1 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Water Quality Condition of Streams and Rivers in Northeast Wyoming Results of the 2011 Northeast Probabilistic Survey

Wyoming Department of Environmental Quality – Water Quality Division

Document #16-0114, February 2016

2 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Water Quality Condition of Streams and Rivers in Northeast Wyoming

Results of the 2011 Northeast Probabilistic Survey

By Eric G. Hargett and Jeremy R. ZumBerge

Document #16-0114

February 2016

Wyoming Department of Environmental Quality Water Quality Division – Watershed Protection Program 122 W. 25th St., Cheyenne, Wyoming 82002

i Water Quality Condition of Streams and Rivers in Northeast Wyoming

Table of Contents EXECUTIVE SUMMARY ...... 1 INTRODUCTION AND OBJECTIVES ...... 3 PROBABILISTIC SURVEYS AND WYOMING’S INTEGRATED REPORT ...... 4 STUDY AREA ...... 5 SURVEY DESIGN ...... 7 DATA COLLECTION ...... 8 SETTING EXPECTATIONS OF STREAM AND RIVER CONDITION ...... 9 INDICATORS OF BIOLOGICAL CONDITION ...... 9 INDICATORS FOR DRINKING WATER SUITABILITY AND HUMAN HEALTH CONDITION ...... 11 STRESSORS TO BIOLOGICAL CONDITION ...... 12 CHEMICAL STRESSORS ...... 12 PHYSICAL STRESSORS ...... 16 RANKING OF STRESSORS ...... 18 Relative Extent ...... 19 Relative Risk ...... 19 DATA ANALYSIS ...... 19 2011 STREAM FLOWS ...... 19 RESULTS ...... 20 EXTENT OF RESOURCE ...... 20 BIOLOGICAL CONDITION ...... 20 DRINKING WATER SUITABILITY AND HUMAN HEALTH CONDITION ...... 21 PHYSICOCHEMICAL STRESSORS TO BIOLOGICAL CONDITION ...... 21 NUTRIENTS ...... 21 SALINITY ...... 21 SELENIUM ...... 21 TOTAL SUSPENDED SOLIDS ...... 21 CHLORIDE, pH and SULFATE ...... 27 ALUMINUM, ARSENIC, CADMIUM, IRON, MANGANESE and ZINC ...... 27 PHYSICAL STRESSORS TO BIOLOGICAL CONDITION ...... 27 RIPARIAN DISTURBANCE ...... 27 CHANNEL INSTABILITY ...... 27 RANKING OF STRESSORS ...... 27 DISCUSSION ...... 28

ii Water Quality Condition of Streams and Rivers in Northeast Wyoming

RECOMMENDATIONS ...... 35 ACKNOWLEDGMENTS ...... 37 REFERENCES ...... 37

Figures Figure 1 – Bioregions, wilderness and selected municipalities of the Northeast...... 6 Figure 2 – Target and non-target/access denied sites evaluated as part of the Northeast probabilistic survey including HUC 8 clusters, municipalities and wilderness...... 22 Figure 3 – Estimated percentage of target stream miles relative to access denied and non-target miles at the Northeast and HUC 8 cluster scales based on 113 evaluated sites. Error bars represent the 95% confidence intervals...... 23 Figure 4 - Biological condition of targeted perennial streams and rivers in the Northeast based on WDEQ/WQD’s aquatic life use matrix. Error bars represent the 95% confidence intervals...... 24 Figure 5 – Most-disturbed condition relative extent (% stream miles) of chemical and physical stressors to biological condition at the Northeast and HUC 8 Cluster scales. Error bars represent the 95% confidence intervals...... 29 Figure 6 - Relative risk values of chemical and physical stressors to biological condition at the Northeast scale. Error bars represent the 95% confidence intervals...... 30 Figure 7 - Biological condition (top) of perennial streams and rivers (by percentage of respective stream length) and relative extents (bottom) of stressors common to the Northeast, Wyoming (Hargett and ZumBerge 2013), Mountains/Basins and Plains/Lowlands regions of the United States (USEPA 2015) and national (USEPA 2015) probabilistic surveys...... 36

Tables Table 1 –Stressor condition estimates associated with drinking water suitability and human health condition for WDEQ/WQD’s 2011 Northeast survey...... 25 Table 2 - Stressor condition estimates associated with biological condition for WDEQ/WQD’s 2011 Northeast survey...... 26

Appendices Appendix 1 – Biological condition stressor thresholds used to establish condition categories for streams and rivers within bioregions of the Northeast survey. Biological condition thresholds are represented as (least- disturbed) / (most-disturbed) expect for sulfate where only most-disturbed values are provided according to the embedded matrix...... 41 Appendix 2 – Drinking water suitability and human health condition thresholds used to establish condition categories for streams and rivers within the Northeast survey. Equations used to translate dissolved concentrations to total concentrations are found within the brackets for each constituent...... 42

iii Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 3 – Relative departures of 2011 flow statistics from means for the periods of record at selected USGS streams gages within the Northeast...... 43 Appendix 4 – Target sites sampled as part of the 2011 Northeast survey...... 44 Appendix 5 - Summary of Escherichia coli results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 46 Appendix 6 – Summary of nitrate+nitrite-N results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 47 Appendix 7 - Summary of total phosphorus results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 48 Appendix 8 - Summary of total nitrogen results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 49 Appendix 9 - Summary of salinity results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 50 Appendix 10 - Summary of selenium results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 51 Appendix 11 - Summary of total suspended solids (TSS) results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 52 Appendix 12 - Summary of chloride results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 53 Appendix 13 - Summary of sulfate results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 54 Appendix 14 - Summary of pH results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 55 Appendix 15 - Summary of physical stressor results (channel instability and riparian disturbance) for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 56 Appendix 16 - Summary of the three component sub-stressors that represent channel instability for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals...... 57

1 Water Quality Condition of Streams and Rivers in Northeast Wyoming

HUC clusters) that comprise the NE: Belle Fourche, EXECUTIVE SUMMARY Cheyenne, East Big Horn and Powder. The Wyoming Department of Environmental Findings from this study indicate that 52% of the Quality-Water Quality Division’s (WDEQ/WQD) perennial streams in the NE were in the least- probabilistic survey of perennial streams and disturbed biological condition or comparable to rivers in Northeast Wyoming (NE) was conducted reference expectations. Approximately 13% of in 2011. Results from this survey provide an NE perennial stream miles were considered most- objective representation of the current status of disturbed, implying an appreciable deviation the biological condition, drinking water suitability from reference expectations associated with and human health condition of NE perennial anthropogenic stressors. The remaining 35% of streams and rivers. This study also identifies the NE perennial stream miles were considered most common stressors and their relative impact to indeterminate with respect to biological condition. biological condition. Information obtained from A combination of historic and current this and other probabilistic surveys also allows anthropogenic disturbances and accelerated Wyoming to fulfill State obligations under channel morphological alterations exacerbated §305(b) of the federal Clean Water Act. by record high flows are presumed to be WDEQ/WQD’s NE survey included all non- primarily responsible for the less favorable headwater, perennial streams that are not biological condition in areas of the NE. located in United States Forest Service wilderness Of 20 stressors evaluated, channel instability areas. This equates to approximately 3,765 miles (35% of stream miles), elevated total suspended of perennial streams and rivers or over 90% of solids (TSS) (32% of stream miles) and riparian the 4,016 total miles of perennial streams and disturbance (26% of stream miles) were the three rivers in the NE. A portion of the stream and river most common stressors that can influence miles classified as perennial is represented by biological condition in the NE. Of the 35% of spring-fed plains streams that may not flow year- perennial stream miles with channel instability, round though generally flow for extended 29% were due to excess sediment, 47% periods in the spring, early summer and/or fall. attributed to accelerated bank erosion and 24% Considering their extended flow periods during linked to channel incision. the growing season combined with permanent perennial features that function as aquatic With regard to the potential influence or relative refuges during drier periods, they are risk of stressors on biological condition, elevated ecologically significant features and thus were chloride ranked highest among stressors likely to included in the NE survey. Therefore the 3,765 be associated with degraded biological condition mile target population of ‘perennial streams’ in NE streams. Specifically, stream benthic refers to both these unique spring-fed systems and macroinvertebrates in the NE were 5.8 times more traditional perennial streams and rivers. likely to be in a most-disturbed biological condition when elevated chloride was present Of the 3,765 perennial stream miles initially than when not present. However, elevated considered for the NE survey, only 1,785 miles chloride was only the 7th most common stressor were assessed. The remaining 1,980 stream miles (8% of stream miles) in the NE. Total phosphorus were identified as completely ephemeral or (4.9) ranked second among stressors associated intermittent, human constructed, wetlands, with degraded biological condition though again inaccessible or access was denied. Biological was less prevalent throughout the NE (7% of condition was evaluated using benthic stream miles). The relative risk of total nitrogen macroinvertebrates as the biological indicator at (4.2) implies its associated with degraded both the NE scale and for four watershed units (i.e.

2 Water Quality Condition of Streams and Rivers in Northeast Wyoming

biological condition though further investigation perennial streams in the NE would require minimal suggests this is likely an overestimate as the treatment as potential drinking water sources with elevated nitrogen is some streams appeared to respect to the aforementioned constituents (with be natural and/or the indirect effects of this the exception of manganese). stressor on the aquatic community is not clear in the NE. Excluding total nitrogen, channel The NE is similar to the entire State of Wyoming instability and elevated total selenium tied for 3rd (based on WDEQ/WQD’s 2008-2011 second (3.7) among stressors associated with degraded statewide probabilistic survey) with regard to biological condition. The wide-spread extent of least-disturbed (52% NE vs. 58% Wyoming) and channel instability and its potential influence to most-disturbed (13% NE vs. 18% Wyoming) biological condition emphasizes its importance as biological condition. Perennial streams in the NE a pollutant of focus in the NE. Similar to chloride fare better than the mountainous and arid regions and total phosphorus, elevated total selenium was of the western States (i.e. Mountains/Basins) only the 10th ranked stressor (4% of stream miles) (based on the U.S. Environmental Protection throughout the NE. Though TSS as ranked as the Agency’s 2008-2009 National Rivers and second most common stressor in NE streams, a Streams Assessment (NRSA)) in terms of least- degraded biological condition was just as likely disturbed (52% NE vs. 46% Mountains/Basins) to occur with or without elevated concentrations of and most-disturbed (13% NE vs. 27% this stressor. Consequently, TSS apparently poses Mountains/Basins) biological conditions. Similar no additional risk to benthic macroinvertebrates results were found when comparing to the plains when present in NE streams. Rather, its subsequent and lowland regions of the central and eastern deposition has the most likely direct impact to the United States (i.e. Plains/Lowlands) with respect to benthic macroinvertebrate component of the least-disturbed (52% NE vs. 25% aquatic community. As such, TSS when deposited Plains/Lowlands) and most-disturbed (13% NE vs. is reflected as part of the channel instability 50% Plains/Lowlands) biological condition. stressor. Nevertheless, the commonality of TSS Excess sediment was the 2nd most common sub- may pose a risk to other aquatic organisms such stressor (19%) of channel instability in the NE, as fish that are potentially more directly affected similar to the Mountains/Basins (18%) and by suspended sediment. Plains/Lowlands (14%), though less than throughout Wyoming (37%). Riparian disturbance With regard to human health condition, 54% of occurred in 36% of Wyoming streams (3rd perennial streams in the NE had Escherichia coli (an ranked), 26% of streams in the NE (3rd ranked), indicator of human health risk for recreational uses 24% in the Mountains/Basins (2th ranked) and of water) concentrations in the least-disturbed least common in the Plains/Lowlands at 17% (4th condition with the potential for a most-disturbed ranked). Elevated total phosphorus was found to condition in 46% of perennial NE streams. One- be the most common stressor throughout the hundred percent of stream miles in the NE Mountains/Basins (33%) and second most common exhibited concentrations of total cadmium, in the Plains/Lowlands (41%), while this stressor nitrate+nitrate-N, total selenium and total zinc in occurred in only 14% of Wyoming streams (5th the least-disturbed condition with respect to ranked) and 7% of streams in the NE (9th ranked). suitability of the water for drinking. Similar findings were evident for 91% of perennial Perennial streams of the NE also fair far better stream miles with respect to total arsenic. Only than the national estimates of least-disturbed 66% of stream miles were in the least-disturbed (52% NE vs. 28% national) and most-disturbed condition for dissolved manganese, which (13% NE vs. 46% national) biological condition appears largely due to natural factors. This (based on USEPA’s 2008-2009 NRSA). Whereas indicates that the vast majority of the evaluated total phosphorus was the most common stressor

3 Water Quality Condition of Streams and Rivers in Northeast Wyoming

nationally (46%), it was considered a stressor in potential need for additional investigation into only 7% of NE streams. Excess sediment and whether aquatic life uses are being supported elevated salinity were considered stressors in only with respect to the individual and combined 15% and 3%, respectively, of streams nationally. influences of channel instability (namely Comparatively, the estimated percentage of accelerated bank erosion), riparian disturbance streams with excess sediment or elevated salinity and elevated TSS, chloride, total selenium and in the NE was 19% and 18%, respectively. total phosphorus. Among all four HUC 8 clusters, Riparian disturbance was the fourth most common the highest relative extents for each of the stressor nationally at 20%, somewhat less than the aforementioned stressors were found within the 26% estimated for the NE. Powder. Combined, this information suggests that where aquatic life may not be supported in these The commonality of channel instability and areas, the causes may be many and their effects riparian disturbance combined with their to aquatic life variable and perhaps inter- moderately high risk to aquatic life, suggest that related. where benthic macroinvertebrates communities have been degraded, efforts aimed at reduction in these two stressors could have broad benefits INTRODUCTION AND OBJECTIVES to biological condition of the NE. Based on the The federal Clean Water Act (CWA) §305(b) survey data, both stressors appear to be linked in requires delegated States to describe the water many circumstances and from a resource quality condition of all their surface waters. To management perspective, efforts that address help fulfill these State obligations to the CWA, one could benefit the other. Accelerated bank Wyoming uses a cost-effective approach known erosion was the most prominent of the three sub- as probabilistic surveys to monitor and evaluate stressors that comprised channel instability. Efforts trends in surface water quality condition. to reduce accelerated bank erosion will not only Probabilistic surveys yield unbiased, statistically- help to address channel instability and derived estimates of the condition of surface consequently elevated TSS, but may also reduce waters based on a representative sample of the nutrient loading to streams in the NE since resource with a known level of statistical sediment can function as a transport mechanism confidence or certainty. Probabilistic surveys are for pollutants such as total phosphorus. The very efficient because they require sampling commonality of elevated total phosphorus in relatively few locations to make valid scientific particular areas of the NE combined with its statements about the condition of waters at the second highest relative risk to biological condition, State or regional scale. suggests efforts to reduce this stressor at watershed-scales could improve overall water The Wyoming Department of Environmental quality condition through minimizing the onset of Quality – Water Quality Division (WDEQ/WQD) eutrophication that could lead to episodes of conducted its first statewide probabilistic survey hypoxia or toxic algal blooms. Elevated chloride of wadeable streams and rivers from 2004 to and total selenium exhibited the highest and third 2007 followed by a second survey conducted highest relative risks, respectively, to biological from 2008 to 2011 (Hargett and ZumBerge condition. Though their prevalence is confined to 2013). The purposes of both statewide particular watersheds, addressing these stressor probabilistic surveys were to ascertain the current could offer large benefits to the biological and temporal changes in the ecological condition condition of some NE streams. of Wyoming’s perennial streams and rivers and the extent to which major stressors could Of the four HUC 8 clusters that comprise the NE, potentially influence this ecological condition. the Powder emerges as an area with the greatest

4 Water Quality Condition of Streams and Rivers in Northeast Wyoming

The findings from both statewide surveys were survey in 2011 which is the focus of this report. informative on the biological condition and The NE was designed to: stressors affecting perennial streams and rivers at  Determine the biological condition of the statewide scale. However, statewide surveys perennial streams and rivers (hereafter do not provide sufficient information to referred to as ‘streams’) within the NE and characterize biological condition and stressor its sub-basins extents at the regional or watershed scales. Smaller scale probabilistic surveys can provide  Determine the most common stressors that this level of information and can lead to better could potentially influence biological informed decisions on future watershed-based condition in the NE and its sub-basins monitoring and management priorities. In  Determine the relative influence of addition smaller-scale probabilistic surveys stressors on biological condition in the NE provide a more focused and unbiased means of  Provide recommendations on focus identifying waters of high quality and those where pollutants and areas where additional designated uses may not be supported. investigation could be conducted to Furthermore, smaller scale surveys can provide a determine whether aquatic life uses are useful measure of the cumulative effectiveness of being supported numerous efforts to improve water quality. For In addition, data collected as part of the NE these reasons, the WDEQ/WQD phased-out survey were used to: statewide probabilistic surveys in 2010 and replaced with rotating basin probabilistic surveys.  Evaluate human health condition with respect to the pathogen indicator Wyoming’s probabilistic rotating basin approach Escherichia coli and drinking water establishes an order of rotation and sampling suitability with respect to dissolved iron, years among five ‘superbasins’ within the State dissolved manganese, total arsenic, total delineated based on six-digit hydrologic unit cadmium, nitrate+nitrite-N, total selenium codes (HUCs) and geographic location and total zinc within the NE (WDEQ/WQD 2010). The five superbasins, their associated HUC 6 basins and projected year of sampling are: PROBABILISTIC SURVEYS AND  Bighorn/Yellowstone [Bighorn and WYOMING’S INTEGRATED REPORT Yellowstone Basins] - 2010 In addition to requiring States to describe the  Northeast [Belle Fourche, Cheyenne, Little water quality condition of all their waters, CWA Missouri, Powder and Tongue Basins] - §303(d) directs each State to develop a list of all 2011 waters which do not fully support their designated  Green [Great Divide, Green and Little uses and require development of a Total Snake Basins] - 2015 Maximum Daily Load (TMDL). Assessments of  Platte [Niobrara, North Platte and South pollutant problems and their impact on Platte Basins] - 2016 designated uses are incorporated into Wyoming’s  Bear/Snake [Bear and Snake Basins] – To Integrated 305(b) and 303(d) Report (hereafter be determined the Integrated Report) that is submitted to the USEPA biennially. The WDEQ/WQD implemented and completed its first rotating-basin probabilistic survey within Probabilistic surveys provide a systematic, broad- the Bighorn/Yellowstone in 2010 (Hargett and scale and quantitative estimate of overall water Zumberge 2014) followed by the Northeast (NE) quality within the targeted population of streams in a region of interest. Conversely, Wyoming’s

