlong; OUT = out of range; SSF = spring, summer, fall; WYL = winter/yearlong; YRL = yearlong.
Figure 29).
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Table 19. Estimated total number of pronghorn in the Bitter Creek watershed
Herd Unit Bitter Creek watershed HU ID No. of Total area Pronghorn Area Relative area Estimated pronghorn (sq. mi.) density (sq. mi.) no. of (no. / sq. mi.) pronghorn a 401 b 38,000 10,690 3.6 537 5% 1,909 412 b 7,300 1,211 6.0 571 47% 3,442 414 b 13,700 2,868 4.8 998 35% 4,767 615 c 12,500 3,385 3.7 122 4% 451 Totals 71,500 18,154 3.9 2,228 12% 10,569 Notes a. Assumes uniform distribution of pronghorn throughout the entire HU. Estimated by multiplying the number of pronghorn in the HU by the relative area of the HU in the Bitter Creek watershed. b. WGFD 2016a c. WGFD 2016b
Figure 30. Pronghorn HUs within the Bitter Creek watershed.
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Notes: CRUWYL = crucial/winter/yearlong; OUT = out of range; SSF = spring, summer, fall; SWR = severe winter relief; WYL = winter/yearlong.
Figure 31. Pronghorn seasonal ranges.
6.4.4.4 Big Game Conclusions and Uncertainty Of the three primary species of big game in the Bitter Creek watershed, pronghorn are the most numerous followed by mule deer and elk (Table 20). The quantities presented herein are estimates based on the best available data and information. Big game densities are not uniform throughout the watershed and densities/populations vary over the short-term (seasonally) and long-term (over periods of years). Variation is due to a number of factors including availability of food and water and disturbance factors (e.g., conflicts with other wildlife, wild horses, and livestock). In dry seasons/periods when water and food are scarce, big game may occasionally frequent the areas along stream courses where water is available and food sources may be greener. During more favorable conditions, big game may be more widely distributed across the landscape.
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Table 20. Estimated big game density and population in the Bitter Creek watershed
Big game Density Total number of animals (no. of animals per sq. mi.) Elk 0.4 1,034 Mule Deer 3.3 5,797 Pronghorn 3.9 10,569
6.4.4.5 Waterfowl No waterfowl survey data are available for the Bitter Creek watershed. Given limited open water and wetland habitat, the watershed is not a large waterfowl concentration area. Waterfowl do, however, use Bitter Creek especially in the spring and fall migration periods when the open waters of Bitter Creek are among the only aquatic habitat in an otherwise arid landscape.
6.4.4.6 Small Mammals As with waterfowl, there are no survey data for small mammals that inhabit aquatic and riparian habitats in the watershed. Based on incidental observations during WDEQ sampling events, raccoons and muskrats are common in these habitats and cottontail rabbits are numerous in the denser stands of sage brush often found adjacent to the streams flowing in the watershed. 6.4.5 Pets Pet waste may be a contributor of bacteria in the Bitter Creek watershed. Pet waste may not be properly disposed of along the stream and within the drainage network, and it can be washed off during precipitation events. According to a source water protection practices bulletin from the U.S. Environmental Protection Agency (2001), pets are significant contributors to source water bacteria contamination. The City of Rock Springs stormwater conveyance system is likely an important pathway for this bacteria source.
According to the American Veterinary Medical Association (2012), 36.5 percent of all households own an average of 1.6 dogs per household. Given 9,591 households within the watershed (Sweetwater County Engineering Department 2017), approximately 5,600 dogs are estimated to be in the watershed ((9,591 households x 0.365) x 1.6). 6.4.6 Other Potential Sources If waste from recreational vehicles (e.g., campers, motorhomes), campsites, and rest areas/pull-offs along remote sections of rural roadways is not disposed of properly, localized discharges of bacteria may occur. This is not thought to be a significant or chronic source, but should be considered as one of the potential sources of bacteria in the watershed.
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7.0 TMDL CALCULATIONS AND ALLOCATIONS TO SOURCES
TMDLs were developed at two locations in the Bitter Creek watershed. This section presents the development of the TMDLs and the allocation of loads, wasteloads and the margin of safety. Given insufficient data during the winter season, TMDLs were only developed for the summer using the PCR criteria. 7.1 TOTAL MAXIMUM DAILY LOAD
A TMDL is the total amount of a pollutant that a receiving waterbody can assimilate while still achieving water quality standards. TMDLs can be expressed in terms of mass per time or by other appropriate measures. TMDLs are composed of the sum of individual wasteload allocations (WLAs) for point sources and load allocations (LAs) for nonpoint sources and natural background levels. In addition, the TMDL must include a margin of safety (MOS), either implicitly or explicitly, that accounts for the uncertainty in the relationship between pollutant loads and the quality of the receiving waterbody. Conceptually, this is defined by the following equation:
TMDL = ∑WLA + LA + MOS
TMDLs for PCR during the summer recreation season were developed for the following sites on Bitter Creek and Killpecker Creek.
Bitter Creek above highway 373 (at monitoring site BC-2; Table 21): This TMDL was developed along impaired segment WYGR140401050506_01 (Bitter Creek from the confluence with the Green River upstream to Point of Rocks) and just below the only major permitted point source in the Bitter Creek watershed. This TMDL accounts for most of the watershed, including sources in the city of Rock Springs (e.g. permitted point sources, urban runoff) and nonpoint sources upstream of the city of Rock Springs Killpecker Creek at Western Wyoming Community College (at monitoring site KC-1; Table 21): This TMDL was developed at the bottom of impaired segment WYGR140401050808_01 (Killpecker Creek from the confluence with the Bitter Creek upstream to Reliance). This TMDL accounts for sources in the Killpecker Creek subwatershed.
These two TMDLs were developed for the PCR during the summer recreation season (May 1 - September 30). No TMDLs were developed for the winter recreation season (October 1 - April 30) because little monitoring data are available for the winter recreation season (see Sections 5.1.2 and 5.2.2). Existing conditions were determined for each TMDL using data provided by SWCCD; the difference between the existing conditions and TMDL is the reduction necessary to achieve the TMDL.
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Table 21. Summer E. coli TMDL for Bitter Creek above highway 373 (at monitoring site BC-2)
Element E. coli load (billion organisms per day) TMDL a 63.9 LA 43.4 WLAs b 20.5 Observed c 153.6 Reduction 58% Notes a. The TMDL is calculated using a flow of 20.73 cfs, which is the arithmetic mean of 49 flows monitored during the summer recreation season at monitoring site BC-2 in 2004, 2005, 2009-2012, 2014, and 2015. b. The WLAs is the summation of WLAs from Superior Wastewater Lagoons (0.2 billion organisms per day), B & R Mobile Home Village (0.3 billion organisms per day), and the Rock Springs Water Reclamation Facility (20.0 billion organisms per day). c. The observed load is the arithmetic mean of 49 E. coli loads, which were calculated from paired flow and E. coli data from the summer recreation season at monitoring site BC-2 in 2004, 2005, 2009-2012, 2014, and 2015.
Table 22. Summer E. coli TMDL for Killpecker Creek at Western Wyoming Community College (at monitoring site KC-1)
Element E. coli load (billion organisms per day) TMDL a 10.3 LA 10.0 WLA b 0.3 Observed 85.6 Reduction 88% Notes a. The TMDL is calculated using a flow of 3.35 cfs, which is the arithmetic mean of 48 flows monitored during the summer recreation season at monitoring site KC-1 in 2004, 2005, 2009-2012, 2014, and 2015. b. The WLA is for the B & R Mobile Home Village (0.3 billion organisms per day). c. The observed load is the arithmetic mean of 48 E. coli loads, which were calculated from paired flow and E. coli data from the summer recreation season at monitoring site KC-1 in 2004, 2005, 2009-2012, 2014, and 2015.
7.2 LOADING CAPACITY
Loading capacity for each TMDL was calculated using the TMDL target of 126 organisms per 100 mL, which is based upon the PCR geometric mean criterion, and the average (i.e., arithmetic mean) of instantaneous flows monitored by SWCCD at the TMDL sites during the summer recreation season. The average of instantaneous flows from several years were determined to be more representative of flow conditions than the continuous flow data available for only 2011; these data are summarized and evaluated in Appendix A. A summer average of monitored instantaneous flows was determined to be appropriate for TMDL development for several reasons, including that the averages are the most representative of in-stream flow conditions using the available datasets (see Appendix A, Section A-4.3.3).
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7.3 LOAD ALLOCATIONS
The LA is the load contribution from nonpoint sources and natural background levels. It was calculated as the remainder of the load from the loading capacity after the WLAs (Section7.4) and MOS (Section 7.5) were allocated.
LA = TMDL - (∑WLA + MOS)
In this case, the LA is presented as a composite of all nonpoint sources and natural background loads. LAs to individual nonpoint sources or categories are not presented. This composite LA approach has been applied because (1) sufficient data are not available to estimate current delivered loads to Bitter Creek and (2) to provide watershed stakeholders with as much flexibility as possible for implementation. 7.4 WASTELOAD ALLOCATIONS
WLAs were developed for the three sanitary treatment facilities covered by individual NPDES permits20: Superior Wastewater Lagoons, B & R Mobile Home Village, and Rock Springs Water Reclamation Facility. The WLAs were calculated using the PCR monthly E. coli limit and design flow reported in each permit.
Superior Wastewater Lagoon21: The design flow of 0.05 mgd (0.08 cfs) and an E. coli limit of 126 organisms per 100 milliliters yields a WLA of 0.24 billion organisms per day. B & R Mobile Home Park: The design flow of 0.06 mgd (0.09 cfs) and an E. coli limit of 126 organisms per 100 milliliters yields a WLA of 0.29 billion organisms per day. Rock Springs Water Reclamation Facility: The design flow of 4.20 mgd (6.50 cfs) and an E. coli limit of 126 organisms per 100 milliliters yields a WLA of 20.03 billion organisms per day. Each of these WLAs is allocated at a daily time-step, even though the Superior Wastewater Lagoon and B & R Mobile Home Village are lagoons that discharge intermittently. Only the Rock Springs Water Reclamation Facility is a continuously discharging facility.
Finally, NSWSD has begun the process to connect the Reliance lagoons and B & R Mobile Home Village to the Rock Springs sewerage system. If and when the connection occurs, sanitary wastewater from Reliance and the mobile home village will be treated at the Rock Springs Water Reclamation Facility. 7.5 MARGIN OF SAFETY
The Clean Water Act requires that a TMDL include an MOS to account for uncertainty in the relationship between LAs and WLAs and water quality. U.S. EPA guidance explains that the MOS may be implicit (i.e., incorporated into the TMDL through conservative assumptions in the analysis) or explicit (i.e., expressed in the TMDL as loadings set aside for the MOS).
