Chapter 7 Physical and chemical characteristics of hydrogeologic units in the Snake-Salt River Basin Timothy T. Bartos, Laura L. Hallberg, and Melanie L. Clark
7-117 he physical and chemical characteristics Jackson Hole: of hydrogeologic units in the Snake River • TBasin (Snake/Salt River Basin) are described in this Jackson Hole chapter of the report. For descriptive and summary Green River and Hoback Basins: purposes, wells from which physical and chemical • characteristics were obtained were grouped and Northernmost Green River Basin summarized using six broad "geographic regions" • Hoback Basin shown in figures 7-1 and 7-2. The Gros Ventre, Teton, and Washakie Ranges are combined in one Overthrust Belt: of the six broad geographic regions (the Northern • Snake River Range Ranges) and the Green River and Hoback Basins are combined into one of six broad geographic • Wyoming Range regions (Green River and Hoback Basins) described • Salt River Range below, but are shown separately on figures 7-1 and 7-2. The Absaroka, Wind River Basin, and Wind • Gannett Hills River Mountain geographic areas also are shown on Star Valley: figures 7-1and 7-2, but are not included in the six broad geographic regions because no groundwater- • Star Valley quality data were available for the Absaroka and Lithostratigraphic and corresponding Wind River Basin geographic areas, and the Wind hydrostratigraphic (hydrogeologic) units in the River Mountain geographic area was outside Snake/Salt River Basin are shown on plates 4, the Snake/Salt River Basin. The six geographic 5, and 6. Lithostratigraphic units for specific regions were based primarily on the areal extent structural areas identified on these plates were of structural and geographic features listed below. taken directly from the statewide Phanerozoic The areal extent of these structural and geographic stratigraphic nomenclature chart of Love and features generally follows the approximate areal others (1993). extents shown in the statewide Phanerozoic stratigraphic nomenclature chart of Love and For this report, previously published data others (1993, fig. 1); however, the areal extent describing the physical characteristics of of some regions also was refined using drainage hydrogeologic units (aquifers and confining areas (using 8-digit hydrologic unit codes). The six units) are summarized in tabular format (pl. 3). regions generally include the following geologic The original sources of the data used to construct structures and associated geographic areas. the summary are listed at the bottom of the plate. Physical characteristics are summarized to Yellowstone Volcanic Area: provide a broad summary of hydrogeologic unit • Madison Plateau characteristics and include spring discharge, well yield, specific capacity, transmissivity, porosity, • Pitchstone Plateau hydraulic conductivity, and storage (storativity/ • Red Mountains storage coefficient). Individual data values and corresponding interpretation were utilized and • Falls River Basin/Cascade Corner summarized as presented in the original reports— no reinterpretation of existing hydraulic data was Northern Ranges: conducted for this study. For example, values • Teton Range of transmissivity derived from aquifer tests were used as published in the original reports, and no • Washakie Range reanalysis of previously published aquifer tests was • Gros Ventre Rang conducted. Existing hydraulic data were converted
7-118 111° R115W 110°30’ R110W 110° EXPLANATION Lake Geographic regions 44°30’ Old Faithful West Thumb Pahaska Tepee Resort Absaroka Range Yellowstone 14 16 Green River Basin Lake Gros Ventre Range (Northern Ranges) PARK Hoback Basin 89 COUNTY Jackson Hole 287 Y e Overthrust Belt ll T50N o w s Star Valley t o n Teton Range (Northern Ranges) S e n
ak R
e i Washakie Range (Northern Ranges) Absaroka Range Flagg Ranch R v iv e er r Wind River Basin Wind River Mountains Yellowstone Volcanic Area
Snake/Salt River Basin study area boundary 44° Federal land boundaries Colter Bay Village John D. Rockefeller Jr. Memorial Parkway
Jackson Grand Teton National Park Lake Moran T45N National Elk Refuge Washakie Range Yellowstone National Park er iv Alta R 89 Environmental groundwater-quality
Teton Range Teton ke a 26 sample location, grouped by n S units of geologic time Moose FREMONT Quaternary COUNTY Kelly Tertiary Teton Village 287 26 Ventre Mesozoic Gros River Wind River Mountains Paleozoic Wilson Gros VentreTETON Range Dubois Precambrian 43°30’ COUNTY Jackson 0 10 20 MILES Rafter J T40N Ranch 0 10 20 KILOMETERS
r e
Hoback Junction v i Base from U.S. Geological Survey digital data, Camp Davis R
n variously dated, various scales
e Wind River Mountains e
r Albers Equal-Area Conic projection
Alpine G Standard parallels 29°30’N and 45°30’N Central meridian -107°W r Rive Bondurant Snake North American Datum of 1983 Palisades er iv Reservoir R k Map area c 191 a b Etna o LINCOLN H 189 Star Valley COUNTY
Ranch S G T35N a re l y t s WYOMING
Freedom Thayne R i R v Cora i Bedford e v
r e
R r
a Salt River n Pinedale Turnerville g Daniel N e e Auburn w Grover F o rk R Afton iv er Boulder Fairview SUBLETTE COUNTY Osmond 191 River
Smoot k T30N or
IDAHO Marbleton F ew
WYOMING N Big Piney 42°30’ 189
r
89 e v Figure 7–1. Environmental groundwater- i
R
n quality sample locations, grouped by units e e r of geologic time and in relation to geographic Geneva G regions, Snake/Salt River Basin. R115W R110W
7-119 111° R115W 110°30’ R110W 110° EXPLANATION Lake Geographic regions 44°30’ Old Faithful West Thumb Pahaska Tepee Resort Absaroka Range Yellowstone 14 16 Green River Basin Lake Gros Ventre Range (Northern Ranges) PARK Hoback Basin 89 COUNTY Jackson Hole 287 Y e Overthrust Belt ll T50N o w s Star Valley t o n Teton Range (Northern Ranges) S e n
ak R
e i Washakie Range (Northern Ranges) Absaroka Range Flagg Ranch R v iv e er r Wind River Basin Wind River Mountains Yellowstone Volcanic Area
Snake/Salt River Basin study area boundary 44° Federal land boundaries Colter Bay Village John D. Rockefeller Jr. Memorial Parkway
Jackson Grand Teton National Park Lake Moran T45N National Elk Refuge Washakie Range Yellowstone National Park er iv Alta R 89 Location of springs and wells with Teton Range Teton ke a 26 physical characteristic information, n S grouped by units of geologic time Moose FREMONT Quaternary Kelly COUNTY Teton Village 287 26 Tertiary Ventre Mesozoic Gros TETON River COUNTY Wind River Mountains Paleozoic Wilson Gros Ventre Range Dubois 43°30’ Precambrian Jackson 0 10 20 MILES Rafter J T40N Ranch 0 10 20 KILOMETERS
r e
Hoback Junction v i
Camp Davis R Base from U.S. Geological Survey digital data,
n
e Wind River Mountains variously dated, various scales e r Albers Equal-Area Conic projection Alpine G Standard parallels 29°30’N and 45°30’N r Central meridian -107°W Rive Bondurant Snake North American Datum of 1983 Palisades er Reservoir iv R k c 191 Map area a b Etna o 189 LINCOLN H Star Valley Ranch COUNTY 43° S G T35N a r l e t y s WYOMING Freedom Thayne R
i Cora v R Bedford e i
r v
R e
a r Salt River n Pinedale Turnerville g Daniel N e e Auburn w Grover F o rk R Afton iv er Boulder Fairview SUBLETTE COUNTY Osmond 191 River
Smoot k T30N or
IDAHO Marbleton F ew
WYOMING N Big Piney 42°30’ 189 Figure 7–2. Locations of springs and wells r
89 e v i with physical characteristic information,
R
n grouped by units of geologic time and in e e r relation to geographic regions, Geneva G Snake/Salt River Basin. R115W R110W
7-120 to consistent units to improve readability and many shallow wells in the Snake/Salt River Basin. facilitate comparability between different studies. Quaternary unconsolidated-deposit aquifers are the most used sources of groundwater in the Snake/ 7.1 Snake/Salt River Basin Salt River Basin for stock, domestic, industrial, irrigation, and public-supply purposes. The largest The physical and chemical characteristics of use of these aquifers occurs in the Snake River hydrogeologic units of Cenozoic, Mesozoic, valley and the Salt River valley (also known as the Paleozoic, and Precambrian age in the Snake/Salt Star Valley); both valleys coincide with much of the River Basin are described in this section of the rural and urban population in the study area. report. Hydrogeologic units of the Snake/Salt River Basin are identified on plates 4, 5, and 6. The areal The physical and chemical characteristics of extent of hydrogeologic units in the Snake/Salt saturated Quaternary unconsolidated-deposits River Basin is shown on plate 2. Many physical aquifers in the Snake/Salt River Basin are described characteristic descriptions were modified from in this section of the report. Bartos and Hallberg (2010), Clarey (2011), and Bartos and others (2012, 2014). In addition, a previously constructed groundwater- flow model of a Quaternary unconsolidated- 7.2 Cenozoic hydrogeologic units deposit aquifer in the Snake/Salt River Basin is identified and briefly described. Hydrogeologic units of Cenozoic (Quaternary and Tertiary) age are described in this section Physical characteristics the report. Cenozoic hydrogeologic units are composed of both unconsolidated deposits such as Quaternary unconsolidated deposits are composed sand and gravel (primarily of Quaternary age) and primarily of sand and gravel interbedded with consolidated sediments (bedrock of Tertiary age) finer-grained sediments such as silt and clay, such as sandstone and conglomerate. Compared although coarser deposits such as cobbles and with aquifers of Mesozoic, Paleozoic, and boulders occur locally (Lines and Glass, 1975; Cox, Precambrian age, Cenozoic aquifers are the most 1976; Ahern and others, 1981; Love and others, used sources of groundwater. Cenozoic aquifers 1992; Sunrise Engineering, 2003, 2009). In places, are used as a source of water for stock, domestic, unconsolidated deposits of Quaternary age are industrial, irrigation, and public-supply purposes in intermixed with unconsolidated deposits of Tertiary the Snake/Salt River Basin. age (for example, Love, 2001a, b, c). Several types of unconsolidated deposits of Quaternary age are 7.2.1 Quaternary unconsolidated present in the Snake/Salt River Basin (pls. 1 and deposits 2). Collectively, the Quaternary unconsolidated deposits can be thought of as "valley fill" or "basin Where saturated and sufficiently permeable, fill" because the deposits partly fill many of the unconsolidated sediments of Quaternary age in narrow and broad river valleys of the Snake/Salt the Snake/Salt River Basin can contain aquifers. River Basin formed by faulting, erosion, or both, Saturated Quaternary unconsolidated deposits that through which the Snake and Salt Rivers and contain aquifers (referred to herein as “Quaternary related tributaries flow. The deposits commonly unconsolidated-deposit aquifers”) in the Snake/ grade into and (or) overlie one another and are Salt River Basin typically include alluvium and bounded laterally or vertically by (rest on top of) colluvium (identified herein as "Quaternary alluvial bedrock. The size of sediments composing the aquifers"), terrace deposits (identified herein as deposits is related primarily to the source of the "Quaternary terrace-deposit aquifers"), and glacial eroded and transported parent material and the deposits (identified herein as "Quaternary glacial- distance the sediments have been transported. deposit aquifers"). These aquifers can be highly productive locally and are the source of water for Estimates of the maximum thickness of Quaternary
7-121 unconsolidated deposits are uncommon for many are composed of unconsolidated sand and gravel, areas in the Snake/Salt River Basin and available and less commonly of cobbles and boulders estimates vary substantially by location, primarily derived from older sedimentary and crystalline because few wells in most areas fully penetrate the rocks; stratification and sorting varies, and coarser deposits. Behrendt and others (1968) estimated sediments commonly are interbedded/intermixed that Holocene deposits (less than 10,000 years with finer-grained sediments such as clay and silt. before present) are as thick as 400 feet (ft) in the The size of sediments composing the deposits Jackson Hole area. North of the Overthrust Belt, is related primarily to the source of the eroded Cox (1976, Sheet 1) estimated that the maximum parent material and distance transported. The thickness of alluvium, terrace deposits, and glacial areal extent of terrace deposits generally is small, outwash deposits was about 200 ft. Lines and Glass and the deposits typically are found along uplands (1975, Sheet 1) noted that wells completed in bordering principal streams of the Snake/Salt River Quaternary alluvial deposits (composed of flood- Basin (pls. 1 and 2); however, areally extensive plain alluvium and alluvial fans) in the Overthrust deposits are found in some areas, most notably in Belt generally were less than 200 ft in depth, and Jackson Hole and Star Valley (pls. 1 and 2). Terrace thus, the maximum thickness was unknown. deposits may be present in many different terrace Because thicknesses vary substantially by location, levels alongside streams draining the basin and in individual geologic maps should be consulted adjacent upland areas. Terrace-deposit thickness to determine thickness ranges for Quaternary varies substantially in the Snake/Salt River Basin unconsolidated deposits in areas of interest in the and depends on stream or river valley association Snake/Salt River Basin. and location.
Quaternary-age alluvium is composed of Colluvium is composed of unconsolidated and unconsolidated, poorly to well sorted mixtures of poorly sorted sediment ranging in size from silt clay, silt, sand, and gravel deposited along streams, to boulder-sized rocks mantling major stream primarily as channel-fill and flood-plain deposits. valley sides, tributary stream valleys, and the bases Locally, alluvium can include alluvial fan and of hillsides/hillslopes (Love and others, 1992). terrace deposits, valley side colluvium or talus, Colluvium generally is deposited by rainwash, sheet reworked glacial outwash deposits, and sediments wash, or slow continuous downslope creep (Bates deposited in small bogs, lakes, or deltas. Alluvium and Jackson, 1980). Locally, colluvium can include commonly grades laterally and vertically into other soil, gravel, and glacial drift. Colluvium commonly adjacent Quaternary unconsolidated deposits, is included (mapped) with alluvium on geologic typically terrace deposits; consequently, it is often maps of the Snake/Salt River Basin. Colluvium, difficult to determine where to differentiate the composed of poorly sorted debris at the base different types of Quaternary unconsolidated of steep slopes or slope wash, is included with deposits in the Snake/Salt River Basin. In addition, alluvium in this report for summary purposes. different investigators have not always been consistent when mapping/identifying ("lumping Quaternary alluvial fan deposits occur along the and splitting") the different types of Quaternary river valleys in the Snake/Salt River Basin (Love unconsolidated deposits. Furthermore, use of and others, 1992). The alluvial fan deposits are different scale geologic maps results in different composed of unconsolidated, poorly sorted, groupings of the unconsolidated deposits. alluvium and colluvium forming well defined fan- shaped deposits at mouths of tributary valleys. Quaternary unconsolidated terrace deposits (also Like colluvium, Quaternary alluvial fan deposits described as gravel, pediment, and fan deposits, commonly are included (mapped) with alluvium terrace gravel deposits, or terrace, gravel, and fan on geologic maps of the Snake/Salt River Basin. deposits) are present in the Snake/Salt River Basin, primarily adjacent to the alluvium in river valleys Glaciation has affected many parts of the Snake/ (pls. 1 and 2). Like alluvium, terrace deposits Salt River Basin. Sediments deposited during
7-122 glaciation (Quaternary glacial deposits) generally unconsolidated-deposit aquifers are located close are till and moraine or outwash deposits, consisting to and along streams and rivers, most commonly of unconsolidated, unstratified to stratified, along parts of the Salt River (Star Valley) and sorted to unsorted mixtures of rock fragments the Snake River valley and associated tributaries (including boulders), gravel, sand, silt, and clay (WSGS needs to add proper figure/map reference deposited by alpine (mountain) glaciers (Love and from earlier chapter here). Most irrigated lands others, 1992). Glacial till and moraine deposits in the Snake/Salt River Basin overlie Quaternary are deposited directly by and underneath glaciers unconsolidated-deposit aquifers (Sunrise without subsequent reworking by meltwater (Bates Engineering, 2003, Figures II-1 and II-2). and Jackson, 1980). Glacial outwash deposits are transported from glaciers by meltwater streams Groundwater in Quaternary unconsolidated- and deposited in front of or beyond the end deposit aquifers in the Snake/Salt River Basin moraine or the margin of an active glacier (Bates typically is unconfined (water-table conditions and Jackson, 1980). Quaternary glacial deposits predominate). However, fine-grained sediments may be considered aquifers and developed where overlying coarse-grained permeable zones can result sufficiently water saturated and permeable. in locally confined conditions or overlying perched Productive wells completed in glacial deposits in water tables at some locations in the Snake/Salt the Snake/Salt River Basin likely are completed River Basin (for example, Walker, 1965). in outwash deposits composed of permeable, stratified coarse sand and gravel because deposits Along the flood plains and stream valleys, aquifers comprising tills and moraines generally are much in alluvium and associated terrace deposits typically less permeable because of lack of stratification, poor are in hydraulic connection with one another and sorting, and fine grain size (Whitehead, 1996). adjacent streams and rivers (Walker, 1965; Lines and Glass, 1975, Sheet 1; Hinckley Consulting Where saturated and permeable, Quaternary and Jorgensen Engineering, 1994; Eddy-Miller unconsolidated deposits can contain aquifers. and others, 1996, 2009, 2013b; Wyoming State Quaternary unconsolidated-deposit aquifers Engineer’s Office, 1995, 2005; Wheeler and Eddy- are small in areal extent and primarily occur in Miller, 2005;. In addition, Quaternary alluvial and alluvium (commonly associated with colluvium terrace-deposit aquifers are in hydraulic connection and referred to herein as "alluvial aquifers"), terrace with adjacent or underlying Tertiary bedrock deposits (sometimes referred to as "terrace gravel aquifers at some locations. deposits" or "terrace, gravel, and fan deposits" in some reports and referred to herein as "terrace- An unconsolidated-deposit aquifer primarily deposit aquifers") and glacial deposits (referred to composed of Quaternary alluvium and terrace herein as "glacial-deposit aquifers") along stream deposits and limited glacial deposits, referred to and river valleys and in adjacent upland areas in the herein as the Snake River alluvial aquifer, underlies Snake/Salt River Basin (pls. 1 and 2). much of the Jackson Hole area (Cox, 1976, Plate 3; Nolan and Miller, 1995; San Juan and Kolm, Although limited in areal extent, Quaternary 1996; Nolan and others, 1998). The areal extent unconsolidated-deposit aquifers (most commonly and generalized potentiometric surface of the alluvial and terrace-deposit aquifers) are the most aquifer are shown on figure 7-3. Nolan and Miller used and some of the most productive aquifers (1995) and Nolan and others (1998) informally in the Snake/Salt River Basin (Lines and Glass, named this aquifer the "Jackson aquifer." This 1975; Cox, 1976; Ahern and others, 1981; Sunrise aquifer provides much of the water used for stock, Engineering, 2003, 2009, and references therein). domestic, irrigation, industrial, and public-supply Much of the population in the Snake/Salt River purposes in the area. Saturated aquifer thickness Basin coincides with and directly overlies the was estimated by Cox (1976, plate 3) to range from Quaternary alluvial and terrace-deposit aquifers. less than 50 ft to as much as 300 ft. Using a time- Consequently, most wells completed in Quaternary domain electromagnetic survey conducted mostly
7-123 110°50’ 110°40’ 110°30’ 110°20’
287 Creek P Qg Creek im Qls P r QTv Map area g l i T. P 46 Colter Bay Pacific T Village M N. WYOMING pC 7,000 7,000 Two Ocean 6,950 6,950 Lake JACKSON T Creek 6,900 WASHAKIE RANGE 6,850 Emma Matilda 6,900 LAKE Qt Lake Lava 6,850 Qg 6,800 Qt 6,750 T. 6,800 Buffalo Fork 45 pC 6,800 6,800 N. Moran QTv 6,850 Qa 43°50’ Leigh Lake River 287 6,750 6,850 Blackrock TETON 6,750 Creek Qg 6,700 P 6,900 Spread T. 6,950 Creek Qt 6,650 Snake Qa 44 So Jenny Lake 6,950 Qls N. Fork
6,600 26 RANGE Spread
6,900 Creek Cottonwood Creek 89 M Cr T T Ditch T. HOLE 43 6,650 Moose N. 43°40’ Phelps Lake 6,550 pC 6,450 6,500 EXPLANATION
6,400 Kelly Qa Quaternary unconsolidated deposits 6,600 6,650
6,350 N GROS Saturated Quaternary O VENTRE Qa Alluvium and colluvium T. S River unconsolidated deposits K RANGE Teton C Jackson Airport that compose the Snake 42 A Qt Terrace deposits Village J River alluvial aquifer N. 6,300 Qt (gravel, pediment, (areal extent of aquifer and fan deposits) Ventre P generally coincides with P potentiometric-surface
6,600 Qg Glacial deposits F contours) 6,250 Gros la 6,550 t C re ek Qls Landslide deposits k 6,500 e 6,200 e Qls r Sheep T. C QTv Quaternary and Tertiary intrusive and extrusive h s 41 Wilson i Butte volcanic rocks F N. 43°30’ 22 West Gros Ventre Qg Creek T Tertiary sedimentary rocks
East Gros Ventre Butte Jackson GROS VENTRE RANGE 6,250 M Mesozoic sedimentary rocks Creek 6,150 Cache Mosquito QT 6,100 v P Paleozoic sedimentary rocks g Creek
n
i Creek r
p T
ood S pC Precambrian igneous, metamorphic, metasedimen- T. nw tto tary, and metavolcanic rocks 40 o Creek 6,050 M C Snake 191 P N. Qa HOBACK RANGE Topographically isolated area with perched ground- 6,050 pC Qg 6,000 water that is not hydrologically connected to M River the Snake River alluvial aquifer 6,050 Potentiometric contour—Shows altitude of the water- Creek level surface July 12–21, 1993. Datum is National P 5,950 Horse Geodetic Vertical Datum of 1929. Dashed where Fall Qls approximately located. Contour interval 50 feet. T. 39 43°20’ Creek N. Hoback Junction 0 3 6 MILES SNAKE RIVER RANGE TETON COUNTY M LINCOLN COUNTY 191 T 0 3 6 KILOMETERS
R. 118 W. R. 117 W. R. 116 W. R. 115 W. R. 114 W. R. 113 W. R. 112 W. Base from U.S. Census Bureau, 2001; Public land survey system from Wyoming Water Resources Center, 1994 Geology from Stoeser and others, 2005 Albers Equal-Area Conic projection, standard parallels 41°N and 45°N, central meridian 110°30’W Figure 7–3. Areal extent and generalized potentiometric surface of the Snake River alluvial aquifer, Jackson Hole, Wyoming, July 12–21, 1993 (modified from Nolan and Miller, 1995, Plate 3).