5 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Integrated Report describes water quality issues varies widely due to the variable topography and identified by the WDEQ/WQD’s Monitoring the orographic effect of the Bighorn Mountains. Program and other federal, state and local The NE is divided into ten bioregions (Figure 1): government agencies, non-profit organizations Bighorn Basin Foothills, Black Hills, Granitic and private entities. Water quality issues are Mountains, High Valleys, NE Plains, Sedimentary normally derived through focused multi-year Mountains, SE Plains, Southern Foothills & Laramie studies, the results of which are evaluated against Range, Southern Rockies, and the Wyoming Basin Wyoming’s surface water quality standards (Hargett 2011). Bioregions are geographic (WDEQ/WQD 2013) to make determinations of classifications that represent groups of streams designated use support including those waters with similar habitat, chemical and biological that do not fully support their designated uses (i.e. characteristics. 303(d) list) (WDEQ/WQD 2014). The Bighorn Basin Foothills (southern Bighorn Findings from probabilistic surveys are Mountains); Black Hills (Bear Lodge Mountains); summarized in Wyoming’s Integrated Report. Granitic Mountains, Sedimentary Mountains and However, data collected as part of the Southern Rockies (Bighorn Mountains); and the probabilistic surveys are not intended to be used Southern Foothills & Laramie Range (Rattlesnake to make designated use-support determinations, Range); collectively represent the mountainous including 303(d) listings. Rather, probabilistic regions of the NE with bedrock geology and surveys may be used to prioritize future targeted elevation as the primary delineators between sampling on which designated use support these six bioregions. The mid to upper montane determinations and 303(d) listings may be made. elevations of Bighorn Mountains are largely covered by coniferous forest, aspen groves, STUDY AREA subalpine meadows and/or alpine tundra. Ponderosa pine interspersed with boxelder, oak, The NE encompasses 24,585 mi2 or about 25% of aspen and birch dominates the forested Wyoming’s 97,100 mi2 area. The majority of the landscape of the Bear Lodge Mountains. NE is characterized as semiarid rolling plains Vegetation cover for the low elevation foothills is punctuated by occasional buttes and badlands a mosaic of conifers, shrubs, sagebrush and (Chapman et al. 2003). The Bighorn Mountains grassland. represent the western boundary of the NE whereas the southwestern portion is bounded by The plains of the NE are represented by the High the arid high elevation plains/desert plateau of Valleys, NE Plains, SE Plains and Wyoming Basin the Casper Arch. The Bear Lodge Mountains bioregions. The High Valleys is considered an represent the northern extent of the Black Hills and ecotone between nearby mountains and the plains comprise the northeast corner of the NE. Exposed proper. Physiographically, the High Valleys are outcrops of shale, sandstone and other sub-irrigated wet meadow systems found in the sedimentary bedrock are common throughout the broad floodplains, low terraces and alluvial fans NE. Elevation ranges from approximately 3,125 commonly covered by cottonwood, sagebrush, ft where the Belle Fourche River crosses into South mixed-grass prairie and scattered conifer Dakota to 13,167 ft at the summit of Cloud Peak (Chapman et al. 2003). The NE and SE Plains in the Bighorn Mountains. Average annual bioregions are dominated by short and mixed- precipitation ranges from 9 inches in the Casper Arch up to 39 inches along the highest peaks in the Bighorn Mountains with values between 13 and 15 inches common throughout most of the NE. As with precipitation, air temperature in the NE

6 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Figure 1 – Bioregions, wilderness and selected municipalities of the Northeast.

7 Water Quality Condition of Streams and Rivers in Northeast Wyoming

grass prairies with conifers present on buttes and Treated sewage effluent may also be discharged rugged escarpments. Lastly, the Wyoming Basin to surface waters in the NE from municipalities that bioregion of the NE is represented as the Casper that are supplied by groundwater. Domestic Arch - a transitional region between the plains water uses are those not supplied by a central and arid high desert. Short-grass prairie, public water system and these uses in the NE are sagebrush, saltbush and greasewood are common almost exclusively supplied by groundwater. in the uplands of the Casper Arch. The streams Similarly, major industrial uses in the NE such as and rivers in the plains of the NE have a mixture power plants, coal mines, oil and gas production of spring and montane snow-melt origins. and oil refining use almost entirely groundwater. Produced water from these industrial uses is often The mountainous regions of the NE are the source discharged into surface waters of the NE, thereby of some major perennial streams that provide potentially influencing water quality. water resources for the semiarid plains region. Recreation, logging, hardrock mining and summer Fishing is a common non-consumptive use of water livestock grazing are common land uses in the in streams and rivers of the NE. According to mountainous areas of the NE. The NE interior is WWDC (2002a and 2002b) annual fishing used for livestock grazing, energy extraction and pressure has been estimated at 140,000 angler- irrigated agriculture with alfalfa and hay the days for streams in the Powder and Tongue basins dominant crops (WWDC 2002a, 2002b). Man- with 15,500 angler-days for the remaining basins made dams, diversions, spreader dikes and trans- in the NE. basin inputs influence the natural flow regimes of many streams within the High Valleys, NE Plains, SE Plains and Wyoming Basin bioregions of the SURVEY DESIGN NE (WWDC 2002a, 2002b). The total length of all waterways (perennial, intermittent, ephemeral, canals) in the NE is According to WWDC (2002a and 2002b), 29,476 miles based on the USEPA-United States approximately 88% of typical annual surface Geological Survey (USGS) 1:100,000 scale water consumption in the NE is used for agriculture enhanced National Hydrography Dataset – predominantly irrigation. This estimate only (NHD+). Approximately 4,016 (14%) miles in the represents the actual surface water consumed by NE are categorized as perennial streams by crops as a significant portion of diverted surface NHD+. Intermittent and ephemeral streams water is lost to conveyance seepage, deep represent approximately 39,687 (83%) miles percolation, headgate leakage and other non- based on NHD+. A portion of the stream miles consumptive factors. Ultimately, much of this non- classified in NHD+ as perennial in the NE is consumptive water is returned back to streams for represented by spring-fed plains streams that downstream reuse. Evaporative losses from may not flow year-round, though generally flow reservoirs used for irrigation water storage, flood for extended periods in the spring, early summer control, stock water and/or recreation represents and/or fall. As a result of their extended flow an estimated 11% of annual surface water periods during the growing season combined with consumption in the NE. Most municipalities in the permanent pools or wet areas that function as NE obtain their drinking water from groundwater aquatic refuges during drier periods, they are sources. However, several municipalities within the ecologically significant features and thus were Tongue and Powder basins use surface water as included in the NE survey. The term ‘perennial their primary drinking water source. These streams’ will be used throughout this report to municipalities represent the remaining 1% of the represent the target population of streams for the total annual surface water consumption in the NE NE survey, which includes all streams classified as with a percentage of this water discharged back perennial by NHD+. to surface waters as treated sewage effluent.

8 Water Quality Condition of Streams and Rivers in Northeast Wyoming

The design for the NE is based on the approach with a brief summary found in Hargett and developed by Stevens and Olsen (2004 and ZumBerge (2013). 1992) and previously implemented in Sample size for the NE was based on a multi- WYDEQ/WQD’s statewide and density categorization of 2nd, 3rd, 4th and 5th+ Bighorn/Yellowstone probabilistic surveys Strahler orders for a total of 50 primary sites to (Hargett and ZumBerge 2013 and 2014) and be sampled on perennial streams. To ensure USEPA’s 2008-2009 NRSA (USEPA 2015). Site spatial uniformity in the design, the 50 sample locations that represent a known proportion of the sites were equally allocated among four eight- target population (in this case perennial streams digit HUC clusters within the NE: Belle Fourche, as classified by NHD+) were computer generated Cheyenne, East Bighorn and Powder (Figure 2). randomly from the digitized NHD+ stream Following the same design and stratification, a network sample frame using a Generalized population of 100 oversample sites was Random Tessellation Stratified (GRTS) design. generated for the NE. Oversample sites were The GRTS design assigns weights to user-specified used as replacements when primary sites could not categories such as Strahler order, ecoregion and be sampled due to access denial, inaccessibility or other geographic variables based on their extents they were non-target (e.g. ephemeral, canal, within the sample frame. The weight assignments wetland, etc.). Within each HUC 8 cluster, sites are integral to GRTS designs so that combined, were chosen in the order of selection by the GRTS randomly selected sites fully represent the variety design. of streams in the sample frame. Each randomly Results of the NE survey are presented at two selected site thus represents a known proportion levels of geographic resolution: NE and the four of total stream miles within the sample frame. HUC 8 clusters. From this information, estimates of stream length and associated biological condition and stressor extents within different landscape categorizations DATA COLLECTION can be calculated. All data collections in 2011 were conducted The stratified survey design for the NE selected during typical baseflow conditions. Chloride, sites from perennial, non-headwater (>1st Strahler dissolved aluminum, dissolved arsenic, dissolved order) streams that are not located in United cadmium, dissolved iron, dissolved manganese, States Forest Service wilderness within the NHD+ dissolved zinc, Escherichia coli, nitrate+nitrite-N, sample frame. Streams in wilderness areas were total hardness, total nitrogen, total phosphorus, excluded since most are not reasonably total selenium, sulfate and total suspended solids accessible. Headwater streams were also (TSS) were analyzed from grab samples collected excluded since the majority within the superbasin at the base of a riffle at each site (WDEQ/WQD are considered non-perennial. This equated to a 2015). Instantaneous water temperature, target population of approximately 3,765 miles dissolved oxygen, pH and specific conductance of perennial streams for the NE (over 90% of the were measured directly in the field total miles of perennial streams in the NE). The (WDEQ/WQD 2015). random site selection was performed with Benthic macroinvertebrates were collected from a Geographic Information Systems (GIS) by the representative riffle, when present, within each USEPA’s Health and Environmental Effects monitoring site following standard procedures in Research Laboratory in Corvallis, Oregon. WDEQ/WQD (2015). Eight randomly selected The statistical procedures used in selecting site samples (each 1 ft2) were collected from the locations from sample frames using GRTS are fully representative riffle with a Surber sampler (500- described in Stevens and Olsen (2004 and 1992) µm mesh collection net), filtered with a 500-µm

9 Water Quality Condition of Streams and Rivers in Northeast Wyoming

mesh sieve and combined into a single composite All sites were evaluated as to the degree and sample. At low-gradient sites where riffles were relative extent the natural stream hydrology was atypical or absent, benthic macroinvertebrates affected by dams, flow diversions and/or flow were collected from multiple habitats augmentation. The number and type of surface (WDEQ/WQD 2015). The multi-habitat sample water diversions or inputs upstream of the site in was a composite of 20 discrete ‘jab’ samples addition to information on water operations in the collected with a dip net, from multiple habitats watershed were used to determine whether flow weighted proportionally based on representation, alterations were present in the watersheds. within a 300 ft reach. Organisms were preserved Sources of this information included but were not in the field with 99% ethyl alcohol. Sample limited to the Wyoming State Engineers Office processing followed methods described in and the U.S. Bureau of Reclamation. In addition, WDEQ/WQD (2015). sites where reservoirs (as depicted on a USGS 1:100,000 scale map) affected 50% or more of Substrate particle size and mean embeddedness the upstream watershed were noted as reservoir within riffles where benthic macroinvertebrates influenced. Lastly, a site was noted as effluent were collected were estimated by measuring at dominant (WDEQ/WQD 2013) if the flow at the least 100 randomly selected particles using a site for the majority of the year was known to be modification of the Wolmann pebble count primarily attributable to the permitted discharge method (WDEQ/WQD 2015). Mean riffle of waste or production water. Information on embeddedness is the degree to which coarse permitted discharges was obtained from the materials are covered or surrounded by very fine WDEQ/WQD’s Wyoming Pollutant Discharge gravel, sands and silts. Surveys were also Elimination System program. performed at permanent cross-sections within representative riffles to calculate existing channel All chemical, physical and biological data dimensions for Rosgen channel classification collected during 2011 that did not meet quality (Rosgen 1996) and to evaluate relative assurance/quality control standards departure from general expected conditions. (WDEQ/WQD 2001) were excluded from Wolman pebble counts (100 count) were analyses. Otherwise, all remaining data were conducted reachwide to characterize substrate determined to be complete and accurate. composition and for use in Rosgen channel classification. Additional semi-quantitative evaluations of streambank stability and cover, SETTING EXPECTATIONS OF human influences within the riparian zone, stream STREAM AND RIVER CONDITION bank and riparian zone condition and channel stability were measured at all sites (considering INDICATORS OF BIOLOGICAL their inherent potential) following approved CONDITION procedures in WDEQ/WQD (2015). Twelve To assess the biological condition of the NE’s human activities (logging, mining, buildings, roads, streams and rivers requires the establishment of landfills, riprap, pavement, pipes, lawn, row minimum biological thresholds. Wyoming uses a crops, pasture and grazing) were evaluated for reference condition approach to develop minimum presence/absence, proximity to the channel and biological condition thresholds for different relative influence to water quality conditions. regions in the State that are derived from benthic Combined, these physical parameters were used macroinvertebrate data collected at a network of to make conservative inferences on the degree of over 200 minimal or least-impacted reference riparian disturbance and relative channel sites. Benthic macroinvertebrates are one of the stability. most common indicators used to assess the biological condition of streams. The Wyoming

10 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Stream Integrity Index (WSII) and the WY from an appropriate set of reference sites that RIVPACS, each of which were developed using are minimally or least impacted by human Wyoming’s reference dataset, were used to disturbance. The deviation of the observed from assess the biological condition of perennial the expected taxa, a ratio known as the O/E streams in the NE. Because results from the WSII value, is a measure of compositional similarity and WY RIVPACS provide strong inference about expressed in units of taxa richness and thus a water quality conditions over a multi-year period, community level measure of biological condition. they are important tools for evaluating the O/E values near 1 imply high biological condition biological condition of the NE’s perennial streams. while values <1 imply some degree of biological degradation. O/E values are codified into one of WYOMING STREAM INTEGRITY INDEX (WSII) is three narrative aquatic life use categories of ‘full- a statewide regionally-calibrated support’, ‘indeterminate’ and ‘partial/non- macroinvertebrate-based multimetric index support’. designed to assess biological condition in Wyoming perennial streams (Hargett 2011). The ‘full-support’ and ‘partial/non-support’ Index scores for the WSII are calculated by categories derived from the WSII and WY averaging the standardized values of selected RIVPACS represent the ‘least-disturbed’ and metrics (composition, structure, tolerance, ‘most-disturbed’ biological conditions, functional guilds) derived from the riffle-based respectively (Appendix 1). Sites that fall between macroinvertebrate sample. The selected metrics these two categories are categorized as are those that best discriminate between ‘indeterminate’. reference and degraded waters. The assessment The WSII and WY RIVPACS were designed to of biological condition is made by comparing the evaluate only riffle-based benthic index score for a site of unknown biological macroinvertebrate samples thus application to condition to expected values that are derived samples collected with multi-habitat sampling from an appropriate set of regional reference procedures is limited. For sites in the NE survey sites that are minimally or least impacted by where multi-habitat procedures were used, human disturbance. WSII index values that fall biological condition was determined through the within the range of expected, or reference values, use of Wyoming’s Northeast Plains Multihabitat imply high biological condition, whereas values Index (NEPMI) and multiple lines of biological, lower than that observed at reference sites imply chemical and physical evidence; alternative biological degradation. Index scores are codified analytical procedures; comparisons to applicable into one of three narrative aquatic life use- numeric criteria protective of aquatic life and support categories of ‘full-support’, professional judgment. The NEPMI is a trial index ‘indeterminate’ and ‘partial/non-support’ based developed specifically for interpretation of on numeric thresholds for each of Wyoming’s multihabitat samples collected on spring-fed, low eleven bioregions and two reservoir-regulated gradient plains streams in northeast Wyoming. large river segments. The NEPMI has undergone limited testing though WYOMING RIVER INVERTEBRATE PREDICTION shows promise as a supplemental indicator of AND CLASSIFICATION SYSTEM (WYRIVPACS) is biological condition combined with other lines of a statewide macroinvertebrate-based predictive evidence as previously described. Biological model that assesses stream biological condition by condition for approximately fourteen sites was comparing the riffle-based macroinvertebrate evaluated in part with the NEPMI. community observed at a site of unknown The biological condition of effluent dominant biological condition with that expected to occur streams is almost entirely dependent on the under reference condition (Hargett 2012). The quality and quantity of wastewater in addition to expected macroinvertebrate taxa are derived