The Bitter Creek and Killpecker Creek TMDLs have an implicit MOS. The in-stream PCR E. coli geometric mean criterion of 126 organisms per 100 mL was applied as a daily target in both TMDLs. The selection of a conservative target (60-day geometric mean criterion applied as a daily target) creates implicit MOS. 7.6 SEASONALITY
Addressing seasonal variations is an important and required component of TMDL development. TMDLs were developed for the summer recreation season, which is the critical period when impairment occurs. The TMDLs
20 The Reliance facultative lagoons, Point of Rocks lagoons, and West Side Water and Sewer District lagoons are not allocated WLAs because the lagoon systems are not permitted to discharge to surface waterways. Any discharges (treated or untreated effluent) would be illicit and would addressed through the WYPDES Program at WDEQ WPD. 21 Effluent flows from the Superior Wastewater Lagoons that are discharged to Horsethief Canyon Creek may not be regularly transported to Bitter Creek. Horsethief Canyon Creek has been observed to be intermittent near the Bitter Creek confluence throughout the duration of the SWCCD monitoring program. Page 52 of 59
were calculated using (1) the average of instantaneous flows collected during the summer recreation season and (2) the in-stream PCR geometric mean criterion applied as a daily target.
8.0 MONITORING STRATEGY
Monitoring strategies are an important component of watershed restoration and the foundation of adaptive management. The monitoring strategy presented in this section provides a starting point for the development of more detailed planning efforts regarding monitoring needs; it does not assign monitoring responsibility. Monitoring recommendations provided are intended to assist local land managers, stakeholder groups, and federal and state agencies in developing appropriate monitoring plans to meet the water quality improvement goals outlined in this document. Funding for future monitoring is uncertain and can vary with economic and political changes. Prioritizing monitoring activities depends on funding opportunities and stakeholder priorities for restoration. 8.1 TREND MONITORING
Since 2004, SWCCD has collected E. coli samples from 19 sites on Bitter Creek, 9 sites on Killpecker Creek, 9 sites on their tributaries, 2 wells, and 5 sources of runoff. Many sites were sampled infrequently. A revised monitoring plan that focuses on collecting a greater number of samples from fewer sites should be considered. A recommended minimum site list is presented in Table 23. Water quality samples should be collected at a sufficient frequency to evaluate E. coli results with the PCR and SCR criteria.
Table 23. Key monitoring locations along Bitter and Killpecker Creeks
Name ID Objective Bitter Creek above Belt Route BC-9a Evaluate E. coli sources upstream of the city of Rock Springs Bitter Creek above Killpecker Creek BC-4 Evaluate flow contribution of Killpecker Creek and load of Killpecker Creek relative to Bitter Creek Bitter Creek above highway 373 BC-2 Evaluate TMDL implementation Evaluate flow and load contribution of the Rock Springs Water Reclamation Facility Bitter Creek above Green River BC-1 Evaluate flow and load contribution of Bitter Creek to the Green River Killpecker Creek at highway 191 bridge KC-2 Evaluate E. coli sources upstream of the city of Rock Springs Killpecker Creek at WWCC KC-1 Evaluate TMDL implementation Evaluate load of Killpecker Creek relative to Bitter Creek
8.2 FLOW MONITORING
Additional continuous flow data are needed to better characterize and understand the hydrology of the Bitter Creek watershed and to put inflows (e.g., abandoned mines and wastewater treatment facilities) and outflows (e.g., irrigation diversions) into context with the natural streamflow regime. Another objective is to develop a better understanding of the spatial extent of perennial flow in Bitter Creek and its tributaries. Additional continuous flow data should be collected from the monitoring sites listed in Table 23, and additional sites may be needed to characterize inflows, outflows, and the perennial nature of stream flows.
Since the Bitter Creek watershed is composed of flashy, desert streams, future continuous flow monitoring efforts should include deployment of one or more precipitation gages to help characterize surface runoff response to precipitation.
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8.3 SOURCE SAMPLING
Urban storm water from the city of Rock Springs and surrounding development likely contributes to the recreation use impairments along Bitter Creek and Killpecker Creek. SWCCD collected water quality samples from several urban sources in Rock Springs during June 2006, September 2007, June 2008, and November 2008. However, corresponding data from the same timeframe are not available for key in-stream locations in and around the city of Rock Springs. Future synoptic source sampling should be considered that includes both the collection of source samples (e.g., stormwater discharges, mine inflows) and in-stream samples at the same time. Paired E. coli and flow data should be collected. 8.4 POINT SOURCES
The potential impacts of several permitted and unpermitted sanitary wastewater treatment facilities should be further assessed and/or tracked over time.
Rock Springs Water Reclamation Facility: Effluent flows reported in the DMRs tended to be higher than measured in-stream flows at site BC-2 (downstream of the facility) reported by SWCCD and WDEQ. DMR data are reported as monthly averages or daily maximum per month, while in-stream data are calculated as instantaneous flows using a rating curve and observed water levels. Effluent flow from outfall 001 and paired in-stream flow at site BC-2 should both be directly monitored on several occasions. The paired data can be used to validate effluent flows reported in the DMR and to evaluate the relative contribution of the Rock Springs Water Reclamation Facility upon flow in Bitter Creek. Superior Wastewater Lagoons: Anecdotal information indicates that the lagoon discharges to Horsethief Canyon Creek do not reach Bitter Creek because Horsethief Canyon Creek often runs dry. The lagoons discharge infrequently and if the effluent discharge does not reach Bitter Creek, then the lagoons do not cause or contribute to the recreation use impairment in Bitter Creek. Several effluent discharges from the Superior Wastewater Lagoon should be tracked along Horsethief Canyon Creek to determine if the discharges reach Bitter Creek. Preferably, several effluent discharges would be tracked during both (1) in-stream high flow conditions (likely following a precipitation event) and (2) in-stream low flow conditions.
Reliance Facultative Lagoons and B&R Mobile Home Village: The Reliance facultative lagoons and B & R Mobile Home Village are proposed to be connected to the city of Rock Springs sewerage system and their effluent would be treated by the Rock Springs Water Reclamation Facility. If the lagoons are not connected to Rock Springs sewerage system, then a study should be conducted to determine if illicit discharges from the lagoons cause or contribute to recreation use impairments along Killpecker Creek.
8.5 BMP TRACKING AND EFFECTIVENESS MONITORING
As restoration activities are implemented, a system should be established to track best management practices (BMPs). The system should include the type, location, and installation date of each BMP.
Pre- and post-installation effectiveness monitoring at “end of pipe” should be used to document potential upgrades or modifications made to point source facilities and to document implementation of stormwater BMPs. Such monitoring and documentation may provide valuable information relative to changes in bacteria concentrations and loads associated with this type of implementation activity. Effectiveness monitoring before and after the implementation of nonpoint source BMPs, however, is not likely to provide meaningful results given the low frequency of runoff events, diffuse nature of the runoff, and confounding nature of inflows from upstream. For nonpoint source implementation, the trend monitoring program described in Section 8.4 should provide information regarding long-term changes in E. coli concentrations and loads.
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9.0 RESTORATION STRATEGY
The Bitter Killpecker Watershed Advisory Group (BKWAG) formed in 2004 and, in conjunction with the SWCCD, developed the Bitter and Killpecker Creeks Watershed Management Plan in 2006 (BKWAG and SWCCD 2006). The following provides general recommendations to be considered by the BKWAG, SWCCD, and watershed stakeholders as they proceed with watershed restoration activities. Recommendations are provided to address each of the potential sources of bacteria. 9.1 POINT SOURCES
The Rock Springs Water Reclamation Facility currently discharges at or below permit limits and appears to have additional capacity. Connecting the B&R Mobile Home Village and Reliance Facultative Lagoons to this facility should be a priority. Consideration should also be given for the connection of other high-density septic system areas in close proximity to the city (refer back to Section 6.4.1 and Figure 23 for information regarding septic systems near Rock Springs). Also, as described in Section 8.4, additional flow monitoring is warranted to put the load from this facility into better context with the receiving water body. 9.2 SEPTIC SYSTEMS
With the exception of the periphery of the City of Rock Springs, septic systems are at a very low density in the watershed and are not expected to be a significant source of bacteria unless the systems are in close proximity and/or hydrologically connected to natural stream courses and are failing. As described above, however, consideration should be given to connecting the septic systems in the high density areas adjacent to Rock Springs to the Rock Springs Water Reclamation Facility. 9.3 PETS
Pet waste may be a contributor of bacteria in the Bitter Creek watershed and the City of Rock Springs stormwater conveyance system is likely an important pathway for this bacteria source. The storm water conveyance system should be further investigated and BMPs should be developed to minimize loading via this pathway. SWCCD has already developed and distributed a pet waste brochure and implemented an educational program regarding this source of bacteria (Figure 32). Continued education is recommended.
9.4 LIVESTOCK Figure 32. Pet waste brochure developed by SWCCD While there are relatively large numbers of livestock in the watershed, the overall density of sheep and cattle is relatively low and grazing along Bitter and Killpecker creeks appears to be minor. Livestock are managed to maintain forage and range condition. At times, however, livestock can concentrate along stream courses and become a significant source of bacteria loading, both through direct deposition and runoff. A use pattern analysis is recommended to identify areas where BMPs could be located to maximize E. coli reductions. If such areas are identified, voluntary measures can then be developed to minimize the E. coli contribution from livestock22. The objective will be to work collaboratively with livestock owners to ensure that practical solutions are developed.
22 Examples of management measures that may be voluntarily implemented included grazing management, providing off-stream water sources and shade, riparian buffers, and in limited applications, fencing. Page 55 of 59
9.5 WILD HORSES
As with livestock, wild horses are at relatively low densities throughout the watershed (approximately 0.6 horses per square mile). However, wild horses may also, at times, concentrate along stream courses and become significant sources of bacteria. Many of the same measures that may minimize E. coli contributions from livestock will likely also work with wild horses. Coordination with the Bureau of Land Management, the agency responsible for the management of wild horses, is recommended. 9.6 WILDLIFE
Wildlife are considered a natural source of bacteria. Game species such as big game and waterfowl are managed by the Wyoming Game and Fish Department. As with wild horses, many of the management measures that may distribute livestock away from stream courses may also work with some, but, not all of the wildlife species. 9.7 COORDINATION WITH THE ROCK SPRINGS BEAUTIFICATION COMMITTEE
The Rock Springs Beautification Committee, a committee of the Sweetwater County Travel and Tourism Board, has a number of goals and objectives in common with this TMDL:
“Establish Bitter Creek as a community asset and positive reflection on the community.” “Creating an environmentally and aesthetically pleasing stream system throughout the City.”
Additionally, a master plan for the reclamation and development of the Bitter Creek Drainage (Rock Springs 2007) is being implemented. Coordination between TMDL implementation and these efforts is recommended.