7-124 in Grand Teton National Park, Nolan and Miller (1975, Sheet 1) noted that landslide deposits (1995) estimated that the depth of Quaternary (identified as "rock debris") in the Overthrust Belt unconsolidated deposits at nine locations within likely were not a potential source of water because the areal extent of the aquifer ranged from about of poor sediment sorting and small saturated 380 to 2,400 ft. Using audio-magnetotellurics thickness. Cox (1976, Sheet 1) noted that wells (a deep exploration electromagnetic method), completed in these deposits probably would not Nolan and others (1998) estimated depth of yield more than a few gallons per minute. Only one the base of the aquifer for the southern part of well completed in Quaternary landslide deposits the aquifer (area from about 4.5 miles north of was inventoried as part of this study, but springs Hoback Junction to less than 1 mile north of Teton commonly issue from the base of the Quaternary Village). Estimated depth of the base of the aquifer landslide deposits in the study area. for this area ranged from about 100 ft in the south, near the confluences of Spring Creek and Flat Hydrogeologic data describing the Quaternary Creek with the Snake River, to about 700 ft in the unconsolidated deposits in the Snake/Salt River west, near the town of Wilson, Wyoming; median Basin (alluvial aquifers, terrace-deposit aquifers, depth of the base of the aquifer was estimated to glacial-deposit aquifers, landslide deposits, and be about 200 ft. Much of the aquifer is underlain loess deposits), including spring-discharge and by Quaternary unconsolidated lacustrine well-yield measurements, and other hydraulic deposits and other finer grained, less permeable properties, are summarized on plate 3. Well lithostratigraphic units (Cox, 1976, pl. 3; Nolan yields and physical properties of Quaternary and Miller, 1995; Nolan and others, 1998). unconsolidated-deposit aquifers are highly variable (pl. 3), reflecting the variable size, sorting, and Quaternary loess deposits, also defined as eolian stratification of sediments comprising the deposits, deposits in some publications, consist of wind- as well as saturated thickness that changes in blown, light gray, unconsolidated silt (Love and response to different amounts of aquifer recharge Albee, 1972). Saturated, loess deposits typically and discharge (water withdrawal). In some areas yield very small volumes of groundwater because of the Snake/Salt River Basin, most notably in of predominantly fine grain size. In some parts alluvium and terrace deposits of the Jackson Hole of the Snake/Salt River Basin, Quaternary loess area (part of the Snake River alluvial aquifer), deposits are intermixed with Quaternary lithified well yields, specific capacities, and conductivities/ talus deposits. Quaternary lithified talus deposits transmissivities are high because of large saturated (breccias) are composed of angular Paleozoic rock thicknesses and coarse-grained deposits. fragments (primarily eroded from the Madison Limestone) cemented by a white limey cement Because the areal extent of Quaternary (Love and Albee, 1972). Locally, saturated loess unconsolidated-deposit aquifers coincides with and lithified talus deposits in the Snake/Salt River most of the population and irrigated cropland Basin may be sufficiently saturated and permeable in the Snake/Salt River Basin, these aquifers to yield water to wells, as several wells likely particularly are susceptible to effects from human completed in these deposits were inventoried as activities (Hamerlinck and Arneson, 1998). part of this study (pl. 3). Evidence of localized effects to groundwater quality in Quaternary unconsolidated-deposit aquifers Quaternary landslide deposits are composed by human activities in the Snake/Salt River Basin of masses of soil, sediment, and older bedrock has been indicated by detection of elevated nitrate that have moved downward under gravity and concentrations, as well as by low-level detections accumulated at the base of hillsides and steep of organic compounds such as pesticides (Eddy- slopes (Love and others, 1992; Love and Reed, Miller and others, 1996; Eddy-Miller and Norris, 2000; Love and Albee, 1972). Quaternary landslide 2000; Eddy-Miller and Remley, 2004; Sunrise deposits in the Snake/Salt River Basin (pls. 1 and Engineering, 2009; Eddy-Miller and others, 2) are saturated at some locations. Lines and Glass 2013a). Hedmark and Young (1999) documented
7-125 groundwater-quality degradation from disposal and Glass, 1975, Sheet 1). of wastewater into sewage lagoons overlying Quaternary unconsolidated-deposit aquifers Water levels in Quaternary unconsolidated deposit used to supply water for different uses in Grand aquifers in the Snake/Salt River Basin also can Teton National Park and the John D. Rockefeller be affected by water-surface elevations in nearby Memorial Parkway. Anti-icing/deicing compounds reservoirs. In the Alpine Junction area (includes were found in the Snake River alluvial aquifer near town of Alpine and adjacent unincorporated the Jackson Hole Airport (Wright, 2013). lands), groundwater-level fluctuations in the Quaternary unconsolidated deposits or Tertiary Recharge, discharge, and groundwater Salt Lake Formation in the area (difficult to movement differentiate these lithostratigraphic units in the subsurface in the vicinity of the town), or both Recharge to Quaternary unconsolidated-deposit have been correlated to changes in the water- aquifers primarily is from direct infiltration of surface elevation of nearby Palisades Reservoir precipitation (snowmelt and rain), snowmelt (Sunrise Engineering, 1995). runoff, lakes, and ephemeral and perennial streamflow losses (Walker, 1965; Lines and Glass, In irrigated areas, water levels in the Quaternary 1975, Sheet 1; Cox, 1976; Ahern and others, unconsolidated-deposit aquifers in the Snake/Salt 1981; Nelson Engineering, 1992; Wyoming River Basin may increase in response to recharge State Engineer’s Office, 1995, 2005; Hinckley from seasonal application of diverted surface water Consulting and Jorgensen Engineering, 1994; through flooding or sprinkler methods used to Wheeler and Eddy-Miller, 2005; Eddy-Miller irrigate crops (Walker, 1965; Lines and Glass, and others, 2009, 2013b; Wright, 2010, 2013). 1975, Sheet 1; Cox, 1976; Ahern and others, 1981; Infiltration of diverted surface water through Hinckley Consulting and Jorgensen Engineering, unlined irrigation canals and ditches, from 1994; Wyoming State Engineer’s Office, water applied to fields using flood and sprinkler 1995). Water levels in some wells completed in irrigation, and discharge from adjacent and Quaternary unconsolidated-deposit aquifers in underlying bedrock aquifers also provide recharge Star Valley may be highest (shallowest) during the in some areas (Walker, 1965; Lines and Glass, growing season when irrigation water recharges the 1975, Sheet 1; Ahern and others, 1981; Sando and aquifers, and water levels may be lowest (deepest) others, 1985; Hinckley Consulting and Jorgensen after irrigation has ceased during the winter when Engineering, 1994; Wyoming State Engineer’s water is discharged from the aquifers (Walker, Office, 1995, 2005). In areas coinciding with 1965). population, additional recharge may occur from localized lawn watering, septic leach fields, and Because of ongoing concerns about high (shallow) wastewater injection wells (Hinckley Consulting groundwater levels in the Snake River alluvial and Jorgensen Engineering, 1994). Most recharge aquifer east of Fish Creek and west of the Snake occurs in the spring as a result of infiltration and River (area known as the west bank of the Snake percolation of rainfall, snowmelt, and snowmelt River or Snake River west bank), the effects of runoff (Walker, 1965; Lines and Glass, 1975, Sheet potential recharge from residential ponds to the 1; Nelson Engineering, 1992; Hinckley Consulting aquifer was investigated by Hinckley Consulting and Jorgensen Engineering, 1994; Hedmark and and Jorgensen Engineering (1994). Residential Young, 1999; Wyoming State Engineer’s Office, ponds are constructed into unconsolidated 1995, 2005; Eddy-Miller and others, 2009, 2013b; deposits composing the Snake River alluvial Wright, 2010, 2013). Some of the recharge to aquifer in this area to "enhance aesthetics, provide Quaternary unconsolidated-deposit aquifers from seasonal fisheries, create wildlife habitat, and streams may occur as water infiltrates the heads of provide recreational use" (Hinckley Consulting alluvial fans along the margins of stream valleys in and Jorgensen Engineering, 1994, pl. 1). Study the Snake/Salt River Basin (Walker, 1965; Lines findings indicated that the ponds had little effect
7-126 on surrounding groundwater levels relative to the Potentiometric-surface contours on the maps substantially larger normal seasonal and annual constructed by Cox (1976, Sheet 3) and Nolan groundwater-level fluctuations measured in the and Miller (1995, Plate 3; reproduced herein as aquifer (Hinckley Consulting and Jorgensen figure 7-3) show the general direction of regional Engineering, 1994). groundwater flow; site-specific groundwater- flow directions could differ. Groundwater is Discharge from Quaternary unconsolidated-deposit assumed to flow in a direction perpendicular to aquifers occurs from withdrawals by pumped the potentiometric-surface contours, from areas of wells and naturally by evapotranspiration, gaining high hydraulic head to areas of low hydraulic head. streams, seeps, and spring flows (Walker, 1965; Groundwater-flow directions are not constant, Lines and Glass, 1975, Sheet 1; Cox, 1976; Ahern and flow direction can change during different and others, 1981; Nelson Engineering, 1992; times of the year. Potentiometric-surface maps by Hinckley Consulting and Jorgensen Engineering, Cox (1976, Sheet 3) and Nolan and Miller (1995, 1994; Wheeler and Eddy-Miller, 2005; Wyoming Plate 3, reproduced herein as figure 7-3) show that State Engineer’s Office, 2005; Eddy-Miller and groundwater in the Snake River alluvial aquifer others, 2009, 2013b). Evapotranspiration from generally moves from topographically high areas Quaternary unconsolidated-deposit aquifers is toward the Snake River and southwest through the likely to be highest in the summer and in areas valley in the direction of the river. where the water table is at or near the land surface, such as in alluvium near streams. Contours on potentiometric-surface maps in the immediate vicinity of streams can indicate gaining Groundwater flow in the Quaternary alluvial streams by pointing in an upstream direction aquifers generally is towards the center of the river (potentiometric surface above water in the stream) or stream valley or generally in a downstream or losing streams by pointing in a downstream direction paralleling the direction of the surface- direction (potentiometric surface below water in water flow in the river or streams, including the stream). General areas of streamflow loss to as underflow parallel to streamflow (Lines and and gain from the Snake River alluvial aquifer Glass, 1975, Sheet 1; Cox, 1976; Ahern and can be visually identified on the maps of Cox others, 1981; Nolan and Miller, 1995). In terrace- (1976, Sheet 3) and Nolan and Miller (1995, deposit aquifers, the direction of groundwater Plate 3; reproduced herein as figure 7-3). Because flow generally is similar to groundwater flow in the contours point in an upstream direction, the Quaternary alluvial aquifers and is toward the Snake River generally was gaining water from the principal surface drainage. aquifer throughout most of the valley at the time groundwater levels were measured to construct Several potentiometric-surface maps have been the maps (Cox, 1976, Sheet 3; Nolan and Miller, constructed showing the direction of horizontal 1995, Plate 3). Cox (1976, Sheets 2, 3) used the groundwater flow in the Snake River alluvial contour map, in combination with streamflow loss aquifer (composed of saturated Quaternary alluvial, and gain measurements for selected stream reaches, terrace, and glacial deposits along the Snake River to determine that the Snake River and Buffalo Fork and some of the valleys of tributaries to the Snake were gaining streams, Pilgrim and Cottonwood River; areal extent of aquifer shown in figure 7-3) Creeks were losing streams, and the Gros Ventre (Cox, 1976, Sheet 3; Nolan and Miller, 1995) or River was neither gaining nor losing. parts of the aquifer in the Snake River west bank area (Wyoming State Engineer’s Office, 2005). The Wyoming State Engineer’s Office (2005, The generalized potentiometric-surface map of the Figure 2) constructed a potentiometric-surface Snake River alluvial aquifer in the Jackson Hole map for part of the Snake River alluvial aquifer area constructed by Nolan and Miller (1995, Plate in the west bank of the Snake River. The map was 3) is reproduced herein as figure 7-3. constructed using water levels measured in June
7-127 1998, and shows that groundwater in the west 7.2.1.1 Quaternary alluvial aquifers bank area generally moves southwest from the Snake River towards Fish Creek. The chemical characteristics of groundwater from Quaternary alluvial aquifers in the Snake/Salt Wright (2011, 2013) examined groundwater levels River Basin are described in this section of the and seasonal groundwater-level fluctuations of the report. Groundwater quality of Quaternary alluvial Snake River alluvial aquifer at the Jackson Hole aquifers is described in terms of a water’s suitability Airport. Large groundwater-level fluctuations for domestic, irrigation, and livestock use, on the associated with infiltration and percolation basis of USEPA and WDEQ standards (table 5-2), of spring precipitation and snowmelt were and groundwater-quality sample summary statistics documented in both studies. Potentiometric- tabulated by hydrogeologic unit as quantile values surface maps of the Snake River alluvial aquifer (appendices E–1 to E–6). were constructed for the airport area as part of both studies. Yellowstone Volcanic Area The chemical composition of Quaternary alluvial Groundwater-flow model aquifers in the Yellowstone Volcanic Area (YVA) was characterized and the quality evaluated on the A groundwater-flow model of the Snake River basis of environmental water samples from as many alluvial aquifer from Jackson Lake southward to as four wells. Summary statistics calculated for the Snake River Canyon of the Snake River was available constituents are listed in appendix E–1, constructed by San Juan and Kolm (1996). The and major-ion composition in relation to TDS unconfined aquifer was modeled using two layers, is shown on a trilinear diagram (appendix F–1, and was constructed using the then-current version diagram A). TDS concentrations indicated that all of the finite-difference groundwater-flow model waters were fresh (TDS concentrations less than MODFLOW (McDonald and Harbaugh, 1988). or equal to 999 mg/L) (appendix E–1; appendix The investigators used the groundwater-flow model F–1, diagram A). TDS concentrations ranged from to improve conceptualization and characterization 131 to 248 mg/L, with a median of 147 mg/L. of the aquifer with particular emphasis on using then-current geographic information system data Concentrations of some properties and constituents management and analysis tools. Much of the in water from Quaternary alluvial aquifers in the hydrologic data used to construct the model was YVA approached or exceeded applicable USEPA from Cox (1976). The model was constructed to or State of Wyoming water-quality standards simulate two-dimensional steady-state conditions, and could limit suitability for some uses. Most and the investigators concluded that refinement of environmental waters were suitable for domestic both the conceptual and numerical models would use, but concentrations of one constituent be necessary to evaluate potential groundwater- exceeded health-based standards: arsenic (both management scenarios. samples exceeded the USEPA MCL of 10 µg/L). Concentrations of several properties and Chemical characteristics constituents exceeded aesthetic standards (USEPA SMCLs) for domestic use: fluoride (all 4 samples The chemical characteristics of saturated exceeded the SMCL of 2 mg/L) and aluminum (1 Quaternary unconsolidated deposits in the Snake/ of 2 samples exceeded the lower SMCL limit of Salt River Basin (Quaternary alluvial aquifers, 50 µg/L and the upper SMCL limit of 200 µg/L). terrace-deposit aquifers, glacial-deposit aquifers, No characteristics or constituents approached or landslide deposits, and loess and lithified talus exceeded applicable State of Wyoming agriculture deposits) are described in this section of the or livestock water-quality standards. report.
7-128 Northern Ranges or livestock water-quality standards in the spring The chemical composition of Quaternary alluvial samples. aquifers in the Northern Ranges (NR) was characterized and the quality evaluated on the basis Concentrations of some properties and of environmental water samples from as many constituents in water from wells completed in as five wells and one spring. Summary statistics alluvial aquifers in JH approached or exceeded calculated for available constituents are listed in applicable USEPA or State of Wyoming water- appendix E–2, and major-ion composition in quality standards and could limit suitability for relation to TDS is shown on a trilinear diagram some uses. Most environmental waters from wells (appendix F–2, diagram A). TDS concentrations were suitable for domestic use, but concentrations indicated that all waters were fresh (TDS of two constituents exceeded USEPA health-based concentrations less than or equal to 999 mg/L) standards: radon (all 11 samples exceeded the (appendix E–2; Appendix F–2, diagram A). TDS proposed MCL of 300 pCi/L, but none exceeded concentrations for the wells ranged from 160 to the AMCL of 4,000 pCi/L), and uranium (1 267 mg/L, with a median of 233 mg/L. The TDS of 2 samples exceeded the MCL of 30 mg/L). concentration for the spring was 159 mg/L. On Concentrations of several characteristics and the basis of the characteristics and constituents constituents exceeded aesthetic standards for analyzed for, the quality of water from Quaternary domestic use: aluminum (1 of 13 samples exceeded alluvial aquifers in the NR was suitable for most the lower SMCL limit of 50 µg/L and the upper uses. No characteristics or constituents approached SMCL limit of 200 µg/L), iron (3 of 44 samples or exceeded applicable USEPA or State of exceeded the SMCL of 300 µg/L), manganese (2 Wyoming domestic, agriculture, or livestock water- of 31 samples exceeded the SMCL of 50 µg/L), quality standards. TDS (2 of 71 samples exceeded the SMCL of 500 mg/L), fluoride (1 of 71 samples exceeded Jackson Hole the SMCL of 2 mg/L), sulfate (1 of 72 samples The chemical composition of Quaternary alluvial exceeded the SMCL of 250 mg/L), and pH (1 of aquifers in Jackson Hole (JH) was characterized 97 samples above upper SMCL limit of 8.5). and the quality evaluated on the basis of environmental water samples from as many as Concentrations of some characteristics and two springs and 117 wells. Summary statistics constituents in water from wells completed in calculated for available constituents are listed in alluvial aquifers in JH exceeded State of Wyoming appendix E–3. Major-ion composition in relation standards for agricultural and livestock use. One to TDS for water samples collected from wells characteristic and one constituent in environmental is shown on a trilinear diagram (appendix F–3, water samples from wells were measured at diagram A). TDS concentrations were variable concentrations greater than agricultural-use and indicated that all waters were fresh (TDS standards: sulfate (2 of 72 samples exceeded the concentrations less than or equal to 999 mg/L) WDEQ Class II standard of 200 mg/L) and SAR (appendix E–3; appendix F–3, diagram A). The (1 of 68 samples exceeded the WDEQ Class TDS concentration for one spring was 470 mg/L. II standard of 8). One characteristic (pH) was TDS concentrations for the wells ranged from 52.0 measured outside the range for livestock use (1 of to 628 mg/L, with a median of 250 mg/L. 97 samples above upper WDEQ Class III limit of 8.5). On the basis of the characteristics and constituents analyzed for, the quality of water from springs Green River and Hoback Basins issuing from Quaternary alluvial aquifers in JH The chemical composition of Quaternary alluvial was suitable for most uses. No characteristics or aquifers in the Green River and Hoback Basins constituents approached or exceeded applicable (GH) was characterized and the quality evaluated USEPA or State of Wyoming domestic, agriculture, on the basis of environmental water samples from
7-129 one spring and as many as eight wells. Summary Star Valley statistics calculated for available constituents are The chemical composition of Quaternary alluvial listed in appendix E–4. Major-ion composition in aquifers in Star Valley (SV) was characterized and relation to TDS for water samples collected from the quality evaluated on the basis of environmental wells is shown on a trilinear diagram (appendix water samples from as many as 83 wells. Summary F–4, diagram A). TDS concentrations indicated statistics calculated for available constituents that all waters were fresh (TDS concentrations are listed in appendix E–6, and major-ion less than or equal to 999 mg/L) (appendix composition in relation to TDS is shown on a E–4; appendix F–4, diagram A). The TDS trilinear diagram (appendix F–6, diagram A). concentration for the spring was 250 mg/L. TDS TDS concentrations indicated that all waters concentrations for the wells ranged from 285 were fresh (TDS concentrations less than or equal to 445 mg/L, with a median of 356 mg/L. On to 999 mg/L) (appendix E–6; appendix F–6, the basis of the characteristics and constituents diagram A). TDS concentrations for the wells analyzed for, the quality of water from Quaternary ranged from 198 to 589 mg/L, with a median of alluvial aquifers in the GH was suitable for most 262 mg/L. uses. Most environmental waters were suitable for domestic use, but concentrations of one constituent Concentrations of some properties and constituents (radon) exceeded health-based standards (the 1 in water from wells completed in alluvial aquifers sample analyzed for this constituent exceeded the in SV approached or exceeded applicable USEPA proposed MCL of 300 pCi/L, but did not exceed or State of Wyoming water-quality standards the AMCL of 4,000 pCi/L) No State of Wyoming and could limit suitability for some uses. Most domestic, agriculture, or livestock water-quality environmental waters were suitable for domestic standards were exceeded. use, but concentrations of some constituents exceeded health-based standards: radon (all 6 Overthrust Belt samples exceeded the proposed USEPA MCL of The chemical composition of Quaternary alluvial 300 pCi/L, but none exceeded the AMCL of 4,000 aquifers in the Overthrust Belt (OTB) was pCi/L), nitrate (3 of 38 samples exceeded the characterized and the quality evaluated on the USEPA MCL of 10 mg/L), and nitrate plus nitrite basis of environmental water samples from as (3 of 51 samples exceeded the USEPA MCL of 10 many as eight wells. Summary statistics calculated mg/L. Concentrations of one constituent and one for available constituents are listed in appendix characteristic exceeded USEPA aesthetic standards E–5, and major-ion composition in relation to for domestic use: iron (1 of 14 samples exceeded TDS is shown on a trilinear diagram (appendix the SMCL of 300 µg/L) and TDS (1 of 47 samples F–5, diagram A). TDS concentrations indicated exceeded the SMCL of 500 mg/L). that all waters were fresh (TDS concentrations less than or equal to 999 mg/L) (appendix E–5; Concentrations of some properties and appendix F–5, diagram A). TDS concentrations constituents in water from wells completed in for the wells ranged from 230 to 333 mg/L, with a alluvial aquifers in SV exceeded State of Wyoming median of 311 mg/L. Most environmental waters standards for agricultural and livestock use. One were suitable for domestic use, but concentrations constituent in environmental water samples that of one constituent (radon) exceeded health- had concentrations greater than agricultural-use based standards (the 1 sample analyzed for this standards was chloride (2 of 46 samples exceeded constituent exceeded the proposed MCL of the WDEQ Class II standard of 100 mg/L). No 300 pCi/L, but did not exceed the AMCL of characteristics or constituents had concentrations 4,000 pCi/L) No State of Wyoming domestic, that approached or exceeded applicable State of agriculture, or livestock water-quality standards Wyoming livestock water-quality standards. were exceeded.