11 Water Quality Condition of Streams and Rivers in Northeast Wyoming

any physical changes to the channel as a result of drinking water supplies though are not considered the effluent discharges. Consequently, the use of health threatening according to the USEPA the WSII and WY RIVPACS is limited in the (http://water.epa.gov/drink/contaminants/secon assessment of biological condition for effluent darystandards.cfm). Wyoming’s most-stringent dominant systems. Biological condition for five numeric criteria protective of human health (fish effluent dominant sites sampled as part of the NE consumption and drinking water) were used to survey was evaluated through comparisons to represent the least- disturbed condition for applicable numeric criteria protective of aquatic drinking water suitability (WDEQ/WQD 2013). life, multiple lines of chemical, physical and Specifically, the least-disturbed thresholds are: biological evidence and professional judgment. dissolved iron (300 µg/L), dissolved manganese (50 µg/L), total arsenic (10 µg/L), total cadmium With the exceptions for effluent-dominant waters (5 µg/L), nitrate+nitrate-N (10 mg/L), total and streams represented by multi-habitat selenium (50 µg/L) and total zinc (5,000 µg/L) samples, results from the WSII and WY RIVPACS (Appendix 2). were incorporated into Wyoming’s aquatic life use-support decision matrix (WDEQ/WQD Concentrations of these parameters that equal or 2014). This matrix was used to determine overall exceed the least-disturbed thresholds represent biological condition using the three categories of the most-disturbed drinking water suitability least-disturbed, indeterminate and most- condition. Only the dissolved fractions of these disturbed. analytes were collected as part of the NE survey. Therefore, translator equations (USEPA INDICATORS FOR DRINKING WATER 1996,1985) using the dissolved fraction SUITABILITY AND HUMAN HEALTH concentrations were used to estimate the total CONDITION fraction concentrations for each analyte that were Although this report focuses almost exclusively on then compared to the least-disturbed thresholds. the biological condition of perennial streams, These translator equations are described in seven analytes (dissolved iron, dissolved Appendix 2. manganese, total arsenic, total cadmium, E. coli is a fecal coliform bacterium commonly nitrate+nitrite-N, total selenium and total zinc) found in the intestines of warm-blooded animals were also evaluated with respect to suitability of and humans and is used as an indicator of public perennial streams in the NE as drinking water health risk of recreational waters in Wyoming sources. In addition, the pathogen indicator (WDEQ/WQD 2013). Elevated concentrations of Escherichia coli (E. coli) was evaluated with respect E. coli increase the risk that humans may contract to human health condition in the NE. According to pathogens, and thus gastrointestinal illnesses the USEPA (http://water.epa.gov/drink/ through recreational use of the water. contaminants/index.cfm), long-term drinking Anthropogenic sources of E. coli are human or water intake of elevated concentrations of warm-blooded animal fecal material conveyed arsenic, cadmium, nitrate+nitrate-N, selenium and via multiple pathways that include septic systems, zinc increases the risk for following effects to wastewater effluent, storm drains, overland runoff human health: arsenic (skin problems and cancer), and direct deposit in or near the stream. cadmium (kidney damage), nitrate+nitrate-N Wyoming’s 60-day geometric mean E. coli (blue baby syndrome in pregnant women), criterion of 126 cfu/100 mL that is protective of selenium (hair and fingernail loss along with primary contact recreation was used to represent circulatory problems) and zinc (taste, odor or the least-disturbed human health condition for gastrointestinal issues with drinking water). streams and rivers in the NE (WDEQ/WQD Elevated concentrations of iron or manganese can 2013). Conversely, E. coli concentrations equal to result in undesirable taste, odor or color to or greater than the least-disturbed threshold

12 Water Quality Condition of Streams and Rivers in Northeast Wyoming

represent the most-disturbed human health life uses from that stressor. Further investigation condition. would be necessary to determine if aquatic life uses are in fact impaired. Temperature and STRESSORS TO BIOLOGICAL dissolved oxygen were not evaluated as stressors CONDITION for this study because their diurnal fluctuations are For the purposes of this study, stressors are not accurately represented by the instantaneous chemical and physical factors that negatively measurements collected as part of this project. affect the biological condition of a stream. Stressors used in this report, their descriptions and Wyoming has water quality criteria to protect the established expectations are described designated aquatic life uses of streams below. (WDEQ/WQD 2013). For parameters such as pH, chloride and select metals, Wyoming’s CHEMICAL STRESSORS respective numeric aquatic life criteria were used NUTRIENTS – Parameters such as nitrate+nitrite- to evaluate conditions throughout the NE and for N (commonly referred to as nitrate), total nitrogen each HUC 8 cluster. For parameters with acute and total phosphorus are essential to the and chronic criteria, the chronic criterion was used. biological productivity of streams, though are The water quality condition was considered least- generally found in low concentrations naturally disturbed when concentrations were less than the and are therefore considered limiting constituents numeric criterion. Conversely, water quality for plant and algal growth. However, excess condition was considered most-disturbed when the contributions of nutrients associated with human numeric criterion was equaled or exceeded. activities, otherwise known as nutrient enrichment, can cause problems that range from annoyances For parameters without numeric criteria, percentile to serious effects to aquatic life (USEPA 2000). distributions (25th and 95th percentiles) of Nutrient concentrations in streams may be reference site values within individual or collective increased above ambient concentrations through bioregions in the NE were used to establish the land fertilization, direct deposits of animal and least and most-disturbed thresholds for each human wastes, sewage discharges or leaking stressor, respectively. This percentile-based septic systems, and elevated upland or bank methodology for establishing least and most- erosion (USEPA 2000). Nutrient enrichment may disturbed thresholds is similar to that used for stimulate excessive growth of phytoplankton EMAP-West (Stoddard et al., 2005) and the (free-floating algae) in slow moving rivers, NRSA (USEPA 2015). Stressor thresholds periphyton (algae attached to substrate) in developed by Stoddard et al. (2005) and USEPA shallow streams and macrophytes (aquatic (2015) were not used in this study as they were vascular plants) in all waters (USEPA 2015). developed for broad regions of the United States Nutrient enrichment can negatively affect aquatic and may have limited representativeness in communities through high concentrations of certain areas of Wyoming. nitrogen in the form of ammonia (NH3), dissolved- It is important to emphasize that these percentile- oxygen depletion (hypoxia), increases in pH, or based stressor thresholds were established only decreases in habitat quality (USEPA 2015, Munn for the objectives of this study and are not to be and Hamilton 2003, Peterson et al. 2007). viewed as future numeric criteria. Furthermore, Nuisance levels of plant and algal growth exceedance of these percentile-derived interfere with aesthetic and recreational uses of thresholds does not imply the stream is ‘impaired’ streams and can clog water intakes. Blooms of with respect to support of designated aquatic life certain blue-green algae produce toxins that can uses. Rather, an exceedance of the most- disturbed percentile threshold suggests an increased risk of detrimental effects to the aquatic

13 Water Quality Condition of Streams and Rivers in Northeast Wyoming

affect animal and human health (USEPA 2000). generally considered unacceptably high for maintenance of aquatic life (Dodds et al. 2002, Excess nutrients may either run off the land during Peterson et al. 2004, Vollenweider 1971) in storms and snow-melt or infiltrate into perennial waters. The intermittent/perennial groundwater aquifers. Nutrients may reside in streams of the NE Plains most-disturbed total groundwater aquifers for years to decades phosphorus condition is higher at 0.576 mg/L. before reaching a stream. Excess nutrients can Total nitrogen thresholds were derived similarly enter a stream through decomposition of excess though developed from pooled data for the accumulations of organic material in the channel. mountainous, plains, combined High The WDEQ/WQD currently has no numeric Valleys/Wyoming Basin and intermittent aquatic life criteria for total phosphorus, total /perennial NE Plains streams due in large part to nitrogen or nitrates. Therefore, nitrate thresholds the similarity in detectable concentrations within were derived using conservative 25th and 95th each of the pooled groups in addition to the percentiles of nitrate concentrations among limited total nitrogen data within each individual Wyoming reference sites for all bioregions bioregion (Appendix 1).

Nutrient enrichment can stimulate excessive Elevated TSS can interfere with gill function and growth of algae and aquatic macrophytes. feeding ability of aquatic life in addition to human uses of the water. combined, that represented the least and most- disturbed conditions, respectively (Appendix 1). TOTAL SUSPENDED SOLIDS - TSS is the Reference-based nitrate data were pooled for all concentration of both inorganic and organic bioregions due to the high proportion of materials suspended in the water column. Natural laboratory non-detect results and the similarity in TSS concentrations are seasonally variable and detectable concentrations among bioregions. For normally highest during spring snowmelt runoff these same reasons, total phosphorus thresholds and after thunderstorms. Elevated TSS were developed for the collective bioregions. An concentrations may affect aquatic life through exception were the spring-fed intermittent alterations to feeding mechanisms, reduced /perennial streams of the NE Plains. Total photosynthesis by algae and macrophytes, phosphorus concentrations in these physical abrasion, streambed scouring and intermittent/perennial streams are often naturally increased water temperatures. Elevated higher as the fate and transport of organic concentrations of suspended solids can also materials in their watersheds is spatiotemporally interfere with agricultural, municipal and industrial variable and associated with the temporally uses of the water. Human activities such as variable flow regime. The percentile-derived construction, mining, logging, irrigation drainage, most-disturbed total phosphorus condition of sewage discharges, animal waste, and elevated 0.100 mg/L equates to the concentration that is upland or bank erosion may contribute to

14 Water Quality Condition of Streams and Rivers in Northeast Wyoming

elevated TSS beyond ambient concentrations. (Appendix 1). There is no federal or Wyoming criterion for TSS ARSENIC – Arsenic is a naturally occurring protective of aquatic life. Therefore, least and element found largely in trace concentrations in most-disturbed TSS expectations for each streams. Elevated concentrations can result in bioregion were derived from the 25th and 95th morphological alterations, liver neoplasms or percentiles of TSS concentrations among NE death of aquatic life. Human sources of arsenic reference sites, respectively (Appendix 1). include pesticides, coal-fired power plants and SALINITY - Specific conductance is an indicator of mine tailings. The WDEQ/WQD has established salinity or the concentration of dissolved salts. a numeric aquatic life chronic criterion of 150 Dissolved salts may include ions of chloride, µg/L dissolved arsenic (WDEQ/WQD 2013). nitrate, phosphate, sulfate, selenium, magnesium, Dissolved arsenic concentrations that equal or calcium, sodium and iron. Natural salinity of exceed the 150 µg/L criterion were used to streams varies considerably and is primarily represent the most-disturbed biological condition dependent on geology and soils of the for this stressor (Appendix 1). watersheds. Elevated salinity may negatively CADMIUM – The most common forms of cadmium affect soils and drinking water, as well as structure are naturally occurring and found in combination and functions of aquatic communities. Human with other elements in low concentrations in sources of salinity occur as byproducts from streams. Cadmium is bioaccumulative and activities such as irrigated agriculture, mineral and elevated concentrations can result in reduced industrial development, municipal wastewater growth, reproductive disruptions and mortality in discharges and road salt application. Elevated aquatic life. Anthropogenic sources of cadmium soil erosion can also increase the salinity of include automobile emissions, mine drainage and streams. There is no federal or Wyoming criterion tailings, phosphate fertilizers, and industrial for specific conductance protective of aquatic life. effluent from coal mines, refineries, oil or coal bed Therefore, least and most-disturbed salinity natural gas facilities. The WDEQ/WQD has expectations for each bioregion were derived established formula-based hardness-dependent from the 25th and 95th percentiles of specific numeric acute and chronic dissolved cadmium conductance measurements among reference sites criteria considered protective of aquatic life uses in the NE, respectively (Appendix 1). (WDEQ/WQD 2013). Dissolved cadmium ALUMINUM – Aluminum is the most abundant concentrations that equal or exceed the chronic naturally occurring metal in the earth’s crust formula-based hardness-dependent criterion though typically is found in very low were used to represent the most-disturbed concentrations in streams. Elevated concentrations biological condition for this stressor (Appendix 1). interfere with gill function and influence growth of CHLORIDE - This is a naturally occurring aquatic life, particularly at low pH. Human constituent commonly found as a compound with sources of aluminum include coal mines, coal-fired sodium, potassium or magnesium and as noted power plants, oil production facilities, sewage, previously can contribute to the salinity of streams. accelerated bank erosion or channel degradation Elevated concentrations of chloride can be toxic to and mine tailings. The WDEQ/WQD has aquatic life and can interfere with municipal and established a numeric acute and a hardness and industrial processes. Human sources of chloride pH-dependent chronic dissolved aluminum include sewage; industrial effluent from coal criterion considered protective of aquatic life uses mines, refineries, oil or coal bed natural gas (WDEQ/WQD 2013). Dissolved aluminum facilities; fertilizers; irrigation drainage and road concentrations that equal or exceed the chronic salt application. The WDEQ/WQD has criterion were used to represent the most- established a numeric chloride aquatic life chronic disturbed biological condition for this stressor

15 Water Quality Condition of Streams and Rivers in Northeast Wyoming

criterion of 230 mg/L considered protective of criterion were used to represent the most- game or non-game fisheries (WDEQ/WQD disturbed biological condition for this stressor 2013). Chloride concentrations that equal or (Appendix 1). exceed the 230 mg/L criterion would represent PH - The pH of a stream has important implications the most-disturbed condition for this stressor to the growth and survival of aquatic life since it (Appendix 1). can affect physiological functions and the toxicity IRON – The fourth most abundant element in the of constituents such as heavy metals and ammonia. earth’s crust, iron can occur in naturally in streams Human sources that can contribute to alterations in at elevated concentrations where geological pH from background include byproducts of formations and soils contain abundant iron oxides. industrial processes and indirectly from nutrient Iron in appreciably elevated concentrations enrichment. The WDEQ/WQD has established a appears to have a direct toxic effect to aquatic pH chronic criteria range of 6.5 to 9.0 as life that can impair growth and survival as a result protective of aquatic life in all waters of of the motion inhibiting or smothering effects of Wyoming (WDEQ/WQD 2013). Values of pH < iron precipitates on the gills, eggs and other 6.5 or > 9.0 would be considered most-disturbed surfaces. Formation of iron precipitates on stream (Appendix 1). channel surfaces has an indirect effect on the SELENIUM – A contributor to salinity and an survival, growth and reproduction of aquatic life. essential trace element for animal nutrition, Anthropogenic sources of iron include mine and elevated selenium can occur naturally in many irrigation drainage, fertilizers, industrial effluent streams of the west where seleniferous soils and (coal mines, oil treaters, coal bed natural gas, marine shales are common. Selenium is refineries) and sewage discharges. The bioaccumulative primarily through dietary WDEQ/WQD has established a numeric chronic pathways and in elevated concentrations causes dissolved iron criterion of 1,000 µg/L considered skeletal deformities and disruptions to growth and protective of aquatic life uses (WDEQ/WQD survival of aquatic life. Mortality, birth defects 2013). Dissolved iron concentrations that equal or and reproductive failures can also occur in exceed the chronic criterion were used to waterfowl and other birds that feed on aquatic represent the most-disturbed biological condition life whose tissues contain elevated selenium for this stressor (Appendix 1). concentrations. Irrigation induced leaching of MANGANESE – This is a naturally occurring metal seleniferous soils and marine shales, industrial that can occur in streams at elevated effluent (coal mines, oil treaters, refineries, coal concentrations where surrounding geology and bed natural gas) and runoff from certain mining soils contain abundant manganese oxides, silicates activities are anthropogenic sources of selenium. or carbonates. The toxicity of elevated The WDEQ/WQD has established a numeric total manganese concentrations to aquatic life is selenium aquatic life chronic criterion of 5 µg/L hardness-dependent and can result in disruptions (WDEQ/WQD 2013). Total selenium to osmoregulation, growth and reproduction. concentrations that equal or exceed the 5 µg/L Human sources of manganese include mine and criterion would represent the most-disturbed irrigation drainage, fertilizers, industrial effluent condition for this stressor (Appendix 1). (coal mines, oil treaters, coal bed natural gas, SULFATE – As with chloride, sulfate occurs refineries) and sewage discharges. The naturally in aquatic systems and generally WDEQ/WQD has established numeric hardness- originates from the decomposition of organic dependent acute and chronic dissolved matter, atmospheric deposition or geologic manganese criteria protective of aquatic life uses weathering. Depending on the background (WDEQ/WQD 2013). Dissolved manganese concentrations of chloride and hardness, elevated concentrations that equal or exceed the chronic

16 Water Quality Condition of Streams and Rivers in Northeast Wyoming

concentrations of sulfate may be toxic to aquatic vegetation is present. In many streams, this life (Soucek and Kennedy 2005). Anthropogenic vegetation is vital to stream bank integrity, sources of sulfate include sewage and industrial allowing stream banks to withstand the erosive effluent (coal mines and oil treaters in particular), forces of water at high flows. The vegetation also irrigation induced leaching of sulfate rich soils and captures surface flows which facilitates agricultural runoff. There are currently no groundwater recharge and reduces flooding national or WDEQ/WQD water quality criteria while filtering sediment, nutrients and other for sulfate protective of aquatic life. However, constituents (Gregory et al. 1991). Aquatic life the Illinois Environmental Protection Agency (ILEPA depends on riparian vegetation for habitat (e.g. 2012) and Pennsylvania Department of roots and large woody debris) and shading which Environmental Protection (PDEP 2012) have helps maintain cooler stream temperatures in promulgated and drafted sulfate criteria, smaller streams. Vegetation is also critical for respectively, based on the study by Soucek and providing food such as leaf litter for Kennedy (2005). Because the toxicity of sulfate macroinvertebrates and terrestrial insects for fish. varies with chloride and hardness and results from the Soucek and Kennedy (2005) study appear to be applicable nation-wide, these criteria, rather than percentiles based on distributions of sulfate from Wyoming reference sites, were used to set appropriate sulfate expectations in Wyoming. Sulfate concentrations that exceeded the chloride and hardness-dependent criteria described in Appendix 1 represented the most-disturbed condition for this stressor. ZINC – Zinc is an essential mineral for nutrition and ubiquitous in the environment at varying concentrations depending on the origin and Riparian disturbance can impact aquatic life composition of soils and geology. Human sources through alterations to habitat. of zinc include mining activities and industrial Anthropogenic disturbances to the riparian zone effluent from coal mines, refineries, oil or coal bed can negatively affect one or more of these natural gas facilities. A bioaccumulative element, processes. The closer human disturbances are to dissolved zinc in elevated concentrations is toxic to a stream, the greater the risk of negative impact aquatic life resulting in disruptions to growth, to the stream and its aquatic life. When severe, reproduction and survival. The WDEQ/WQD has these disturbances can accelerate natural established a formula-based hardness-dependent geomorphic processes and can threaten the numeric aquatic life chronic zinc criterion physical stability of a stream, which in turn can (WDEQ/WQD 2013). Dissolved zinc limit its ability to support aquatic life. The degree concentrations that equal or exceed the chronic of riparian disturbance was evaluated in this formula-based hardness-dependent criterion study by combining several semi-quantitative would represent the most-disturbed condition for measures. Specifically, evaluations of human this stressor (Appendix 1). activity, mean percentage of riparian stream bank cover, percentage of bare ground and PHYSICAL STRESSORS stream bank and riparian zone condition were RIPARIAN DISTURBANCE - The riparian zone, or estimated at each sampled site. Riparian the interface between a stream and surrounding disturbance was noted most-disturbed when either uplands, helps to protect streams from both mean streambank cover was < 70% or bare natural and human disturbances when adequate