10.0 PUBLIC PARTICIPATION SUMMARY
Stakeholder and public involvement is a component of TMDL planning supported by EPA guidelines and the Wyoming Department of Environmental Quality. Technical advisors, stakeholders and interested parties, state and federal agencies, interest groups, and the public were solicited to participate in differing capacities throughout the TMDL development process in the Bitter Creek watershed.
The SCCD Board of Supervisors, through a series of community meetings throughout the watershed, formed the Bitter Creek and Killpecker Watershed Advisory Group (BKWAG) comprised of local citizens, municipal, and county governments with a vested interest in the integrity of the natural resources found within their watershed. The Sweetwater Conservation District and the BKWAG has been actively involved with water quality issues since they received their first Clean Water Act Section 319 Grant in 2001.
WDEQ worked with the SCCD and BKWAG to form a TMDL Technical Advisory Committee (TAC) comprised of individuals with intimate knowledge about scientific issues, processes, and sampling design, as well as familiarity with the Bitter Creek watershed. Individuals include representatives from state and federal agencies, local resource professionals, and members of local governments. The first TAC meeting was held in May 2015.
A list of the key TMDL related meetings and public involvement activities since that time is provided in Table 24.
Page 56 of 59
Table 24. Key Public Involvement Activities.
Date Description 5/12/2015 TAC Meeting 8/11/2015 TAC Meeting 4/13/2016 BKWAG TMDL Update 9/19/2017 TAC Meeting 10/10/2017 Public Informational Meeting 10/16 - 11/30/2017 TMDL Public Comment Period 11/7/2017 Rock Springs City Council TMDL Presentation
Upon completion of the draft TMDL document, DEQ issued a press release and entered into a 45-day public comment period extending from October 16, 2017 through November 30, 2017. Immediately prior to the public comment period, WDEQ held a public informational meeting in Rock Springs on October 10, 2017. The TMDL was also discussed during the public comment period at the Rock Springs City Council meeting on November 7, 2017.
DEQ received public comments from two entities during the public comment period. Appendix D contains excerpts and summaries of the comments, along with DEQ’s responses. Original comment letters and submissions are held on file at DEQ and may be viewed upon request.
Page 57 of 59
11.0 REFERENCES
American Veterinary Medical Association. 2017. U.S. Pet Ownership Statistics. https://www.avma.org/KB/Resources/Statistics/Pages/Market-research-statistics-US-pet-ownership.aspx. Accessed August 11, 2017.
BKWAG and SWCCD (Bitter Killpecker Creek Watershed Advisory Group and Sweetwater County Conservation District). 2006. Bitter and Killpecker Creeks Watershed Management Plan. http://www.swccd.us/docs/BKWatershedPlanFINALDRAFT.pdf. Accessed September 1, 2017.
Geldreich, E. E. 1978. Bacterial populations and indicator concepts in feces, sewage, stormwater and solid wastes. In Indicators of Viruses in Water and Food, ed. G. Berg. Ann Arbor, Mich.: Ann Arbor Science.
Hemken, Christy. 2017. Grazing assoc assists shareholders for over 100 years. Wyoming Livestock Roundup. http://www.wylr.net/component/content/article?id=2043:grazing-assoc-assists-shareholders-for-over-100- years. Accessed August 9, 2017.
BLM (U.S. Bureau of Land Management). 2017. Rangeland Administration System Reports. U.S. Department of the Interior, Bureau of Land management. https://reports.blm.gov/reports.cfm?application=ras. Accessed August 8, 2017.
EDE Consultants. 2006. Bitter & Killpecker Creeks Watershed Study 319 (h) Grant Project Report 2004-2005 Monitoring Period. Prepared for Bitter Creek & Killpecker Creek Watershed Advisory Group & Sweetwater County Conservation District, Sheridan, Wyoming.
KQSW 96.5. 2016. Reliance Water And Sewer Board Hosts Meeting, Public Invited To Attend. March 8, 2016. http://96kqsw.com/reliance-water-and-sewer-board-hosts-meeting-public-invited-to-attend/. Accessed August 10, 2017.
OSLI (Office of State Lands and Investment). 2014. Board Matter F-1. Wyoming OSLI. August 14, 2014. http://slf- web.state.wy.us/osli/boardmatters/2014/0814/slib/F-1.pdf. Accessed August 10, 2017.
Rock Springs. 2007. Bitter Creek Reconstruction Plan & Design: A Master Plan for the Reclamation and Development of the Bitter Creek Drainage through Downtown Rock Springs, Wyoming. December 14, 2007. http://www.rswy.net/egov/documents/1256142169_342285.pdf. Accessed October 12, 2017.
U.S. Census Bureau, 2000. Fact Sheet, Sweetwater County Wyoming. https://www.census.gov/quickfacts/fact/table/WY/EDU685215. Accessed June 27, 2016.
USDA Natural Resource Conservation Service. 2016. Major Land Resource Regions Custom Report Data. USDA Agriculture Handbook 296 (2006)
WDEQ (Wyoming Department of Environmental Quality). 2010. Notice of Violation and Order, Docket No. 4647- 10. Letter from John V. Corra (WDEQ, director) and John F. Wagner (WDEQ WQD, administrator) to Ted Hamilton (Regency of Wyoming) on March 12, 2010.
———. 2013a. Chapter 1: Wyoming Surface Water Quality Standards. Administrative Rule 020.0011.1.09242013. September 24, 2013.
———. 2013b. WY0023825 RENEWAL 12-20-12 INDC1. WDEQ WQD WYPDES Program. February 5, 2013.
———. 2014a. Notice of Violation and Order, Docket No. 5080-12. Unauthorized discharge from lagoon system, North Sweetwater Water and Sewer District. Letter from Todd T. Parfitt (WDEQ, director) and Kevin Fredrick (WDEQ WQD, administrator) to the Chairman of the Board of Directors of the Sweetwater Water and Sewer District on May 8, 2014.
———. 2014b. WY0022357-RENEWAL-10-14-2014 STPW. WDEQ WQD WYPDES Program. October 14, 2014.
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———. 2016a. Categorical Use Attainability Analysis for Recreation. September 2016. WDEQ, WQD, Cheyenne, Wyoming.
———. 2016b. Wyoming’s 2014 Integrated 305(b) and 303(d) Report. Document #16-0126. WDEQ, Water Quality Division, Watershed Section. Cheyenne, Wyoming. February 25, 2016. http://sgirt.webfactional.com/media/attachments/Water%20Quality/Water%20Quality%20Assessment/Rep orts/2014-Integrated-305b-and-303d-Report.pdf. Accessed January 26, 2017.
———. 2016d. WY0022128-RENEWAL-12-28-16 STPM. WDEQ WQD WYPDES Program. December 28, 2016.
———. 2017a. 2015-0316_WQD-WPP-NonpointSource_MonitoringSite_SWCCD.xlsx. Excel file with SWCCD station descriptions. Provided by Sol Birch (WDEQ WQD) via electronic mail on March 2017.
———. 2017b. North Sweetwater Water and Sewer District - Bid Package 1 - Regional Sewer Sweetwater County, T19N, R105W and T20N, R105W; Lat. 41.6581, Long. -109.2550. Permit to Construct. 17-034. WDEQ WQD. May 26, 2017.
WGFD (Wyoming Game and Fish Department). 2016a. 2016 Big Game Job Completion Reports - Green River Region. https://wgfd.wyo.gov/Hunting/Job-Completion-Reports/2016-Big-Game-Job-Completion-Reports. Accessed August 7, 2017.
———. 2016b. 2016 Big Game Job Completion Reports - Lander Region. https://wgfd.wyo.gov/Hunting/Job- Completion-Reports/2016-Big-Game-Job-Completion-Reports. Accessed August 7, 2017.
———. 2016c. 2016 Big Game Job Completion Reports - Pinedale Region. https://wgfd.wyo.gov/Hunting/Job- Completion-Reports/2016-Big-Game-Job-Completion-Reports. Accessed August 7, 2017.WWC Engineering. 2014. Sampling and Analysis Plan AML Project 6A-IVB Rock Springs, WY. Prepared for WDEQ AML. Laramie, Wyoming.
Zeckoski, R.W., B. L. Benham, S. B. Shah, M. L. Wolfe, K. M. Brannan, M. Al-Smadi, T. A. Dillaha, S. Mostaghimi, and C. D. Heatwole. 2005. BSLC: A Tool for Bacteria Source Characterization for Watershed Management. American Society of Agricultural Engineers ISSN 0883−8542. Vol. 21(5): 879−889.
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Appendix A – Summary of Available Hydrology Data
Page 1 of 23 of Appendix A
CONTENTS
A-1.0 AVAILABLE CONTINUOUS FLOW DATA ...... A-4 A-2.0 AVAILABLE INSTANTANEOUS FLOW DATA ...... A-6 A-3.0 INSTANTANEOUS FLOW DATA SUMMARIES ...... A-11 A-4.0 EVALUATION OF HYDROLOGY DATA AT TWO KEY SITES ...... A-17 A-4.1 Bitter Creek above Highway 373 (BC-2) ...... A-17 A-4.2 Killpecker Creek at WWCC (KC-1) ...... A-19 A-4.3 Flow Dataset Selection for TMDL Development ...... A-21 A-4.3.1 Instantaneous and Continuous Flow Datasets Differences ...... A-21 A-4.3.2 Flow Datasets Uncertainty ...... A-21 A-4.3.3 Flow Dataset Selection for TMDL Development ...... A-22
TABLES
Table A-1. Continuous flow monitoring sites ...... A-4 Table A-2. Instantaneous flow monitoring sites on Bitter Creek ...... A-6 Table A-3. Instantaneous flow monitoring sites on Killpecker Creek ...... A-7 Table A-4. Instantaneous flow monitoring sites on tributaries to Bitter Creek...... A-7 Table A-5. Instantaneous flow monitoring at wells ...... A-8 Table A-6. Instantaneous flow monitoring sites at potential sources ...... A-8 Table A-7. Instantaneous flow monitoring sites from mine drainage ...... A-8 Table A-8. Summary of flow data at monitoring site BC-2 ...... A-17 Table A-9. Concurrent flow data at monitoring site BC-2 ...... A-17 Table A-10. Summary of flow data at monitoring site KC-1 ...... A-19 Table A-11. Concurrent flow data at monitoring site KC-1 ...... A-19 Table A-12. Differences in sampling...... A-21
Page 2 of 23 of Appendix A
FIGURES
Figure A-1. Continuous flow monitoring sites...... A-5 Figure A-2. Instantaneous flow monitoring sites...... A-9 Figure A-3. Instantaneous flow monitoring sites (zoomed-in to show cluster of sites in Rock Springs)...... A-10 Figure A-4. Flows in 2004 along Bitter Creek...... A-12 Figure A-5. Flows in August 2004 along Killpecker Creek...... A-13 Figure A-6. Flows in 2012 along Bitter Creek...... A-14 Figure A-7. Flows in 2012 along Killpecker Creek...... A-14 Figure A-8. Flows on May 19, 2015 along Bitter Creek...... A-15 Figure A-9. Flows on August 24-25, 2015 along Bitter Creek...... A-15 Figure A-10. Flows on May 19, 2015 along Killpecker Creek...... A-16 Figure A-11. Flows on August 24-25, 2015 along Killpecker Creek...... A-16 Figure A-12. Box-and-whisker plots of summer flow data at monitoring site BC-2...... A-18 Figure A-13. Flow duration curves of summer flow data at monitoring site BC-2...... A-18 Figure A-14. Box-and-whisker plots of summer flow data at monitoring site KC-1...... A-20 Figure A-15. Flow duration curves of summer flow data at monitoring site KC-1...... A-20
ACRONYMS/ABBREVIATIONS
Acronyms/Abbreviations Definition AML Abandoned Mine Lands Division (WDEQ) DMR discharge monitoring report FDC flow duration curve LDC load duration curve LQD Land Quality Division (WDEQ) SWCCD Sweetwater County Conservation District TMDL total maximum daily load USGS U.S. Geological Survey (U.S. Department of the Interior) WDEQ Wyoming Department of Environmental Quality WQD Water Quality Division (WDEQ) WWCC Wester Wyoming Community College
Unit of measure Definition cfs cubic foot per second
Page 3 of 23 of Appendix A
A-12.0 AVAILABLE CONTINUOUS FLOW DATA
Continuous flow was measured by U.S. Geological Survey (USGS) at two locations on Bitter Creek and one in Salt Wells Creek between 1974 and 1981 (Figure 4 and Table A-25). The Sweet Water County Conservation District (SWCCD)23 reports continuous flow data for 2004 and early 2005 for sites on Bitter Creek, Deadman Draw, and Tenmile Draw. Continuous flow was monitored by the Wyoming Department of Environmental Quality (WDEQ) Water Quality Division (WQD)24 at six sites on Bitter Creek, two sites on Killpecker Creek, and one site each on Deadman Draw and Ten Mile Draw from May to November 2011. Additionally, WDEQ Abandoned Mine Lands Division (AML) reports daily average flow from three mine discharge sites for several multi-month periods in late 2012 through early 2016.