7-130 7.2.1.2 Quaternary terrace-deposit concentrations less than or equal to 999 mg/L) aquifers (appendix E–2).
The chemical characteristics of groundwater from On the basis of the characteristics and constituents Quaternary terrace-deposit aquifers in the Snake/ analyzed for, the quality of water from one Salt River Basin are described in this section of the spring issuing from Quaternary terrace-deposit report. Groundwater quality of Quaternary terrace- aquifers in the NR was suitable for most uses. No deposit aquifers is described in terms of a water’s characteristics or constituents measured in the suitability for domestic, irrigation, and livestock spring sample approached or exceeded applicable use, on the basis of USEPA and WDEQ standards USEPA or State of Wyoming domestic, agriculture, (table 5-2), and groundwater-quality sample or livestock water-quality standards. summary statistics tabulated by hydrogeologic unit as quantile values (appendices E–1, E–2, E–3, Concentrations of some characteristics and E–5, and E–6). constituents in water from wells completed in the Quaternary terrace-deposit aquifers in the NR Yellowstone Volcanic Area approached or exceeded applicable USEPA or State The chemical composition of Quaternary terrace- of Wyoming water-quality standards and could deposit aquifers in the Yellowstone Volcanic Area limit suitability for some uses. Most environmental (YVA) was characterized and the quality evaluated waters were suitable for domestic use, but on the basis of environmental water samples from concentrations of one constituent in one of the well as many as three wells. Individual constituent samples exceeded USEPA health-based standards: concentrations for available constituents are listed fluoride (MCL of 4 mg/L). Concentrations of one in appendix E–1, and major-ion composition in characteristic and one constituent exceeded USEPA relation to TDS is shown on a trilinear diagram aesthetic standards for domestic use in one of two (appendix F–1, diagram B). TDS concentrations well samples: TDS (SMCL of 500 mg/L) and indicated that all waters were fresh (TDS fluoride (SMCL of 2 mg/L). concentrations less than or equal to 999 mg/L) (appendix E–1; appendix F–1, diagram B). TDS Concentrations of some characteristics and concentrations ranged from 143 to 198 milligrams constituents in water from wells completed in per liter (mg/L), with a median of 192 mg/L. On the Quaternary terrace-deposit aquifers exceeded the basis of the characteristics and constituents State of Wyoming standards for agricultural and analyzed for, the quality of water from Quaternary livestock use in the NR. One characteristic and terrace-deposit aquifers in the YVA was suitable one constituent in environmental water samples for most uses. No characteristics or constituents from one of the wells had concentrations greater approached or exceeded applicable USEPA or State than agricultural-use standards: SAR (WDEQ of Wyoming domestic, agriculture, or livestock Class II standard of 8) and chloride (WDEQ Class water-quality standards. II standard of 100 mg/L). No characteristics or constituents had concentrations that approached Northern Ranges or exceeded applicable State of Wyoming livestock The chemical composition of groundwater water-quality standards. in Quaternary terrace-deposit aquifers in the Northern Ranges (NR) was characterized and the Jackson Hole quality evaluated on the basis of environmental The chemical composition of Quaternary terrace- water samples from one spring and two wells. deposit aquifers in Jackson Hole (JH) was Individual constituent concentrations for available characterized and the quality evaluated on the constituents are listed in appendix E–2. TDS basis of environmental water samples from one concentrations measured in water from the spring and as many as 22 wells. Summary statistics spring (172 mg/L) and both wells (173 and 601 calculated for available constituents are listed in mg/L) indicate that the water is fresh (TDS appendix E–3, and major-ion composition in
7-131 relation to TDS is shown on a trilinear diagram for the WDEQ Class II standard of 8). The value of the well samples (appendix F–3, diagram B). TDS one characteristic (pH) was outside the range for concentrations indicated that all waters were fresh livestock-use standards (1 of 22 samples above (TDS concentrations less than or equal to 999 upper WDEQ Class III limit of 8.5). mg/L) (appendix E–3; appendix F–3, diagram B). The TDS concentration for the spring was 173 Overthrust Belt mg/L.TDS concentrations for the wells ranged The chemical composition of Quaternary terrace- from 58.0 to 267 mg/L, with a median of 178 deposit aquifers in the Overthrust Belt (OTB) mg/L. was characterized and the quality evaluated on the basis of one environmental water sample from one On the basis of the characteristics and constituents spring. Individual constituent concentrations are analyzed for, the quality of water from the one listed in appendix E–5. The TDS concentration spring issuing from Quaternary terrace-deposit from the spring (231 mg/L) indicated that the aquifers in JH was suitable for most uses. No water was fresh (TDS concentration less than characteristics or constituents approached or or equal to 999 mg/L). No characteristics or exceeded applicable USEPA or State of Wyoming constituents approached or exceeded applicable domestic, agriculture, or livestock water-quality USEPA or State of Wyoming domestic, agriculture, standards. or livestock water-quality standards, indicating the water was suitable for most uses. Concentrations of some properties and constituents in water from wells completed in Quaternary Star Valley terrace-deposit aquifers in JH approached or The chemical composition of Quaternary exceeded applicable USEPA or State of Wyoming terrace-deposit aquifers in Star Valley (SV) was water-quality standards and could limit suitability characterized and the quality evaluated on the basis for some uses. Most environmental waters were of environmental water samples from as many as suitable for domestic use, but concentrations two wells. Individual constituent concentrations are of one constituent (radon) exceeded health- listed in appendix E–6. The TDS concentration based standards (the 1 sample analyzed for this from one well sample (206 mg/L) indicated that constituent exceeded the proposed MCL of 300 the water was fresh (TDS concentrations less pCi/L, but did not exceed the AMCL of 4,000 than or equal to 999 mg/L). On the basis of the pCi/L). Concentrations of two constituents and characteristics and constituents analyzed for, the one characteristic exceeded USEPA aesthetic quality of water from Quaternary terrace-deposit standards for domestic use: manganese (6 of 13 aquifers in the SV was suitable for most uses. samples exceeded the SMCL of 50 µg/L), iron (3 of No characteristics or constituents approached or 16 samples exceeded the SMCL of 300 µg/L), and exceeded applicable USEPA or State of Wyoming pH (one of 22 samples above upper SMCL limit of domestic, agriculture, or livestock water-quality 8.5). standards.
Concentrations of some characteristics and 7.2.1.3 Quaternary glacial-deposit constituents in water from wells completed in aquifers Quaternary terrace-deposit aquifers exceeded State of Wyoming standards for agricultural The chemical characteristics of groundwater from and livestock use in JH. The characteristic and Quaternary glacial-deposit aquifers in the Snake/ constituent in environmental water samples Salt River Basin are described in this section of from wells that had concentrations greater than the report. Groundwater quality of glacial-deposit agricultural-use standards were manganese (5 of aquifers is described in terms of a water’s suitability 13 samples exceeded the WDEQ Class II standard for domestic, irrigation, and livestock use, on the of 200 µg/L) and SAR (1 of 20 samples exceeded basis of USEPA and WDEQ standards (table 5-2),
7-132 and groundwater-quality sample summary statistics Jackson Hole tabulated as quantile values (appendices E–1 to The chemical composition of Quaternary glacial- E–5). deposit aquifers in Jackson Hole (JH) was characterized and the quality evaluated on the Yellowstone Volcanic Area basis of environmental water samples from as The chemical composition of aquifers in many as 4 springs and 37 wells. Summary statistics Quaternary glacial-deposit aquifers in the calculated for available constituents are listed in Yellowstone Volcanic Area (YVA) was characterized appendix E–3, and major-ion composition in and the quality evaluated on the basis of one relation to TDS is shown on a trilinear diagram environmental water sample from one well. (appendix F–3, diagrams C and D). TDS Individual constituent concentrations for available concentrations indicated that all waters were fresh constituents are listed in appendix E–1. The (TDS concentrations less than or equal to 999 TDS concentration (91.0 mg/L) for the well mg/L) (appendix E–3; appendix F–3, diagrams sample indicated that the water was fresh (TDS C and D). The TDS concentrations for the springs concentration less than or equal to 999 mg/L) ranged from 78.0 to 312 mg/L, with a median (appendix E–1). On the basis of the characteristics of 232 mg/L. TDS concentrations for the wells and constituents analyzed for, the quality of water ranged from 18.0 to 378 mg/L, with a median of from Quaternary glacial-deposit aquifers in the 176 mg/L. YVA was suitable for most uses. No characteristics or constituents approached or exceeded applicable On the basis of the characteristics and constituents USEPA or State of Wyoming domestic, agriculture, analyzed for, the quality of water from springs or livestock water-quality standards. issuing from Quaternary glacial-deposit aquifers in JH was suitable for most uses. No characteristics Northern Ranges or constituents approached or exceeded applicable The chemical composition of groundwater in USEPA or State of Wyoming domestic, agriculture, Quaternary glacial-deposit aquifers in the Northern or livestock water-quality standards. Ranges (NR) was characterized and the quality evaluated on the basis of environmental water Concentrations of some properties and constituents samples from as many as two springs and six wells. in water from wells completed in the Quaternary Individual constituent concentrations for available glacial-deposit aquifers in JH approached or constituents are listed in appendix E–2. Major- exceeded applicable USEPA or State of Wyoming ion composition in relation to TDS for wells is water-quality standards and could limit suitability shown on a trilinear diagram (appendix F–2, for some uses. Most environmental waters were diagram B). TDS concentrations indicated that all suitable for domestic use, but concentrations of waters were fresh (TDS concentrations less than one constituent exceeded health-based standards: or equal to 999 mg/L) (appendix E–2; appendix radon (one of two samples exceeded the proposed F–2, diagram B). The TDS concentrations USEPA MCL of 300 pCi/L and the AMCL of for the springs were 173 and 219 mg/L. TDS 4,000 pCi/L). Concentrations of two constituents concentrations for the wells ranged from 162 and one characteristic exceeded USEPA aesthetic to 228 mg/L, with a median of 178 mg/L. On standards for domestic use: manganese (2 of 7 the basis of the characteristics and constituents samples exceeded the SMCL of 50 µg/L), iron (2 analyzed for, the quality of water from Quaternary of 16 samples exceeded the SMCL of 300 µg/L), glacial-deposit aquifers in the NR was suitable and pH (2 of 37 samples below lower SMCL limit for most uses. No characteristics or constituents of 6.5). approached or exceeded applicable USEPA or State of Wyoming domestic, agriculture, or livestock Concentrations of some characteristics and water-quality standards. constituents in water from wells in Quaternary glacial-deposit aquifers exceeded State of Wyoming
7-133 standards for agricultural and livestock use in domestic, agriculture, or livestock water-quality JH. One constituent (manganese) was measured standards. in environmental water samples from wells at concentrations greater than agricultural-use 7.2.1.4 Quaternary landslide deposits standards (1 of 7 samples exceeded the WDEQ Class II standard of 200 µg/L). One characteristic The chemical characteristics of groundwater from (pH) was measured at values outside the range Quaternary landslide deposits in the Snake/Salt for livestock-use standards (2 of 37 samples below River Basin are described in this section of the lower WDEQ Class III limit of 6.5). report. Groundwater quality is described in terms of a water’s suitability for domestic, irrigation, Green River and Hoback Basins and livestock use, on the basis of USEPA and The chemical composition of Quaternary glacial- WDEQ standards (table 5-2), and groundwater- deposit aquifers in the Green River and Hoback quality sample summary statistics tabulated by Basins (GH) was characterized and the quality hydrogeologic unit as quantile values (appendices evaluated on the basis of environmental water E–2 to E–5). samples from three springs. Individual constituent concentrations are listed in appendix E–4, and Northern Ranges major-ion composition in relation to TDS is shown The chemical composition of groundwater in on a trilinear diagram (appendix F–4, diagram Quaternary landslide deposits in the Northern B). TDS concentrations indicated that all waters Ranges (NR) was characterized and the quality were fresh (TDS concentrations less than or equal evaluated on the basis of environmental water to 999 mg/L) (appendix E–4; appendix F–4, samples from three springs and one well. diagram B). TDS concentrations for the springs Individual constituent concentrations for available ranged from 205 to 228 mg/L, with a median of constituents are listed in appendix E–2, and 224 mg/L. On the basis of the characteristics and major-ion composition in relation to TDS is constituents analyzed for, the quality of water from shown on a trilinear diagram for the spring samples springs issuing from Quaternary glacial-deposit (appendix F–2, diagram C). TDS concentrations aquifers in the GH was suitable for most uses. indicated that all waters were fresh (TDS No characteristics or constituents approached or concentrations less than or equal to 999 mg/L) exceeded applicable USEPA or State of Wyoming (appendix E–2; appendix F–2, diagram C). TDS domestic, agriculture, or livestock water-quality concentrations for the three springs ranged from standards. 79.8 to 276 mg/L, with a median of 127 mg/L. The TDS concentration for the well sample was Overthrust Belt 495 mg/L. The chemical composition of Quaternary glacial- deposit aquifers in the Overthrust Belt (OTB) was On the basis of the characteristics and constituents characterized and the quality evaluated on the basis analyzed for, the quality of water from springs of environmental water samples from as many as issuing from Quaternary landslide deposits in the three springs. Individual constituent concentrations NR was suitable for most uses. No characteristics are listed in appendix E–5. TDS concentrations or constituents in the spring samples approached or from two springs (149 and 215 mg/L) indicated exceeded applicable USEPA or State of Wyoming that all waters were fresh (TDS concentrations domestic, agriculture, or livestock water-quality less than or equal to 999 mg/L) (appendix standards. E–5). On the basis of the characteristics and constituents analyzed for, the quality of water from Concentrations of some characteristics and springs issuing from Quaternary glacial-deposit constituents in water from Quaternary landslide aquifers in the OTB was suitable for most uses. deposits in the well sample in the NR approached No characteristics or constituents approached or or exceeded applicable USEPA or State of exceeded applicable USEPA or State of Wyoming Wyoming water-quality standards and could limit
7-134 suitability for some uses. All environmental waters ranged from 93.0 to 179 mg/L, with a median were suitable for domestic use, as no concentrations of 139 mg/L. On the basis of the characteristics of constituents exceeded health-based standards. and constituents analyzed for, the quality of water One characteristic (pH) exceeded the aesthetic from springs issuing from Quaternary landslide standard for domestic use in the one well sample deposits in the GH was suitable for most uses. (pH above upper USEPA SMCL limit of 8.5). No characteristics or constituents approached or exceeded applicable USEPA or State of Wyoming Concentrations of some characteristics and domestic, agriculture, or livestock water-quality constituents in water from the well completed in standards. Quaternary landslide deposits exceeded State of Wyoming standards for agricultural and livestock Overthrust Belt use in the NR. One characteristic (SAR) was The chemical composition of Quaternary landslide measured in the well sample at a concentration deposits in the Overthrust Belt (OTB) was greater than the agricultural-use standard (WDEQ characterized and the quality evaluated on the Class II standard of 8). One characteristic (pH) was basis of one environmental water sample from one measured at values greater than the upper livestock- spring. Individual constituent concentrations are use standard (above upper WDEQ Class III limit listed in appendix E–5. The TDS concentration of 8.5). from the spring (234 mg/L) indicated that the water was fresh (TDS concentration less than Jackson Hole or equal to 999 mg/L). On the basis of the The chemical composition of Quaternary landslide characteristics and constituents analyzed for, deposits in Jackson Hole (JH) was characterized the quality of water from the one spring issuing and the quality evaluated on the basis of an from Quaternary landslide deposits in the OTB environmental water sample from one spring. was suitable for most uses. No characteristics or Individual constituent concentrations are listed in constituents approached or exceeded applicable appendix E–3. The TDS concentration from the USEPA or State of Wyoming domestic, agriculture, spring (179 mg/L) indicated that the water was or livestock water-quality standards. fresh (TDS concentration less than or equal to 999 mg/L). On the basis of the characteristics and 7.2.1.5 Quaternary loess and lithified constituents analyzed for, the quality of water from talus deposits Quaternary landslide deposits in JH was suitable for most uses. No characteristics or constituents The chemical characteristics of groundwater approached or exceeded applicable USEPA or State from Quaternary loess and lithified talus deposits of Wyoming domestic, agriculture, or livestock in the Snake/Salt River Basin are described in water-quality standards. this section of the report. Groundwater quality of Quaternary loess and lithified talus deposits Green River and Hoback Basins is described in terms of a water’s suitability for The chemical composition of Quaternary landslide domestic, irrigation, and livestock use, on the basis deposits in the Green River and Hoback Basins of USEPA and WDEQ standards (table 5-2), and (GH) was characterized and the quality evaluated groundwater-quality sample summary statistics on the basis of environmental water samples from tabulated by hydrogeologic unit as quantile values three springs. Individual constituent concentrations (appendix E–3). are listed in appendix E–4, and major-ion composition in relation to TDS is shown on a Jackson Hole trilinear diagram (appendix F–4, diagram C). The chemical composition of Quaternary loess TDS concentrations indicated that all waters and lithified talus deposits in Jackson Hole (JH) were fresh (TDS concentrations less than or equal was characterized and the quality evaluated on the to 999 mg/L) (appendix E–4; appendix F–4, basis of environmental water samples from as many diagram C). TDS concentrations for the springs as four wells. Summary statistics calculated for