17 Water Quality Condition of Streams and Rivers in Northeast Wyoming

ground represented > 40% of the riparian zone Nation’s waters (Paulsen et al. 2008, USEPA within 30 feet of the channel (Appendix 1) 2009). Excess sediment creates unstable physical (Cowley 2002, USDA/NRCS 1998, USDI/BLM conditions that can lead to channel aggradation 1998, USEPA 1998). Riparian disturbance was or degradation and consequently degradation of also conservatively documented as most-disturbed habitat for aquatic life. This pollutant can also when at least four of seventeen indicators noted smother fish eggs and fill interstitial spaces in in Appendix 1 were documented in the reach stream beds as well as scour those beds where within 30 feet of the channel. At least four benthic organisms live, thereby severely impacting indicators were chosen to minimize false positive growth, reproduction, recruitment and survival. assignments of riparian disturbance. Direct abrasion to aquatic life is also possible. Excess sediment can also clog surface water CHANNEL INSTABILITY - Changes in sediment diversions and reduce channel capacity; increase load or channel boundary conditions (e.g. slope, flood stage and flood hazard through dimension, profile, planform, stream bank aggradation and accelerate reservoir stability) can disrupt the dynamic equilibrium of sedimentation and reduce storage. In addition to streams, resulting in accelerated rates of riparian disturbance, alterations to a natural flow morphological change (e.g. stream bank erosion, regime that reduce sediment transport incision, aggradation) that ultimately degrade competency or capacity can result in an habitat for aquatic life. accumulation of sediment. In short, accelerated stream bank erosion, active Excess sediment often results in the development channel incision and/or excess sediment of extensive un-vegetated mid-channel, (aggradation) create conditions of channel bed transverse, delta and side bars (Barbour et al. and bank instability (hereafter referred to as 1999, Rosgen 2006 and 2008, Schumm 1977). channel instability) that have major impacts on Bimodal distributions in bed material (Rosgen stream ecosystems. These impacts can include 2006) and elevated riffle embeddedness (Sylte reduced aquatic habitat diversity and quality for and Fischenich 2002) can be indicative of excess spawning and rearing; reduced recruitment, sedimentation. Though variable, the combined growth and reproduction of aquatic life; altered results from several studies suggest that a food resources and in-stream cover; increased conservative threshold of at least 30% mean riffle temperatures and ultimately a diminished and less embeddedness may be suitable for detection of diverse aquatic life community comprised of channel aggradation in cobble-bed streams (Sylte generalist, short-lived taxa tolerant to elevated and Fischenich 2002). The mean riffle levels of environmental stressors. embeddedness that corresponded to the 95th Channel instability was noted as most-disturbed percentile of the reference site distribution in when any of the three following sub-stressors Wyoming was 38%. Considering this information were present: accelerated stream bank erosion, and accounting for the diversity of substrate channel incision or excess sediment. Descriptions composition among reference sites in Wyoming of each sub-stressor and their most-disturbed and a margin of sampling error, a conservative thresholds are described below. mean riffle embeddedness of ≥50% may be a Excess Sediment - Excess sediment has been reasonable threshold for detection of channel labeled the most important pollutant in United aggradation. Excess sediment was noted as States streams (Waters 1995). In the latest present when either mean riffle embeddedness USEPA summary of the Nation’s water quality, was ≥50% or when both of the following were excess sediment was again recognized as one of documented in the reach: bimodal reachwide the top four stressors to streams and posed the particle distribution, new or extensive greatest risk to the biological condition of the

18 Water Quality Condition of Streams and Rivers in Northeast Wyoming

unvegetated bar development (Appendix 1). are unexpected (Rosgen 1996). Therefore, accelerated bank erosion was noted as present when either mean streambank stability was < 70% or Rosgen F or G channels were present in valley types where they are unexpected (Appendix 1). Channel Incision - Accelerated stream bank erosion and excess sediment are sometimes associated with channel incision. Channel incision is abandonment of an active floodplain and a lowering of the channel bed with concomitant lowering of the water table. Channel incision may be triggered by a variety of historic and/or Accelerated bank erosion is a common source current causes, though is often associated with of excess sediment that can impact aquatic life channel enlargement or straightening and interfere with water supply intakes, (channelization). Other causes of channel incision surface water diversions and accelerates include reduced sediment load due to upstream reservoir filling. dams, increased peak flows caused by Accelerated Bank Erosion - Stable stream banks anthropogenic activities and land use changes are able to dissipate stream energy at high flows, (Fischenich and Morrow 2000, Galay 1983). minimizing alterations to channel dimension, Channel incision was noted as present when pattern or profile while also capturing sediment evidence of active channel incision (e.g. evident and other pollutants (Waters 1995). Accelerated headcuts or unexpected shifts in channel gradient) bank erosion generally occurs when riparian or recent (within the past 10 years) channelization areas and stream banks are lacking adequate was documented within the reach (Appendix 1). vegetation with well-developed root structures due to riparian vegetation removal, trampling, hoof shear, or recreational traffic and thus cannot retain soil and stabilize streambanks during high flows. Accelerated bank erosion may occur when stream banks exhibit high bank-height ratios where more of the bank surface is exposed above bankfull elevation and thus the bank is at greater risk for surface erosion, bank slumping and failure and mass erosion processes (Rosgen 2006). Accelerated bank erosion is a form of channel degradation that not only reduces in-stream aquatic habitat along the banks but also Channel incision and accelerated bank erosion contributes excess sediment to a channel. Cowley can be triggered by alterations to channel (2002) suggests that 70% unaltered stream banks boundary conditions such as from disturbances appear to be the minimum level that would to the riparian zone. maintain stable conditions. In addition, Rosgen F and G channels are deeply entrenched, highly susceptible to changes in dimension, profile and RANKING OF STRESSORS planform and are general indicators of channel Findings from the NE can be used for making bed or bank instability in valley types where they policy and management decisions when framed

19 Water Quality Condition of Streams and Rivers in Northeast Wyoming

as the relative importance of elevated (most- disturbed stressor condition as they are under a disturbed) stressors on the biological condition. least-disturbed stressor condition. However, This study defines the ‘importance’ of each most- relative risk values greater than 1 suggest an disturbed stressor on biological condition within increased association between the stressor and the context of relative extent and relative risk. biological condition. The higher the relative risk of a stressor, the more likely that stressor is to be Relative Extent associated with a most-disturbed biological Relative extent is presented as a percentage and condition. looks at how extensive the most-disturbed stressor condition is among the evaluated perennial One fundamental disadvantage with relative risk stream length of the NE. Conceptually, stressors in is that the simultaneous interactive and cumulative the most-disturbed condition can be found in all effects of multiple stressors are not considered. geographic regions though their pervasiveness Relative risk values for stressors in this study are may vary. Areas where a stressor in the most- only ranked at the NE scale. Valid relative risk disturbed condition occurs in a high percentage of values were generally not obtainable at the HUC stream miles would be considered to have a high 8 Cluster scale due to small sample sizes. relative extent. For this study, stressors are ranked according to their relative extents at both the NE and HUC 8 Cluster scales. DATA ANALYSIS All probabilistic survey analyses were performed Relative Risk using modifications of the ‘spsurvey.analysis’ A concept that originates from medical scripts developed in the R programming language epidemiology, relative risk is a measure of the (Version 3.0.1) by the USEPA’s Office of Research strength of association between a stressor and a and Development in Corvallis, Oregon or with response variable. Relative risk (RR) in the BYS STATISTICA (Version 10) (Statsoft 2011). The was used to evaluate the potential effect of each statistical procedures used in ‘spsurvey.analysis’ to stressor on biological condition using the following extrapolate estimates of evaluated and assessed equation: stream lengths and biological condition, stressor relative extents and stressor relative risks from 푃푅푚푑푏/푃푅푚푑푠 푅푅 = ( ) collected data are fully described in Paulsen 푃푅푚푑푏/푃푅푙푑푠 (2008), Van Sickle and Paulsen (2008) and Van Where PR is the percentage of stream miles, mdb Sickle et al. (2006). is the most-disturbed biological condition given a most-disturbed stressor condition, mds the most- disturbed stressor condition and lds the least- 2011 STREAM FLOWS disturbed stressor condition. The NE survey was conducted during a year of above average precipitation throughout the study Relative risk simply measures the likelihood that a area (WSCO 2014). The above average stream is in the most-disturbed biological condition snowpack in the mountains and uplands combined when a stressor in the most-disturbed condition is with abundant rainfall that occurred throughout present (Van Sickle et al. 2006). Relative risk northeast Wyoming in May triggered above does not imply that a most-disturbed biological average peak flows in the area (NOAA 2014). condition will occur in the presence of a most- Data collected at several USGS stream gage disturbed stressor condition, only the likelihood stations distributed throughout the NE show that it could occur. Relative risk values of 1 appreciable above average peak flows in 2011 indicate that the most-disturbed biological (Appendix 3). At the NE scale, peak flows in condition is just as likely to occur under a most-

20 Water Quality Condition of Streams and Rivers in Northeast Wyoming

2011 were on average 65% (range: -70% to Fourche: 45% target (391 miles), 34% access 435%) above the mean peak flows for the denied (301 miles) and 21% non-target (179 periods of record. Along with historical peak miles). Cheyenne: 35% target (411 miles), 12% flows, cooler than normal air temperatures during access denied (150 miles) and 53% non-target May and June (NOAA 2014) helped prolong (629 miles). peak flows in several areas well into July. These conditions helped recharge soils, springs and An important finding from the NE survey is that a shallow alluvial aquifers while also lessening the sizeable portion of the targeted perennial stream demand on surface water for consumptive uses. length was found to be non-target based on field The culmination of these conditions contributed to determinations. This indicates that the NHD+ the mean of 2011 mean annual flows that were overestimated targeted perennial stream length 89% (range: -2 to 280%) above the mean annual in the NE by approximately 25%. Among the four flow for the periods of record (Appendix 3). HUC 8 clusters, overestimates of target perennial stream length in the NE were greatest in the Cheyenne (53%) due to the greater occurrence of RESULTS ephemeral streams or linear wetlands misidentified in the NHD+ as perennial streams. EXTENT OF RESOURCE Of the 1,785 assessed targeted stream miles in A total of 113 sites were evaluated as part of the the NE survey, approximately 5% (83 miles) were NE survey that represented 3,765 perennial identified as effluent dominant. All effluent stream miles or the target stream length. The dominant streams were located in the Powder target stream length equates to over 90% of the HUC 8 cluster. 4,016 total perennial stream miles in the NE. Approximately 25% (958 miles) of the target The flow regimes of approximately 3% (45 miles) stream length was found to be non-target (Figures of the assessed targeted stream miles for the NE 2 and 3). Non-target sites were those identified survey were reservoir influenced (≥50% of the as completely ephemeral or intermittent, wetlands respective watershed areas). or human constructed channels such as irrigation canals. Approximately 27% (1,022 miles) of the Flow alterations represented by diversions, target streams could not be assessed because spreader dikes or trans-basin inputs had varying access was denied. The remainder of the influences on approximately 74% (1,320 miles) of sampling frame represented the assessed the 1,785 assessed targeted stream miles for the targeted stream length for the NE survey – 1,785 NE survey. Flow alterations were identified miles (52 sites) (Figures 2-3, Appendix 4). This throughout the NE. assessed targeted length represents 47% of the total perennial stream length in the NE (less Sampling sites on the assessed targeted streams wilderness) and 44% of the targeted perennial were near equally distributed among the Belle stream length from the GRTS modified sample Fourche (12), Cheyenne (13), East Bighorn (14) frame. and Powder (13) HUC 8 clusters.

The extent of the perennial stream resource for BIOLOGICAL CONDITION the NE survey at the HUC 8 cluster scale is as Information from both the WSII and WY RIVPACS follows (Figures 2-3, Appendix 4). East Big Horn: were incorporated into WDEQ/WQD’s aquatic 53% target (616 miles), 39% access denied (446 life use decision matrix (WDEQ/WQD 2014) miles) and 8% non-target (94 miles). Powder: along with considerations for multi-habitat 67% target (367 miles), 23% access denied (125 samples (including NEPMI results) and effluent miles) and 10% non-target (56 miles). Belle dominant systems, were used to determine the

21 Water Quality Condition of Streams and Rivers in Northeast Wyoming

final biological condition for the NE. NE stream miles were in the least-disturbed total Approximately 52% and 13% of the NE assessed phosphorus condition (Appendix 7, Table 2). targeted perennial streams were in the ‘least- Seven percent of targeted streams in the NE were disturbed’ and ‘most-disturbed’ condition, in the most-disturbed total phosphorus condition respectively (Figure 4). (Appendix 7, Table 2). The percentage of stream miles in the most-disturbed total phosphorus Among the four HUC 8 clusters, the Cheyenne and condition was highest in the Powder at 16%. East Bighorn attained the highest percentages of ‘least-disturbed’ stream miles at 69% and 64%, The percentage of NE streams miles in the least- respectively (Figure 4). Among all HUC 8 clusters, disturbed total nitrogen condition was 35% with the Belle Fourche and East Bighorn exhibited the the majority considered indeterminate (56%) and highest percentages of ‘most-disturbed’ stream 9% in the most-disturbed condition (Appendix 8, miles at 21% and 16%, respectively (Figure 4). Table 2). Among the four HUC 8 clusters, the Belle The Powder displayed the highest percentage Fourche exhibited the highest percentage of most- (73%) of ‘indeterminate’ stream miles among all disturbed stream miles for total nitrogen at 25%. HUC 8 clusters (Figure 4). SALINITY DRINKING WATER SUITABILITY AND The NE survey identified least-disturbed salinity HUMAN HEALTH CONDITION conditions in 20% of stream miles (Appendix 9, For the NE survey, 54% of the assessed targeted Table 2). Approximately 18% of stream miles for stream miles were in the least-disturbed condition the NE survey were in the most-disturbed condition for E. coli (Appendix 5, Table 1). The percentages (Appendix 9, Table 2). Among the four HUC 8 of least-disturbed E. coli condition stream miles clusters, the Powder (26%) exhibited the highest among HUC 8 clusters was similar (51-56%). All percentage of most-disturbed stream miles for streams were in the least disturbed condition for salinity. drinking water suitability with respect to total SELENIUM cadmium, nitrate+nitrite-N, total selenium, The NE survey identified 4% of stream miles in the dissolved iron and total zinc. Approximately 91% most-disturbed condition for selenium with the and 66% of stream miles in the NE were in the remaining 96% in the least-disturbed condition least-disturbed condition for drinking water (Appendix 10, Table 2). Among HUC 8 clusters, suitability with regard to arsenic and manganese, only the Powder contained stream miles within the respectively. The percentage of stream miles in most-disturbed selenium condition at 20%. NE the least-disturbed dissolved manganese stream miles in the most-disturbed selenium condition was lowest in the Belle Fourche (54%) condition were often associated with the most- and Cheyenne (23%) HUC 8 clusters. disturbed chloride and/or salinity.

PHYSICOCHEMICAL STRESSORS TO TOTAL SUSPENDED SOLIDS BIOLOGICAL CONDITION Throughout the NE, 32% of streams miles were in the most-disturbed condition and the majority NUTRIENTS (67%) in the indeterminate condition for total Throughout the NE, the percentage of stream miles suspended solids (Appendix 11, Table 2). The in the least-disturbed nitrate+nitrite-N condition highest percentage of stream miles in the most- was 83% whereas 14% of streams were in the disturbed TSS condition was found in the Powder most-disturbed condition (Appendix 6, Table 2). (46%). Similar to the NE scale results, the majority The highest percentage of NE streams in the most- of stream miles among the four HUC 8 clusters disturbed nitrate+nitrite-N condition (31%) were found to be in indeterminate TSS condition. occurred in the Powder. Approximately 82% of

22 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Figure 2 – Target and non-target/access denied sites evaluated as part of the Northeast probabilistic survey including HUC 8 clusters, municipalities and wilderness.

23 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Figure 3 – Estimated percentage of target stream miles relative to access denied and non-target miles at the Northeast and HUC 8 cluster scales based on 113 evaluated sites. Error bars represent the 95% confidence intervals.

Basin-wide Belle Fourche T 47.4% T 44.9%

AD 27.2% AD 34.6%

NT 25.4 NT 20.5%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne T 53.3% T 34.5%

AD 38.6% AD 12.6%

NT 8.1% NT 52.9%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder 67.0% T

AD 22.7% T = Target AD = Access Denied

NT 10.3% NT = Non-Target

0 25 50 75 100 Percent of Stream Miles

24 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Figure 4 - Biological condition of targeted perennial streams and rivers in the Northeast based on WDEQ/WQD’s aquatic life use matrix. Error bars represent the 95% confidence intervals.