Table A-25. Continuous flow monitoring sites
No. of daily Site ID Site Name Org. Period of Record average flows Bitter Creek 09216545 Near Bitter Creek, Wyoming USGS Jul 1975 - Sep 1981 2,283 BC-6 Black Buttes Road Spur WQD May 2011 - Nov 2011 164 BC-10 Above Salt Wells Creek WQD May 2011 - Nov 2011 a 130 09216562 Above Salt Wells Creek near Salt USGS Jun 1976 - Sep 1981 1,947 Wells, Wyoming BC-4 Above Killpecker Creek WQD May 2011 - Nov 2011 165 BC3D n/a AML Dec 2012 - May 2013 138 Jun 2013 - Jul 2014 378 Dec 2014 - Nov 2015 297 Jan 2016 - Feb 2016 35 BC2D n/a AML Feb 2013 - Jul 2014 495 Jan 2015 - Jun 2015 173 Jan 2016 - Mar 2016 53 BC-2 Above Hwy 373 WQD May 2011 - Nov 2011 166 BC-1 Above Green River SWCCD Apr 2004 - Nov 2004 -- b Apr 2005 - May 2005 -- b Killpecker Creek KC-2 Hwy 191 Bridge WQD May 2011 - Nov 2011 165 KC-1 WWCC WQD May 2011 - Nov 2011 165 Salt Wells Creek 09216750 Near Salt Wells, Wyoming USGS Jun 1976 - Sep 1981 1,947 Deadman Draw DM-1 Above Ten Mile Draw SWCCD Mar 2004 - Oct 2004 -- b Apr 2005 - Jul 2005 -- b Ten Mile Draw TM-1 Below Bridger Coal SWCCD Mar 2004 - Dec 2004 -- b Mar 2005 - Apr 2005 -- b Notes Sample sites are sorted top to bottom for each stream as headwaters to mouth. a. Several flows are missing from August, September, and October 2011. b. Daily average flows were not reported.
23 Instantaneous flow data were calculated by SWCCD using a rating curve methodology and staff gages. After staff gages were installed, SWCCD measured in-stream flow on several occasions and recorded water levels using the staff gages. A rating curve was developed to be able to predict in-stream flow using observed water levels measured at the staff gages. 24 Continuous flow data were calculated by WDEQ WQD using a rating curve methodology and in-stream level loggers. WDEQ measured in- stream flow and water levels on several occasions. A rating curve was developed to be able to predicted daily in-stream flow using daily water levels recorded by the in-stream level loggers. Page 4 of 23 of Appendix A
Figure A-33. Continuous flow monitoring sites.
Page 5 of 23 of Appendix A
A-13.0 AVAILABLE INSTANTANEOUS FLOW DATA
Instantaneous flow was measured on Bitter Creek (Table A-26), Killpecker Creek (Table A-27), tributaries to Bitter Creek (Table A-28). SWCCD measured instantaneous flow at 21 sites on Bitter Creek, 15 sites on Killpecker Creek, and 12 sites on Bitter Creek tributaries. SWCCD also monitored flow at 2 wells (Table A-29) and runoff from 15 sources (Table A-30). WDEQ Land Quality Division (LQD) measured flow at two sites in upper Bitter Creek and AML measured flow at 6 sites on Bitter Creek (4 sites were co-located with SWCCD sites), 2 sites on Killpecker Creek (1 site was co-located with a SWCCD site), and 3 sites from mine drainages along Bitter Creek (Table A-31).
Table A-26. Instantaneous flow monitoring sites on Bitter Creek
No. of flows Site ID Site Name Org. Period of Record PCR SCR BC-7 Above Patrick Draw SWCCD Mar 2004 - Aug 2015 34 10 BC-15 Bitter Creek SWCCD May 2009 - Sep 2009 4 -- BC-14 Below Patrick Draw SWCCD May 2009 - Sep 2009 2 -- SBC1 Lower Bitter Creek LQD Sep 1987 - Dec 2015 167 126 SBC2 Lower Bitter Creek LQD Sep 1987 - Dec 2015 165 129 BC-13 Overland SWCCD May 2009 1 -- BC-17 Above Ten Mile Draw SWCCD May 2010 1 -- BC-6 Black Buttes Rd Spur SWCCD Mar 2004 - Aug 2016 75 8 BC-18 Ponds SWCCD May 2012 - Aug 2015 13 -- BC-12 Above Horsethief Canyon SWCCD May 2009 - Sep 2012 21 -- BC-11 Above Headcut SWCCD May 2009 - Aug 2015 3 -- BC-22 Below Headcut SWCCD Aug 2015 3 -- BC-10 Above Salt Wells Creek SWCCD May 2009 - Jun 2016 32 -- BC-5 Hwy 370 AML Apr 2010 - Oct 2016 13 10 SWCCD Mar 2004 - Aug 2015 23 7 BC-9a Above Belt Route SWCCD May 2015 - Aug 2016 9 -- BC-SYN-4 Belt Route Bridge SWCCD Sep 2009 - Sep 2012 7 -- BC-8 Circle Drive SWCCD May 2009 - Sep 2012 18 -- BC-4 Above Killpecker Creek AML Apr 2010 - Oct 2016 14 7 SWCCD Mar 2004 - Aug 2016 70 8 BC-3C n/a AML Oct 2010 - Oct 2016 12 8 BC-3B n/a AML Oct 2010 - Oct 2016 12 9 BC-16 Above Sweetwater Creek SWCCD May 2009 - Sep 2012 18 -- BC-3A n/a AML Oct 2010 - Oct 2016 12 9 BC-3 At Sweetwater Creek AML Apr 2010 - Oct 2016 14 10 SWCCD Mar 2004 - Aug 2016 43 10 BC-21 Above Interchange Rd SWCCD Jun 2012 - Sept 2012 4 -- BC-2 Above Hwy 373 AML Apr 2010 - Oct 2016 14 10 SWCCD Mar 2004 - Aug 2016 95 8 BC-1 Above Green River SWCCD Mar 2004 - Sep 2012 25 8 Note: Sample sites are sorted top to bottom as headwaters to mouth.
Page 6 of 23 of Appendix A
Table A-27. Instantaneous flow monitoring sites on Killpecker Creek
No. of flows Site ID Site Name Org. Period of Record PCR SCR KC-3 Chiltons Cutoff SWCCD Mar 2004 - Aug 2015 8 7 KC-7 Above County Rd 17 SWCCD May 2009 - Aug 2015 2 -- KC-2 Hwy 191 Bridge SWCCD Mar 2004 - Aug 2016 57 8 KC-1H NE Golf SWCCD Aug 2004 1 -- KC-1G SE Golf SWCCD Aug 2004 1 -- KC-13 Fairgrounds SWCCD May 2012 - Sep 2012 6 -- KC-5 Above Yellowstone Blvd SWCCD Aug 2004 - Sep 2016 19 -- KC-4 Above Industrial Dr SWCCD May 2009 - Sep 2012 9 -- KC-1D Rail Spur SWCCD Aug 2004 1 -- KC-14 Mineral Dr SWCCD May 2012 - Sep 2012 6 -- KC-1C Production Dr SWCCD Aug 2004 1 -- KC-1B Above Stagecoach Blvd SWCCD Aug 2004 - Sep 2012 7 -- KC-1A Spring Dr SWCCD Aug 2004 1 -- KC-1 WWCC AML Apr 2010 - Oct 2016 14 7 SWCCD Mar 2004 - Aug 2016 83 7 BC-3D n/a AML May 2013 - Oct 2016 7 3 KC-15 At Bitter Creek SWCCD May 2012 - Sep 2012 6 -- Note: Sample sites are sorted top to bottom as headwaters to mouth.
Table A-28. Instantaneous flow monitoring sites on tributaries to Bitter Creek
No. of flows Site ID Site Name Org. Period of Record PCR SCR Little Bitter Creek LBC-1 Mouth SWCCD Apr 2004 - May 2005 5 5 Unnamed tributary to Bitter Creek BC-RSTrib-1 Dewar Dr SWCCD Sep 2009 1 -- Unnamed tributary to Bitter Creek BC-RSTrib-2 Sunset Dr SWCCD Sep 2009 1 -- Sweetwater Creek BC-3a n/a SWCCD Apr 2004 - Sep 2015 17 6 Dead Horse Canyon DHC-1 Below UPR SWCCD Apr 2004 - Aug 2015 3 6 Salt Wells Creek SWC-1 Below Hwy 430 SWCCD May 2011 - Jun 2016 10 -- Dead Man Draw DM-1 Above Ten Mile Draw SWCCD Mar 2004 - Aug 2016 16 11 DM-2 I80 SWCCD May 2010 1 -- Ten Mile Draw TM-2 Flats SWCCD May 2010 1 -- TM-1 Below Bridger Coal SWCCD Mar 2004 - Aug 2015 22 9 Patrick Draw PD-1 At Bitter Creek SWCCD Aug 2015 1 -- Antelope Creek AC-1 County Road 19 SWCCD Aug 2015 1 -- Note: Sample sites are sorted top to bottom for each stream as headwaters to mouth.