7-135 available constituents are listed in appendix E–3, Formation shown on plate 6). Quaternary and and major-ion composition in relation to TDS Tertiary volcanic rocks are essentially undeveloped is shown on a trilinear diagram (appendix F–3, in the Snake/Salt River Basin because they occur diagram E). TDS concentrations indicated that all primarily in sparsely populated areas with no major waters were fresh (TDS concentrations less than population centers. Much of the areal extent of or equal to 999 mg/L) (appendix E–3; appendix these rocks is within the boundary of Yellowstone F–3, diagram E). TDS concentrations for the wells National Park (pls. 1 and 2). Most investigations ranged from 130 to 469 mg/L, with a median of related to Quaternary and Tertiary volcanic rocks 165 mg/L. have been of thermal waters and related features in Yellowstone National Park (Gooch and Whitfield, On the basis of the characteristics and constituents 1888; Weed, 1889; Schlundt and Moore, 1909; analyzed for, the quality of water from wells Stearns and others, 1937; Fix, 1949; Morey and completed in Quaternary loess and lithified talus others, 1961; Marler, 1964; Rowe and others, deposits in JH was suitable for most uses. No 1965, 1973; Fournier and Rowe, 1966; Fournier characteristics or constituents approached or and Truesdell, 1970; Fournier and Morgenstern, exceeded applicable USEPA or State of Wyoming 1971; Marler and White, 1975; Thompson and domestic, agriculture, or livestock water-quality others, 1975; Truesdell and Fournier, 1976a,b; standards. Truesdell and others, 1977, 1978; Bargar, 1978; Pearson and Truesdell, 1978; Stauffer and 7.2.2 Leidy Formation Thompson, 1978, 1984; Thompson and Yadav, 1979; Stauffer and others, 1980; Thompson and The Quaternary-age Leidy Formation (pl. 5) Hutchinson, 1981; Friedman and Norton, 1982, consists of very fine-grained, chocolate-brown, 1990; Truesdell and Thompson, 1982; White and pink, and gray clay, laminated in part, interbedded others, 1988; White, 1991; Rye and Truesdell, with gray sand; lenticular quartzite pebble gravels; 1993, 2007; Fournier and others, 1994; Ball, and basal quartzite boulder conglomerate in Nordstrom, Cunningham, and others, 1998; some places (Love and others, 1992). The Leidy Ball, Nordstrom, Jenne, and others, 1998; Ball Formation intertongues laterally with glacial drift and others, 2001, 2002; Gemery-Hill and others, and outwash deposits, and reported thickness 2007). ranges from 0 to 450 ft (Love and others, 1992). No data were located describing the physical and Information describing the physical and chemical chemical hydrogeologic characteristics of the characteristics of Quaternary and Tertiary volcanic lithostratigraphic unit. rocks is sparse because few wells have been completed into the deposits. Hydrogeologic data 7.2.3 Quaternary and Tertiary volcanic describing Quaternary and Tertiary volcanic rocks rocks in the Snake/Salt River Basin, including spring- discharge measurements and other hydraulic Quaternary and Tertiary volcanic rocks are properties, are summarized on plate 3. Much of composed of intrusive igneous rocks, extrusive the information describing the characteristics of igneous rocks (primarily basalt and rhyolite), and Quaternary and Tertiary volcanic rocks is from beds of tuff and volcanic ash classified as many springs (commonly hot springs) issuing from the different lithostratigraphic units (pls. 4, 5, and deposits (pl .3; appendices E and F). 6). Lithostratigraphic units composed either partially or entirely of tuff and volcanic ash in Previous investigators have speculated that aquifer the Absaroka Volcanic Supergroup also could potential is poor (Wyoming Water Planning be classified as sedimentary rocks composed of Program, 1972, Table III-2) or marginal (WWC volcaniclastic sediments, but they are grouped Engineering and others, 2007, Figure 4-9). Other herein with the Quaternary and Tertiary volcanic investigators have noted aquifer development rocks for convenience (for example, Wiggins potential is limited to localized areas with favorable
7-136 hydrogeologic characteristics, and widespread (appendix E–1). development was unlikely because the rocks occur mostly within the boundaries of Yellowstone Yellowstone Volcanic Area National Park and areas that are geographically The chemical composition of aquifers in inaccessible and located away from any substantial Quaternary basalt flows in the Yellowstone population (Cox, 1976, Sheet 1; Whitehead, Volcanic Area (YVA) was characterized and the 1996; Bartos and others, 2012). Cox (1976, Sheet quality evaluated on the basis of one environmental 1) speculated on the potential well yield of the water sample from one well. Individual constituent various Quaternary and Tertiary volcanic rocks concentrations for available constituents are and noted that the Yellowstone Group may yield listed in appendix E–1. The TDS concentration a few tens of gallons per minute per well from (69.0 mg/L) from the well indicated that the porous and fracture zones” (rhyolitic ash, welded water was fresh (concentration less than or equal tuff, lava flows, breccia, and volcanic glass) or to 999 mg/L) (appendix E–1). On the basis “may yield a few tens of gallons per minute per of the characteristics and constituents analyzed well from brecciated zones and fractures” (basalt for, the quality of water from Quaternary basalt lava flows). The investigator (Cox, 1976, Sheet flows in the YVA was suitable for most uses. No 1) also speculated that the Absaroka Volcanic characteristics or constituents approached or Supergroup, composed of andesitic, basaltic, and exceeded applicable USEPA or State of Wyoming dacitic volcaniclastic rocks, “probably would not domestic, agriculture, or livestock water-quality yield more than a few gallons per minute per standards. well.” Large springs issuing from Quaternary and Tertiary volcanic rocks in some areas indicate 7.2.3.2 Quaternary rhyolite flows that permeability locally can be high, but is likely extremely variable because of widely varying rock The chemical characteristics of groundwater from types (Whitehead, 1996). In most areas, yields Quaternary rhyolite flows in the Snake/Salt River of wells completed in Quaternary and Tertiary Basin are described in this section of the report. volcanic rocks likely would only be adequate for Groundwater quality of Quaternary rhyolite flows domestic use (Whitehead, 1996). is described in terms of a water’s suitability for domestic, irrigation, and livestock use, on the basis Chemical characteristics of USEPA and WDEQ standards (table 5-2), and groundwater-quality sample summary statistics The chemical characteristics of saturated tabulated by hydrogeologic unit as quantile values Quaternary and Tertiary volcanic rocks in the (appendix E–1). Snake/Salt River Basin (Quaternary basalt flows, Quaternary rhyolite flows, Yellowstone Group, and Yellowstone Volcanic Area Tertiary volcanic rocks) are described in this section The chemical composition of Quaternary rhyolite of the report. flows in the YVA was characterized and the quality evaluated on the basis of environmental water 7.2.3.1 Quaternary basalt flows samples from as many as 75 hot springs. Summary statistics calculated for available constituents are The chemical characteristics of groundwater from listed in appendix E–1. Major-ion composition Quaternary basalt flows in the Snake/Salt River in relation to TDS is shown on a trilinear diagram Basin are described in this section of the report. (appendix F–1, diagram C). TDS concentrations Groundwater quality of Quaternary basalt flows indicated that waters from one-half the hot springs is described in terms of a water’s suitability for were fresh (TDS concentrations less than or equal domestic, irrigation, and livestock use, on the basis to 999 mg/L), and waters from the remaining of USEPA and WDEQ standards (table 5-2), and one-half of the hot springs were slightly saline groundwater-quality sample summary statistics (1,000 to 2,999 mg/L) (appendix E–1; appendix tabulated by hydrogeologic unit as quantile values F–1, diagram C). TDS concentrations for the hot
7-137 springs ranged from 298 to 1,470 mg/L, with a samples above upper WDEQ Class II limit of 9). median of 1,000 mg/L. One characteristic and one constituent had values outside the range for livestock-use standards: pH Concentrations of some properties and constituents (9 of 73 samples below lower WDEQ Class III in water from rhyolite flows in the YVA hot limit of 6.5 and 8 of 73 samples above upper limit springs approached or exceeded applicable USEPA of 8.5) and boron (1 of 75 samples exceeded the or State of Wyoming water-quality standards WDEQ Class III standard of 5,000 µg/L). and could limit suitability for some uses. Most environmental waters were suitable for domestic The chemical composition of Quaternary rhyolite use, but concentrations of four constituents flows in the Yellowstone Volcanic Area (YVA) also exceeded health-based standards: arsenic (the one was characterized and the quality evaluated on sample analyzed for this constituent exceeded the basis of environmental water samples from the USEPA MCL of 10 µg/L), mercury (the one as many as two springs. Individual constituent sample analyzed for this constituent exceeded concentrations are listed in appendix E–1. TDS the MCL of 2 µg/L), fluoride (74 of 75 samples concentrations (26.0 and 54.0 mg/L) indicated exceeded the USEPA MCL of 4 mg/L), and boron that both waters were fresh (TDS concentrations (1 of 75 samples exceeded the USEPA LHA of less than or equal to 999 mg/L) (appendix E–1). 6,000 µg/L). Concentrations of four constituents On the basis of the characteristics and constituents and two characteristics exceeded USEPA aesthetic analyzed for, the quality of water from Quaternary standards for domestic use: aluminum (all 22 rhyolite flows in the YVA was suitable for most samples exceeded the lower SMCL standard of uses. One characteristic (pH) was measured in both 50 µg/L and 12 of 22 samples exceeded the upper samples at values outside the range for USEPA SMCL standard of 200 µg/L), fluoride (74 of 75 aesthetic standards for domestic use and WDEQ samples exceeded the SMCL of 2 mg/L), TDS (68 livestock-use standards (below lower USEPA of 74 samples exceeded the SMCL of 500 mg/L), SMCL and WDEQ Class III limit of 6.5). manganese (17 of 24 samples exceeded the SMCL of 50 µg/L), pH (9 of 73 samples below lower 7.2.3.3 Yellowstone Group SMCL limit of 6.5 and 8 of 73 samples above upper SMCL limit of 8.5), and chloride (9 of 75 The chemical characteristics of groundwater from samples exceeded the SMCL of 250 mg/L). the Yellowstone Group in the Snake/Salt River Basin are described in this section of the report. Concentrations of some characteristics and Groundwater quality of the Yellowstone Group constituents in water from hot springs in rhyolite is described in terms of a water’s suitability for flows exceeded State of Wyoming standards for domestic, irrigation, and livestock use, on the basis agricultural and livestock use in the YVA. The of USEPA and WDEQ standards (table 5-2), and characteristics and constituents in environmental groundwater-quality sample summary statistics water samples from hot springs that had tabulated by hydrogeologic unit as quantile values concentrations greater than agricultural-use (appendices E–1 and F–1). standards were mercury (one sample analyzed for this constituent exceeded the WDEQ Class II Yellowstone Volcanic Area standard of 0.05 µg/L), SAR (71 of 74 samples The chemical composition of water from the exceeded the WDEQ Class II standard of 8), Yellowstone Group in the YVA was characterized boron (71 of 75 samples exceeded the WDEQ and the quality evaluated on the basis of Class II standard of 750 µg/L), chloride (45 of 75 environmental water samples from as many as samples exceeded the WDEQ Class II standard 11 hot springs. Summary statistics calculated of 100 mg/L), lithium (7 of 73 samples exceeded for available constituents are listed in appendix the WDEQ Class II standard of 2,500 µg/L), E–1. Major-ion composition in relation to TDS manganese (2 of 24 samples exceeded the WDEQ is shown on trilinear diagrams (appendix F–1, Class II standard of 200 µg/L), and pH (2 of 73 diagram D). TDS concentrations indicated
7-138 that waters ranged from slightly saline (10 of 11 standard of 750 µg/L), mercury (2 of 4 samples samples, concentrations between 1,000 to 2,999 exceeded the WDEQ Class II standard of 0.05 mg/L) to fresh (TDS concentrations less than or µg/L), and pH (2 of 10 samples above upper equal to 999 mg/L) (appendix E–1; appendix WDEQ Class II limit of 9). One constituent and F–1, diagram D). TDS concentrations in samples one characteristic had values outside the range from the hot springs ranged from 734 to 1,430 for livestock-use standards: arsenic (all 4 samples mg/L, with a median of 1,210 mg/L. exceeded the WDEQ Class III standard of 200 µg/L) and pH (3 of 10 samples above upper Concentrations of some properties and constituents WDEQ Class III limit of 8.5 and 1 of 10 samples measured in water from hot springs issuing from below lower limit of 6.5). the Yellowstone Group in the YVA approached or exceeded applicable USEPA or State of Wyoming The chemical composition of the Yellowstone water-quality standards and could limit suitability Group in the Yellowstone Volcanic Area (YVA) also for some uses. Concentrations of five constituents was characterized and the quality evaluated on the measured in environmental waters exceeded health- basis of environmental water samples from as many based standards: antimony (all 4 samples exceeded as six springs and six wells. Summary statistics the USEPA MCL of 6 µg/L), arsenic (all 4 samples calculated for available constituents are listed in exceeded the USEPA MCL of 10 µg/L), fluoride appendix E–1, and major-ion composition in (all 11 samples exceeded the USEPA MCL of 4 relation to TDS is shown on trilinear diagrams mg/L), molybdenum (all 4 samples exceeded the (appendix F–1, diagrams E and F). TDS USEPA LHA of 40 µg/L), and beryllium (2 of 4 concentrations indicated that all waters were fresh samples exceeded the USEPA MCL of 4 µg/L). (TDS concentrations less than or equal to 999 Concentrations of two characteristics and three mg/L) (appendix E–1; appendix F–1, diagrams constituents exceeded USEPA aesthetic standards E and F). The TDS concentrations for the springs for domestic use: TDS (all 11 samples exceeded ranged from 22.0 to 133 mg/L, with a median the SMCL of 500 mg/L), fluoride (all 11 samples of 55.0 mg/L. TDS concentrations for the wells exceeded the SMCL of 2 mg/L), aluminum (3 of 4 ranged from 133 to 209 mg/L, with a median of samples exceeded the lower SMCL standard of 50 150 mg/L. On the basis of the characteristics and µg/L and 2 of 4 samples exceeded the upper SMCL constituents analyzed for, the quality of water from standard of 200 µg/L), chloride (7 of 11 samples the Yellowstone Group in YVA was suitable for exceeded the SMCL of 250 mg/L), and pH (3 of most uses. The concentration of one constituent 10 samples above upper SMCL limit of 8.5 and 1 (manganese) in one of two well samples analyzed of 10 samples below lower limit of 6.5). for that constituent exceeded the USEPA aesthetic standards for domestic use (SMCL of 50 µg/L). Concentrations of some characteristics and constituents measured in water from hot springs Northern Ranges issuing from the Yellowstone Group exceeded The chemical composition of the Yellowstone State of Wyoming standards for agricultural Group in the Northern Ranges (NR) was and livestock use in YVA. Characteristics and characterized and the quality evaluated on the constituents measured in environmental water basis of environmental water samples from two samples from hot springs at concentrations greater wells and one spring. Individual constituent than agricultural-use standards were SAR (all 11 concentrations are listed in appendix E–2. The samples exceeded the WDEQ Class II standard TDS concentration measured in the spring sample of 8), arsenic (all 4 samples exceeded the WDEQ was 61 mg/L and indicated that the water was Class II standard of 100 µg/L), chloride (all 11 fresh (TDS concentration less than or equal to 999 samples exceeded the WDEQ Class II standard of mg/L) (appendix E–2). TDS was not measured 100 mg/L), lithium (all 11 samples exceeded the in the two well samples. However, specific WDEQ Class II standard of 2,500 µg/L), boron conductance was measured in both well samples, (10 of 11 samples exceeded the WDEQ Class II and both values (392 and 483 microsiemens
7-139 per centimeter at 25 degrees Celsius, appendix E–3. The TDS concentrations (275 and 288 E–2) would be much smaller than 999 mg/L mg/L) indicated that the waters were fresh (TDS when converted into equivalent TDS values by concentrations less than or equal to 999 mg/L) multiplying by 0.60 (Hem, 1985), indicating (appendix E–3). On the basis of the characteristics that both waters were fresh. On the basis of the and constituents analyzed for, the quality of water characteristics and constituents analyzed for, the from Tertiary intrusive rocks in JH was suitable quality of water from the Yellowstone Group in the for most uses. Concentrations of one constituent NR was suitable for most uses. No characteristics exceeded health-based standards: radon (the 1 or constituents approached or exceeded applicable sample analyzed for this constituent exceeded the USEPA or State of Wyoming domestic, agriculture, proposed USEPA MCL of 300 pCi/L, but did not or livestock water-quality standards. exceed the AMCL of 4,000 pCi/L). Manganese was measured in one of the two well samples, and 7.2.3.4 Tertiary intrusive rocks the concentration exceeded the USEPA aesthetic standard for domestic use (SMCL of 50 µg/L) and The chemical characteristics of groundwater from the State of Wyoming agricultural-use standard Tertiary intrusive rocks in the Snake/Salt River (WDEQ Class II standard of 200 µg/L). Basin are described in this section of the report. Groundwater quality of the Tertiary intrusive rocks 7.2.3.5 Quaternary obsidian gravel and is described in terms of a water’s suitability for sand deposits domestic, irrigation, and livestock use, on the basis of USEPA and WDEQ standards (table 5-2), and The physical and chemical characteristics of groundwater-quality sample summary statistics Quaternary obsidian gravel and sand deposits in tabulated by hydrogeologic unit as quantile values the Snake/Salt River Basin are described in this (appendices E–2 and E–3). section of the report.
Northern Ranges Physical characteristics The chemical composition of the Tertiary intrusive rocks in the Northern Ranges (NR) was One well completed in Quaternary unconsolidated characterized and the quality evaluated on the basis deposits composed of gravel and sand with of environmental water samples from two wells. some silt and clay (Lowry and Gordon, 1964, Individual constituent concentrations are listed p. 33) was inventoried as part of this study. The in appendix E–2. The TDS concentrations (296 investigators reported that the unconsolidated and 306 mg/L) indicated that the waters were deposits were overlain by rhyolite. Based on fresh (TDS concentrations less than or equal to currently used lithostratigraphic terminology, the 999 mg/L) (appendix E–2). On the basis of the rhyolite overlying the unconsolidated deposits characteristics and constituents analyzed for, the was interpreted herein to be the Lava Creek Tuff quality of water from the Tertiary intrusive rocks in (Member B) of the Yellowstone Group (pl. 6). The NR was suitable for most uses. No characteristics gravel and sand-sized sediments were composed or constituents approached or exceeded applicable primarily of angular obsidian, so these deposits State of Wyoming domestic or livestock water- were informally named "Quaternary obsidian quality standards. gravel and sand deposits" herein to reflect their unique composition and to differentiate them Jackson Hole from other Quaternary unconsolidated deposits. The chemical composition of the Tertiary intrusive Thickness of these deposits was at least 50 ft in the rocks in Jackson Hole (JH) was characterized and inventoried well. Existing hydrogeologic data for the quality evaluated on the basis of environmental the well completed in these deposits, including water samples from two wells. Individual well-yield and other hydraulic properties, are constituent concentrations are listed in appendix summarized on plate 3.