Basin-wide Belle Fourche LD 52.1% LD 46.3%

I 34.6% I 32.9%

MD 13.4% MD 20.8%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne 63.8% 69.2% LD LD

I 20.1% I 23.6%

MD 16.1% MD 7.2%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder LD 19.2% LD = Least-disturbed 72.9% I I = Indeterminate

MD 7.9% MD = Most-disturbed

0 25 50 75 100 Percent of Stream Miles

25 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Table 1 –Stressor condition estimates associated with drinking water suitability and human health condition for WDEQ/WQD’s 2011 Northeast survey.

Northeast Superbasin HUC 8 Clusters

East Big Horn Powder Belle Fourche Cheyenne Northeast Superbasin % of Stream % of Stream % of Stream % of Stream Stressor [Human Health Condition] % of Stream Miles Miles Miles Miles Miles Escherichia coli Least-disturbed 54 56 54 51 56 Most-disturbed 46 44 46 49 44

Stressor [Drinking Water Suitability] Nitrate+Nitrite-N Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Dissolved Iron Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Dissolved Manganese Least-disturbed 66 93 82 54 23 Most-disturbed 34 7 18 46 77

Total Arsenic Least-disturbed 91 100 98 66 93 Most-disturbed 9 0 2 34 7

Total Cadmium Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Total Zinc Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Total Selenium Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

26 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Table 2 - Stressor condition estimates associated with biological condition for WDEQ/WQD’s 2011 Northeast survey. Northeast Superbasin HUC 8 Clusters Northeast East Big Horn Powder Belle Fourche Cheyenne Superbasin % of Stream % of Stream % of Stream % of Stream Biological Condition % of Stream Miles Miles Miles Miles Miles Least-disturbed 52 64 19 46 69 Indeterminate 35 20 73 33 24 Most-disturbed 13 16 8 21 7 Stressor [Indicator] Nitrate+Nitrite-N Least-disturbed 83 76 69 88 100 Indeterminate 3 9 0 0 0 Most-disturbed 14 15 31 12 0

Total Phosphorus Least-disturbed 82 100 84 75 59 Indeterminate 11 0 0 17 34 Most-disturbed 7 0 16 8 7

Total Nitrogen Least-disturbed 35 15 55 25 56 Indeterminate 56 76 45 50 44 Most-disturbed 9 9 0 25 0

Salinity Least-disturbed 20 14 15 25 31 Indeterminate 62 66 59 54 62 Most-disturbed 18 20 26 21 7

TSS Least-disturbed 1 0 4 0 0 Indeterminate 67 76 50 62 75 Most-disturbed 32 24 46 38 25

Chloride Least-disturbed 92 100 67 100 93 Most-disturbed 8 0 33 0 7

Sulfate Least-disturbed 92 100 85 100 78 Most-disturbed 8 0 15 0 22

pH Least-disturbed 96 100 100 83 100 Most-disturbed 4 0 0 17 0

Dissolved Aluminum Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Dissolved Arsenic Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Dissolved Cadmium Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Dissolved Iron Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Dissolved Manganese Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Dissolved Zinc Least-disturbed 100 100 100 100 100 Most-disturbed 0 0 0 0 0

Total Selenium Least-disturbed 96 100 80 100 100 Most-disturbed 4 0 20 0 0

Riparian Disturbance Least-disturbed 74 87 39 67 93 Most-disturbed 26 13 61 33 7

Channel Instability Least-disturbed 65 87 22 67 69 Most-disturbed 35 13 78 33 31

Excess Sediment Least-disturbed 81 93 38 91 92 Most-disturbed 19 7 62 9 8

Accelerated Bank Erosion Least-disturbed 70 87 36 75 69 Most-disturbed 30 13 64 25 31

Channel Incision Least-disturbed 84 87 81 83 85 Most-disturbed 16 13 19 17 15

27 Water Quality Condition of Streams and Rivers in Northeast Wyoming

CHLORIDE, pH and SULFATE disturbed riparian disturbance condition was most Approximately 92% of stream miles were in the prevalent in the Powder at 61% of stream miles. least-disturbed condition for chloride (Appendix 12, Table 2). The remaining 8% of NE stream CHANNEL INSTABILITY miles represented the most-disturbed condition Throughout the NE, 35% of stream miles exhibited which was found predominantly within the Powder indicators of channel instability (excess sediment, HUC 8 cluster. accelerated bank erosion and/or active channel incision) (Appendix 15, Table 2). The highest Only 8% of stream miles were in the most- proportion of stream miles with channel instability disturbed sulfate condition with the remaining occurred in the Powder (78%). 92% in the least-disturbed condition (Appendix 13, Table 2). NE stream miles in the most- Partitioning channel instability into its three disturbed sulfate condition were represented in component sub-stressors revealed that a large the Cheyenne and Powder HUC 8 clusters. Stream proportion (30%) of the 35% of NE stream miles miles in the most-disturbed sulfate condition were with channel instability, were attributed to often associated with elevated dissolved accelerated bank erosion (Appendix 16, Table 2). manganese concentrations that exceeded the Similarly, of the 35% of NE stream miles with drinking water suitability most-disturbed channel instability, 19% were attributed to excess threshold. sediment whereas 16% exhibited active channel incision (Appendix 16, Table 2). Among the four Around 96% of waters monitored for the NE HUC 8 clusters, accelerated bank erosion (64%) survey were within WDEQ/WQD’s pH criteria and excess sediment (62%) were most common in range protective of aquatic life uses (Appendix the Powder. Percentages of stream miles with 14, Table 2). The 4% of stream miles in the most- active channel incision were similar (13-19%) disturbed pH condition were exclusively found in among the four HUC 8 clusters. intermittent/perennial streams of the Belle Fourche. RANKING OF STRESSORS Relative Extent – For both the NE and HUC 8 ALUMINUM, ARSENIC, CADMIUM, IRON, clusters, stressors are ranked according to the MANGANESE and ZINC proportion of stream miles that was in the most- All streams monitored as part of the NE survey for disturbed condition for that stressor (Figure 5). the dissolved fractions of aluminum, arsenic, Channel instability was the most common stressor cadmium, iron, manganese and zinc were in the (35%) that has the potential to affect aquatic life least-disturbed condition (Table 2). in targeted streams of the NE (Figure 5). TSS was the second most common stressor affecting 32% PHYSICAL STRESSORS TO BIOLOGICAL of stream miles, followed by riparian disturbance, CONDITION which affected 26% of stream miles. Salinity and nitrate+nitrite-N were mid-range among stressor RIPARIAN DISTURBANCE rankings for relative extent, affecting 18% and Riparian disturbance exceeded the most- 14% of stream miles within the NE, respectively disturbed condition thresholds in only 26% of (Figure 5). Total nitrogen, total phosphorus, total stream miles in the NE (Appendix 15, Table 2). selenium, sulfate, chloride and pH were the least Riparian disturbance in the NE was often common stressors, each affecting less than 10% of associated with limited or absent riparian NE stream miles (Figure 5). vegetation cover along stream banks combined with low diversity in age-class and/or composition Channel instability and riparian disturbance were of riparian/wetland vegetation. The most- the most common stressors within the Powder (78% and 61%, respectively) HUC 8 cluster (Figure 5).

28 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Channel instability (31%) was also the top stressor The water quality condition of perennial streams in the Cheyenne, with TSS and sulfate a general in the NE is favorable, with approximately one- tie for second at 25% and 23%, respectively. TSS half (52%) of the resource currently considered in was the most common stressor in the Belle Fourche the least-disturbed biological condition and only at 38% with channel instability and riparian 13% of the resource in the most-disturbed disturbance both second ranked at 33% (Figure condition. Among the four HUC 8 clusters, 5). The top two most common stressors in the East perennial streams in the Cheyenne and East Big Big Horn were TSS (24%) and salinity (20%) with Horn are in much better condition biologically nitrate+nitrite-N coming in third at 15% (Figure (69% and 64% least-disturbed, respectively) 5). relative to those in the Belle Fourche (46% least- disturbed) and Powder (19% least-disturbed). Relative Risk - For the biological condition of NE The Belle Fourche and East Big Horn exhibit the targeted streams as measured with benthic highest percentages of perennial stream miles in macroinvertebrates, elevated chloride presents the most-disturbed condition (21% and 16%, the greatest relative risk at 5.8 (Figure 6). In other respectively) compared to the Powder (8%) and words, the most-disturbed biological condition is Cheyenne (7%). Despite the low percentage of 5.8 times more likely to occur in streams having stream miles with a most-disturbed biological the most-disturbed chloride condition as streams condition, the Powder attained a high percentage with the least-disturbed chloride condition. (73%) of stream miles in an indeterminate Elevated total phosphorus and total nitrogen biological condition. All streams in the Powder exhibit the second-highest risks at 4.9 and 4.2, assigned indeterminate biological condition respectively (Figure 6). Channel instability and ratings exhibited chemical and/or physical elevated total selenium present the third-highest stressors though their overall influence only equivalent risk to biological condition at 3.7 resulted in a moderate departure from biological (Figure 6). Results also indicate that elevated TSS, reference expectations. salinity, nitrate+nitrite-N, sulfate and pH present little direct risk to the benthic macroinvertebrate This survey found that the most widespread or communities of the NE assuming no interactive common stressors in the NE were channel instability effects with other pollutants. and total suspended solids (TSS), affecting approximately 35% and 32% of perennial stream miles, respectively. Channel instability was DISCUSSION also the dominant stressor in the Powder (78%) Results from the 2011 NE survey provide the first and Cheyenne (31%). TSS was the top stressor in focused and standardized baseline evaluation on the Belle Fourche (38%) and East Big Horn (24%). the biological and human health condition of Riparian disturbance was the second most common perennial streams within the Belle Fourche, stressor in the Powder (61%) and Belle Fourche Cheyenne, Powder and Tongue basins of (33%). TSS (25%) and salinity (20%) were the northeast Wyoming. The NE survey represented second most common stressors in the Cheyenne the second of five ‘superbasins’ that will be and East Big Horn, respectively. monitored as part of WDEQ/WQD’s rotating basin probabilistic survey. Results from the NE survey enhance WDEQs ability to provide the most representative picture of current water quality conditions and identify chemical and physical stressors to biological and human health without a complete census of all perennial streams within the basins of northeast Wyoming.

29 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Figure 5 – Most-disturbed condition relative extent (% stream miles) of chemical and physical stressors to biological condition at the Northeast and HUC 8 Cluster scales. Error bars represent the 95% confidence intervals.

Basin-wide Belle Fourche CI 34.8% TSS 37.5% 31.7% TSS RD 33.1% RD 25.8% S 18.4% CI 33.1% N 14.3% TN 25.4% TN 8.6% S 20.8% CL 8.4% SU 8.2% PH 17.2% TP 6.8% N 12.4% TS 4.1% TP 8.4% PH 3.8%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne TSS 23.9% CI 30.7% TSS S 20.1% 25.3% SU 22.5% N 15.2% TP 7.2% RD 12.7% S 7.2% CI 12.7% CL 7.2% TN 8.7% RD 7.2%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder 78.4% CI RD 60.6% TSS = Total Suspended Solids RD = Riparian Disturbance SU = Sulfate TSS 46.1% CI = Channel Instability N = Nitrate+Nitrate-N CL = Chloride CL 33.0% N 30.7% TN = Total Nitrogen S = Salinity PH = pH S 25.6% TP = Total Phosphorus TS = Total Selenium TS 20.0% TP 16.1% SU 14.6%

0 25 50 75 100 Percent of Stream Miles

30 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Figure 6 - Relative risk values of chemical and physical stressors to biological condition at the Northeast scale. Error bars represent the 95% confidence intervals.

3.7 Basin-wide CI TSS 1 RD 2.3 TSS = Total Suspended Solids RD = Riparian Disturbance SU = Sulfate S 1 CI = Channel Instability N = Nitrate+Nitrate-N CL = Chloride N 1 TN 4.2 TN = Total Nitrogen S = Salinity PH = pH CL 5.8 TP = Total Phosphorus TS = Total Selenium SU 1 TP 4.9 TS 3.7 PH 1

1 2 3 4 5 6 7 8 9 10

Relative Risk

31 Water Quality Condition of Streams and Rivers in Northeast Wyoming

The most common stressor in the NE, channel that corresponded to historical floodplains and instability, is a composite physical stressor that the 2011 record flows. In addition, existing includes excess sediment, accelerated stream headcuts or nick points in some streams exhibited bank erosion and channel incision. Accelerated active headward migration which contributed to stream bank erosion was the dominant of the three the active channel incision noted in 16% of stream sub-stressors in the NE (30%) and among all four miles in the NE with documented channel regions’ (13% to 64%) stream miles documented instability. It’s possible that the record 2011 flows for channel instability. The elevated percentage accelerated the rate of active channel incision in of accelerated bank erosion during the NE survey some streams. Active channel incision in turn appeared to be partially attributed to riparian contributed to excess sediment in 19% of stream disturbance. This inference is supported by miles with documented channel instability in the evidence that indicates many streams in the NE NE. Considered together, these observations with accelerated bank erosion also exhibited suggest channel instability associated with legacy indicators of riparian disturbance, predominantly impacts (e.g. channel relocation, meander cutoffs, in the form of marginal (mean: 47%) riparian riparian vegetation removal). vegetative bank cover. Corresponding to the low percentage of riparian vegetative bank cover Flow alterations can also facilitate excess were evidence of homogenous composition and sedimentation via a reduction in sediment age-class distributions of riparian vegetation and transport capacity of the channel or in the case of limited riparian woody vegetation. In fact, augmentation, accelerated bank erosion and/or riparian disturbance ranked as the third most incision due to increased shear stresses from common stressor (26%) to influence biological above normal flows. Varying degrees of flow condition in the NE. Riparian disturbance was alterations affect almost 74% of perennial stream considered the second most common stressor in the miles in the NE. Belle Fourche and Powder with 33% and 61%, Together, channel adjustment processes due to respectively. Considering that the banks of most past and present anthropogenic disturbances that streams in the NE are comprised of erodible sand, influence physical attributes of the channel, as well silt and gravel matrices, rates of bank erosion as record high flows were the most important (which contribute to channel instability) are factors driving the widespread channel instability greatly influenced by the presence, density and stressors that influenced biological condition of NE condition of riparian vegetation. streams in 2011. The wide-spread extent of The accelerated bank erosion (and channel channel instability in the NE and its potential effect incision) in the NE may also be attributed to on aquatic life is apparent in that NE streams are increased rates of geomorphic adjustments 3.7 times more likely to be in a most-disturbed initiated by anthropogenic and/or natural biological condition when channel instability is disturbances that occurred recently to anytime present as when channel instability is not present. between a few decades to a century in the past. The prevalence of TSS as the second most common It is likely that rates of bank erosion, incision and stressor throughout the NE and the most common aggradation were accelerated by the record stressor in the Belle Fourche and East Big Horn flows of 2011. This is supported by evidence raises questions as to the potential sources of TSS indicating that some streams with channel and its relative influence on aquatic life. TSS instability had become deeply incised in the past consists of both organic and inorganic suspended though exhibited entrenched active floodplains materials and is naturally greater during runoff and were eroding steep banks and lower terraces from snowmelt or thunderstorms. TSS samples with minimal surface protection. Indeed, flood gathered for this study were collected during debris was observed in these areas at elevations

32 Water Quality Condition of Streams and Rivers in Northeast Wyoming

baseflows, therefore flow-dependent increases in inorganic suspended sediment occur after TSS were minimized as a possible cause of deposition on the channel bed (Ward 1992). elevated TSS in the NE. Elevated TSS in some NE Thus, the use of benthic macroinvertebrates as the streams can occur naturally as their watersheds biological indicator for this study may have may contain highly erodible silt/clay bearing precluded the ability to detect direct effects from geology and soils combined with naturally sparse TSS to the aquatic benthos. vegetation cover (Peterson et al. 2004). However, in areas absent such overriding natural Another explanation for the high relative extent influences, human activities associated with of TSS and no relative risk may be due in part to irrigation drainage, flow augmentation and the inherent tolerance of some benthic communities industrial or municipal effluent may be chronic to elevated TSS. Some watersheds of northeast contributors to NE streams with a most-disturbed Wyoming are characterized by badland-type TSS condition. landscapes of limited vegetation and highly erodible silt/clay geology and soils. Sediments in Anthropogenic contributions of inorganic TSS (silts streams that drain these watersheds can remain and clays) may also be a transport mechanism for suspended in the water column throughout their other pollutants in the NE (Peterson et al. 2004). flow regimes. Considering these conditions and Indeed, silt and clay are often chemically active applicable evidence from Troelstrup Jr. and Rust and pollutants such as nutrients, metals, pesticides (2008), it seems plausible that indigenous benthic or their breakdown products are strongly bound macroinvertebrate communities of these systems to these particles. There may be a linkage could display natural tolerances to elevated TSS. between TSS and nutrients in the NE, as several streams with a most-disturbed TSS condition were Once elevated TSS is deposited, the excess also assigned a most-disturbed condition for one sediment and its influence to aquatic life can be or more nutrients. Whether TSS-linked accounted for (in many cases) by the channel detrimental effects to aquatic life occur in the NE instability stressor evaluated as part of this study. may vary considerably depending on the size of What cannot be accounted for in this study though, particles in question, the frequency and duration is the capture of elevated TSS by abundant of elevated TSS, the mechanisms of influence (e.g. benthic algae which can result in a dense physical abrasion, scouring, reduced visibility, algal/sediment matrix that is of particular altered feeding dynamics, increased water importance in some streams of the NE. temperatures), the influence of bounded pollutants Excess sediment while in suspension may be more and the aquatic organism(s) affected (i.e. benthic problematic for fishes due to reduced visibility, macroinvertebrates, fishes, periphyton). From a physical abrasion of extremities including gills and relative risk perspective, a most-disturbed TSS increased heat absorption. In summary, excess condition apparently poses no additional risk to sediment can have varying detrimental effects on aquatic life when present in NE streams. This different components of the aquatic community apparent dichotomy in TSS between its second depending on whether it is in suspension or highest extent and no additional risk may be due deposited and the detection of such effects may in part to the fact that TSS indirectly impacts the be dependent on the biological indicator used in biological indicator selected for this study. addition to their varying levels of natural Definitive data on the direct effects of suspended tolerance to elevated TSS among watersheds. In inorganic sediment to benthic macroinvertebrates light of these complexities, the prevalence of is limited (Ward 1992). Existing empirical studies elevated TSS in the NE may warrant further suggest that stream insects as a group are investigation to ascertain whether TSS in the most- relatively tolerant of elevated concentrations of TSS and that the most dramatic effects of