Page 7 of 23 of Appendix A
Table A-29. Instantaneous flow monitoring at wells
No. of flows Site ID Site Name Period of Record PCR SCR BCW-1 N Center St Sep 2007 - Nov 2008 11 5 BCW-2 Meade St Jun 2006 - Nov 2008 12 5 Note: Both wells were sampled by the Sweetwater County Conservation District
Table A-30. Instantaneous flow monitoring sites at potential sources
No. of flows Site ID Site Name Period of Record PCR SCR Sources in the Bitter Creek watershed BCS-1 Bitter Creek - Dealership Jun 2006 - Nov 2008 18 7 BCS-2 Bitter Creek - Smith St Sep 2007 - Nov 2008 12 6 BCS-3 Bitter Creek - Logan St Sep 2007 - Nov 2008 11 6 BCS-4 Bitter Creek - Grant St Sep 2007 - Nov 2008 11 6 BCS-5 Unnamed Spring - Oct 2009 1 -- Gravel Pits BCS-6 Unnamed Spring 2 - Oct 2009 2 -- Gravel Pits Sources in the Killpecker Creek watershed KC-6 Killpecker Creek - Pond May 2009 - Sep 2009 11 -- KCS-1 Killpecker Creek - Rail Pond Jun 2006 1 -- KCS-2 Fairgrounds Pond - Sep 2007 - Nov 2008 Above Yellowstone Blvd 2 1 KCS-3 Killpecker Creek - Above Industrial Dr 2 Jun 2006 - Sepp 2009 6 1 KCS-4 Unnamed Tributary - Rail Spur 2 Jun 2006 - Sepp 2009 5 2 KCS-5 Killpecker Creek - Production Dr 2 Jun 2006 - Sepp 2007 2 -- KCS-6 Unnamed Tributary - Greasewood Jun 2008 1 -- KCS-7 Unnamed Tributary - Trail Jun 2008 1 -- KCS-8 Unnamed Tributary - Antelope Dr Jun 2008 1 -- KCS-9 Unnamed Tributary - Foothill Blvd Nov 2008 -- 1 Note: The sources were sampled by the Sweetwater County Conservation District
Table A-31. Instantaneous flow monitoring sites from mine drainage
No. of flows Site ID Site Name Period of Record PCR SCR BC4D n/a Aug 2009 - Oct 2016 33 28 BC3D n/a Aug 2009 - Oct 2016 23 19 BC2D n/a Sep 2009 - Oct 2016 24 23 Note: The mine drainages were sampled by AML
Page 8 of 23 of Appendix A
Figure A-34. Instantaneous flow monitoring sites.
Page 9 of 23 of Appendix A
Figure A-35. Instantaneous flow monitoring sites (zoomed-in to show cluster of sites in Rock Springs).
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A-14.0 INSTANTANEOUS FLOW DATA SUMMARIES
This section of Appendix A summaries selected instantaneous flow data along Bitter Creek and Killpecker Creek. The figures represent periods when multiple locations on each stream were sampled. As discussed in Section 3 of the main report, the hydrology of Bitter Creek and Killpecker Creek is complex.
Instantaneous flows collected at seven sites along Bitter Creek and ten sites along Killpecker Creek in 2004 are summarized in Figure A-36 and Figure A-37; in each figure, the arithmetic mean of several flows collected within a week at each site are presented. Flows were summarized in the same manner for 2012 as shown in Figure A- 38 and Figure A-39. These figures show that flows increase and decrease along both Bitter Creek and Killpecker Creek. Decreases in flow may be indicative of irrigation withdrawals and diversions while flow increases may be indicative of point sources and mine discharges.
Instantaneous flows collected on the same day were summarized for two dates in 2015 for Bitter Creek (Figure A-40 and Figure A-41) and Killpecker Creek (Figure A-42 and Figure A-43). These figures show that flow in both streams is significantly higher in May than it is in August.
Page 11 of 23 of Appendix A
Note: Average of several instantaneous flows measured on separate days in the specified month.
Figure A-36. Flows in 2004 along Bitter Creek.
Page 12 of 23 of Appendix A
Note: Average of several instantaneous flows measured on separate days.
Figure A-37. Flows in August 2004 along Killpecker Creek.
Page 13 of 23 of Appendix A
Note: Average of several instantaneous flows measured on separate days in the specified months.
Figure A-38. Flows in 2012 along Bitter Creek.
Note: Average of several instantaneous flows measured on separate days in the specified months.
Figure A-39. Flows in 2012 along Killpecker Creek.
Page 14 of 23 of Appendix A
Figure A-40. Flows on May 19, 2015 along Bitter Creek.
Figure A-41. Flows on August 24-25, 2015 along Bitter Creek.
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Figure A-42. Flows on May 19, 2015 along Killpecker Creek.
Figure A-43. Flows on August 24-25, 2015 along Killpecker Creek.
Page 16 of 23 of Appendix A
A-15.0 EVALUATION OF HYDROLOGY DATA AT TWO KEY SITES
Limited flow data are available at key sites throughout the Bitter Creek watershed. To support total maximum daily load (TMDL) development, instantaneous and continuous flow data were further evaluated on Bitter Creek at site BC-2 and on Killpecker Creek at site KC-1. A-15.1 BITTER CREEK ABOVE HIGHWAY 373 (BC-2)
Instantaneous and continuous flow data were calculated by SWCCD and WDEQ (respectively) for Bitter Creek at monitoring site BC-2 above highway 373. This monitoring location is immediately downstream of the Rock Springs Water Reclamation Facility, which is a continuously discharging permitted point source. Monthly average effluent flow data for the sanitary wastewater treatment facility (January 2004 through May 2017) were provided by WDEQ WQD. The facility discharges an average of 4.3 cfs during summer months (May through September). Additionally point sources are also located upstream of monitoring site BC-2 but their effluent flows are considerably smaller than the effluent flows from the Rock Springs Water Reclamation Facility.
Except for a few flows, instantaneous and continuous flow data are not available for a concurrent timeframe; continuous data are only available for the year 2011, while few instantaneous measurements were collected in 2011 (Table A-32 and Table A-33). Summaries of the available flow data show that the two flow datasets are considerably different from one another (Table A-32 and box and whisker). Flow duration curves (FDCs) developed for each dataset are also considerably different (Figure A-45); the continuous dataset appears to reflect the continuous discharge from point source and likely represents the influence of the Rock Springs Water Reclamation Facility. Differences with the shapes of the FDCs could be the result of several factors, including sampling methodology, frequency, and timeframe; these issues are discussed in Section A-15.3.
Table A-32. Summary of flow data at monitoring site BC-2
No. of Range of summer flows Entity Period of record summer records a (cfs) b SWCCD Apr. 2004 - Aug. 2016 56 0.78 - 589 WDEQ May 2011 - Nov. 2011 128 8.68 - 59 Notes a. Number of flow records during the summer recreation season (May 1 through September 30). b. Minimum and maximum flows recorded during the summer recreation season (May 1 through September 30).
Table A-33. Concurrent flow data at monitoring site BC-2
Continuous flow Date Instantaneous flow (cfs) Difference a (cfs) 5/31/2011 32.21 29.26 5% 6/1/2011 27.19 23.51 7% 6/2/2011 21.78 20.03 4% 6/15/2011 8.89 9.88 5% 6/16/2011 8.89 10.02 6% 6/28/2011 6.89 9.73 17% 6/29/2011 6.89 9.90 18% Note a: The difference is calculated as the absolute value of (instantaneous - continuous) / (instantaneous + continuous).
Page 17 of 23 of Appendix A
Figure A-44. Box-and-whisker plots of summer flow data at monitoring site BC-2.
Figure A-45. Flow duration curves of summer flow data at monitoring site BC-2.
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A-15.2 KILLPECKER CREEK AT WWCC (KC-1)
Instantaneous and continuous flow data were calculated by SWCCD and WDEQ (respectively) for Killpecker Creek at monitoring site KC-1 at the Western Wyoming Community College (WWCC). This monitoring location is just upstream of the confluence of Killpecker Creek with Bitter Creek. Two sanitary wastewater treatment systems drain to Killpecker Creek. B & R Mobile Home Village is a permitted lagoon system while the Reliance facultative lagoons are not permitted to discharge; refer to Section 6.3 of the main report for discussions of these facilities. Monthly average effluent flow data for the B & R Mobile Home Village (January 2004 through December 2016) were provided by WDEQ WQD. This facility discharges an average of 0.08 cfs25 during summer months (May through September).
Except for a few flows, instantaneous and continuous flow data are not available for a concurrent timeframe; continuous data are only available for the year 2011, while few instantaneous measurements were collected in 2011 (Table A-34 and Table A-35). Similar to the evaluation of Bitter Creek at monitoring site BC-2, summaries of the available flow data show that the two flow datasets are considerably different from one another (Table A-34 and Figure A-46). FDCs developed for each dataset are also considerably different (Figure A-47); differences with the shapes of the FDCs could be the result of several factors, including sampling methodology, frequency, and timeframe; these issues are discussed in Section A-15.3. The continuous dataset appears to reflect continuous discharge of about 1 cfs. This continuous discharge may include effluent flow from the B & R Mobile Home Village or discharges from several historic mines26. As the apparent continuous discharge is only 1 cubic foot per second (cfs), it may also reflect the limitations of estimating very low flows using a rating curve methodology.
Table A-34. Summary of flow data at monitoring site KC-1
No. of Range of summer flows Entity Period of record summer records a (cfs) b SWCCD Mar. 2004 - Aug. 2016 57 0.03 - 55 WDEQ May 2011 - Nov. 2011 127 0.98 - 12 Notes a. Number of flow records during the summer recreation season (May 1 through September 30). b. Minimum and maximum flows recorded during the summer recreation season (May 1 through September 30).
Table A-35. Concurrent flow data at monitoring site KC-1
Continuous flow Date Instantaneous flow (cfs) Difference a (cfs) 5/31/2011 4.42 7.13 23% 6/1/2011 2.83 3.92 16% 6/2/2011 1.65 2.09 12% 6/15/2011 0.31 1.52 66% 6/16/2011 0.31 1.48 65% 6/28/2011 0.06 1.12 90% 6/29/2011 0.06 1.10 90% Note a: The difference is calculated as the absolute value of (instantaneous - continuous) / (instantaneous + continuous).