7-140 Chemical characteristics units commonly interfinger with other formations and lithologies. These units are relatively flat-lying The chemical characteristics of groundwater from and unconformably overlie eroded and older Quaternary obsidian gravel and sand deposits in bedrock formations. the Snake/Salt River Basin are described in this section of the report. Groundwater quality of 7.2.4.1 Heart Lake Conglomerate Quaternary obsidian gravel and sand deposits is described in terms of the water’s suitability for The Pliocene Heart Lake Conglomerate (pl. 6) domestic, irrigation, and livestock use, on the basis consists of abundant gray limestone and dolomite of USEPA and WDEQ standards (table 5-2). clasts, and sparse rhyolite and quartz clasts in a talc and clay matrix (Love and Christiansen, 1985). Yellowstone Volcanic Area No data were located describing the physical and The chemical composition of aquifers in chemical hydrogeologic characteristics of the Quaternary obsidian gravel and sand deposits lithostratigraphic unit in the Snake/Salt River in the Yellowstone Volcanic Area (YVA) was Basin. characterized and the quality evaluated on the basis of one environmental water sample from one well. 7.2.4.2 Shooting Iron Formation Individual constituent concentrations for available constituents are listed in appendix E–1. The TDS The Pliocene Shooting Iron Formation (pl. 5) concentration (183 mg/L) from the well indicated consists of pink, red, green, yellow, dark-gray, and that the water was fresh (concentration less than or brown bentonitic, mollusk-bearing, lacustrine equal to 999 mg/L) (appendix E–1). On the basis and fluvial claystone; gray and yellow tuffaceous of the characteristics and constituents analyzed sandstone and siltstone; and pebble conglomerate for, the quality of water from Quaternary obsidian of volcanic rock fragments in a bentonitic matrix gravel and sand deposits in the YVA was suitable (Love and others, 1992). Maximum thickness of for most uses. One constituent (fluoride) exceeded the Shooting Iron Formation is greater than 100 the USEPA aesthetic standard for domestic ft (Love and others, 1992). No data were located use (SMCL of 2 mg/L). No characteristics or describing the physical and chemical hydrogeologic constituents approached or exceeded applicable characteristics of the lithostratigraphic unit in the State of Wyoming domestic, agriculture, or Snake/Salt River Basin. livestock water-quality standards. 7.2.4.3 Salt Lake aquifer 7.2.4 Tertiary hydrogeologic units The physical and chemical characteristics of the The physical and chemical characteristics of Salt Lake aquifer in the Snake/Salt River Basin are Tertiary-age hydrogeologic units are described in described in this section of the report. this section of the report. Stock, domestic, and public-supply wells are completed in these units in Physical characteristics the Snake/Salt River Basin. Tertiary hydrogeologic units are composed of lithostratigraphic units Saturated and permeable parts of the Pliocene and ranging from Pliocene to Paleocene in age (pls. 4, Miocene Salt Lake Formation compose the Salt 5, and 6). The Upper Cretaceous to Paleocene-age Lake aquifer in the Snake/Salt River Basin (pl. 4). Pinyon Conglomerate (pls. 5 and 6) is described in The Salt Lake Formation consists of pale reddish this section for convenience. Tertiary hydrogeologic gray poorly to well-cemented conglomerate, units are composed of nonmarine (continental) sandstone, siltstone, clay/claystone, and beds of mixtures of shale, mudstone, siltstone, sandstone, white volcanic ash (tuff) (Rubey, 1973a,b; Lines conglomerate, lacustrine limestone, volcanic tuff, and Glass, 1975, Sheet 1; Oriel and Platt, 1980; and other lithologies. Tertiary lithostratigraphic Rubey and others, 1980; Ahern and others, 1981, Table IV-1). Reported maximum thickness of
7-141 the Salt Lake Formation in the Overthrust Belt is 1992, 1993b,c, 1995, 1997, 2008; TriHydro 1,000 ft (Lines and Glass, 1975, Sheet 1). The Salt Corporation, 1993a; Sunrise Engineering, 1995, Lake Formation is present in the structurally down- 2009; Rendezvous Engineering, PC, 2002; dropped valley floors within the Snake/Salt River Rendezvous Engineering, PC, and Hinckley Basin, most notably in the Star Valley area (Rubey, Consulting, 2009). Where the Salt Lake Formation 1973a,b). is composed primarily of fine-grained rocks (clay/ claystone, siltstone, and tuff) and is unfractured, The Salt Lake Formation was classified as a permeability is small and the formation is not major aquifer by Ahern and others (1981) and an aquifer. In areas where impermeable, the Salt in the Statewide Framework Water Plan (WWC Lake Formation in Star Valley may "act as a leaky Engineering and others, 2007), and that definition confining layer to underlying aquifers" (Forsgren was retained herein (pl. 4). Springs issuing from Associates, 1995, p. 3-2). and wells completed in the aquifer provide water for domestic and public-supply use in the Snake/ Recharge to the Salt Lake aquifer in the Star Valley Salt River Basin (Forsgren Associates, 1991c, e, area is from direct infiltration of precipitation f, 1992, 1995; Trihydro Corporation, 1993a; (snowmelt and rain), runoff, streamflow losses, Rendezvous Engineering, 2002; Rendezvous and irrigation losses (Forsgren Associates, 1995; Engineering, PC, and Hinckley Consulting, Rendezvous Engineering, PC, and Hinckley 2009; Sunrise Engineering, 2009), primarily in Consulting, 2009). This recharge occurs directly Star Valley where the unit commonly underlies on aquifer outcrops, as well as through overlying Quaternary unconsolidated deposits (pl. 1). Quaternary unconsolidated deposits. Hydrogeologic data describing the Salt Lake aquifer in the Snake/Salt River Basin, including Chemical characteristics spring-discharge and well-yield measurements and other hydraulic properties, are summarized on pl. The chemical characteristics of groundwater from 3. the Salt Lake aquifer in the Snake/Salt River Basin are described in this section of the report. Salt Lake Formation permeability is both primary Groundwater quality of the Salt Lake aquifer and secondary and highly localized. Lines and is described in terms of a water’s suitability for Glass (1975, Sheet 1) noted that conglomerates domestic, irrigation, and livestock use, on the basis in the Salt Lake Formation were well cemented of USEPA and WDEQ standards (table 5-2), and and poorly sorted, and consequently had little groundwater-quality sample summary statistics primary permeability; however, the investigators tabulated by hydrogeologic unit as quantile values noted secondary permeability development may (appendix E–5). occur in areas where the formation is fractured, as exemplified by spring discharges as large as 8,000 Overthrust Belt gallons per minute (gal/min) from Flat Creek The chemical composition of the Salt Lake aquifer Springs, which is a spring issuing from fractured in the Overthrust Belt (OTB) was characterized conglomerate in the Salt Lake Formation and is and the quality evaluated on the basis of used to provide water to the town of Thayne in environmental water samples from two springs. Star Valley. Subsequent studies of the Salt Lake Individual constituent concentrations are listed Formation conducted in relation to public water- in appendix E–5. The TDS concentrations (193 supply exploration and development in Star Valley and 202 mg/L) indicated that all waters were have indicated that both primary and secondary fresh (TDS concentrations less than or equal to permeability can be sufficient for public water- 999 mg/L) (appendix E–5). On the basis of the supply development, although aquifer productivity characteristics and constituents analyzed for, the was highly spatially variable and dependent on quality of water from the Salt Lake aquifer in the local aquifer characteristics such as lithology OTB was suitable for most uses. No characteristics and amount of fracturing (Forsgren Associates, or constituents approached or exceeded applicable
7-142 USEPA or State of Wyoming domestic, agriculture, aquifer exceeded State of Wyoming standards or livestock water-quality standards. for agricultural and livestock use in SV. Two constituents in environmental water samples from Star Valley wells were measured at concentrations greater The chemical composition of the Salt Lake aquifer than agricultural-use standards: radium-226 plus in Star Valley (SV) was characterized and the radium-228 (1 of 3 samples exceeded the WDEQ quality evaluated on the basis of environmental Class II standard of 5 pCi/L) and iron (1 of 11 water samples from as many as 4 springs and 23 samples exceeded the WDEQ Class II standard of wells. Summary statistics calculated for available 5,000 µg/L). The concentration of one constituent constituents are listed in appendix E–6, and (radium-226 plus radium-228) exceeded the major-ion composition in relation to TDS for livestock-use standard (1 of 3 samples exceeded the wells completed in the aquifer is shown on a WDEQ Class III standard of 5 pCi/L). trilinear diagram (appendix F–6, diagram B). TDS concentrations indicated that all waters 7.2.4.4 Miocene gravel deposits were fresh (TDS concentrations less than or equal to 999 mg/L) (appendix E–6; appendix F–6, The physical and chemical characteristics of diagram B). TDS concentrations available for Miocene gravel deposits in the Snake/Salt River two of four springs were 236 and 287 mg/L. TDS Basin are described in this section of the report. concentrations for the wells ranged from 141 to 347 mg/L, with a median of 270 mg/L. Physical characteristics
On the basis of the characteristics and constituents Unnamed gravel deposits of Miocene age analyzed for, the quality of water from springs ("Miocene gravel deposits") are composed of issuing from the Salt Lake aquifer in SV was gray, unconsolidated gravel to poorly cemented suitable for all uses. No characteristics or conglomerate that underlies the Conant Creek Tuff constituents approached or exceeded applicable on the northeast and east sides of Signal Mountain; USEPA or State of Wyoming domestic, agriculture, clasts are composed primarily of rounded quartzite, or livestock water-quality standards. Paleozoic and Mesozoic sedimentary rock fragments, and Tertiary andesite (Love, 1989; Love Concentrations of some properties and constituents and others, 1992). The unnamed gravel deposits in water from wells in the Salt Lake aquifer in the are estimated to be 1,000- to 1,200-ft thick and SV approached or exceeded applicable USEPA have been identified only on Signal Mountain or State of Wyoming water-quality standards (Love, 1989, p. C40; Love and others, 1992). and could limit suitability for some uses. Most environmental waters were suitable for domestic Chemical characteristics use, but concentrations of two constituents exceeded health-based standards: radon (the 1 The chemical characteristics of groundwater from sample analyzed for this constituent exceeded the Miocene gravel deposits in the Snake/Salt River proposed MCL of 300 pCi/L, but did not exceed Basin are described in this section of the report. the AMCL of 4,000 pCi/L) and radium-226 Groundwater quality of Miocene gravel deposits plus radium-228 [1 of 3 samples exceeded the is described in terms of a water’s suitability for USEPA MCL of 5 pCi/L]. Concentrations of two domestic, irrigation, and livestock use, on the basis constituents exceeded USEPA aesthetic standards of USEPA and WDEQ standards (table 5-2), and for domestic use: iron (1 of 11 samples exceeded groundwater-quality sample summary statistics the SMCL of 300 µg/L) and manganese (1 of 11 tabulated by hydrogeologic unit as quantile values samples exceeded the SMCL of 50 µg/L). (appendix E–3).
Concentrations of some characteristics and Jackson Hole constituents in water from wells in the Salt Lake The chemical composition of groundwater from
7-143 Miocene gravel deposits in Jackson Hole (JH) 4 and 5). Cox (1976, Sheet 1) speculated that was characterized and the quality evaluated on the conglomerate in the Camp Davis Formation basis of one environmental water sample from one might "yield a few tens of gallons per minute from well. Individual constituent concentrations for conglomerate," larger than the two well yields (2 available constituents are listed in appendix E–3. and 10 gal/min) inventoried for the formation as The TDS concentration (102 mg/L) from the well part of this study (pl. 3). sample indicated that the water was fresh (TDS concentrations less than or equal to 999 mg/L) Chemical characteristics (appendix E–3). On the basis of the characteristics and constituents analyzed for, the quality of water The chemical characteristics of groundwater from from Miocene gravel deposits in JH was suitable the Camp Davis aquifer in the Snake/Salt River for most uses. No characteristics or constituents Basin are described in this section of the report. approached or exceeded applicable USEPA or State Groundwater quality of the Camp Davis aquifer of Wyoming domestic, agriculture, or livestock is described in terms of a water’s suitability for water-quality standards. domestic, irrigation, and livestock use, on the basis of USEPA and WDEQ standards (table 5-2), and 7.2.4.5 Camp Davis aquifer groundwater-quality sample summary statistics tabulated by hydrogeologic unit as quantile values The physical and chemical characteristics of the (appendices E–3 and E–5). Camp Davis aquifer in the Snake/Salt River Basin are described in this section of the report. Jackson Hole The chemical composition of the Camp Davis Physical characteristics aquifer in Jackson Hole (JH) was characterized and the quality evaluated on the basis of environmental Saturated and permeable parts of the Miocene water samples from as many as three springs and Camp Davis Formation compose the Camp Davis one well. Individual constituents are listed in aquifer in the Snake/Salt River Basin (pls. 4, 5) appendix E–3. Major-ion composition in relation (Love and Christiansen, 1985). The Camp Davis to TDS for springs issuing from the Camp Davis Formation consists of conglomeratic lower and aquifer is shown on a trilinear diagram (appendix upper members separated by a middle member F–3, diagram F). TDS concentrations indicated composed of lacustrine limestone, siltstone, and that all waters were fresh (TDS concentrations tuff (Love, 1956a,c; Olson and Schmitt, 1987, less than or equal to 999 mg/L) (appendix E–3; and references therein). Reported thickness of the appendix F–3, diagram F). TDS concentrations Camp Davis Formation in the Overthrust Belt for the springs ranged from 252 to 292 mg/L, with ranges from about 100 to 5,500 ft (Love, 1956a, a median of 288 mg/L. The TDS concentration for b, c; Schroeder, 1973, 1974, 1976, 1987; Love and the well was 180 mg/L. Love, 2000). On the basis of the characteristics and constituents Hydrogeologic data describing the Camp Davis analyzed for, the quality of water from three aquifer in the Snake/Salt River Basin, including springs issuing from the Camp Davis aquifer in spring-discharge and well-yield measurements JH was suitable for most uses. One constituent are summarized on plate 3. The Wyoming Water (aluminum) exceeded USEPA aesthetic standards Planning Program (1972, Table III-2) speculated for domestic use (1 of 2 samples above lower that the Camp Davis Formation might be a fair SMCL standard of 50 µg/L). No characteristics or to good aquifer (pls. 4 and 5). The Camp Davis constituents approached or exceeded applicable Formation was classified as a major aquifer by State of Wyoming domestic, agriculture, or Ahern and others (1981) and as a marginal aquifer livestock water-quality standards. in the Wyoming Framework Water Plan (WWC Engineering and others, 2007, Figure 4-9) (pls. Concentrations of some properties and
7-144 constituents in water from one well completed in the Snake/Salt River Basin (pls. 4 and 5). The in the Camp Davis aquifer in JH approached or Teewinot Formation consists of chalky white exceeded applicable USEPA or State of Wyoming to light-gray, soft, porous limestone, claystone, water-quality standards and could limit suitability and pumicite (Love, 1956a; Love and others, for some uses. One constituent (fluoride) was 1992). The upper part of the formation is very measured at a concentration greater than a fossiliferous, thin-bedded claystone, marlstone, and health-based standard (USEPA MCL of 4 mg/L) tuff, and the lower two-thirds of the formation is and one constituent (arsenic) was measured at a composed primarily of nodular porous limestone concentration equal to its health-based standard in 100- to 200-ft thick beds interbedded with (USEPA MCL of 10 µg/L). Concentrations of one pumicite in 20- to 75-ft thick beds (Love, characteristic and one constituent exceeded USEPA 1956a; Love and others, 1992). A 110-ft thick aesthetic standards for domestic use: pH (exceeded conglomerate composed of limestone, quartzite, the upper SMCL limit of 8.5) and fluoride and obsidian clasts is present in the middle part (exceeded the SMCL of 2 mg/L). No characteristics of the formation (Love, 1956a, b; Love and or constituents in the well sample approached or others, 1992). Reported thickness of the Teewinot exceeded applicable State of Wyoming standards Formation is as much as 6,000 ft or more (Love for agricultural-use standards. One characteristic and others, 1992; Love and Reed, 2000, 2001a,b; (pH) was measured at values that exceeded the Love, 2001a,b,c, 2003b). livestock-use standard (upper WDEQ Class III standard of 8.5). The Wyoming Water Planning Program (1972, Table III-2) speculated that the Teewinot Overthrust Belt Formation might be a poor aquifer (pls. 4 and The chemical composition of the Camp Davis 5). The Teewinot Formation was classified as a aquifer in the Overthrust Belt (OTB) was major aquifer by Ahern and others (1981) and characterized and the quality evaluated on the in the Wyoming Framework Water Plan (WWC basis of one environmental water sample from one Engineering and others, 2007, Figure 4-9) well. Individual constituent concentrations are (pls. 4 and 5). Hydrogeologic data describing listed in appendix E–5. The TDS concentration the Teewinot aquifer in the Snake/Salt River (306 mg/L) from the well indicated that the Basin, including spring-discharge and well-yield water was fresh (concentration less than or equal measurements, are summarized on plate 3. Cox to 999 mg/L) (appendix E–5). On the basis (1976, Sheet 1) reported yields as much as 120 gal/ of the characteristics and constituents analyzed min per well from fractures and solution channels for, the quality of water from the Camp Davis in limestone in the formation. Yields of four wells aquifer in the OTB was suitable for most uses. completed in the Teewinot aquifer inventoried as No characteristics or constituents approached or part of this study were smaller than reported by exceeded applicable USEPA or State of Wyoming Cox, ranging from 10 to 50 gal/min (pl. 3). domestic, agriculture, or livestock water-quality standards. Chemical characteristics
7.2.4.6 Teewinot aquifer The chemical characteristics of groundwater from the Teewinot aquifer in the Snake/Salt River The physical and chemical characteristics of the Basin are described in this section of the report. Teewinot aquifer in the Snake/Salt River Basin are Groundwater quality of the Teewinot aquifer described in this section of the report. is described in terms of a water’s suitability for domestic, irrigation, and livestock use, on the basis Physical characteristics of USEPA and WDEQ standards (table 5-2), and groundwater-quality sample summary statistics Saturated and permeable parts of the Miocene tabulated by hydrogeologic unit as quantile values Teewinot Formation compose the Teewinot aquifer (appendix E–3).
7-145 Jackson Hole were inventoried as part of this study, but one The chemical composition of the Teewinot aquifer available spring-discharge measurement (1 gal/min) in Jackson Hole (JH) was characterized and the is shown on plate 3. quality evaluated on the basis of environmental water samples from as many as three springs and Chemical characteristics three wells. Individual constituents are listed in appendix E–3. Major-ion composition in The chemical characteristics of groundwater from relation to TDS for springs issuing from and wells the Colter Formation in the Snake/Salt River completed in the Teewinot aquifer is shown on Basin are described in this section of the report. trilinear diagrams (appendix F–3, diagrams G and Groundwater quality of the Colter Formation H). TDS concentrations indicated that all waters is described in terms of a water’s suitability for were fresh (TDS concentrations less than or equal domestic, irrigation, and livestock use, on the basis to 999 mg/L) (appendix E–3; appendix F–3, of USEPA and WDEQ standards (table 5-2), and diagrams G and H). The TDS concentrations for groundwater-quality sample summary statistics the springs ranged from 244 to 254 mg/L, with tabulated by hydrogeologic unit as quantile values a median of 247 mg/L. The TDS concentration (appendix E–3). for the wells ranged from 166 to 260 mg/L, with a median of 212 mg/L. On the basis of the Jackson Hole characteristics and constituents analyzed for, the The chemical composition of the Colter Formation quality of water from the Teewinot aquifer in in Jackson Hole (JH) was characterized and the springs and wells in JH was suitable for most uses. quality evaluated on the basis of one environmental No characteristics or constituents approached or water sample from one spring. Individual exceeded applicable USEPA or State of Wyoming constituents are listed in appendix E–3. The TDS domestic, agriculture, or livestock water-quality concentration (114 mg/L) indicated that the water standards. was fresh (TDS concentration less than or equal to 999 mg/L) (appendix E–3). On the basis of 7.2.4.7 Colter Formation the characteristics and constituents analyzed for, the quality of water from the Colter Formation The physical and chemical characteristics of the in one spring in JH was suitable for most uses. Colter Formation in the Snake/Salt River Basin are No characteristics or constituents approached or described in this section of the report. exceeded applicable USEPA or State of Wyoming domestic, agriculture, or livestock water-quality Physical characteristics standards.