33 Water Quality Condition of Streams and Rivers in Northeast Wyoming

disturbed condition translates to a direct found in plains streams of the NE. Nutrients such degradation of biological condition. as nitrate+nitrite-N, total nitrogen and total phosphorus are not directly toxic to aquatic life. Salinity was mid-range among stressor rankings in However, the processes that control metabolism terms of relative extent, affecting 18% of and nutrient cycling in streams, their influences to perennial streams in the NE. NE streams that parameters such as dissolved oxygen and pH, and exhibited elevated salinity were predominantly the critical thresholds at which different aquatic plains streams with salinity levels two to seven life (e.g. fishes versus benthic macroinvertebrates) times the most-disturbed salinity threshold. The begin to be negatively affected can vary majority of these NE plains streams with elevated considerably in streams. Similar to salinity, there salinity were influenced by effluent from industrial was no higher risk of a most-disturbed biological facilities, irrigated agriculture and/or high condition when elevated nitrate+nitrite-N was degrees of flow alteration. Interestingly, present in a NE stream. This may be attributable elevated salinity appears to pose no additional to its variable effects to aquatic life though may risk to aquatic life when present in NE streams. also be influenced by the ameliorating effects of Macroinvertebrate communities of plains streams naturally elevated salinity common in plains are adapted to harsh and stochastic environments streams on nitrate+nitrite-N toxicity to (Dodds et al. 2004, Fausch and Bestgen 1997, macroinvertebrates (Camargo and Alonso 2006, Higgens and Wilde 2005, Matthews 1988, Camargo et al. 2005). For other nutrients such as Taylor et al. 1993) such as naturally elevated and total nitrogen and total phosphorus, their wide-ranging salinities dependent on geology respective most-disturbed condition relative and flow regime. The direct influences of extents in the NE were both less than 10% of elevated salinity may not be as readily stream miles. Though in contrast to nitrate+nitrite- observable in communities with such adaptive N, it appears that there is a 4.2 and 4.9 greater tolerances. Rather, elevated salinity may have risk, respectively, of having a most-disturbed an indirect effect on macroinvertebrates of plains biological condition when a most-disturbed total streams via direct effects to other ecosystem nitrogen or total phosphorus condition is present. components such as macrophyte diversity and Stream miles that exhibited both a most-disturbed density. In some cases salinity may be too broad total nitrogen condition and biological condition of an analyte to discern direct effects to possessed total nitrogen concentrations up to 1.3 macroinvertebrate communities that are adapted times the threshold. Streams with a most-disturbed to the inherently harsh environments of plains total phosphorus condition and biological streams. For example, elevated concentrations of condition had total phosphorus concentrations up chloride, which is one component of salinity, was to 1.4 times the threshold. For some of these found in 8% of stream miles in the NE. The stream miles, total nitrogen and/or total greatest number of stream miles with elevated phosphorus were a few of multiple stressors that chloride was in the Powder (33%). Furthermore, exceeded thresholds. Considering the indirect and this study found NE streams are 5.8 times (the non-toxic effects of elevated total nitrogen and highest relative risk of all stressors evaluated for total phosphorus on the aquatic community it is this study) more likely to be in a most-disturbed unknown as to what degree these analytes biological condition when chloride in the most- contributed to the most-disturbed biological disturbed condition is present. condition when other stressors, which are known to negatively affect biological condition in elevated Nitrate+nitrite-N was another mid-range stressor concentrations, were present. In cases of some in terms of relative extent, affecting 14% of intermittent/perennial plains streams, the perennial streams in the NE. This percentage is elevated total nitrogen and/or total phosphorus largely the result of elevated nitrate+nitrite-N appeared to be naturally occurring considering

34 Water Quality Condition of Streams and Rivers in Northeast Wyoming

the inherent limited hydrology and expected additional risk to biological condition with respect naturally periodic accumulation of organic to benthic macroinvertebrates. material within these streams. There is however evidence to suggest anthropogenic activities (e.g. The extent of most-disturbed E. coli concentrations industrial effluent, irrigated agriculture, etc.) may (an indicator of human health condition for contribute to the elevated total phosphorus and recreational uses) in the NE survey was 46%. total nitrogen. Relative extents of the most-disturbed E. coli condition was relatively similar among all four Dissolved fractions of aluminum, arsenic, cadmium, regions of the NE. These results imply that there is iron, manganese and zinc as well as sulfate and an approximate equal chance for the presence of total selenium are known to be detrimental to a least or most-disturbed recreational condition in aquatic life at elevated concentrations. However, perennial streams of the NE. All streams were in all but two of these analytes (sulfate and total the least-disturbed condition for drinking water selenium) were in the least-disturbed condition. suitability with respect to total cadmium, Less than 10% of stream miles in the NE exhibited nitrate+nitrite-N, total selenium, dissolved iron most-disturbed conditions for total selenium and and total zinc. Approximately 91% and 66% of sulfate. Stream miles in the most-disturbed total stream miles in the NE were in the least-disturbed selenium condition exhibited concentrations that condition for drinking water suitability with were approximately 1.4 to 2.4 times the threshold regard to arsenic and manganese, respectively. and could be influenced by a combination of These exceedences were predominantly confined anthropogenic sources (e.g. industrial effluent, to the Belle Fourche and Cheyenne. Potential irrigation-induced soil leaching) and natural sources of the elevated manganese are seleniferous-bearing soils and marine shale predominantly associated with the local geology geology. Stream miles in the most-disturbed and soils though industrial effluent may be a sulfate condition had concentrations around 1.3 factor in some circumstances. With the exception times the threshold with potential influences similar of dissolved manganese, the combined to those mentioned for selenium. Like salinity information suggests that waters within the NE though, elevated sulfate appears to pose no would require minimal treatment for these additional risk to biological condition when parameters to be suitable as drinking water present for reasons likely similar to those for supplies. salinity. Levels of pH that exceeded the most- disturbed threshold were noted in a small To place these results into a regional and national percentage of stream miles in the NE all of which perspective, the NE was compared to Wyoming, were confined to intermittent/perennial plains the combined mountainous and arid regions of streams in the Little Missouri River watershed twelve western states (e.g. Mountains/Basins), the within the Belle Fourche HUC 8 cluster. These combined prairie regions of the central and streams are very low gradient, slow-moving eastern states (e.g. Plains/Lowlands) and almost lentic systems with extensive aquatic nationally with respect to biological condition and macrophyte beds and corresponding high rates of associated stressors. The NE was compared to photosynthesis that likely contributed to the both the Mountains/Basins and Plains/Lowlands elevated pH. Because of their limited hydrology, because the superbasin contains elements of both these systems naturally accumulate organic mountainous and plains environments. material for long periods of time until runoff from Comparisons of the NE survey to the most recent infrequent thunderstorm events provide the flows statewide probabilistic survey for Wyoming are to flush the accumulated material downstream. relatively straightforward due to similarities in Perhaps this explains why elevated pH poses no design and evaluation. Comparisons made to the most current biological condition status for the

35 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Mountains/Basins, Plains/Lowlands and the lower ninth-ranked stressor in the NE (7%) and fifth- 48 contiguous states of the nation are limited as a ranked at the Wyoming scale (14%). result of differences in biological expectations and stressor thresholds. Nevertheless, comparisons Nationally (lower 48 contiguous states), the were justified since many of the same fundamental percentage of stream miles in the least-disturbed principles and design methodology were applied biological condition (28%) is much less relative to to the evaluation of biological condition the NE (52%) (USEPA 2015) (Figure 7). Likewise, regardless of scale or location. Only stressors the percentage of national stream miles in the common to the NE, Wyoming, Mountains/Basins, most-disturbed biological condition is 46% - much Plains/Lowlands and national surveys were greater than the NE estimate of 13%. Whereas compared. total phosphorus was the most common (46% of stream miles) stressor nationally, it was considered The NE is similar to the entire state of Wyoming a stressor in only 7% of NE stream miles or 9th with regard to the percentage of stream miles in ranked in terms of relative extent (Figure 9). the least-disturbed (52% NE vs. 58% Wyoming) and most-disturbed (13% NE vs. 18% Wyoming) Total nitrogen and riparian disturbance (41% and biological condition (Figure 7) (Hargett and 20% of stream miles, respectively) were the ZumBerge 2013). The NE fairs better than the second and fourth most common stressors Mountains/Basins of the United States with regard nationally. Estimates for total nitrogen in the NE to least-disturbed (52% NE vs. 46% (9%) were less than the 41% nationally, though Mountains/Basins) and most-disturbed (13% NE the extent of riparian disturbance (26%) in the NE vs. 27% Mountains/Basins) biological conditions was greater than the national estimate. Excess (USEPA 2015) (Figure 7). Similarly, the NE which sediment and particularly salinity are less common proportionally contains a greater percentage of stressors (15% and 3%, respectively) nationally plains relative to mountain streams, is in far better relative to the NE (19% and 18%, respectively). condition than the Plains/Lowlands of the United States: least-disturbed (52% NE vs. 25% Plains/Lowlands), most-disturbed (13% NE vs. RECOMMENDATIONS 50% Plains/Lowlands) (Figure 7). Excess sediment The NE survey was designed to provide an was the second most common sub-stressor of objective representative ‘snap-shot’ of biological channel instability in the NE (19%) and the most and human health condition and identify common throughout Wyoming (37%) though associated stressors in perennial streams and affected only 18% of stream miles in the rivers of the Belle Fourche, Cheyenne, Powder and Mountains/Basins (Figure 7). Riparian disturbance Tongue River basins. While the NE survey was not was a notable stressor at varying spatial scales in designed to determine if specific waterbodies are the western United States (Wyoming-36%, NE- impaired or non-supportive of their designated 26%, Mountains/Basins-24%) though was less aquatic life uses, the results do provide a baseline prevalent in terms of relative extent in the from which future progress can be measured and Plains/Lowlands (17%). Riparian disturbance was areas that may warrant additional investigation the third most common stressor in both the NE and to ultimately improve water quality. This throughout Wyoming. Total nitrogen and total information can be integrated with existing phosphorus were considered stressors in similar planning, management directives and current percentages of stream miles in the NE (9% and pollutant reduction efforts being organized and 7%, respectively) though much less than in the implemented at the federal, state and local levels. Mountains/Basins (20% and 33%, respectively) It should be noted that results from this survey do and Plains/Lowlands (47% and 41%, not account for the synergistic effects of multiple respectively (Figure 7). Total phosphorus was the stressors nor do they identify all the potential

36 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Figure 7 - Biological condition (top) of perennial streams and rivers (by percentage of respective stream length) and relative extents (bottom) of stressors common to the Northeast, Wyoming (Hargett and ZumBerge 2013), Mountains/Basins and Plains/Lowlands regions of the United States (USEPA 2015) and national (USEPA 2015) probabilistic surveys.

13% 18% 27% 25% 28% 46% 35% 52% 24% 58% 46% 50% 27% 25% 26%

Northeast Wyoming Mountains/Basins Plains/Lowlands Nation Least-Disturbed Indeterminate Most-Disturbed

Total Nitrogen

Total Phosphorus

Riparian Disturbance

Excess Sediment

Salinity

0 20 40 60 80 100 Percent of Most-Disturbed Stream Miles Northeast Wyoming Mountains/Basins Plains/Lowlands

37 Water Quality Condition of Streams and Rivers in Northeast Wyoming

environmental stressors that may be limiting the to high relative risks though varied in their biological condition of particular streams. Based commonality within different HUC 8 clusters in the on the results of this survey, channel instability, NE. elevated TSS and riparian disturbance were the three most common stressors in the NE. The Applying the relative risk values derived at the NE commonality of channel instability and riparian scale and considering the relative extents of disturbance combined with their moderate stressors within each HUC 8 cluster, the Powder relative risks, suggest that where benthic emerges as an area with the greatest potential macroinvertebrates communities have been need for additional investigation into whether degraded, efforts aimed at reduction in these two aquatic life uses are being supported with respect stressors could have broad benefits on biological to the individual and combined influences of condition of the NE. Based on the survey data, channel instability, riparian disturbance and both stressors appear to be linked in many elevated concentrations of TSS, chloride, total circumstances and from a resource management selenium and total phosphorus. Among all four perspective, efforts that address one will likely HUC 8 clusters, the highest relative extent benefit the other. Accelerated bank erosion was percentages for each of the aforementioned the most prominent of the three sub-stressors that stressors was found within the Powder. The comprised channel instability. Efforts to reduce combination of multiple stressors along with accelerated bank erosion will not only help to varying extents and relative risks imply that address channel instability, but may also reduce where aquatic life may not be supported, there nutrient loading to streams in the NE since may be multiple causes and their effects to sediment can function as a transport mechanism aquatic life variable and perhaps inter-related. for pollutants such as total phosphorus.

Because of its varying influences on different ACKNOWLEDGMENTS components of the aquatic community, evaluations Appreciation is extended to the numerous private of the effects of elevated TSS may require landowners, conservation districts, private investigation into an additional component of the companies and federal, state, county and local aquatic community. Specifically, fishes may be entities whom helped make the WDEQ/WQD more directly affected by suspended sediment Northeast probabilistic survey a success. than benthic macroinvertebrates that are more likely to experience detrimental effects once the sediment is deposited. Because TSS can also serve REFERENCES as a vector for nutrients and other pollutants, Barbour, M.T., J. Gerritsen, B.D. Snyder and J.B. linkages between TSS and these pollutants should Stribling. 1999. Rapid Bioassessment Protocols for be considered as part of these investigations. Use in Streams and Wadeable Rivers: Periphyton, nd Elevated total phosphorus (9th most common Benthic Macroinvertebrates and Fish, 2 Edition. U.S. Environmental Protection Agency, Office of stressor) occurred in <10% of stream miles Water, EPA 841-B-99-002, Washington, D.C. throughout the NE though possesses the second highest relative risk to biological condition. Camargo, J.A. and A. Alonso. 2006. Ecological Elevated total phosphorus attained its greatest and toxicological effects of inorganic nitrogen in relative extent within the Powder (16%) region. aquatic ecosystems: a global assessment. Environmental International 32:831-849. This information could make total phosphorus a potential target for reduction efforts in select Camargo, J.A., A. Alonso and A. Salamanca. areas of this region where it may be a concern. 2005. Nitrate toxicity to aquatic animals: a This same rationale could be applied to elevated review with new data for freshwater total selenium and chloride which had moderate invertebrates. Chemosphere 58:1255-1267.

38 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Chapman, S.S., S.A. Bryce, J.M. Omernik, D.G. Second (2008-2011) Statewide probability Despain, J. ZumBerge and M. Conrad. 2003. surveys. Document #13-0049. Wyoming Ecoregions of Wyoming (color poster with map, Department of Environmental Quality, Water descriptive text, summary tables and Quality Division, Cheyenne, Wyoming. 54 p. photographs). Reston, Virginia. United States Geological Survey (map scale 1:1,400,000). Hargett, E.G. 2012. Assessment of aquatic Cowley, E.R. 2002. Guidelines for establishing biological condition using WY RIVPACS with allowable levels of streambank alteration. United comparisons to the Wyoming Stream Integrity States Bureau of Land Management, Idaho State Index (WSII). Document #12-0151. Wyoming Office. 12 p. Department of Environmental Quality, Water Quality Division, Cheyenne, Wyoming. 77 p. Dodds, W.K., K. Gido, M.R. Whiles, K.M. Fritz and W.J. Matthews. 2004. Life on the edge: the Hargett, E.G. 2011. The Wyoming Stream ecology of Great Plains prairie streams. Bioscience 54:205-216. Integrity Index (WSII) – multimetric indices for assessment of wadeable streams and large rivers Dodds, W.K., V.H. Smith and K. Kohman. 2002. in Wyoming. Document #11-0787. Wyoming Nitrogen and phosphorus relationships to benthic Department of Environmental Quality, Water algal biomass in temperate streams. Canadian Quality Division, Cheyenne, Wyoming. 101 p. Journal of Fisheries and Aquatic Sciences 59:865- 874. Higgens, C.L. and G.R. Wilde. 2005. The role of salinity in structuring fish assemblages in a prairie Fausch, K.D. and K.R. Bestgen. 1997. Ecology of stream system. Hydrobiologia 549:197-203. fishes indigenous to the central and southwestern Great Plains. Pages 131-166 in F.L. Knopf and ILEPA. 2012. Title 35 of the Illinois Administrative F.B. Samson, Eds. Ecology and Conservation of Code, Subtitle C: Water Pollution, Chapter I: Great Plains Vertebrates. Springer-Verlag, New Pollution Control Board, Part 302: Water Quality York. Standards §302.208. http://www.ipcb.state.il.us/ Fischenich, C. and J.V. Morrow Jr. 2000. Reconnection of floodplains with incised channels. Matthews, W.J. 1988. North American prairie Technical Note EMRPP. streams as systems for ecological study. Journal of the North American Benthological Society 7:387- Galay, V.J. 1983. Causes of river bed degradation. Water Resources Research 409. 19:1057-1090. Munn, M.D. and P.A. Hamilton. 2003. New Gregory, S.V., F.J. Swanson, W.A. McKee and studies initiated by the U.S. Geological Survey – K.W. Cummins. 1991. An ecosystem perspective Effects of nutrient enrichment on stream ecosystems. United States Geological Survey Fact of riparian zones. BioScience 41:540-551. Sheet 118-03, 4 p.