25 Refer to Section 6.3 of the main report for a discussion of potentially erroneous data that were excluded from analysis. 26 The Stansbury Mine (Rocky Mountain Coal Company) near the town of Reliance is permitted to discharge wastewater through four outfalls to Killpecker Creek. The mine has only discharged once between 1998 and 2016, and thus, is not a source of flow to Killpecker Creek. Page 19 of 23 of Appendix A
Figure A-46. Box-and-whisker plots of summer flow data at monitoring site KC-1.
Figure A-47. Flow duration curves of summer flow data at monitoring site KC-1.
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A-15.3 FLOW DATASET SELECTION FOR TMDL DEVELOPMENT
Averages of instantaneous flows across the summer recreation seasons of several years are the best representations of in-stream flow conditions, for which to develop the TMDLs, given the limited instantaneous and continuous flow data available for Bitter Creek and Killpecker Creek. Evaluation of both datasets indicates considerable differences between the instantaneous and continuous flow datasets (Section A-15.3.1) and the uncertainties associated with each dataset limit their usefulness with TMDL development (Section A-15.3.2). The limitations of the flow datasets precluded the development of TMDLs through a load duration curve (LDC) framework or a flow condition framework. These frameworks rely upon an understanding of watershed hydrology that is lacking in the Bitter Creek watershed (Section A-15.3.3). A-15.3.1 Instantaneous and Continuous Flow Datasets Differences Generally, summer flows from the continuous datasets for Bitter Creek and Killpecker Creek were larger than summer flows from the instantaneous dataset. This was especially true during lower flow conditions. However, during a few higher flow conditions, instantaneous flows were significantly larger than continuous flows. With the concurrent measurements in Killpecker Creek (Table A-35), summertime continuous flows were always significantly larger than concurrent instantaneous flows. In Bitter Creek, the differences in summer flows between datasets were smaller (Table A-33) and each dataset sometimes had larger flows that the other dataset.
The summer FDCs for the continuous flow datasets for both Bitter Creek and Killpecker Creek were asymptotic and may indicate the dominance of point source impacts. In Bitter Creek at monitoring site BC-2, such a pattern is expected because the monitoring site is immediately downstream of the Rock Springs Water Reclamation Facility, which is a major continuously discharge sanitary wastewater treatment facility. Monitoring site BC-2 is also downstream of the other permitted point sources in the watershed, though their flows are relatively insignificant.
The summer FDCs for both monitoring sites BC-2 and KC-1 may reflect the contributions of mine drainage. The area within the city of Rock Springs was historically mined and nearby areas are currently mined. Their continuous discharged combined may be significant. A-15.3.2 Flow Datasets Uncertainty The instantaneous and continuous flow datasets were developed using different types of data and the differences in the datasets may contribute to the differences between concurrent measurements and the FDCs. Sampling methodology (i.e., equipment installation, measurement collection, and sampling frequency and timeframe; Table A-36) and sample error may contribute to the differences between datasets. Due to differences in the sampling methodology and data collection, the two datasets may not be representative of similar physical conditions. Physical characteristics of the watershed are dynamic (e.g., precipitation patterns, channel morphology, urban development) and may have varied between 2004 and 2015.
Table A-36. Differences in sampling
Instantaneous Continuous Equipment Staff gage Level logger Measurements Visual observation Meter logging Sampling frequency Instantaneous Daily average Timeframe 2004, 2005, 2009-2012, 2014, 2015 2011
Issues with equipment installation and operation (staff gage or level logger) would impact all of the flow measurements within a given dataset. For example, if a staff gage or level logger was installed at a poor site or non-representative location, then the resulting data would not characterize in-stream flow. Similarly, if the in- stream equipment were moved, malfunctioned, or broke, the data may be invalid.
Sampling error may also contribute to the difference between datasets, especially as in this case, when the datasets are relatively small. A few misread water levels from the staff gage or a malfunctioning logger could have significant impacts.
Page 21 of 23 of Appendix A
Instantaneous and continuous flow datasets were developed using rating curves. Any errors or uncertainty that affected the development of the rating curves would also effect all of the estimated flows. Since the rating curves were developed with only a few pairs of measurements (i.e., water levels and corresponding instantaneous flows), if one or more of the pairs of measurements was in error, then the entire rating curve could be erroneous. A-15.3.3 Flow Dataset Selection for TMDL Development Limitations of the flow datasets in the Bitter Creek watershed preclude the development of TMDLs through typical techniques the involve water quality modeling, LDCs, and flow conditions. These frameworks rely upon an understanding of watershed hydrology that is lacking for the Bitter Creek watershed. The typical desert streams of the Bitter Creek watershed are flashy and watershed hydrology is complex due to (1) discharges from major and minor permitted point sources; (2) discharges from unpermitted lagoon systems; (3) mine discharges and groundwater interaction at current and historic mining operations; and (4) irrigation withdrawals and return flows. A summer average of monitored instantaneous flows was determined to be appropriate for TMDL development for several reasons.
Limited flow data: Averages of instantaneous flows across several years at sites BC-2 and KC-1 are considered to be more representative of flow in Bitter Creek and Killpecker Creek than (1) FDCs developed from May through November 2011 daily flows and (2) statistics of flow bins developed by categorizing instantaneous flows into several flow conditions. o Continuous flow data were collected at a few locations in the Bitter Creek watershed but were not collected from Bitter Creek or Killpecker Creek during the same years when most of the water quality samples were collected and evaluated for E. coli. If the continuous flow dataset were used to develop FDCs and LDCs, then insufficient E. coli data would be available to evaluate existing conditions and the reductions necessary to meet the TMDLs. o Less than one dozen instantaneous flows were collected at most monitoring sites over a two decade timeframe. Categorizing instantaneous flows into several hydrologic conditions would be very uncertain due to the lack of instantaneous flow data and the lack of understanding the hydrology of the watershed. Low-flow conditions: Averages of instantaneous flows across several years at sites BC-2 and KC-1 are not constrained by the limitations associated with developing allocations and TMDLs for low flow conditions using data with considerable uncertainty. o Continuous flow data are only available for May through November 2011. A TMDL developed using only this data would be representative of low flow conditions for only the year 2011. Additionally, concurrent flow records (between the instantaneous and continuous flow datasets) indicates that continuous flows are typically larger than instantaneous flows. The continuous flow dataset may overestimate low flows but insufficient data are available to confidently evaluate flows during low flow conditions. o Instantaneous and continuous flows monitored during drier conditions in Bitter Creek and Killpecker Creek were often about 1 cfs or less. Such flows are problematic because these in- stream flows were less than the monthly average effluent flows27 reported in the discharge monitoring reports (DMRs) for the sanitary wastewater treatment plants. Even with assuming that the DMRs are representative of effluent flows on the days that in-stream flows were monitored, with such a limited amount of in-stream and DMR flow data, it was not possible to determine if effluent flow persisted in certain streams, including Bitter Creek, or if it was lost (e.g., seeped to groundwater, diverted to irrigation). o Additionally, these very low flows were often far less than the design flows of the sanitary wastewater facilities. In the Bitter Creek watershed, a review of the DMRs indicated that these facilities typically discharge at rates well below their design flows. WLAs developed at design flows would likely exceed TMDLs developed for low flow conditions.
27 WDEQ does not require sanitary wastewater treatment facilities to report daily effluent flows in their DMRs. Thus, the only available data are monthly average flows and daily maximum flows per month. Page 22 of 23 of Appendix A
Flow data quality: Averages of instantaneous flows across several years at sites BC-2 and KC-1 may be less influenced by potential errors with the rating curves, especially when flows are estimated using the upper or lower limits of the rating curves. o Instantaneous and continuous flow datasets were developed using rating curves. The rating curves and paired instantaneous flow measurements with water level observations are not available for review. o The ranges of flows estimated for each dataset are considerably different. o The quality of the calculated flows may be limited because the rating curves may be of limited accuracy. Rating curves rely on the assumption that channel morphology is directly related to flow rate. If channel morphology changes, its relationship with flow likely changes, and a new rating curve needs to be developed. . SWCCD instantaneous flows were calculated for 2004, 2005, 2009-2012, 2014, and 2015. Information regarding rating curve development, revision, and replacement is not available. . The desert streams of the Bitter Creek watershed do not likely have static channel morphology. Flashy, desert streams often have dynamic channel morphology that is altered by large flow events.
For the reasons discussed in this subsection (limited flow data with potentially high uncertainty and unknown representativeness), averages of instantaneous flows across several years at sites BC-2 and KC-1 were used to develop TMDLs. The averages may be less affected by the data limitations than FDCs and flow bin characterizations would be.
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Appendix B – Water Quality Data and Analysis
Page 1 of 15 of Appendix B
CONTENTS
B-1.0 AVAILABLE E.COLI QUALITY DATA ...... B-3 B-2.0 E. COLI DATA SUMMARIES ...... B-7
TABLES
Table B-1. E. coli monitoring sites on Bitter Creek ...... B-3 Table B-2. E. coli monitoring sites on Killpecker Creek ...... B-4 Table B-3. E. coli monitoring sites on tributaries to Bitter Creek and Killpecker Creek ...... B-4 Table B-4. E. coli monitoring at wells ...... B-4 Table B-5. E. coli monitoring sites at sources ...... B-5
FIGURES
Figure B-1. Location of SWCCD monitoring sites in the Bitter Creek watershed...... B-5 Figure B-2. SWCCD E. coli monitoring sites (zoomed-in to show cluster of sites in Rock Springs)...... B-6 Figure B-3. E. coli concentration at SWCCD monitoring sites BC-2, BC-3, BC-4, and BC-6...... B-8 Figure B-4. E. coli concentration at SWCCD monitoring sites KC-1 and KC-2...... B-9 Figure B-5. E. coli load at SWCCD monitoring sites BC-2, BC-3, BC-4, and BC-6...... B-10 Figure B-6. E. coli load at SWCCD monitoring sites KC-1 and KC-2...... B-11 Figure B-7. E. coli concentrations in April 2004 (left) and September 2005 (right) along Bitter Creek (top) and Killpecker Creek (bottom)...... B-12 Figure B-8. E. coli concentrations at SWCCD monitoring sites along Bitter Creek on September 17-18, 2012...... B-13 Figure B-9. E. coli concentrations at SWCCD monitoring sites along Killpecker Creek on September 19, 2012...... B-13 Figure B-10. E. coli concentrations at SWCCD monitoring sites along Bitter Creek on June 7, 2016...... B-14 Figure B-11. Paired E. coli and flow data across all SWCCD monitoring sites in the Bitter Creek watershed. ... B-14 Figure B-12. Paired E. coli and flow data at SWCCD monitoring site BC-6...... B-15 Figure B-13. Paired E. coli and flow data at SWCCD monitoring site BC-2...... B-15
ACRONYMS/ABBREVIATIONS
Acronyms/Abbreviations Definition LQD Land Quality Division (WDEQ) SWCCD Sweetwater County Conservation District WDEQ Wyoming Department of Environmental Quality WQD Water Quality Division (WDEQ)
Page 2 of 15 of Appendix B
B-16.0 AVAILABLE E.COLI QUALITY DATA
E. coli data were first collected in the Bitter Creek watershed in the 1970’s by WDEQ LQD at numerous locations in the vicinity of the Jim Bridger Mine. These data are not considered representative of current conditions and are not discussed further herein. In the late 1990s and early 2000s DEQ WQD collected fecal coliform samples, but, no E. coli data were collected. Since 2004, SWCCD has collected E. coli samples from 19 sites on Bitter Creek (Table B-37), 9 sites on Killpecker Creek (Table B-38), 9 sites on their tributaries (Table B-39), two wells (Table B-40), and 5 sources of runoff (Table B-41, Figure B-48 and Figure B-49). The SWCCD data are relied upon herein to characterize the current condition and complete the necessary TMDL calculations.