The Miocene Colter Formation in the Snake/Salt 7.2.4.8 White River aquifer River Basin (pls. 5 and 6) consists of pyroclastic conglomerate, sandstone, and claystone (Love, Saturated and permeable parts of the Oligocene 1956a; Love and others, 1992). Reported thickness White River Formation compose the White of the Colter Formation in the Jackson Hole area is River aquifer in the Snake/Salt River Basin (pls. as much as 7,000 ft (Love, 1956a; Love and others, 5 and 6). The White River Formation consists 1992). of white nodular calcareous siltstone and pale- green bentonitic claystone that locally can contain The Wyoming Water Planning Program (1972, vertebrate fossils (Love and others, 1992). Reported Table III-2) speculated that the Colter Formation thickness of the White River Formation in the might be a fair to poor aquifer (pls. 5 and 6). Overthrust Belt ranges from 0 to 200 ft (Lines and Cox (1976, Sheet 1) speculated that the Colter Glass, 1975, Sheet 1; Love and others, 1992; Love, Formation might yield a few gallons per minute 2002). Despite the predominant fine grain size of per well. Few hydrogeologic data describing the sediments composing the unit, the formation is Colter Formation in the Snake/Salt River Basin tentatively classified as an aquifer herein (pls. 5
7-146 and 6). The White River Formation generally is of the Wasatch aquifer in the Snake/Salt River defined as an aquifer throughout Wyoming where Basin likely are similar to those in the Bear River permeable, including areas immediately east of Basin. the Snake/Salt River Basin in the Wind River and Bighorn Basins (pls. 5 and 6). Permeability in The Wasatch Formation consists of variegated the predominantly fine-grained rocks composing mudstone, claystone, siltstone, shale, sandstone, the unit is provided primarily by local secondary conglomeratic sandstone, and conglomerate. It is permeability development (for example, fractures), a thick sequence of nonmarine sedimentary rock and much less commonly occurring local coarse- with named members of the formation (described grained zones (Bartos and others, 2012). In areas below but individual members not shown on plate where secondary permeability or coarse-grained 4) in some areas of the Overthrust Belt. zones are not present, the formation is defined as a confining unit. No data were located describing the The Wasatch Formation in the Overthrust Belt physical and chemical hydrogeologic characteristics (including the Snake/Salt River Basin) is divided of the lithostratigraphic unit in the Snake/Salt into a basal conglomerate, a lower unnamed River Basin. member, the main body of the formation, and the Bullpen and Tunp Members (Oriel and Tracey, 7.2.4.9 Conglomerate of Sublette 1970; Lines and Glass, 1975, Sheet 1; Rubey and Range others, 1980; M’Gonigle and Dover, 1992; Dover and M’Gonigle, 1993) (individual members not The Eocene and Paleocene Conglomerate of shown on Plate 4). The basal conglomerate is a Sublette Range of Love and others (1993) (pl. lenticular conglomerate of sandstone pebbles and 4) [also called the Sublette Range Conglomerate cobbles, and ranges from 0 to 300 ft in thickness (Salat and Steidtmann, 1991)] consists of white, (Oriel and Tracey, 1970; Lines and Glass, 1975, pink, dark gray, well-rounded, poorly sorted, Sheet 1; Rubey and others, 1980; M’Gonigle pebble to boulder gravel composed of quartzite and Dover, 1992). The lower unnamed member and gray chert mixed with silt and sand (Love and is composed predominantly of drab-colored Christiansen, 1985, Sheet 2; Salat, 1989; Salat mudstone and sandstone, and ranges from 0 to and Steidtmann, 1991). Reported maximum 300 ft in thickness (Oriel and Tracey, 1970; Lines thickness of the Conglomerate of Sublette Range and Glass, 1975, Sheet 1; Rubey and others, 1980; is about 591 ft (Oriel and Platt, 1980). No M’Gonigle and Dover, 1992). The main body data were located describing the physical and is composed predominantly of red, purple, and chemical hydrogeologic characteristics of the tan mudstone, with some sandstone, and ranges lithostratigraphic unit in the Snake/Salt River from 1,500 to 2,000 ft in thickness (Oriel and Basin. Tracey, 1970; Lines and Glass, 1975, Sheet 1; Rubey and others, 1980; M’Gonigle and Dover, 7.2.4.10 Wasatch aquifer (Overthrust 1992; Dover and M’Gonigle, 1993). The Bullpen Belt) Member is composed predominantly of red and salmon mudstone, and gray and brown mudstone, The Eocene Wasatch Formation comprises the and ranges from 0 to 400 ft in thickness (Oriel Wasatch aquifer within the Overthrust Belt part and Tracey, 1970; Lines and Glass, 1975, Sheet of the Snake/Salt River Basin (pl. 4). The Wasatch 1; M’Gonigle and Dover, 1992). The Tunp aquifer is undeveloped as a water supply within Member is composed of conglomeratic mudstone the Snake/Salt River Basin study boundary within and diamictite, and ranges from 200 to 500 ft in the Overthrust Belt. However, immediately south thickness (Oriel and Tracey, 1970; Lines and Glass, in the Bear River Basin within the Overthrust 1975, Sheet 1; Rubey and others, 1980; Hurst, Belt, the aquifer is used as a source of water for 1984; Hurst and Steidtmann, 1986; M’Gonigle domestic, stock, industrial, and public-supply and Dover, 1992). purposes (Bartos and others, 2014). Characteristics
7-147 The Wasatch Formation is considered to be conditions are present. Although no data were an aquifer in the Overthrust Belt by previous located describing the physical and chemical investigators (Robinove and Berry, 1963; Lines characteristics of the hydrogeologic unit within the and Glass, 1975, Sheet 1; Ahern and others, 1981; boundary of the Snake/Salt River Basin, Wasatch Forsgren Associates, 2000; TriHydro Corporation, aquifer characteristics in the Bear River Basin 2000, 2003) (pl. 4). In the Wyoming Water to the south and within the Overthrust Belt are Framework Plan, the Wasatch Formation is provided in Bartos and others (2014). classified as a major aquifer (WWC Engineering and others, 2007, Figure 4-9) (pl. 4). The Wasatch 7.2.4.11 Wasatch-Fort Union aquifer aquifer is an important aquifer in the adjacent (Green River and Hoback Basins) Green River Basin to the east (Ahern and others, 1981; Martin, 1996; Naftz, 1996; Glover and The physical and chemical characteristics of the others, 1998; Bartos and Hallberg, 2010). Ahern Wasatch-Fort Union aquifer in the Green River and others (1981, Figure II-7) classified the and Hoback Basins within the Snake/Salt River formation as a major aquifer in the Overthrust Basin are described in this section of the report. Belt (pl. 4) and noted that both springs issuing The Wasatch-Fort Union aquifer is composed of from and wells completed in the formation locally two zones represented by the Wasatch and Fort yielded water. The Wasatch Formation has been Union Formations and related formations such as defined as a "productive aquifer" in the Deer the Pass Peak and Hoback Formations (Bartos and Mountain Subdivision area near the town of Bear Hallberg, 2010, Figure 5-1, and references therein). River in the Bear River Basin located immediately The aquifer forms the base of the lower Tertiary south of the Snake/Salt River Basin (Forsgren aquifer system in the Green River Basin, and is in Associates, 2000; TriHydro Corporation, 2000). direct contact with underlying Upper Cretaceous rocks at the top of the Mesaverde aquifer (Bartos Although little information was available at and Hallberg, 2010, Figure 5-1). No regional the time of their studies, previous investigators confining unit separates the lower Tertiary speculated that small to moderate yields sufficient aquifer system in the Green River Basin from for domestic and stock use were likely from the underlying Mesaverde aquifer. The Wasatch- permeable beds in the Wasatch Formation in the Fort Union aquifer is the thickest Cenozoic Overthrust Belt (Berry, 1955; Robinove and Berry, hydrogeologic unit in the Green River Basin, as 1963; Wyoming Water Planning Program, 1972, much as 11,000-ft thick. Table III-2). Lines and Glass (1975, Sheet 1) noted that conglomeratic sandstones and conglomerates Physical characteristics in the Wasatch Formation likely were capable of yielding "moderate to large quantities" of water The physical characteristics of the Wasatch and Fort to wells. In addition, the investigators (Lines and Union zones of the Wasatch-Fort Union aquifer Glass, 1975, Sheet 1) noted that fine-grained in the Green River and Hoback Basins within the sandstones in the Wasatch Formation were capable Snake/Salt River Basin are described in this section of yielding "small to moderate" quantities of water, of the report. but that well yields were likely "greatly dependent" on the saturated thickness of the sandstone beds. 7.2.4.12 Wasatch Zone of the Wasatch- Similarly, Ahern and others (1981) noted that Fort Union aquifer (including Pass permeable sandstones, conglomeratic sandstones, Peak Formation) and conglomerates of the Wasatch Formation could yield moderate to large quantities of water The Wasatch zone of the Wasatch-Fort Union to wells. Sandstones, conglomeratic sandstones, aquifer is composed of the Wasatch Formation and conglomerates composing the Wasatch aquifer (main body), undifferentiated Green River and primarily are under confined conditions, except Wasatch Formations along the western edge of the in outcrop areas where unconfined (water-table) Green River Basin, the Pass Peak Formation in the
7-148 northwestern Green River Basin, various Eocene Groundwater in the Wasatch zone of the Wasatch- (and possibly younger) rocks in the northeastern Fort Union aquifer in the Green River Basin Green River Basin, as well as numerous small generally flows from basin margins (assumed to tongues and members including the Farson represent recharge areas) toward the center of Sandstone Member of the Green River Formation the basin and to the south (assumed to represent and the Alkali Creek Member of the Wasatch discharge areas) (Martin, 1996). Water-table Formation between the New Fork River and the conditions in the aquifer predominate in the southernmost exposure of the Laney aquifer in the northern Green River Basin, whereas artesian north and central Green River Basin; the Niland (confined) conditions predominate elsewhere. Tongue of the Wasatch Formation in the southeast Green River Basin; the "La Barge Member"; the 7.2.4.13 Fort Union Zone of the Chappo Member of the Wasatch Formation; and Wasatch-Fort Union aquifer (including the Luman Tongue of the Green River Formation the Hoback Formation) in the southeast Green River Basin (Martin, 1996; Glover and others, 1998; Bartos and Hallberg, The Fort Union zone of the Wasatch-Fort Union 2010, and references therein). The Eocene aquifer is composed of the Fort Union Formation Pass Peak Formation consists of conglomerate, and the Hoback Formation (Martin, 1996; Glover sandstone, and shale; thickness is as much as 5,000 and others, 1998; Bartos and Hallberg, 2010, ft (Welder, 1968, Sheet 2; Cox, 1976, Sheet 1). and references therein). The Hoback Formation is equivalent to the Fort Union Formation in the Sandstone beds, interbedded with various fine- northwestern Green River Basin. The Fort Union grained sedimentary rocks in these various units Formation is lithologically very similar to the composing the Wasatch zone, generally provide Wasatch Formation; it is also composed of fluvial most of the water to wells completed in the aquifer. sandstones and fine-grained sedimentary rocks. In The thickness and amount of sandstone at a given the subsurface, it is often difficult to differentiate location generally depends on the distance from the two formations. The Hoback Formation the sediment source area. Throughout the northern is composed of gray and brown sandstone, Green River Basin, many investigators have noted conglomerate, shale, siltstone, and shaley thick, permeable, areally extensive sandstones at or limestone; maximum thickness is about 16,000 ft, near land surface. In fact, Welder (1968, sheet 2) but the formation thins southward in its outcrop noted that "aggregate thickness of water-bearing area to about 8,000 ft (Spearing, 1969, Figure sandstone probably ranges from one-third to two- 4; Lines and Glass, 1975, Sheet 1; Cox, 1976, thirds of total formation thickness; consequently, Sheet 1). Although the Fort Union zone is present a large amount of water is in storage and the water throughout the Green River Basin, Martin (1996, is under pressure where deeply buried." In the p. 21) noted that the "northwestern part of the southern Green River Basin, the Wasatch zone is [Green River] structural basin where the Hoback overlain by the Green River Formation, and the Formation is exposed at the surface, the Fort Union number and thickness of sandstone beds in the zone is not included as part of the aquifer system aquifer varies greatly both laterally and vertically. because it is north of a groundwater divide outside Large well yields in thick sandstone have been of the hydrologic basin." reported along basin margins. Welder (1968, Sheet 2) speculated that groundwater-development Few hydrologic data are available for the Hoback possibilities were "good" in the Green River Basin. Formation in the Snake/Salt River Basin (pl. 3), Cox (1976, Sheet 1) speculated that conglomerate but because of large thicknesses of sandstone and and sandstone in the Pass Peak Formation might conglomerate, it is considered a potential source of "yield a few tens of gallons per minute per well," water (Lines and Glass, 1975, Sheet 1). Cox (1976, larger than the two well yields (2 and 5 gal/min) Sheet 1) speculated that sandstone in the Hoback inventoried for the formation as part of this study Formation might "yield a few tens of gallons per (pl. 3). minute per well," similar to the one well yield (20
7-149 gal/min) inventoried for the formation as part of sample was greater than the State of Wyoming this study (pl. 3). agricultural-use standard (WDEQ Class II standard of 0.05 µg/L). No characteristics or constituents Chemical characteristics approached or exceeded applicable USEPA or State of Wyoming domestic or livestock water-quality The chemical characteristics of groundwater from standards in the spring sample. On the basis of the Wasatch-Fort Union aquifer (samples collected the characteristics and constituents analyzed for, from the Pass Peak and Hoback Formations) the quality of water from the two wells completed in the Snake/Salt River Basin, are described in in the Wasatch-Fort Union aquifer (Hoback this section of the report. Groundwater quality Formation) in the GH was suitable for most uses. from both the Pass Peak and Hoback Formations No characteristics or constituents measured in is described in terms of a water’s suitability for the two well samples approached or exceeded domestic, irrigation, and livestock use, on the basis applicable USEPA or State of Wyoming domestic, of USEPA and WDEQ standards (table 5-2), and agriculture, or livestock water-quality standards in groundwater-quality sample summary statistics environmental samples from wells. tabulated by hydrogeologic unit as quantile values (appendix E–4). 7.2.4.14 Tepee Trail Formation
Green River and Hoback Basins The Eocene Tepee Trail Formation in the Snake/ The chemical composition of the Wasatch-Fort Salt River Basin (pls. 5 and 6) consists of Union aquifer (samples collected from the Pass tuffaceous sandstone, mudstone, and claystone Peak Formation) in the Green River and Hoback (Love, 1956a; Love and others, 1992). Reported Basins (GH) was characterized and the quality thickness of the Tepee Trail Formation in the evaluated on the basis of environmental water Jackson Hole area is as much as 1,500 ft (Love and samples from two springs. Individual constituent Keefer, 1972). For the Wind River Basin, Bartos concentrations are listed in appendix E–4. TDS and others (2012, Plate 2) assigned the Tepee Trail concentrations (283 and 367 mg/L) indicated Formation to part of a confining unit identified that waters from both springs were fresh (TDS as the "Aycross-Wagon Bed confining unit" (pls. concentrations less than or equal to 999 mg/L) 5 and 6) composed of the volcaniclastic Eocene (appendix E–4). On the basis of the characteristics Tepee Trail and Aycross Formations or siliciclastic and constituents analyzed for, the quality of water Wagon Bed Formation. No data were located from the Wasatch-Fort Union aquifer (Pass Peak describing the physical and chemical hydrogeologic Formation) in the GH was suitable for most uses. characteristics of the lithostratigraphic unit in the No characteristics or constituents approached or Snake/Salt River Basin. exceeded applicable USEPA or State of Wyoming domestic, agriculture, or livestock water-quality 7.2.4.15 Hominy Peak Formation standards. The Eocene Hominy Peak Formation in the The chemical composition of the Wasatch-Fort Snake/Salt River Basin (pls. 5 and 6) consists of Union aquifer (samples collected from the Hoback mafic volcaniclastic conglomerate, tuff with sparse Formation) in the GH was characterized and the claystone in the upper part of the formation, quality evaluated on the basis of environmental and gold-bearing conglomerate at the base of water samples from one spring and two wells. the formation (Love and others, 1978). The Individual constituent concentrations are listed in formation is exposed at the north end and on appendix E–4. TDS concentrations for the spring the west flank of the Teton Range and the south (275 mg/L) and for the wells (215 and 327 mg/L) boundary of Yellowstone National Park (pl. 1). indicated waters were fresh (TDS concentrations Love and others (1978) assigned the formation to less than or equal to 999 mg/L) (appendix E–4). the Absaroka Volcanic Supergroup of Smedes and One constituent (mercury) measured in the spring Prostka (1972). Reported thickness of the Hominy
7-150 Peak Formation is as much as 2,000 ft (Love and references therein). The Wind River Formation is others, 1978). No data were located describing the composed of an interbedded sequence of claystone, physical and chemical hydrogeologic characteristics shale, siltstone, and conglomerate, with lenticular of the lithostratigraphic unit in the Snake/Salt beds of fine- to coarse-grained sandstone of variable River Basin. thickness and areal extent; small amounts of bentonite, tuff, and limestone also may be present 7.2.4.16 Aycross Formation (Morris and others, 1959; McGreevy and others, 1969; Richter, 1981). Coarser deposits may be The Eocene Aycross Formation in the Snake/ more abundant along the basin margins because of Salt River Basin (pls. 5 and 6) consists of proximity to sediment sources such as the Washakie tuffaceous sandstone, mudstone, and claystone Range and Wind River Mountains (Whitcomb and (Love, 1956a; Love and others, 1992). Reported Lowry, 1968). thickness of the Aycross Formation in the Jackson Hole area is as much as 1,500 ft (Love, 1956a; In the Wind River Basin, the Wind River aquifer Rohrer and Obradovich, 1969). In the Wind is underlain by the Indian Meadows confining River Basin, Bartos and others (2012, Plate 2) unit or by the Fort Union aquifer, in the absence assigned the Aycross Formation to part of a of the Eocene Indian Meadows Formation (Bartos confining unit identified as the "Aycross-Wagon and others, 2012, Plate II). In the Wind River Bed confining unit" (pls. 5 and 6) composed of Mountains, the Wind River Formation may be the volcaniclastic Eocene Tepee Trail and Aycross underlain by the Conglomerate of Roaring Fork Formations or siliciclastic Wagon Bed Formation. (Bartos and others, 2012, Plate II). Where buried No data were located describing the physical and in the Wind River Basin, the aquifer is overlain by chemical hydrogeologic characteristics of the the Aycross-Wagon Bed confining unit [composed lithostratigraphic unit in the Snake/Salt River of the volcaniclastic Eocene Tepee Trail and Aycross Basin. Formations or siliciclastic Wagon Bed Formation (Bartos and others, 2012, Plate II)], or Quaternary 7.2.4.17 Crandall Conglomerate unconsolidated deposits (Bartos and others, 2012, Plate II). The Eocene Crandall Conglomerate (pl. 6) is a clast-supported conglomerate composed of locally The Wind River aquifer is used as a source of water derived Paleozoic carbonate clasts (Love and for domestic, stock, irrigation, industrial, and Christiansen, 1985; Breeden and others, 2012). public-supply purposes throughout the Wind River Thickness of the formation is as much as 328 ft Basin (Richter, 1981; Bartos and others, 2012). (Breeden and others, 2012). No data were located Many wells are installed in the Wind River aquifer describing the physical and chemical hydrogeologic in the Wind River Basin because it is present at or characteristics of the lithostratigraphic unit in the near land surface (crops out) throughout most of Snake/Salt River Basin. the basin. Most wells completed in the Wind River aquifer are for stock and domestic use because of 7.2.4.18 Wind River aquifer relatively low yields and water quality that may preclude some uses without treatment (Morris Present within a small part of the east-central and others, 1959; Whitcomb and Lowry, 1968; Snake/Salt River Basin study area (pls. 1 and 2), McGreevy and others, 1969; Richter, 1981; Bartos the Wind River aquifer consists of the Eocene and others, 2012). Because of limited areal extent Wind River Formation (pls. 5 and 6) (Bartos and and location away from any population, the aquifer others, 2012, and references therein). Thickness is unused in the Snake/Salt River Basin. No data of the Wind River Formation in the Wind River were located describing the physical and chemical Basin ranges from about 100 ft along mountain characteristics of the hydrogeologic unit in the flanks to about 5,000 ft in the central part of the Snake/Salt River Basin. Wind River Basin (Bartos and others, 2012, and
7-151 7.2.4.19 Devils Basin Formation hydrogeologic units.
The Paleocene Devils Basin Formation (pl. 5) Development of most Mesozoic aquifers in the consists of gray, soft, lenticular, poorly bedded Snake/Salt River Basin has been very limited to sandstones; bedded gray and pale-green siltstones date (2014), except in areas where aquifers crop and claystones; thin-bedded brown to black out and are directly exposed at land surface or carbonaceous shale; and thin beds of coal (Love, at shallow depth below younger hydrogeologic 1989). Thickness of the type section is about units. Hydraulic properties, great depth, minimal 1,500 ft (Love, 1989). No data were located precipitation and recharge, and generally poor describing the physical and chemical hydrogeologic water quality except near recharge areas prevents characteristics of the Devils Basin Formation in the extensive groundwater development of aquifers in Snake/Salt River Basin. Mesozoic hydrogeologic units.
7.2.4.20 Pinyon Conglomerate 7.3.1 Landslide Creek Formation
The Upper Cretaceous to Paleocene Pinyon The Upper Cretaceous Landslide Creek Formation Conglomerate (pls. 5 and 6) consists of rusty- (pl. 6) consists of greenish-gray, bentonitic, brown conglomerate composed of quartzite tuffaceous sandstone and conglomerate (Love cobbles and pebbles in a matrix of rusty coarse- and Christiansen, 1985). The Wyoming Water grained sandstone and occasional boulders of Planning Program (1972, Table III-2) speculated older conglomerate and quartzite (Lindsey, 1972; that the Landslide Creek Formation might be Love and others, 1992). The formation is as much a poor aquifer (pl. 6). No data were located as 3,800-ft thick in the Snake/Salt River Basin describing the physical and chemical hydrogeologic (Lindsey, 1972; Love, 1974a,b, 2001c, 2003b; characteristics of the Landslide Creek Formation in Love and others, 1992). The Wyoming Water the Snake/Salt River Basin. Planning Program (1972, Table III-2) speculated that the Pinyon Conglomerate might be a "fair 7.3.2 Harebell Formation to poor aquifer." Cox (1976, Sheet 1) speculated that wells completed in the formation might yield The physical and chemical characteristics of the a few tens of gallons per minute per well. No data Harebell Formation in the Snake/Salt River Basin were located describing the physical and chemical are described in this section of the report. hydrogeologic characteristics of the Pinyon Conglomerate in the Snake/Salt River Basin. Physical characteristics
7.3 Mesozoic hydrogeologic units The Upper Cretaceous Harebell Formation (pls. 5 and 6) consists of sandstone, shale, conglomerate, Mesozoic hydrogeologic units (aquifers and sandstone, claystone, and tuff (Love, 1956a; confining units) are described in this section of Lindsey, 1972; Love and others, 1992). The the report. Lithostratigraphic units of Cretaceous, conglomerate consists of quartzite roundstones in Jurassic, and Triassic age compose the Mesozoic a matrix of brown, gold-bearing sandstone. The hydrogeologic units (aquifers and confining sandstone is brown, gray, dull green, silty, hard, and units) in the Snake/Salt River Basin (pls. 4, 5, tuffaceous. The claystone is gray, dark green, black, and 6). Depending on location and depth, wells and mustard yellow, silty, and tuffaceous. Reported completed in Mesozoic hydrogeologic units maximum thickness of the Harebell Formation produce highly variable quantities and quality of ranges from 5,000 to 10,000 ft (Love, 1974a,b, water. The highly complex structural features of 1975a,b, 2002; Love and others, 1992). the Overthrust Belt require site-specific geologic and hydrogeologic investigation to characterize Few hydrogeologic data are available describing and develop groundwater resources from Mesozoic the hydrogeologic characteristics of the Harebell
7-152 Formation in the Snake/Salt River Basin. approached or exceeded applicable USEPA or State Hydrogeologic data describing the physical of Wyoming domestic, agriculture, or livestock characteristics of the Harebell Formation, water-quality standards. including well-yield measurements and other hydraulic properties, are summarized on plate 3. Concentrations of some properties and The Wyoming Water Planning Program (1972, constituents in water from wells completed in Table III-2) speculated that the Harebell Formation the Harebell Formation approached or exceeded might be a good aquifer (pls. 5 and 6). The applicable USEPA or State of Wyoming water- Harebell Formation was classified as a marginal quality standards and could limit suitability for aquifer in the Wyoming Framework Water Plan some uses. Most environmental waters were (WWC Engineering and others, 2007, Figure 4-9) suitable for domestic use, but concentrations (pls. 5 and 6). Cox (1976, Sheet 1) speculated that of one constituent (fluoride) exceeded health- the Harebell Formation might yield a few tens of based standards (1 of 2 samples exceeded the gallons per minute per well from conglomerate USEPA MCL of 4 mg/L). Concentrations of and sandstone. Yields of two wells completed in one characteristic and one constituent exceeded the Harebell Formation inventoried as part of this aesthetic standards for domestic use: pH (1 of 2 study (12 and 20 gal/min) were similar to those samples exceeded the upper SMCL limit of 8.5) speculated by Cox (pl. 3). and fluoride (1 of 2 samples exceeded the SMCL of 2 mg/L). Chemical characteristics Concentrations of some characteristics and The chemical characteristics of groundwater from constituents in water from wells completed in the the Harebell Formation in the Snake/Salt River Harebell Formation exceeded State of Wyoming Basin are described in this section of the report. standards for agricultural and livestock use in JH. Groundwater quality of the Harebell Formation Two characteristics in the wells approached or is described in terms of a water’s suitability for exceeded applicable State of Wyoming standards domestic, irrigation, and livestock use, on the basis for agricultural-use standards: pH (1 of 2 samples of USEPA and WDEQ standards (table 5-2), and exceeded upper WDEQ Class II standard of 9) groundwater-quality sample summary statistics and SAR (1 of 2 samples exceeded WDEQ Class II tabulated by hydrogeologic unit as quantile values standard of 8). The value of one characteristic (pH) (appendix E–3). exceeded the livestock-use standard (1 of 2 samples exceeded upper WDEQ Class III standard of 8.5). Jackson Hole The chemical composition of the Harebell 7.3.3 Meeteetse Formation Formation in Jackson Hole (JH) was characterized and the quality evaluated on the basis of The Upper Cretaceous Meeteetse Formation (pl. environmental water samples from one spring and 5) consists of chalky-white to gray salt-and-pepper two wells. Individual constituents are listed in soft sandstone, interbedded with yellow, pale green, appendix E–3. TDS concentrations indicated that and dark-gray carbonaceous shale, thin coal beds, all waters were fresh (TDS concentrations less than white slabby tuff, and yellow to gray bentonite or equal to 999 mg/L) (appendix E–3). The TDS beds (Love and others, 1992). Conglomerate in concentration for the spring was 278 mg/L. The the formation consists of quartzite cobbles that TDS concentrations for the wells were 280 and can be in a gold-bearing sandstone matrix in some 314 mg/L. horizons. Maximum thickness of the formation ranges from about 500 to 1,000 ft (Cox, 1976, On the basis of the characteristics and constituents Sheet 1; Love, 1975a, 2002, 2003b; Love and analyzed for, the quality of water from the Harebell others, 1992). Formation in the spring in JH was suitable for most uses. No characteristics or constituents Few hydrogeologic data are available describing
7-153 the hydrogeologic characteristics of the Meeteetse Planning Program (1972, Table III-2) speculated Formation in the Snake/Salt River Basin. The that the Mesaverde Formation might be a poor Wyoming Water Planning Program (1972, Table aquifer in the Snake/Salt River Basin (pls. 5 and 6). III-2) speculated that the Meeteetse Formation Ahern and others (1981) classified the Mesaverde might be a poor aquifer in the Snake/Salt River Formation as an aquifer in the Overthrust Belt. Basin (pl. 5). The Meeteetse Formation was The Mesaverde Formation was classified as a minor classified as a major aquitard in the Wyoming aquifer in the Wyoming Framework Water Plan Framework Water Plan (WWC Engineering and (WWC Engineering and others, 2007, Figure 4-9) others, 2007, Figure 4-9) (pl. 5). Cox (1976, Sheet (pls. 5 and 6). Cox (1976, Sheet 1) speculated that 1) speculated that the Meeteetse Formation might the Mesaverde Formation might yield a few tens yield a few tens of gallons per minute per well from of gallons per minute per well from sandstone. sandstone. No data were located describing the No data were located describing the physical and physical and chemical hydrogeologic characteristics chemical hydrogeologic characteristics of the of the hydrogeologic unit in the Snake/Salt River lithostratigraphic unit in the Snake/Salt River Basin. Basin.