Hargett, E.G. and J.R. ZumBerge. 2014. Water NOAA. 2014. National Oceanic and Atmospheric quality condition of perennial streams and rivers Administration National Climate Data Center. in the Bighorn and Yellowstone basins. Document www.climate.gov/#climateWatch #14-0586. Wyoming Department of Environmental Quality, Water Quality Division, Paulsen, S.G., A. Mayio, D.V. Peck, J.L. Stoddard, Cheyenne, Wyoming. 58 p. E. Tarquinio, S.M. Holdsworth, J. Van Sickle, L.L. Yuan, C.P. Hawkins, A.T. Herlihy, P.R. Kaufmann, Hargett, E.G. and J.R. ZumBerge. 2013. Water M.T. Barbour, D.P. Larsen and A.R. Olsen. 2008. Condition of stream ecosystems in the US: an quality condition of Wyoming perennial streams overview of the first national assessment. Journal and rivers – Results of the First (2004-2007) and

39 Water Quality Condition of Streams and Rivers in Northeast Wyoming

of the North American Benthological Society 27:812-821. Stoddard, J.L., D.V. Peck, S.G. Paulson, J. Van Sickle, C.P. Hawkins, A.T. Herlihy, R.M. Hughes, PDEP. 2012. Rationale for the development of P.R. Kaufman, D.P. Larsen, G.A. Lomnicky, A.R. ambient water quality criteria for sulfate, Olsen, S.A. Peterson, P.L. Ringold and T. R. protection of aquatic life use. Pennsylvania Whittier. 2005. An ecological assessment of Department of Environmental Protection. 4p. western streams and rivers. United States Environmental Protection Agency, 620/R- Peterson, D.A., E.G. Hargett, P.R. Wright and J.R. 05/005. 49 p. Zumberge. 2007. Ecological status of Wyoming streams, 2000-2003. United States Geological Sylte, T. and C. Fischenich. 2002. Techniques for Survey, Scientific Investigations Report, 2007- measuring substrate embeddedness. United 5130. 32 p. States Army Corp of Engineers. EMRRP SR-36. 25 p. Peterson, D.A., K.A. Miller, T.T. Bartos, M.L. Clark, S.D. Porter and T.L. Quinn. 2004. Water quality Taylor, C.M., M.R. Winston and W.J. Matthews. in the Yellowstone River Basin, Wyoming, 1993. Fish species-environment and abundance Montana and North Dakota, 1999-2001. United relationships in a Great Plains river system. States Geological Survey, Circular 1234, 40 p. Ecography 16:16-23.

Rosgen, D.L. 2008. River Stability Field Guide. Troelstrup Jr., N.H. and J.D. Rust. 2008. Water Wildland Hydrology. Fort Collins, CO. quality, stream habitat and macroinvertebrates of Sage Creek, Badlands National Park. Proceeding Rosgen, D.L. 2006. Watershed Assessment of of the South Dakota Academy of Science 87:17- River Stability and Sediment Supply (WARSSS). 28. Wildland Hydrology. Fort Collins, CO. USDA/NRCS. 1998. Stream visual assessment Rosgen, D.L. 1996. Applied River Morphology. protocol. United States Department of Agriculture, Wildland Hydrology. Fort Collins, CO. Natural Resources Conservation Service, National Water and Climate Center, Technical Note 99-1. Schumm, S.A. 1977. The Fluvial System. John Wiley and Sons, New York. 338 p. USDI/BLM. 1998. Riparian area management – a user guide to assessing proper functioning Soucek, D.J. and A.J. Kennedy. 2005. Effects of condition and the supporting science for lotic hardness, chloride and acclimation on the acute areas. United States Department of the Interior, toxicity of sulfate to freshwater invertebrates. Bureau of Land Management, National Applied Environmental Toxicology and Chemistry Resource Sciences Center, Technical Reference 24:1204-1210. 1737-15. Statsoft. 2011. STATISTICA, Version 10. Statsoft, USEPA. 2015. National Rivers and Streams Inc., Tulsa, Oklahoma. Assessment 2008-2009, A Collaborative Study DRAFT. United States Environmental Protection Stevens, Jr., D.L. and A.R. Olsen. 2004. Spatially Agency; Office of Wetlands, Oceans and balanced sampling of natural resources. Journal Watersheds; Office of Research and of the American Statistical Association 99:262- Development; EPA-841-D-13-001. 278. USEPA. 2009. National Water Quality Inventory: Stevens, Jr., D.L. and A.R Olsen. 1992. Statistical Report to Congress [2004 Reporting Cycle]. issues in environmental monitoring and assessemnt. United States Environmental Protection Agency, In: Proceedings of the Joint Statistical Meetings, American Statistical Association, Section on Office of Water, EPA-841-R-08-001. Statistics and the Environment; 18-22 Aug 1991; USEPA. 2000. Nutrient criteria technical guidance Atlanta, GA. American Statistical Association, Alexandria, VA. p13. manual – rivers and streams. United States

40 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Environmental Protection Agency, Office of WDEQ/WQD. 2015. Manual of standard Water, EPA-822-B-00-002. operating procedure for sample collection and analysis. Wyoming Department of Environmental USEPA. 1998. Environmental Monitoring and Quality, Water Quality Division, Cheyenne, Assessment Program – Surface Waters: Field Wyoming. Operations and Methods for Measuring the Ecological Condition of Wadeable Streams. WDEQ/WQD. 2014. Wyoming’s Methods for United States Environmental Protection Agency, Determining Surface Water Quality Condition National Exposure Research Laboratory and and TMDL Prioritization. Document #14-0367. National Health and Environmental Effects Wyoming Department of Environmental Quality, Research Laboratory, EPA 620-R-94-004F. Water Quality Division, Cheyenne, Wyoming.

USEPA. 1996. A metals translator: guidance for WDEQ/WQD. 2013. Water Quality Rules and calculating a total recoverable permit limit from a Regulations, Chapter 1, Wyoming Surface Water dissolved criterion. United States Environmental Quality Standards. Wyoming Department of Protection Agency, Office of Water, EPA 823-B- Environmental Quality. Water Quality Division. 96-007. Cheyenne, Wyoming.

USEPA. 1985. A screening procedure for toxic WDEQ/WQD. 2010. Surface Water Monitoring and conventional pollutants in surface and ground Strategy 2010-2019. Wyoming Department of water. Part I (Revised-1985). United States Environmental Quality. Water Quality Division. Environmental Protection Agency, EPA 440-4-84- Cheyenne, Wyoming. 020. WDEQ/WQD. 2001. Quality assurance project Van Sickle, J. and S.G. Paulsen. 2008. Assessing plan (QAPP) for Beneficial Use Reconnaissance the attributable risks, relative risks, and regional Program (BURP) water quality monitoring. extents of aquatic stressors. Journal of the North Wyoming Department of Environmental Quality. American Benthological Society 27:920-931 Water Quality Division. Cheyenne, Wyoming.

Van Sickle, J., J.L. Stoddard, S.G. Paulsen and A.R. WSCO. 2014. Wyoming State Climate Office. Olsen. 2006. Using relative risk to compare www.wrds.uwyo.edu/sco/data/data.html effects of aquatic stressors at a regional scale. WWDC. 2002a. Northeast Wyoming River Basins Environmental Management 38:1020-1030. Plan Final Report. Wyoming Water Development Vollenweider, R.A. 1971. Scientific fundamental Commission. Cheyenne, Wyoming.

of the eutrophication of lakes and flowing waters WWDC. 2002b. Powder/Tongue River Basin Plan with particular reference to nitrogen and Final Report. Wyoming Water Development phosphorus as factors in eutrophication. Commission. Cheyenne, Wyoming. Organization for Economic Cooperation and Development, Paris, France. 193 p.

Ward, J.V. 1992. Aquatic Insect Ecology – 1. Biology and Habitat. John Wiley & Sons, Inc. 438

p.

Waters, T.F. 1995. Sediment in Streams-Sources,

Biological Effects, and Control. American Fisheries Society Monograph 7. American Fisheries Society, Bethesda, Maryland. 251 pp.

41 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 1 – Biological condition stressor thresholds used to establish condition categories for streams and rivers within bioregions of the Northeast survey. Biological condition thresholds are represented as (least-disturbed) / (most- disturbed) expect for sulfate where only most-disturbed values are provided according to the embedded matrix.

Bioregion NE Plains NE Plains Bighorn Basin Foothills Black Hills Sedimentary Mountains Southern Rockies High Valleys Wyoming Basin SE Plains (spring-fed; semi- (perennial) perennial) Chloride (mg/L) < 230 / ≥ 230 Conductivity (µS/cm) < 240 / ≥ 401 < 148 / ≥ 841 < 215 / ≥ 429 < 49 / ≥ 248 < 177 / ≥ 580 < 266 / ≥ 547 < 352 / ≥ 769 < 1552 / ≥ 2541 < 2303 / ≥ 4718 < 87 (when pH< 7.00 and Total Hardness as mg/L CaCO3 < 50 mg/L) or < 750 (when pH ≥ 7.00 and Total Hardness as mg/L CaCO3 ≥ 50 mg/L) Dissolved Aluminum (µg/L) ≥ 87 (when pH< 7.00 and Total Hardness as mg/L CaCO3 < 50 mg/L) or ≥ 750 (when pH ≥ 7.00 and Total Hardness as mg/L CaCO3 ≥ 50 mg/L) Dissolved Arsenic (µg/L) < 150 / ≥ 150 Dissolved Cadmium (µg/L) < e(0.7409[ln(Total Hardness as mg/L CaCO3)]-4.719)(1.101672-[ln(Total Hardness as mg/L CaCO3)]*0.041838) / ≥ e(0.7409[ln(Total Hardness as mg/L CaCO3)]-4.719)(1.101672-[ln(Total Hardness as mg/L CaCO3)]*0.041838) Dissolved Iron (µg/L) < 1000 / ≥ 1000 Dissolved Manganese (µg/L) < e(0.5434[ln(Total Hardness as mg/L CaCO3)]+4.7850) / ≥ e(0.5434[ln(Total Hardness as mg/L CaCO3)]+4.7850) Dissolved Zinc (µg/L) < e(0.8473[ln(Total Hardness as mg/L CaCO3)]+0.884)(0.986) / ≥ e(0.8473[ln(Total Hardness as mg/L CaCO3)]+0.884)(0.986) Nitrate+Nitrite-N (mg/L) < 0.100 / ≥ 0.123 TSS (mg/L) < 3 / ≥ 16 < 3 / ≥ 11 < 3 / ≥ 7 < 3 / ≥ 4 < 3 / ≥ 9 < 3 / ≥ 14 < 3 / ≥ 11 < 3 / ≥ 33 < 3 / ≥ 760 Total Phosphorus (mg/L) < 0.100 / ≥ 0.100 < 0.100 / ≥ 0.576

Water Chemistry Total Nitrogen (mg/L) < 0.100 / ≥ 0.500 < 0.125 / ≥ 0.583 < 0.227 / ≥ 1.828 < 0.734 / ≥ 3.345 Total Selenium (µg/L) < 5 / ≥ 5 Cl < 5 mg/L 5 ≤ Cl < 25 mg/L 25 mg/L ≤ Cl HD < 100 mg/L 500 mg/L 500 mg/L 500 mg/L Cl = Chloride Sulfate (mg/L) 100 ≤ HD ≤ 500 mg/L 500 mg/L SO4 = [-57.478 + 5.79(HD) + 54.163 (Cl)] * 0.65 SO4 = [1276.7 + 5.508(HD) - 1.457(Cl)] * 0.65 HD = Hardness HD > 500 mg/L 500 mg/L 2000 mg/L 2000 mg/L pH > 6.5 and < 9.0 / < 6.5 or > 9.0 WSII > 60.9 / < 40.6 > 46.1 / < 30.7 > 52.3 / < 34.8 > 48.8 / < 32.6 > 48.8 / < 32.5 > 39.9 / < 26.2 > 55.1 / < 36.7 > 58.4 / < 38.9 - NEPMI ------> 72.6 / < 48.4

Biological Condition WY RIVPACS > 0.85 / < 0.63 > 0.88 / < 0.59 > 0.82 / < 0.68 > 0.89 / < 0.62 > 0.86 / < 0.69 > 0.82 / < 0.64 > 0.78 / < 0.51 > 0.75 / < 0.52 - Most-disturbed when mean streambank cover < 70% or bareground > 40% within 30 feet of the channel. Otherwise, at least four of the following indicators must be documented within 30 feet of the channel (unless otherwise noted) to receive a most-disturbed rating: wall/dike/revetment/rip-rap/dam, buildings, pavement/cleared land, road/railroad, pipes/diversion structures, landfill/trash, park/lawn, row crops up to bank, logging operations, Riparian Disturbance gas/oil/mineral mining activity, grazing, low riparian vegetation vigor, no diverse age-class or composition in riparian vegetation, dominant stream bank vegetation comprised of upland or facultative upland species, extensive hoof

Riparian

Disturbance shear/trampling, < 10% woody riparian vegetation or < 10% overhanging vegetation Most-disturbed when either mean riffle embeddedness ≥ 50% or both of the following must be in the reach to constitute a most-disturbed condition: bimodal reachwide particle distribution and new and extensive unvegetation bar Excess Sediment development. Accelerated Stream Bank Erosion Most-disturbed when mean streambank stability < 70% or the channel is classified as an unexpected Rosgen F or G considering its natural valley type.

Channel

Instability Channel Incision Most-disturbed when either either active channel incision (e.g. evident headcuts or unexpected shifts in channel gradient) or recent (within the past 10 years) channelization is present.

42 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 2 – Drinking water suitability and human health condition thresholds used to establish condition categories for streams and rivers within the Northeast survey. Equations used to translate dissolved concentrations to total concentrations are found within the brackets for each constituent.

Northeast Superbasin a -6 Total Arsenic (µg/L) <10 [Total Arsenic as µg/L = Dissolved Arsenic as µg/L(1 + Kp * TSS as µg/L * 10 )] c -6 Total Cadmium (µg/L) <5 [Total Cadmium as µg/L = Dissolved Cadmium as µg/L(1 + Kp * TSS as µg/L * 10 )] Total Selenium (µg/L) <50 z -6 Total Zinc (µg/L) <5000 [Total Zinc as µg/L = Dissolved Zinc as µg/L(1 + Kp * TSS as µg/L * 10 )] Dissolved Manganese (µg/L) <50 Dissolved Iron (µg/L) <300 Nitrate+Nitrite-N (mg/L) <10 Escherichia coli (cfu/100 mL) < 126

a 6 Kp = KpoTSS∞ where Kpo = 0.48X10 and ∞ = -0.73 (USEPA 1985 and 1996) z 6 Kp = KpoTSS∞ where Kpo = 1.25X10 and ∞ = -0.70 (USEPA 1985 and 1996)

c 6 Kp = KpoTSS∞ where Kpo = 4.00X10 and ∞ = -1.13 (USEPA 1985 and 1996)

43 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 3 – Relative departures of 2011 flow statistics from means for the periods of record at selected USGS streams gages within the Northeast.

Mean Peak Flow (cfs) % Departure from Mean Peak Mean Annual Flow (cfs) % Departure from Mean Annual USGS Gage ID USGS Gage Name Period of Record 2011 Peak Flow (cfs) Period of Record Flow for Period of Record 2011 Mean Annual Flow (cfs) Period of Record Flow for Period of Record 06309200 Middle Fork Powder River nr. Barnum, WY 1962-2013 1,280.0 759.7 68.5 50.9 28.9 76.1 06311000 North Fork Powder River nr. Hazelton, WY 1947-2013 627.0 307.8 103.7 25.8 15.0 72.0 06313500 Powder River nr. Sussex, WY 1978-2013 4,140.0 4,503.2 -8.1 272.3 207.1 31.5 06313590 Powder River abv. Burger Draw nr. Buffalo, WY 2003-2013 3,900.0 2,828.8 37.9 313.6 186.3 68.3 06316400 Crazy Woman Creek at Upper Sta. nr. Arvada, WY 2001-2013 938.0 626.5 49.7 86.5 32.1 169.5 06317000 Powder River at Arvada, WY 1931-2013 5,260.0 6,776.1 -22.4 396.4 267.1 48.4 06324000 Clear Creek nr. Arvada, WY 1940-2013 2,200.0 2,778.1 -20.8 301.2 175.3 71.8 06324500 Powder River at Moorhead, MT 1929-2013 6,840.0 6,782.3 0.9 719.1 439.6 63.6 06324970 Little Powder River abv. Dry Creek nr. Weston, WY 1973-2013 1,910.0 876.6 117.9 52.9 21.6 144.9 06365900 Cheyenne River nr. Dull Center, WY 2004-2013 126.0 211.3 -40.4 1.9 1.0 93.9 06386500 Cheyenne River nr. Spencer, WY 2004-2013 2,170.0 1,476.4 47.0 61.9 16.3 279.8 06392900 Beaver Creek at Mallo Camp nr. Four Corners, WY 1991-2013 154.0 37.3 312.9 3.2 1.9 68.4 06392950 Stockade Beaver Creek nr. Newcastle, WY 1991-2013 35.0 117.1 -70.1 15.5 13.6 14.0 06425720 Belle Fourche River blw. Rattlesnake Creek nr. Piney, WY 2001-2013 1,010.0 188.7 435.2 6.9 2.4 187.5 06426130 Donkey Creek nr. Gillette, WY 2000-2013 192.0 358.1 -46.4 4.5 2.1 114.3 06426500 Belle Fourche River blw. Moorcroft, WY 1944-2013 1,380.0 1,210.5 14.0 57.0 23.1 146.8 06428500 Belle Fourche River at WY-SD stateline 1954-2013 5,840.0 1,731.8 237.2 269.3 91.8 193.4 06429500 Cold Springs Creek at Buckhorn, WY 1991-2013 9.9 12.7 -22.0 5.7 4.5 26.7 06429905 Sand Creek nr. Ranch A nr. Beulah, WY 1991-2013 164.0 162.9 0.7 33.6 23.1 45.5 06298000 Tongue River nr. Dayton, WY 1941-2013 2,390.0 1,631.1 46.5 277.3 171.9 61.3 06299980 Tongue River at Monarch, WY 2004-2013 3,880.0 2,047.9 89.5 405.1 238.1 70.1 06306200 Prairie Dog Creek at Wakley Siding nr. Sheridan, WY 2004-2013 411.0 241.4 70.3 20.8 21.2 -1.9 06306250 Prairie Dog Creek nr. Acme, WY 2000-2013 481.0 253.1 90.0 32.5 25.4 28.0 06306300 Tongue River at stateline nr. Decker, MT 1961-2013 6,220.0 3,590.7 73.2 729.1 437.2 66.8

Departure Range: -70.1 to 435.2 Departure Range: -1.9 to 279.8 Mean Departure: 65.2 Mean Departure: 89.2

44 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 4 – Target sites sampled as part of the 2011 Northeast survey.