Table B-37. E. coli monitoring sites on Bitter Creek
No. of E. coli No. of paired Site ID Site Name Period of Record records flows PCR SCR PCR SCR BC-7 Above Patrick Draw Apr 2004 - Sep 2012 24 6 21 5 BC-6 Black Buttes Rd Spur Apr 2004 - Aug 2016 58 6 52 5 BC-18 Ponds May 2012 - Aug 2016 6 -- 6 -- BC-12 Above Horsethief May 2009 - Sep 2012 15 -- Canyon 15 -- BC-22 Below Headcut Aug 2015 1 -- 1 -- BC-10 Above Salt Wells Creek May 2009 - Jun 2016 24 -- 22 -- BC-5 Hwy 370 Apr 2004 - May 2009 14 5 8 5 BC-9a Above Belt Route May 2015 - Aug 2016 5 -- 5 -- BC-SYN-3 Below Belt Route Sep 2009 1 ------BC-SYN-4 Belt Route Bridge Sep 2009 - Sep 2012 7 -- 4 -- BC-8 Circle Drive May 2009 - Sep 2012 15 -- 14 -- BC-SYN-2 Clark St May 2009 1 ------BC-SYN-1 M St May 2009 1 ------BC-4 Above Killpecker Creek Apr 2004 - Aug 2016 55 6 53 5 BC-16 Above Sweetwater May 2009 - Sep 2012 15 -- Creek 15 -- BC-3 At Sweetwater Creek Apr 2004 - Aug 2015 35 6 35 6 BC-21 Above Interchange Rd Jun 2012 - Sept 2012 2 -- 2 -- BC-2 Above Hwy 373 Apr 2004 - Aug 2016 74 6 73 5 BC-1 Above Green River Apr 2004 - Sep 2012 20 6 20 6 Notes Sample sites are sorted top to bottom as headwaters to mouth. All sites were sampled by the Sweetwater County Conservation District
Page 3 of 15 of Appendix B
Table B-38. E. coli monitoring sites on Killpecker Creek
No. of E. coli No. of paired Site ID Site Name Period of Record records flows PCR SCR PCR SCR KC-3 Chiltons Cutoff Apr 2004 - May 2005 6 5 5 5 KC-2 Hwy 191 Bridge Apr 2004 - Aug 2016 38 6 33 5 KC-13 Fairgrounds May 2012 - Sep 2012 2 -- 2 -- KC-5 Above Yellowstone Blvd May 2012 - Aug 2016 7 -- 7 -- KC-4 Above Industrial Dr May 2009 - Sep 2012 3 -- 3 -- KC-14 Mineral Dr May 2012 - Jun 2012 2 -- 2 -- KC-1B Above Stagecoach Blvd May 2012 - Sep 2012 3 -- 3 -- KC-1 WWCC Apr 2004 - Aug 2016 64 5 62 5 KC-15 At Bitter Creek May 2012 - Sep 2012 3 -- 3 -- Notes Sample sites are sorted top to bottom as headwaters to mouth. All sites were sampled by the Sweetwater County Conservation District
Table B-39. E. coli monitoring sites on tributaries to Bitter Creek and Killpecker Creek
No. of E. coli No. of paired Site ID Site Name Period of Record records flows PCR SCR PCR SCR Little Bitter Creek LBC-1 Mouth Apr 2004 - May 2005 5 5 5 5 Unnamed tributary to Bitter Creek BC-RSTrib-1 Dewar Dr Sep 2009 1 -- 1 -- Unnamed tributary to Bitter Creek BC-RSTrib-2 Sunset Dr Apr 2004 - Sep 2005 15 5 15 5 Sweetwater Creek BC-3a n/a Apr 2004 - Sep 2005 15 5 15 5 Unnamed tributary to Killpecker Creek KC-RSTrib-1 Elk St May 2009 - Sep 2009 10 ------Dead Horse Canyon DHC-1 Below UPR Apr 2004 - Aug 2004 2 5 2 5 Salt Wells Creek SWC-1 Below Hwy 430 May 2011 - Jun 2016 8 -- 8 -- Dead Man Draw DM-1 Above Ten Mile Draw Apr 2004 - Sep 2005 11 6 10 5 Ten Mile Draw TM-1 Below Bridger Coal Apr 2004 - Sep 2005 16 5 12 5 Notes Sample sites are sorted top to bottom for each stream as headwaters to mouth. All sites were sampled by the Sweetwater County Conservation District
Table B-40. E. coli monitoring at wells
No. of E. coli No. of paired Site ID Site Name Period of Record records flows PCR SCR PCR SCR BCW-1 N Center St Sep 2007 - Nov 2008 17 5 11 5 BCW-2 Meade St Jun 2006 - Nov 2008 17 5 12 5 Note: Both wells were sampled by the Sweetwater County Conservation District
Page 4 of 15 of Appendix B
Table B-41. E. coli monitoring sites at sources
No. of E. coli No. of paired Site ID Site Name Period of Record records flows PCR SCR PCR SCR Sources in the Bitter Creek watershed BCS-1 Bitter Creek - Dealership Jun 2006 - Nov 2008 18 7 13 7 BCS-2 Bitter Creek - Smith St Jun 2006 - Nov 2008 18 6 11 6 BCS-3 Bitter Creek - Logan St Jun 2006 - Nov 2008 16 6 11 6 BCS-4 Bitter Creek - Grant St Jun 2006 - Nov 2008 17 6 10 6 Sources in the Killpecker Creek watershed KC-6 Killpecker Creek - Pond May 2009 - Sep 2009 11 -- 11 --
Figure B-48. Location of SWCCD monitoring sites in the Bitter Creek watershed.
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Figure B-49. SWCCD E. coli monitoring sites (zoomed-in to show cluster of sites in Rock Springs).
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B-17.0 E. COLI DATA SUMMARIES
This section of Appendix B summaries selected E. coli data along Bitter Creek and Killpecker Creek. The figures represent periods when multiple locations on each stream were sampled. As discussed in Section 5 of the main report, elevated E. coli concentrations and loads occur all along Bitter Creek and Killpecker Creek and strong spatial and temporal trends are not typically evident..
The monitoring sites with the most E. coli data along Bitter Creek and Killpecker Creek were evaluated determine if any seasonal trends were evident. Generally, summer (April-October; PCR) concentrations were greater than winter (November-March; SCR) concentrations (Figure B-50 and Figure B-51), which is expected since the summer season is warmer and more conducive to bacteria growth. Loads along Bitter Creek tended to increase from upstream to downstream and loads from both seasons were comparable (Figure B-52). Loads in Killpecker Creek were similar for both seasons (Figure B-53).
In addition to evaluating E. coli by recreation season, results were evaluated by averaging individual samples collected within a week or two timespan in a given month. E. coli concentrations along Bitter Creek varied between months with no discernable patterns (for example, see April 2004 and September 2005 results shown in Figure B-54). Few monitoring locations were sampled along Killpecker Creek; KC-3 was often dry, while KC-2 indicated a large range of E. coli concentrations (Figure B-54).
More recent sampling consisted of samples collected on single days at several monitoring locations. Data typically showed that E. coli concentrations varied from site to site, which may be indicative of sources along the streams. For example, Figure B-55 shows that E. coli concentrations increase and decreases along Bitter Creek, possibly due to irrigation withdrawals and source inputs within the city of Rock Springs. For Killpecker Creek (Figure B-56), a source may be located upstream of the city of Rock Springs. While some of the more recent data (August 30, 2016) include high E. coli concentrations, other recent data (June 7, 2016) yielded individual results well below the geometric mean criterion at monitoring sites along Bitter Creek (Figure B-57) and Killpecker Creek (8.4, 43.7, and 24.5 counts per 100 mL for monitoring sites KC-2, KC-5, and KC-1 [respectively] ).
Visual and regression analysis of E. coli concentration and flow did not indicate any patterns (Figure B-58, Figure B-59, and Figure B-60). Such results may indicate that E. coli are derived from a variety of sources and transported to surface waterways through a variant of pathways.
Page 7 of 15 of Appendix B
Figure B-50. E. coli concentration at SWCCD monitoring sites BC-2, BC-3, BC-4, and BC-6.
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Figure B-51. E. coli concentration at SWCCD monitoring sites KC-1 and KC-2.
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Figure B-52. E. coli load at SWCCD monitoring sites BC-2, BC-3, BC-4, and BC-6.
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Figure B-53. E. coli load at SWCCD monitoring sites KC-1 and KC-2.
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Note: Average of E. coli results measured on separate days in the specified month.
Figure B-54. E. coli concentrations in April 2004 (left) and September 2005 (right) along Bitter Creek (top) and Killpecker Creek (bottom).
Page 12 of 15 of Appendix B
Figure B-55. E. coli concentrations at SWCCD monitoring sites along Bitter Creek on September 17-18, 2012.
Figure B-56. E. coli concentrations at SWCCD monitoring sites along Killpecker Creek on September 19, 2012.
Page 13 of 15 of Appendix B
Figure B-57. E. coli concentrations at SWCCD monitoring sites along Bitter Creek on June 7, 2016.
Figure B-58. Paired E. coli and flow data across all SWCCD monitoring sites in the Bitter Creek watershed.
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Figure B-59. Paired E. coli and flow data at SWCCD monitoring site BC-6.
Figure B-60. Paired E. coli and flow data at SWCCD monitoring site BC-2.
Page 15 of 15 of Appendix B
Appendix C – Wild Horse Census and Flight Paths
Page 1 of 5 of Appendix C
FIGURES
Figure C-1. Great Divide Basin...... C-3 Figure C-2. Little Colorado and White Mountain...... C-4 Figure C-3. Salt Wells Creek and Adobe Town...... C-5
Figures presented in this appendix were created by the Bureau of Land Management in May 2017.28
28 Bureau of Land Management. 2017. Wyoming Herd Management Areas. U.S. Department of the Interior, Bureau of Land Management, Wild Horse and Burro Program. May 2017. https://www.blm.gov/site- page/programs-wild-horse-and-burro-herd-management-herd-management-areas-wyoming. Accessed September 1, 2017. Page 2 of 5 of Appendix C
Figure C-61. Great Divide Basin. Page 3 of 5 of Appendix C
Figure C-62. Little Colorado and White Mountain. Page 4 of 5 of Appendix C
Figure C-63. Salt Wells Creek and Adobe Town.