7.3.4 Mesaverde aquifer 7.3.5 Everts Formation, Eagle Sandstone, and Telegraph Creek Saturated and permeable parts of the Upper Formation Cretaceous Mesaverde Formation compose the Mesaverde aquifer in the Snake/Salt River Basin The Upper Cretaceous Everts Formation, Eagle (pls. 5 and 6). The Mesaverde Formation (pls. 5 Sandstone, and Telegraph Creek Formation (pl. and 6) consists of white massive to thick-bedded, 6) consist of massive to thin-bedded sandstone, soft, porous, medium- to coarse-grained sandstone mudstone, and shale (Love and Christiansen, 1985, interbedded with thin gray shale and sparse coal Sheet 2). The Wyoming Water Planning Program and bentonite beds (Love and others, 1992). (1972, Table III-2) speculated that the Everts Conglomerate beds containing quartzite cobbles in Formation might be a fair to poor (?) aquifer, the a gold-bearing matrix occur locally in the Grand Eagle Sandstone was probably a fair aquifer, and Teton National Park area. Maximum thickness of the Telegraph Creek Formation might be a fair the formation ranges from about 800 to 1,200 ft to poor aquifer in the Snake/Salt River Basin (pl. or more (Rohrer, 1969; Cox, 1976, Sheet 1; Love, 6). Cox (1976, Sheet 1) speculated that sandstone 1975a, 2002, 2003b; Love and others, 1992). in the formations might yield a few tens of gallons per minute per well. No data were located Few hydrogeologic data are available describing describing the physical and chemical hydrogeologic the hydrogeologic characteristics of the Mesaverde characteristics of the three lithostratigraphic units Formation in the Snake/Salt River Basin, so in the Snake/Salt River Basin. much of what is known about the hydrogeologic characteristics of the formation is from adjacent 7.3.6 Sohare Formation structural basins. The Mesaverde Formation generally is defined as an aquifer throughout The physical and chemical characteristics of the Wyoming, including the Overthrust Belt and in Sohare Formation in the Snake/Salt River Basin are areas immediately east of the Snake/Salt River described in this section of the report. Basin in the Wind River and Bighorn Basins, and southeast in the Green River Basin (pls. 5 Physical characteristics and 6); consequently, the Mesaverde Formation in the Snake/Salt River Basin was classified as an The Upper Cretaceous Sohare Formation (pls. 5 aquifer herein (pls. 5 and 6). The Wyoming Water and 6) consists of lenticular gray and brown fine-
7-154 grained sandstone interbedded with light- and exceeded health-based standards, but one dark-gray shale and siltstone with thin coal beds characteristic (TDS) exceeded USEPA aesthetic (Love, 1989; Love and others, 1992). The Sohare standards for domestic use (exceeded SMCL limit Formation is exposed in broad outcrops along the of 500 mg/L). One characteristic (SAR) exceeded east side of Jackson Hole and is present on both the applicable State of Wyoming standard for flanks of the Gros Ventre Range to the south (pl. agricultural use (exceeded WDEQ Class II standard 1). Thickness varies from about 5,000 ft south of of 8). No characteristics or constituents approached the Gros Ventre Range to an eroded edge just south or exceeded applicable State of Wyoming livestock of Yellowstone National Park (Love, 1989). water-quality standards.
Few data are available describing the hydrogeologic 7.3.7 Blind Bull Formation characteristics of the Sohare Formation in the Snake/Salt River Basin. The Sohare Formation was The physical and chemical characteristics of the classified as a marginal aquifer in the Wyoming Blind Bull Formation in the Snake/Salt River Basin Framework Water Plan (WWC Engineering and are described in this section of the report. others, 2007, Figure 4-9) (pls. 5 and 6). No data were located describing the physical hydrogeologic Physical characteristics characteristics of the lithostratigraphic unit in the Snake/Salt River Basin. The Upper Cretaceous Blind Bull Formation (pl. 4) is present in the Snake/Salt River Basin. The Blind Chemical characteristics Bull Formation consists of partly conglomeratic sandstone, siltstone, claystone, coal, and bentonite The chemical characteristics of groundwater from (Rubey, 1973b; Oriel and Platt, 1980; Rubey the Sohare Formation in the Snake/Salt River and others, 1980). The Blind Bull Formation is a Basin are described in this section of the report. lateral stratigraphic equivalent to part of the Sohare Groundwater quality of the Sohare Formation Formation and Bacon Ridge Sandstone in the is described in terms of a water’s suitability for northern part of the Snake/Salt River Basin, and domestic, irrigation, and livestock use, on the basis to part of the Hilliard Shale in the southern part of of USEPA and WDEQ standards (table 5-2), and the Overthrust Belt, south of the Snake/Salt River groundwater-quality sample summary statistics Basin. The Hilliard Shale is located in the eastern tabulated as quantile values (appendix E–3). and southern parts of the Overthrust Belt, and this shale unit becomes increasingly sandy northward Jackson Hole and northwestward as it laterally grades into the The chemical composition of groundwater from Blind Bull Formation (Rubey, 1973b; Oriel and the Sohare Formation in Jackson Hole (JH) was Platt, 1980; Rubey and others, 1980). Maximum characterized and the quality evaluated on the basis thickness of the Blind Bull Formation in the of one environmental water sample from one well. Overthrust Belt ranges from 5,000 ft to as much Individual constituents are listed in appendix E–3. as 9,186 ft (Rubey, 1973b; Schroeder, 1979, 1987; The TDS concentration (866 mg/L) indicated that Oriel and Platt, 1980; Rubey and others, 1980). the water was fresh (TDS concentration less than or equal to 999 mg/L) (appendix E–3). Few data are available describing the hydrogeologic characteristics of the Blind Bull Formation in Concentrations of some properties and the Snake/Salt River Basin. Lines and Glass constituents in water from the well completed (1975, Sheet 1) speculated that sandstone in the in the Sohare Formation in JH approached or Blind Bull Formation might be able to produce exceeded applicable USEPA or State of Wyoming "small quantities of water." Two spring-discharge water-quality standards and could limit suitability measurements for the formation (20 and 25 gal/ for some uses. No concentrations of constituents min) were inventoried as part of this study (pl. 3).
7-155 Chemical characteristics beds occur near the top and lower parts of the formation, and coal beds occur in parts of the The chemical characteristics of groundwater from formation. A 30-ft thick gold-bearing quartzite the Blind Bull Formation in the Snake/Salt River boulder conglomerate is present in the lower part Basin are described in this section of the report. of the formation and intertongues with marine Groundwater quality of the Blind Bull Formation strata. Reported maximum thickness of the Bacon is described in terms of a water’s suitability for Ridge Formation ranges from 1,000 to 1,500 ft domestic, irrigation, and livestock use, on the basis (Love and others, 1992). of USEPA and WDEQ standards (table 5-2), and groundwater-quality sample summary statistics Few hydrogeologic data are available describing tabulated by hydrogeologic unit as quantile values the hydrogeologic characteristics of the Bacon (appendix E–5). Ridge aquifer in the Snake/Salt River Basin. Hydrogeologic data describing the physical Overthrust Belt characteristics of the Bacon Ridge aquifer, The chemical composition of groundwater from including spring-discharge and well-yield the Blind Bull Formation in the Overthrust measurements, are summarized on plate 3. The Belt (OTB) was characterized and the quality Wyoming Water Planning Program (1972, Table evaluated on the basis of one environmental water III-2) speculated that the Bacon Ridge Formation sample from one spring. Individual constituent might be a good aquifer (pls. 5 and 6). The Bacon concentrations for available constituents are listed Ridge Formation was classified as a marginal in appendix E–5. The TDS concentration (172 aquifer in the Wyoming Framework Water Plan mg/L) from the spring indicated that the water (WWC Engineering and others, 2007, Figure 4-9) was fresh (concentration less than or equal to (pls. 5 and 6). Cox (1976, Sheet 1) speculated that 999 mg/L) (appendix E–5). On the basis of the the Bacon Ridge Formation might yield a few tens characteristics and constituents analyzed for, the of gallons per minute per well from sandstone. quality of water from the Blind Bull Formation in the OTB was suitable for most uses. No Chemical characteristics characteristics or constituents approached or exceeded applicable USEPA or State of Wyoming The chemical characteristics of groundwater from domestic, agriculture, or livestock water-quality the Bacon Ridge aquifer in the Snake/Salt River standards. Basin are described in this section of the report. Groundwater quality of the Bacon Ridge aquifer 7.3.8 Bacon Ridge aquifer is described in terms of a water’s suitability for domestic, irrigation, and livestock use, on the basis The physical and chemical characteristics of the of USEPA and WDEQ standards (table 5-2), and Bacon Ridge aquifer in the Snake/Salt River Basin groundwater-quality sample summary statistics are described in this section of the report. tabulated by hydrogeologic unit as quantile values (appendix E–3). Physical characteristics Jackson Hole Saturated and permeable parts of the Upper The chemical composition of the Bacon Ridge Cretaceous Bacon Ridge Sandstone comprise the aquifer in Jackson Hole (JH) was characterized and Bacon Ridge aquifer in the Snake/Salt River Basin the quality evaluated on the basis of environmental (pls. 5 and 6). The Bacon Ridge Sandstone in water samples from one spring and one well. the Grand Teton National Park area consists of Individual constituents are listed in appendix tan to gray, thick-bedded, fine-grained sandstone E–3. TDS concentrations (216 mg/L in the spring containing abundant marine fossils interbedded sample and 547 mg/L in the well sample) indicated with gray marine and brackish-water shale and that waters were fresh (TDS concentrations less siltstone (Love and others, 1992). Thin bentonite than or equal to 999 mg/L) (appendix E–3).
7-156 On the basis of the characteristics and constituents and references therein), and throughout the State analyzed for, the quality of water from the spring in the Wyoming Water Framework Plan (WWC issuing from the Bacon Ridge aquifer in JH Engineering and others, 2007, Figure 4-9) (pls. was suitable for all uses. No characteristics or 5 and 6). Because lithologic characteristics of the constituents approached or exceeded applicable Cody Shale are similar in all Wyoming structural USEPA or State of Wyoming domestic, agriculture, basins, classification of the lithostratigraphic unit or livestock water-quality standards. as a confining unit was retained herein for the Snake/Salt River Basin (pls. 5 and 6). Despite Concentrations of some properties and being classified as a confining unit, the Cody constituents in water from the well completed confining unit likely can yield water locally in in the Bacon Ridge aquifer in JH approached areas where discontinuous sandstone beds or zones or exceeded applicable USEPA or State of with fractures (secondary permeability) are present Wyoming water-quality standards and could limit (Robinove and Berry, 1963; Lines and Glass, 1975, suitability for some uses. No concentrations of Sheet 1; Cox, 1976, Sheet 1). Cox (1976, Sheet 1) constituents exceeded health-based standards. speculated that the sandstone beds probably would Two characteristics exceeded USEPA aesthetic not yield more than a few gallons per minute per standards for domestic use: pH (value greater well. No data were located describing the physical than the upper SMCL limit of 8.5) and TDS and chemical hydrogeologic characteristics of the (concentration greater than SMCL of 500 lithostratigraphic unit in the Snake/Salt River mg/L). Two characteristics exceeded applicable Basin. State of Wyoming standards for agricultural-use standards: pH (value greater than upper WDEQ 7.3.10 Frontier aquifer Class II standard of 9) and SAR (value exceeded WDEQ Class II standard of 8). The value of The physical and chemical characteristics of the one characteristic (pH) exceeded a livestock-use Frontier aquifer in the Snake/Salt River Basin are standard (value exceeded upper WDEQ Class III described in this section of the report. standard of 8.5). Physical characteristics 7.3.9 Cody confining unit The Frontier aquifer is composed of the Upper The Cody confining unit is composed of the Upper Cretaceous Frontier Formation (pls. 4, 5, and 6). Cretaceous Cody Shale (pls. 5 and 6). Deposited The Frontier Formation consists of interbedded in a marine environment, the Cody Shale consists white to brown fine- to medium-grained sandstone of dull-gray shale interbedded with lesser amounts and dark gray shale with beds of abundant oyster of gray siltstone and gray fine-grained slabby fossils in the upper part of the formation (Oyster glauconitic sandstone (Love and others, 1992). Ridge Sandstone Member), and coal and lignite Thickness of the Cody Shale ranges from 1,400 to beds in the lower part (individual members not 2,200 ft in the Jackson Hole area, 1,000 to 2,000 ft shown on plates. 4, 5, and 6). The Frontier in the Green River and Hoback Basins, and 1,000 Formation is not exposed above and to the west to 2,000 ft in the Gros Ventre Range (Love and of the Absaroka thrust fault (M’Gonigle and others, 1992; Love and Love, 2000; Love, 2003a). Dover, 1992; Dover and M’Gonigle, 1993) (pl. 1), where the Upper Cretaceous lower member of the Because the lithostratigraphic unit is composed Evanston Formation unconformably overlies the primarily of shale, the Cody Shale was classified Lower Cretaceous Sage Junction Formation. The as a confining unit by previous investigators in Frontier Formation was divided into additional the adjacent Wind River and Bighorn Basins east members by Hale (1960), including the Dry of the Snake/Salt River Basin (Bartos and others, Hollow, Allen Hollow Shale, Coalville, and Chalk 2012, and references therein), southeast in the Creek Members. Green River Basin (Bartos and Hallberg, 2010,
7-157 Frontier Formation thickness in the Snake/ Chemical characteristics Salt River Basin varies by geographic area in the Snake/Salt River Basin. Thickness of the Frontier The chemical characteristics of groundwater Formation ranges from 1,200 to 3,000 ft in the from the Frontier aquifer in the Snake/Salt River Overthrust Belt, 1,000 to 2,000 ft in the Northern Basin are described in this section of the report. Ranges, and is about 1,000 ft in Jackson Hole Groundwater quality of the Frontier aquifer is (Jobin, 1965; Love, 1974a, 1975b, 2001c, 2003a; described in terms of a water’s suitability for Schroeder, 1974; Christiansen and others, 1978; domestic, irrigation, and livestock use, on the basis Oriel and Platt, 1980; Rubey and others, 1980; of USEPA and WDEQ standards (table 5-2), and Ahern and others, 1981; Oriel and Moore, 1985; groundwater-quality sample summary statistics Love and others, 1992; Love and Love 2000). tabulated by hydrogeologic unit as quantile values (appendix E–2). Previous investigators have classified the Frontier Formation as an aquifer and that definition Northern Ranges is retained herein (plates 4 and 5). Robinove The chemical composition of the Frontier and Berry (1963, Plate 1) speculated that the aquifer in the Northern Ranges (NR) was Frontier Formation in the Bear River valley in characterized and the quality evaluated on the the Overthrust Belt south of the Snake/Salt River basis of environmental water samples from as Basin was "possibly an aquifer in areas." Lines many as three springs. Individual constituent and Glass (1975, Sheet 1) noted that sandstone concentrations are listed in appendix E–2. TDS aquifers in the Frontier Formation were capable concentrations indicated that the waters were fresh of yielding moderate quantities of water and (TDS concentrations less than or equal to 999 were the "best aquifers" in their "hydrogeologic mg/L) (appendix E–2). Major-ion composition division 5" (identified as being composed of in relation to TDS for the three springs issuing Cretaceous shales and sandstones and shown from the Frontier aquifer is shown on a trilinear on plates 4, 5, and 6) in the Overthrust Belt. diagram (appendix F–2, diagram D). The TDS Similarly, the Frontier Formation was classified as concentrations for the springs ranged from 80 to a minor aquifer yielding moderate quantities of 416 mg/L, with a median concentration of 338 water by Ahern and others (1981, Figure II-7, and mg/L. On the basis of the characteristics and Table IV-1) in the Overthrust Belt and adjacent constituents analyzed for, the quality of water Green River Basin (pls. 4 and 5). North of the from the Frontier aquifer in the NR was suitable Overthrust Belt, Cox (1976, Sheet 1) speculated for most uses. No characteristics or constituents that the Frontier Formation might yield a few tens approached or exceeded applicable USEPA and of gallons per minute per well from sandstone; State of Wyoming domestic, agricultural, or in addition, he noted that springs issuing from livestock water-quality standards. the formation in the Gros Ventre Range yield "a few gallons per minute." In the Wyoming Water 7.3.11 Mowry confining unit Framework Plan, the Frontier Formation was classified as a minor aquifer (WWC Engineering The Mowry confining unit is composed of the and others, 2007, Figure 4-9) (pls. 4, 5, and 6). Upper Cretaceous Mowry Shale (pls. 5 and All the investigators concluded that interbedded 6). The Mowry Shale consists of dark gray to discontinuous sandstone beds compose the aquifer black (weathers silvery gray), very hard, brittle, (Ahern and others, 1981; Lines and Glass, 1975, silicified, thin-bedded shale with some bentonite Sheet 1). Because sandstone beds compose the and secondarily silicified fine-grained sandstone aquifer, permeability is primarily intergranular and (Love and others, 1992). Thickness of the Mowry related to the amount of cementation, except where Shale in the Gros Ventre Range ranges from 500 fractured (Ahern and others, 1981). Hydrogeologic to 700 ft (Love, 1974a, 2001c; Love and Love, data (well yields) inventoried for the Frontier 1978, 2000; Love and others, 1992). Thickness of aquifer are shown on plate 3. the Mowry Shale in Jackson Hole is about 650 ft
7-158 (Love, 2003a). Aspen Shale in the Teton Range is about 2,000 ft (Oriel and Moore, 1985). The Aspen Shale is Because of the predominance of fine-grained laterally equivalent to the Mowry Shale (see pls. 5 lithologies such as shale, the Mowry Shale and 6). Some beds are present that are transitional was classified as a confining unit by previous from the Aspen Shale to the lower part of the Blind investigators in the adjacent Wind River and Bull Formation (Rubey and others, 1980). Bighorn Basins east of the Snake/Salt River Basin (Bartos and others, 2012, and references therein), The Aspen Shale was identified as either southeast in the Green River Basin (Bartos and "discontinuous aquifers with local confining beds" Hallberg, 2010, and references therein), and or a "locally utilized aquifer" in the Overthrust throughout the State in the Wyoming Water Belt by Ahern and others (1981, Figure II-7, and Framework Plan (WWC Engineering and Table IV-1) (pl. 4). The investigators (Ahern and others, 2007, Figure 4-9) (pls. 5 and 6). Because others, 1981, p. 61) also noted that the formation lithologic characteristics of the Mowry Shale was composed primarily of low-permeability shale, are similar in all Wyoming structural basins, and that "exploitable water yields were mainly from classification of the lithostratigraphic unit as a stray sands and fracture zones." In the Wyoming confining unit was retained herein for the Snake/ Water Framework Plan, the Aspen Shale was Salt River Basin (pls. 5 and 6). Despite being classified as a major aquitard (WWC Engineering classified as a confining unit, the Mowry confining and others, 2007, Figure 4-9) (pl. 4). Because unit likely can yield water locally in areas where shale is the predominant lithology, the Aspen discontinuous sandstone beds or zones with Shale is classified as a confining unit herein (pl. 4); fractures (secondary permeability) are present however, it is recognized that water can be obtained (Robinove and Berry, 1963; Lines and Glass, 1975, locally from the Aspen confining unit in areas Sheet 1; Cox, 1976, Sheet 1). No data were located where discontinuous sandstone beds or zones with describing the physical and chemical hydrogeologic fractures are present (Lines and Glass, 1975, Sheet characteristics of the lithostratigraphic unit in the 1; Ahern and others, 1981; Richter, 1981, Table Snake/Salt River Basin. IV-1). Lines and Glass (1975, Sheets 1, 2) noted that some domestic wells completed in permeable 7.3.12 Aspen confining unit parts of the Aspen confining unit along the Snake River were abandoned because of hydrogen The physical and chemical characteristics of the sulfide gas. Hydrogeologic data describing the Aspen confining unit in the Snake/Salt River Basin Aspen confining unit in the Snake/Salt River are described in this section of the report. Basin, including spring-discharge and well-yield measurements, and other hydraulic properties, are Physical characteristics summarized on plate 3.