Watershed Area Survey ID Type StationID WaterbodyName - Reach Name Latitude Longitude HUC 6 Basin Elevation (ft) (mi2) HUC 8 Cluster BIOREGION WY09C-051 Base MRE0034 MIDDLE FORK HAY CREEK - COAL LAND RIDGE 44.670495 -104.247717 BELLE FOURCHE 3870 7.5 Belle Fouche BLACK HILLS WY09C-052 Base MRE0030 BEAVER CREEK - BENDER HILL 44.716973 -104.442311 BELLE FOURCHE 3891 74.7 Belle Fouche BLACK HILLS WY09C-053 Base NGP0251 BELLE FOURCHE RIVER - EAGLE ROCK 43.909436 -105.533126 BELLE FOURCHE 4680 296.9 Belle Fouche NE PLAINS WY09C-059 Base NGP0249 PRAIRIE CREEK - CRACKER 44.723003 -105.017862 LITTLE MISSOURI 3960 85.3 Belle Fouche NE PLAINS WY09C-060 Base MRE0029 BLACKTAIL CREEK - BELOW HERSHEY CREEK 44.589959 -104.521467 BELLE FOURCHE 4420 19.8 Belle Fouche BLACK HILLS WY09C-062 Base NGP0253 FOUR HORSE CREEK - MEXICAN DRAW 44.036722 -105.058342 BELLE FOURCHE 4400 78.9 Belle Fouche NE PLAINS WY09C-063 Base MRC0122 UNNAMED TRIBUTARY TO NORTH FORK RED FORK POWDER - TABLETOP43.853295 -107.063549 POWDER 7780 2.0 East Big Horn SEDIMENTARY MOUNTAINS WY09C-064 Base MRC0127 CLEAR CREEK - BELOW MOSIER GULCH 44.329860 -106.794443 POWDER 5360 118.7 East Big Horn HIGH VALLEYS WY09C-065 Base NGP0248 CLEAR CREEK - BIG BONANZA ROAD 44.524966 -106.548961 POWDER 4120 401.7 East Big Horn HIGH VALLEYS WY09C-067 Base NGP0245 CRAZY WOMAN CREEK - COLORADO FLATS DRAW 44.065303 -106.574609 POWDER 4500 426.9 East Big Horn NE PLAINS WY09C-068 Base NGP0247 ROCK CREEK - MOWRY BASIN 44.447626 -106.860856 POWDER 5160 63.6 East Big Horn SOUTHERN ROCKIES WY09C-069 Base NGP0239 TONGUE RIVER - PORDEN 44.907206 -107.133829 TONGUE 3720 403.9 East Big Horn HIGH VALLEYS WY09C-072 Base MRC0124 NORTH TONGUE RIVER - ABOVE BULL CREEK 44.764373 -107.603417 TONGUE 8100 34.8 East Big Horn SEDIMENTARY MOUNTAINS WY09C-073 Base MRC0126 POISON CREEK - USFS BOUNDARY 44.071052 -106.922257 POWDER 7562 24.7 East Big Horn SEDIMENTARY MOUNTAINS WY09C-074 Base NGP0246 CRAZY WOMAN CREEK - ABOVE JEWELL DRAW 44.488143 -106.182246 POWDER 3780 937.9 East Big Horn NE PLAINS WY09C-076 Base NGP0235 SALT CREEK - DEAD WOMAN CROSSING 43.542269 -106.330166 POWDER 4640 572.0 Powder NE PLAINS WY09C-078 Base WB0376 OKIE DRAW - NOTCHES DOME 43.177639 -106.978958 POWDER 5520 21.0 Powder WYOMING BASIN WY09C-082 Base WB0377 OKIE DRAW - BELOW OIL FIELD 43.186497 -106.944040 POWDER 5410 44.3 Powder WYOMING BASIN WY09C-083 Base NGP0238 POWDER RIVER - ABOVE TWOMILE DRAW 43.754379 -106.253812 POWDER 4310 3083.0 Powder NE PLAINS WY09C-084 Base NGP0231 WILLOW CREEK - BELOW COUNTY ROAD 112 43.482832 -106.675383 POWDER 4910 95.0 Powder NE PLAINS WY09C-086 Base NGP0241 POWDER RIVER - ABOVE BARBER CREEK 44.323649 -106.143940 POWDER 3850 4600.6 Powder NE PLAINS WY09C-088 Base NGP0226 BEAVER CREEK - BELOW IRON CREEK 43.983190 -104.519240 CHEYENNE 4060 132.0 Cheyenne NE PLAINS WY09C-089 Base NGP0220 WALKER CREEK - KAYE 43.130714 -104.886126 CHEYENNE 4280 196.0 Cheyenne NE PLAINS WY09C-095 Base NGP0228 BEAVER CREEK - FIDDLER 43.872946 -104.455274 CHEYENNE 3960 249.0 Cheyenne NE PLAINS WY09C-099 Base NGP0225 CHEYENNE RIVER - SEVENMILE SCHOOL 43.428080 -104.495202 CHEYENNE 3820 2877.0 Cheyenne NE PLAINS WY09C-100 Base NGP0221 ANTELOPE CREEK - BELOW WILDCAT CREEK 43.445104 -105.090753 CHEYENNE 4350 1033.0 Cheyenne NE PLAINS WY09C-301 OverSample MRE0032 COLD SPRINGS CREEK - ABOVE STANTON DRAW 44.198533 -104.148098 BELLE FOURCHE 5685 60.0 Belle Fouche BLACK HILLS WY09C-302 OverSample MRE0028 OAK CREEK - MILLER 44.482938 -104.628644 BELLE FOURCHE 4270 7.3 Belle Fouche BLACK HILLS WY09C-308 OverSample MRE0031 BEAVER CREEK - TOWN OF ALVA 44.714865 -104.442435 BELLE FOURCHE 3895 74.5 Belle Fouche BLACK HILLS WY09C-309 OverSample MRE0027 ARCH CREEK - NEFSY DIVIDE 44.296042 -104.652169 BELLE FOURCHE 4200 43.4 Belle Fouche BLACK HILLS WY09C-310 OverSample NGP0252 BELLE FOURCHE RIVER - ABOVE THREEMILE CREEK 43.909687 -105.535766 BELLE FOURCHE 4660 296.8 Belle Fouche NE PLAINS WY09C-311 OverSample NGP0250 PRAIRIE CREEK - GRAVEL PIT 44.732130 -104.989305 LITTLE MISSOURI 3870 88.1 Belle Fouche NE PLAINS WY09C-325 OverSample NGP0240 TONGUE RIVER - STRIP MINE 44.911152 -106.974109 TONGUE 3600 904.7 East Big Horn HIGH VALLEYS WY09C-327 OverSample NGP0243 NORTH FORK CRAZY WOMAN CREEK - ABOVE KELLY CREEK 44.176291 -106.711938 POWDER 4950 69.1 East Big Horn SOUTHERN ROCKIES WY09C-333 OverSample MRC0125 BIG WILLOW CREEK - BURGESS JUNCTION 44.762733 -107.544100 TONGUE 8140 7.1 East Big Horn SEDIMENTARY MOUNTAINS WY09C-335 OverSample NGP0244 NORTH FORK CRAZY WOMAN CREEK - T.A. HILLS 44.094910 -106.677062 POWDER 4700 143.2 East Big Horn HIGH VALLEYS WY09C-337 OverSample WB0378 BUFFALO CREEK - BELOW NORTH POKER CREEK 43.583716 -106.874734 POWDER 5160 231.0 East Big Horn BIGHORN BASIN FOOTHILLS WY09C-352 OverSample NGP0230 WILLOW CREEK - BELOW ALKALI CREEK 43.421523 -106.785479 POWDER 5380 66.0 Powder NE PLAINS WY09C-353 OverSample NGP0242 POWDER RIVER - SOUTH OF ARVADA 44.644162 -106.128304 POWDER 3640 5918.1 Powder NE PLAINS

45 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 4 (cont.) - Target sites sampled as part of the 2011 Northeast survey.

Watershed Area Survey ID Type StationID WaterbodyName - Reach Name Latitude Longitude HUC 6 Basin Elevation (ft) (mi2) HUC 8 Cluster BIOREGION WY09C-354 OverSample NGP0234 SALT CREEK - ABOVE CASTLE CREEK 43.405342 -106.276240 POWDER 4820 322.0 Powder NE PLAINS WY09C-360 OverSample NGP0233 SOUTH FORK POWDER RIVER - BELOW ELLISON DRAW 43.655927 -106.540026 POWDER 4750 1121.0 Powder NE PLAINS WY09C-361 OverSample NGP0232 WILLOW CREEK - JOHNSON COUNTY LINE 43.492860 -106.661966 POWDER 4880 96.0 Powder NE PLAINS WY09C-362 OverSample NGP0236 MEADOW CREEK - SUSSEX 43.592369 -106.301877 POWDER 4680 68.0 Powder NE PLAINS WY09C-364 OverSample NGP0237 POWDER RIVER - FOUR MILE RANCH 43.690487 -106.339291 POWDER 4890 2274.0 Powder NE PLAINS WY09C-377 OverSample NGP0224 CHEYENNE RIVER - BELOW SNYDER CREEK 43.430018 -104.509157 CHEYENNE 3830 2875.0 Cheyenne NE PLAINS WY09C-382 OverSample NGP0217 LODGEPOLE CREEK - SHURLEY 43.588395 -104.598507 CHEYENNE 4000 301.0 Cheyenne NE PLAINS WY09C-383 OverSample WHP0054 BILLS CREEK - HORSESHOE HILLS 42.850774 -104.739058 CHEYENNE 4920 18.8 Cheyenne SE PLAINS WY09C-384 OverSample NGP0227 BEAVER CREEK - OSAGE FIELD 43.937353 -104.479436 CHEYENNE 4030 211.0 Cheyenne NE PLAINS WY09C-387 OverSample NGP0218 BLACK THUNDER CREEK - BELOW LITTLE MIKE CREEK 43.736534 -105.016127 CHEYENNE 4360 138.0 Cheyenne NE PLAINS WY09C-392 OverSample NGP0219 COW CREEK - BELOW BULL CREEK 43.287712 -104.814494 CHEYENNE 4260 71.0 Cheyenne NE PLAINS WY09C-396 OverSample NGP0223 LANCE CREEK - BELOW DOGIE CREEK 43.273633 -104.562417 CHEYENNE 3960 1502.0 Cheyenne NE PLAINS WY09C-399 OverSample NGP0229 STOCKADE BEAVER CREEK - BELOW MW LAKE 43.613985 -104.134735 CHEYENNE 3750 183.9 Cheyenne NE PLAINS

46 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 5 - Summary of Escherichia coli results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. Escherichia coli Basin-wide Belle Fourche

LD 54.5% LD 51.1%

MD 45.5% MD 48.9%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne

LD 56.0% LD 56.0%

MD 44.0% MD 44.0%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder

LD 53.9% LD = Least-disturbed

MD = Most-disturbed MD 46.1%

0 25 50 75 100 Percent of Stream Miles

47 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 6 – Summary of nitrate+nitrite-N results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. Nitrate+Nitrite-N Basin-wide Belle Fourche 82.7% 87.6% LD LD

I 3.0% I 0.0%

MD 14.3% MD 12.4%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne 76.2% LD LD 100%

I 8.6% I 0.0%

MD 15.2% MD 0.0%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder 69.3% LD LD = Least-disturbed I 0.0% I = Indeterminate MD 30.7% MD = Most-disturbed

0 25 50 75 100 Percent of Stream Miles

48 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 7 - Summary of total phosphorus results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. Total Phosphorus Basin-wide Belle Fourche 81.7% 74.5% LD LD

I 11.5% I 17.1%

MD 6.8% MD 8.4%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne LD 100% LD 59.4%

I 0.0% I 33.4%

MD 0.0% MD 7.2%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder 83.9% LD LD = Least-disturbed I 0.0% I = Indeterminate MD 16.1% MD = Most-disturbed

0 25 50 75 100 Percent of Stream Miles

49 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 8 - Summary of total nitrogen results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals.

Total Nitrogen Basin-wide Belle Fourche LD 34.7% LD 24.7%

I 56.7% I 49.9%

MD 8.6% MD 25.4%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne LD 14.8% LD 56.0%

76.5% I I 44.0%

MD 8.7% MD 0.0%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder LD 54.7% LD = Least-disturbed I 45.3% I = Indeterminate MD 0.0% MD = Most-disturbed

0 25 50 75 100 Percent of Stream Miles

50 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 9 - Summary of salinity results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. Salinity Basin-wide Belle Fourche LD 20.2% LD 24.6%

I 61.5% I 54.7%

MD 18.4% MD 20.8%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne LD 13.6% LD 30.7%

66.3% I I 62.1%

MD 20.1% MD 7.2%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder LD 14.6% LD = Least-disturbed I 59.8% I = Indeterminate MD 25.6% MD = Most-disturbed

0 25 50 75 100 Percent of Stream Miles

51 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 10 - Summary of selenium results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. Total Selenium Basin-wide Belle Fourche

LD 95.9% LD 100%

MD 4.1% MD 0.0%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne

LD 100% LD 100%

MD 0.0% MD 0.0%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder 80.0% LD LD = Least-disturbed

MD = Most-disturbed MD 20.0%

0 25 50 75 100 Percent of Stream Miles

52 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 11 - Summary of total suspended solids (TSS) results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. TSS Basin-wide Belle Fourche LD 0.8% LD 0.0%

I 67.5% I 62.5%

MD 31.7% MD 37.5%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne LD 0.0% LD 0.0%

76.2% 74.7% I I

MD 23.9% MD 25.3%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder LD 3.9% LD = Least-disturbed I 50.0% I = Indeterminate MD 46.1% MD = Most-disturbed

0 25 50 75 100 Percent of Stream Miles

53 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 12 - Summary of chloride results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. Chloride Basin-wide Belle Fourche

LD 91.6% LD 100%

MD 8.4% MD 0.0%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne 92.8% LD 100% LD

MD 0.0% MD 7.2%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder 67.0% LD LD = Least-disturbed

MD = Most-disturbed MD 33.0%

0 25 50 75 100 Percent of Stream Miles

54 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 13 - Summary of sulfate results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. Sulfate Basin-wide Belle Fourche

LD 91.8% LD 100%

MD 8.2% MD 0.0%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne 77.5% LD 100% LD

MD 0.0% MD 22.5%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder 85.4% LD LD = Least-disturbed

MD = Most-disturbed MD 14.6%

0 25 50 75 100 Percent of Stream Miles

55 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 14 - Summary of pH results for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals.

pH Basin-wide Belle Fourche

82.8% LD 96.2% LD

MD 3.8% MD 17.2%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne

LD 100% LD 100%

MD 0.0% MD 0.0%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder

LD 100% LD = Least-disturbed

MD = Most-disturbed MD 0.0%

0 25 50 75 100 Percent of Stream Miles

56 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 15 - Summary of physical stressor results (channel instability and riparian disturbance) for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. Channel Instability and Riparian Disturbance Basin-wide Belle Fourche

CI 34.8% CI 33.1%

RD 25.8% RD 33.1%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne

CI 12.7% CI 30.7%

RD 12.7% RD 7.2%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder 78.4% CI CI = Channel Instability

60.6% RD = Riparian Disturbance RD

0 25 50 75 100 Percent of Stream Miles

57 Water Quality Condition of Streams and Rivers in Northeast Wyoming

Appendix 16 - Summary of the three component sub-stressors that represent channel instability for the Northeast and corresponding HUC 8 Clusters. Error bars represent the 95% confidence intervals. Channel Instability Substressors Basin-wide Belle Fourche ES 18.8% ES 8.6%

ABE 30.3% ABE 24.6%

CIn 15.5% CIn 17.0%

0 25 50 75 100 0 25 50 75 100

East Big Horn Cheyenne ES 6.5% ES 8.2%

ABE 12.7% ABE 30.7%

CIn 12.7% CIn 15.4%

0 25 50 75 100 0 25 50 75 100 Percent of Stream Miles Powder 62.3% ES ES = Excess Sediment 63.8% ABE ABE = Accelerated Bank Erosion CIn 18.6% CIn = Channel Incision

0 25 50 75 100 Percent of Stream Miles