Page 5 of 5 of Appendix C
Appendix D – Response to Comments
As described in Section 10, the formal public comment period for the Bitter Creek watershed TMDLs extended from October 16, 2017 to November 30, 2017. Formal written comments were received from two organizations. DEQ evaluates all comments and related information to ensure no critical information was excluded from the document.
The public comments received are presented below (verbatim as provided), each followed by DEQ’s response. The original comment letters are located in the project files at DEQ and may be reviewed upon request.
Comment 1. Rational for Impairment. The focus of the report is water quality of Bitter Creek and Killpecker Creek and its impact to Recreation Use of the creeks. The report fails to define Recreation Use and what recreational use is specifically impaired. Common sense, dictated by history and observation, is Bitter Creek does not attract or support recreation beyond trespass camping, unauthorized wading, and residents walking along the bank to exercise pets, and those uses are concentrated within or immediately adjacent to established commercial and residential areas. The report would imply there is a loss of public enjoyment due to the water quality of Bitter Creek and Killpecker Creek. This rational requires additional definition in-order to define and design corrective action – and where. Irrespective of the impairment to Recreational Use, the presence of significant E. coli justifies further investigation, identification, clean up and prevention.
Response 1. In accordance with the Wyoming Surface Water Quality Standards:
“Recreational use” protection involves maintaining a level of water quality which is safe for human contact. It does not guarantee the availability of water for any recreational purpose.29
Wyoming has two designated uses for recreation, primary and secondary contact recreation, and a summer recreation season (May 1 through September 30). Primary contact recreation is defined as “any recreational or other surface water use that could be expected to result in ingestion of the water or immersion (full body contact).” Full body contact water recreation is defined as “any recreational or other surface water use in which there is contact with the water sufficient to pose a significant health hazard (i.e., water skiing, swimming).” Secondary contact recreation is defined as “any recreational or other surface water use in which contact with the water is either incidental or accidental and that would not be expected to result in ingestion of the water or immersion.”
As described above, Wyoming’s recreation designated uses are intended to protect people, including young children, from getting sick while recreating in surface waters. WDEQ recognizes that in many locations in Wyoming that there is either insufficient water, no access, or no use of surface waters for recreation. The federal Clean Water Act, however, requires that states designate all waters for primary contact recreation and that states must complete a technical analysis, called a use attainability analysis (UAA), to change the designated use. Recognizing the most waters in Wyoming are not used for and cannot be used for primary contact recreation due to lack of water, WDEQ undertook a multi-year project in coordination with Wyoming’s Conservation Districts to modify the recreation designated uses of low flow channels in Wyoming.
In September 2016, WDEQ completed the statewide Categorical Use Attainability Analysis (UAA) for Recreation to change many of Wyoming’s low flow streams from primary to secondary contact recreation.30 The United States Environmental Protection Agency approved the designated use changes in September 2017. As shown in Figure 11, the areas in proximity to the population centers within the
29 WDEQ. 2013. Chapter 1: Wyoming Surface Water Quality Standards. Section 3 (e). Wyoming Department of Environmental Quality, Water Quality Division, Cheyenne, Wyoming. September 24, 2013. 30 WDEQ. 2016. Categorical Use Attainability Analysis for Recreation. Wyoming Department of Environmental Quality, Water Quality Division, Cheyenne, Wyoming. September 2016.http://deq.wyoming.gov/media/attachments/Water%20Quality/Surface%20Water%20Quality%20Standards/UAAs/01_20 16-0830_Categorical_UAA_for_Recreation.pdf
Page 1 of 3 of Appendix D
Bitter Creek watershed continue to be designated for primary contact recreation because small children may have access to these waters. The remainder of the watershed is designated for secondary contact recreation.
Comment 2. Significance of Grazing Use and Location. The vast majority of the area of the watersheds are remote rangelands that begin at the edges of residential and commercial occupation and extending many hundreds of square miles in all directions. These lands are isolated from the residential and industrial development by distance, lack of water and access. The report defines various suspected sources and reasons for negative contribution to the water quality, but the report fails to differentiate the casual contribution within the densely populated areas from the causal contributions of the rangelands which are scattered across 1500 plus square miles of unpopulated space. For example, in-addition to human activity in the residential areas, the report estimates 5600 plus dogs (6.4.5 Pets) occupy the watershed. Dogs and pets are logically confined to relatively small (city) sub-watershed areas which are paved over and can yield up to 80% of storm water events, compared to livestock and wildlife scattered across open range land on raw land often many miles from channels and maximum 10% yield from storm runoff events. Yet the influence, impact and mitigation for dogs is down played (9.3 Pets suggest owner education) compared to discussions on livestock and wildlife, especially livestock along “streams”, with potential recommendation to limit access to watersheds where sampling was conducted. The majority of grazing that does occur in watersheds is winter grazing of sheep, where the herds are moved, and rely on snow for water-not stream bottoms.
Response 2. Observed E. coli concentrations exceeded 125 organisms per 100 mL from the upper portion of the watershed to the mouth (see Section 5.0) indicating the presence of sources of bacteria in both the remote rangelands and developed portions of the watershed. The available data do not suggest a spatial trend or otherwise indicate that any single source (e.g., pets, livestock) is more important than the others.
Narrative was added to Section 9 (Restoration Strategy) to recommend further investigation of the urban stormwater pathway. Additional narrative was also added to Section 6.4.2 to point out that the majority of grazing that occurs in the watershed is winter grazing of sheep.
Comment 3. Footnote 18 Page 38. This footnote alone and the narrative for Livestock 6.4.2 is inaccurate and misleading in terms of livestock use in the watersheds. Actual use for grazing along the reaches of the watersheds, where sampling was conducted, is minor. The footnote should be eliminated as it is an opinion of an individual not responsible for management of winter grazing operations and his opinion is misleading the reader to understand all the livestock in the Rock Springs Allotment graze inside the watershed, and graze year round. The inserted window (Pg. 38/39) A Range of Numbers should be removed. The livestock are not uniformly distributed across Sweetwater County or the Rock Springs Allotment, and to imply so equates to unbalanced number of livestock that graze the watersheds. Wild horses and wildlife graze year round; permitted sheep only graze in the winter, and summer grazing by cattle is limited, and much of it outside the watershed. (Source RSGA and BLM records).
Response 3. As stated in Section 6.2.4 and shown in Figure 24, many of the grazing allotments within the Bitter Creek watershed extend beyond the watershed boundary. The records available on the BLM Rangeland Administration System Reports are provided at the grazing allotment scale. As a result, the total number of cattle and sheep that may be grazed within the Bitter Creek watershed had to be estimated. Footnote 18 describes the method by which the total number of cattle and sheep that may be grazed within the Bitter Creek watershed was estimated.
It is acknowledged that livestock distribution is not uniform throughout the watershed. Additional narrative was provided in the final document and the text box on page 38 was deleted.
Comment 4. Irrigation Withdrawals. The report describes irrigation as a significant hydrologic factor for Bitter Creek. This is an incomplete description as Pierotto Ditch maybe the only permitted diversion within the watershed.
Page 2 of 3 of Appendix D
Response 4. Narrative was added to Section 3.0 to point out that the Pierotto Ditch is the only known diversion in the watershed.
Comment 5. Accuracy of Point Samples. A common problem with point sampling is the practical error of point samples at the time of storm events. The taking of samples at the peak of an event or early stages sways the analysis as high volumes of organic materials arrive in the channel early, and do not represent water quality over time.
Response 5. Since 2004, greater than 800 E. coli samples have been collected across a wide range of flow (low flow, high flow, storm event) and seasonal conditions from 19 sites on Bitter Creek, nine sites on Killpecker Creek, nine sites on their tributaries, two wells, and five sources of runoff. It is felt that the volume of E. coli data, when examined collectively, adequately represents ambient water quality conditions.
Comment 6. Additional Sources of Raw Sewage. In addition to the identified unlicensed sewer lagoons, there are other sources not mentioned. Lack of access to public dump stations along I-80 and state highways will cause RV and camp trailer owners to dump black water waste along state highways and county roads before they reach their destination, and into storm sewers within city limits. Pull outs and rest areas for long haul truckers on I-80 are littered with “yellow bombs” of human waste. Storm runoff in both situations can easily enter the creeks adjacent to roads and highways.
Response 6. A new document section was added (i.e., 6.4.6) to acknowledge these potential additional sources.
Comment 7. Restoration Strategy 9.0. The mitigation for unlicensed sewer lagoons is not specific enough, and needs additional discussion of the options for enforcement of discharge regulations. The mitigation for the reported population of 23,000 wild horses, elk, deer, pronghorn and dogs is mentioned as a problem and the narrative suggests it may have to be tolerated. But for livestock, it is implied that there are too many livestock and owners need to keep them away from stream courses. Footnote 23, suggests management measures for livestock, but lacks clarification that fencing and off site water could conflict with other interests. There is not mention that proper livestock management facilitates excellent range condition that benefits the watershed, and retains runoff during storm events. Also grazing is limited to winter use, and sheep are herded and not free to roam at will as the report implies. The report should be proactive to outline how to first mitigate the suspected and conferment human sources of E. coli within and near populated areas, to be followed other studies to confirm the continued nonpoint sources contribute before emphasis is directed toward livestock, and other suspected nonpoint sources, in the vast remote rangelands of the watersheds.
Response 7. Additional narrative was included in Sections 6.3 and 8.4 to clarify DEQ’s view of the discharging and non-discharging wastewater facilities in the Bitter Creek watershed. The two “unlicensed sewer lagoons” in the watershed include the facilities in Reliance and Point of Rocks. As described in Section 6.3.10, DEQ issued a Notice of Violation and Order to North Sweetwater Water and Sewer District (for Reliance) on May 8, 2014 and has since issued a Permit to Construct the necessary infrastructure to discharge the wastewater from both the Reliance and B&R Mobile Home Park to the City of Rock Springs waste water treatment facility. WDEQ and the Office of State Lands will continue to work with the North Sweetwater Water and Sewer District to provide compliance assistance and ensure that any future violations are addressed.
Based on further investigation, the Point of Rocks facility has been inspected by WDEQ and SWCCD and evidence of discharges from this facility are not apparent.
It is not stated or otherwise implied that there are too many livestock in the watershed. Livestock, as with pets, septic systems, and wastewater discharge, are the anthropogenic sources of bacteria in the watershed that can be controlled to reduce bacteria loading.
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