The Aspen confining unit is composed of the Chemical characteristics Upper and Lower Cretaceous Aspen Shale (pl. 4). The Aspen Shale consists of interbedded light to The chemical characteristics of groundwater from dark gray shale, siltstone, and claystone with minor the Aspen confining unit in the Snake/Salt River quartz-rich sandstone and porcellanite. Maximum Basin are described in this section of the report. thickness of the Aspen Shale in the Overthrust Groundwater quality of the Aspen confining unit Belt ranges from less than 1,000 to 5,000 ft or is described in terms of a water’s suitability for more (Jobin, 1965, 1972; Pampeyan and others, domestic, irrigation, and livestock use, on the basis 1967; Albee, 1968, 1973; Schroeder, 1969, 1973, of USEPA and WDEQ standards (table 5-2), and 1974, 1976, 1979, 1987; Oriel and Platt, 1980; groundwater-quality sample summary statistics Schroeder and others, 1981; Oriel and Moore, tabulated by hydrogeologic unit as quantile values 1985; Lageson, 1986). Maximum thickness of the (appendices E–3 and E–5).
7-159 Jackson Hole approached or exceeded applicable USEPA or State The chemical composition of the Aspen confining of Wyoming domestic, agriculture, or livestock unit in Jackson Hole (JH) was characterized and water-quality standards. the quality evaluated on the basis of environmental water samples from two wells. Individual 7.3.13 Sage Junction Formation constituents are listed in appendix E–3. TDS concentrations measured in water from the wells Present in the Overthrust Belt, the Upper (284 and 312 mg/L) indicated that both waters Cretaceous Sage Junction Formation (pl. 4) is were fresh (TDS concentrations less than or equal more than 3,000-ft thick and consists primarily to 999 mg/L) (appendix E–3). of gray and tan siltstone, sandstone, and quartzite with minor amounts of porcellanite, limestone, Concentrations of some properties and constituents conglomerate, and some coal beds (Rubey, 1973a, in water from the Aspen confining unit in JH b; Lines and Glass, 1975, Sheet 1; Rubey and approached or exceeded applicable USEPA or State others, 1980; M’Gonigle and Dover, 1992; Dover of Wyoming water-quality standards and could and M’Gonigle, 1993). The formation is a lateral limit suitability for some uses. The concentration western stratigraphic equivalent to part of the of one constituent (fluoride) exceeded health- Aspen Shale. The uppermost several hundred feet based standards (1 of 2 samples exceeded the of the Sage Junction Formation may be equivalent USEPA MCL of 4 mg/L). Concentrations of two in age to the lower part of the Upper Cretaceous constituents exceeded USEPA aesthetic standards Frontier Formation (Rubey, 1973b). The Sage for domestic use: iron (1 of 2 samples exceeded Junction Formation is at least 3,375-ft thick above SMCL of 300 µg/L) and fluoride (1 of 2 samples and to the west of the Absaroka thrust fault (pl. exceeded the SMCL of 2 mg/L). No characteristics 1) and in the northwestern part of the Kemmerer or constituents approached or exceeded applicable area in the Bear River Basin south of the Snake/ State of Wyoming domestic, agricultural, or Salt River Basin (M’Gonigle and Dover, 1992). livestock water-quality standards. West and above the Absaroka thrust fault, the Upper Cretaceous lower member of the Evanston Overthrust Belt Formation unconformably overlies the Sage The chemical composition of the Aspen Junction Formation (M’Gonigle and Dover, 1992; confining unit in the Overthrust Belt (OTB) Dover and M’Gonigle, 1993). was characterized and the quality evaluated on the basis of environmental water samples from Changes in stratigraphic nomenclature between the as many as nine springs and one well. Summary western and eastern Cretaceous lithostratigraphic statistics calculated for available constituents are units occur at the Absaroka thrust fault in the listed in appendix E–5. Major-ion composition in Wyoming Overthrust Belt (Rubey, 1973b). relation to TDS for springs issuing from the Aspen Lithostratigraphic units located above and to confining unit is shown on a trilinear diagram the west of the Absaroka thrust, including the (appendix F–5, diagram B). TDS concentrations hanging wall of the fault, are the western units indicated that all waters were fresh (TDS (Smiths, Thomas Fork, Cokeville, Quealy, and Sage concentrations less than or equal to 999 mg/L) Junction Formations), whereas those located below (appendix E–5; appendix F–5, diagram B). TDS and to the east of the Absaroka thrust, including concentrations in the spring samples ranged from the footwall of the fault, are the eastern units (Bear 107 to 228 mg/L, with a median of 195 mg/L. River Formation and Aspen Shale) (pl. 1; pl. The TDS concentration in the well sample was 4). No data were located describing the physical 308 mg/L. On the basis of the characteristics and and chemical hydrogeologic characteristics of the constituents analyzed for, the quality of water from lithostratigraphic unit in the Snake/Salt River the Aspen confining unit in the OTB was suitable Basin. for most uses. No characteristics or constituents
7-160 7.3.14 Wayan Formation part of the formation is the western stratigraphic equivalent to the upper Bear River Formation The Upper and Lower Cretaceous Wayan (Rubey, 1973b) (pl. 4). No data were located Formation (pl. 4) consists of variegated mudstone, describing the physical and chemical hydrogeologic siltstone, and sandstone with minor porcellanite, characteristics of the lithostratigraphic unit in the bentonite, and coal (Oriel and Platt, 1980) (pl. Snake/Salt River Basin. 4). The formation is about 3,937-ft thick (Oriel and Platt, 1980). One spring discharge (10 gal/ 7.3.17 Muddy Sandstone aquifer min) was inventoried for the formation as part of this study (pl. 3). No data were located describing The Muddy Sandstone aquifer is composed of the chemical hydrogeologic characteristics of the the Lower Cretaceous Muddy Sandstone (pls. 5 lithostratigraphic unit in the Snake/Salt River and 6). The Muddy Sandstone consists of a 20- Basin. to 100-ft-thick rusty-brown to gray sandstone 7.3.15 Quealy Formation interbedded with black and gray siltstone and shale (Love, 1974a, 1975b, 2001c; Love and others, The Upper Cretaceous Quealy Formation (pl. 1992; Love and Love, 2000). The formation 4) consists of red and variegated pastel-tinted is sometimes identified as a member of the mudstone and minor interbedded pink, gray, and underlying Thermopolis Shale (Love and others, tan sandstone (Rubey, 1973b; Lines and Glass, 1992). The Muddy Sandstone aquifer is a major 1975). The Quealy Formation thins eastward oil and gas reservoir in much of Wyoming. Because from about 1,100 ft in Idaho to about 500 ft in the lithostratigraphic unit is composed primarily of Wyoming (Oriel and Platt, 1980; Rubey and sandstone, the Muddy Sandstone was classified as others, 1980). The Quealy Formation is the an aquifer by previous investigators in the adjacent western stratigraphic equivalent of the middle Wind River and Bighorn Basins east of the Snake/ to lower part of the Aspen Shale (Rubey, 1973b) Salt River Basin (Bartos and others, 2012, and (plate 4). No data were located describing the references therein), southeast in the Green River physical and chemical characteristics of the Basin (Bartos and Hallberg, 2010, and references lithostratigraphic unit in the Snake/Salt River therein), and throughout the State in the Wyoming Basin. Water Framework Plan (WWC Engineering and others, 2007, Figure 4-9) (pls. 5 and 6). Because 7.3.16 Cokeville Formation lithologic characteristics of the Muddy Sandstone are similar in all Wyoming structural basins, The Lower Cretaceous Cokeville Formation (pl. 4) classification of the lithostratigraphic unit as an consists of gray to tan fossiliferous sandstone, sandy aquifer was retained herein for the Snake/Salt River siltstone, and light to dark gray claystone/mudstone Basin (pls. 5 and 6). In the subsurface, the Muddy with minor fossiliferous tan limestone; light gray, Sandstone aquifer is confined from above by the tan, and pink porcellanite; bentonite; and a few Mowry confining unit and from below by the coal beds (Rubey, 1973b; Lines and Glass 1975; Thermopolis confining unit (pls. 5 and 6). No data Rubey and others, 1980; M’Gonigle and Dover, were located describing the physical and chemical 1992; Dover and M’Gonigle, 1993). The coal hydrogeologic characteristics of the hydrogeologic beds are located in the upper part of the Cokeville lithostratigraphic unit in the Snake/Salt River Formation (Rubey, 1973b). The Cokeville Basin. Formation thickens southeastward from about 850 ft in Idaho to about 3,000 ft in Wyoming 7.3.18 Thermopolis confining unit (Oriel and Platt, 1980; Rubey and others, 1980; M’Gonigle and Dover, 1992; Dover and The Thermopolis confining unit is composed of M’Gonigle, 1993). The upper part of the Cokeville the Lower Cretaceous Thermopolis Shale (pls. 5 Formation is the western stratigraphic equivalent and 6). The Thermopolis Shale primarily consists of the lower part of the Aspen Shale, and the lower of black, flaky, soft shale (Love and others,
7-161 1992). The Thermopolis Shale is the northern Physical characteristics and eastern stratigraphic equivalent to the Bear River Formation. Thickness of the Thermopolis The Lower Cretaceous Bear River Formation Shale in the Gros Ventre Range ranges from 100 (pl. 4) consists of fissile black shale interbedded to 200 ft (Love and others, 1992; Love and Love, with brown fine-grained sandstone, and minor 2000; Love, 2001c, 2003c). Thickness of the interbedded fossiliferous limestone and bentonite. Thermopolis Shale in the Overthrust Belt east of Maximum thickness of the Bear River Formation the Hoback fault ranges from 100 to 200 ft (Love in the Overthrust Belt ranges from less than 100 and Love, 2000). North of Jackson Lake in the to about 1,800 ft (Jobin, 1965, 1972; Albee, 1968, northern Teton Range, the Thermopolis Shale is 1973; Schroeder, 1973, 1974, 1976, 1979, 1981, only about 55-ft thick (Love and others, 1992). In 1987; Oriel and Platt, 1980; Schroeder and others, the subsurface, the Thermopolis confining unit is 1981; Oriel and Moore, 1985; Lageson, 1986; overlain by the the Muddy Sandstone aquifer and Love and others, 1992; Love, 2003c). Maximum underlain by the Cloverly aquifer (pls. 5 and 6). thickness of the Bear River Formation in the Teton Range is about 1,000 ft (Oriel and Moore, 1985). Because the lithostratigraphic unit is composed primarily of shale, the Thermopolis Shale Previous investigators have classified the Bear River was classified as a confining unit by previous Formation as an aquifer, and that definition is investigators in the adjacent Wind River and retained herein (pl. 4). Berry (1955) identified the Bighorn Basins east of the Snake/Salt River Basin Bear River Formation as a potential aquifer in the (Bartos and others, 2012, and references therein), Cokeville area in the Bear River Basin within the southeast in the Green River Basin (Bartos and Overthrust Belt immediately south of the Snake/ Hallberg, 2010, and references therein), and Salt River Basin. Robinove and Berry (1963, Plate throughout the State in the Wyoming Water 1) speculated that the Bear River Formation in Framework Plan (WWC Engineering and others, the Bear River valley in the Overthrust Belt south 2007, Figure 4-9) (pls. 5 and 6). Because lithologic of the Snake/Salt River Basin "possibly may yield characteristics of the Thermopolis Shale are similar small amounts of water." Lines and Glass (1975, in all Wyoming structural basins, classification of Sheet 1) noted that "small quantities" of water the lithostratigraphic unit as a confining unit was were available from the discontinuous sandstone retained herein for the Snake/Salt River Basin (pls. beds in the formation. In the Overthrust Belt, 5 and 6). Despite being classified as a confining the Bear River Formation was identified as either unit, the Thermopolis confining unit likely can "discontinuous aquifers with local confining beds" yield water locally in areas where discontinuous or a "minor aquifer" by Ahern and others (1981, sandstone beds or zones with fractures (secondary Figure II-7, and Table IV-1) (pl. 4). Interbedded permeability) are present (Robinove and Berry, discontinuous sandstone beds compose the aquifer 1963; Lines and Glass, 1975, Sheet 1; Cox, 1976, (Ahern and others, 1981; Lines and Glass, 1975, Sheet 1). No data were located describing the Sheet 1). In the Wyoming Water Framework physical and chemical hydrogeologic characteristics Plan, the Bear River Formation was classified as a of the lithostratigraphic unit in the Snake/Salt marginal aquifer (WWC Engineering and others, River Basin. 2007, Figure 4-9) (pl. 4). Lines and Glass (1975, Sheets 1, 2) noted that some wells completed 7.3.19 Bear River aquifer in the Bear River aquifer along the Snake River were abandoned because of hydrogen sulfide gas. The physical and chemical characteristics of the Hydrogeologic data describing the Bear River Bear River aquifer in the Snake/Salt River Basin are aquifer in the Snake/Salt River Basin, including described in this section of the report. spring-discharge and well-yield measurements, and other hydraulic properties, are summarized on plate 3.
7-162 Chemical characteristics for some uses. Most environmental waters were suitable for domestic use, as no concentrations The chemical characteristics of groundwater from of constituents exceeded health-based standards. the Bear River aquifer in the Snake/Salt River Concentrations of two characteristics and two Basin are described in this section of the report. constituents exceeded USEPA aesthetic standards Groundwater quality of the Bear River aquifer for domestic use: TDS (4 of 8 samples exceeded the is described in terms of a water’s suitability for SMCL of 500 mg/L), pH (1 of 8 samples exceeded domestic, irrigation, and livestock use, on the basis the upper SMCL limit of 8.5), chloride (1 of 8 of USEPA and WDEQ standards (table 5-2), and samples exceeded the SMCL of 250 mg/L), and groundwater-quality sample summary statistics fluoride (1 of 7 samples exceeded the SMCL of 2 tabulated by hydrogeologic unit as quantile values mg/L). (appendix E–5). Concentrations of some characteristics and Overthrust Belt constituents in water from wells completed in the The chemical composition of aquifers in the Bear Bear River aquifer exceeded State of Wyoming River aquifer in the Overthrust Belt (OTB) was standards for agricultural and livestock use in the characterized and the quality evaluated on the OTB. One characteristic and two constituents basis of environmental water samples from as in the wells approached or exceeded applicable many as four springs and eight wells. Summary State of Wyoming standards for agricultural-use statistics calculated for available constituents are standards: chloride (2 of 8 samples exceeded listed in appendix E–5. Major-ion composition in WDEQ Class II standard of 100 mg/L), SAR (1 of relation to TDS for springs issuing from and wells 8 samples exceeded the WDEQ Class II standard completed in the Bear River aquifer is shown on of 8), and sulfate (1 of 8 samples exceeded the two trilinear diagrams (appendix F–5, diagrams WDEQ Class II standard of 200 mg/L). The value C and D). TDS concentrations indicated that of one characteristic (pH) exceeded the livestock- waters from all four springs and six of eight wells use standard (1 of 8 samples exceeded upper were fresh (TDS concentrations less than or equal WDEQ Class III standard of 8.5). to 999 mg/L), and waters from two of eight wells were slightly saline (TDS concentration ranging 7.3.20 Thomas Fork aquifer from 1,000 to 2,999 mg/L) (appendix E–5; appendix F–5, diagrams C and D). The TDS The Thomas Fork aquifer is composed of saturated concentrations for the springs ranged from 226 to and permeable parts of the Lower Cretaceous 264 mg/L, with a median of 248 mg/L. The TDS Thomas Fork Formation (pl. 4). The Thomas concentrations for the wells ranged from 197 to Fork Formation consists of variegated, banded, 1,120 mg/L, with a median of 504 mg/L. red, purple, brown, and green mudstone and minor interbedded gray to tan sandstone (Rubey, On the basis of the characteristics and constituents 1973b; Lines and Glass 1975; Rubey and others, analyzed for, the quality of water from springs 1980; M’Gonigle and Dover, 1992; Dover issuing from the Bear River aquifer in the OTB and M’Gonigle, 1993). In part, the sandstone was suitable for most uses. No characteristics or is conglomeratic with sediments (pebbles and constituents approached or exceeded applicable cobbles) as large as 4 inches in diameter, and USEPA or State of Wyoming domestic, agriculture, the mudstone contains gray to brown limestone or livestock water-quality standards. nodules as large as several inches in diameter (Rubey, 1973b). The formation is about 2,000- Concentrations of some properties and ft thick in the southwestern part of Star Valley constituents in water from wells completed in (Rubey, 1973b; Oriel and Platt, 1980; M’Gonigle the Bear River aquifer in the OTB approached or and Dover, 1992; Dover and M’Gonigle, 1993). exceeded applicable USEPA or State of Wyoming The formation merges to the south with and is water-quality standards and could limit suitability lithologically indistinguishable from the upper part
7-163 of the Early Cretaceous-age Kelvin Formation in 7.3.21 Smiths Formation northeastern Utah (Dover and M’Gonigle, 1993). The Lower Cretaceous Smiths Formation (pl. 4) No data were located describing the physical consists of ferruginous black shale and interbedded and chemical characteristics of the Thomas tan, quartz-rich, very fine-grained sandstone. The Fork Formation in the Snake/Salt River Basin, black shale and tan sandstone are interbedded but considerable insight into the hydrogeologic throughout the formation, but the upper unnamed properties of the unit is provided by investigations member primarily is tan sandstone, and the lower in the Bear River Basin immediately to the south. unnamed member primarily is black shale (Rubey, Most information about the physical and chemical 1973b; Rubey and others, 1980). The Smiths characteristics of the Thomas Fork aquifer was Formation thickens eastward from about 300 obtained through installation and subsequent ft in Idaho to about 850 ft in Wyoming (Oriel testing of three wells completed in the aquifer to and Platt, 1980; Rubey and others, 1980). No replace three springs as the water supply for the data were located describing the physical and town of Cokeville in the Bear River Basin south chemical hydrogeologic characteristics of the of the Snake/Salt River Basin (Forsgren Associates, lithostratigraphic unit in the Snake/Salt River 1993b,c; TriHydro Corporation, 1993b, 2002, Basin. 2003). The Thomas Fork Formation is tentatively classified as an aquifer herein in the Snake/Salt 7.3.22 Kootenai Formation River Basin based on these investigations. In fact, previous descriptions of the hydrogeologic The Lower Cretaceous Kootenai Formation (pl. characteristics of the Thomas Fork Formation 6) consists of rusty thin-bedded sandstone, and were very limited. Lines and Glass (1975, Sheet grayish-red, soft claystone, white limestone, and 1) speculated that sandstone beds in the Thomas chert-pebble conglomerate (Love and Christiansen, Fork Formation in the Overthrust Belt might yield 1985, Sheet 2). Cox (1976, Sheet 1) speculated "small quantities" of water to wells. that sandstone in the Kootenai Formation probably would not yield more than a few TriHydro Corporation (2002, p. 3-7) reported gallons per minute per well. No data were located that sandstone beds composing the Thomas Fork describing the physical and chemical hydrogeologic aquifer in the Cokeville area typically were well characteristics of the lithostratigraphic unit in the cemented with calcite cement, and typically have Snake/Salt River Basin. poor intergranular porosity in "an unweathered and unfractured condition." Porosity and permeability 7.3.23 Cloverly aquifer were attributed to fractures in the sandstone beds composing the aquifer. Based on interpretation of The Cloverly aquifer consists of saturated and aquifer tests conducted on the production wells, permeable parts of the Lower Cretaceous Cloverly the investigators concluded that the Thomas Fork Formation in the Snake/Salt River Basin (pls. aquifer was a semiconfined, fracture-flow aquifer 5 and 6). The formation consists of two units with primarily conduit flow. The investigators in the Snake/Salt River Basin (Love and others, (TriHydro Corporation, 2002, p. 3-10) also 1992). The upper unit is a 100- to 200-ft thick, conceptually described potential sources of recharge olive-green, gray, and buff thin-bedded sandstone to the aquifer in the area. Potential sources of that commonly weathers to a rusty color and is recharge identified were (1) streamflow losses and informally known as the "rusty beds member." The direct infiltration of precipitation and seepage to lower unit is a 290- to 545-ft thick, variegated red, overlying lithostratigraphic units and subsequent gray, lilac colored, and pink bentonitic claystone movement of water in these units downward into that commonly weathers to a "puffy surface;" the underlying Thomas Fork aquifer; and (2) direct thin beds of hard nodular dense cream-colored infiltration of precipitation (rain and snow) on limestone also are present. Thomas Fork aquifer outcrop areas.
7-164 The Cloverly Formation is classified as an aquifer by Eyer (1969) and Furer (1967, 1970). The by previous investigators in the adjacent Wind Gannett Group is composed of five formations River and Bighorn Basins east of the Snake/ (in descending order from top to bottom): Salt River Basin (Bartos and others, 2012, Smoot Formation, Draney Limestone, Bechler and references therein), and southeast in the Conglomerate, Peterson Limestone, and Ephraim Green River Basin (Bartos and Hallberg, 2010, Conglomerate. and references therein). The Wyoming Water Planning Program (1972, Table III-2) speculated The Smoot Formation of the Gannett Group was that the Cloverly Formation was a fair to poor described as the unnamed upper redbed member aquifer (pls. 5 and 6). The Cloverly Formation until named by Eyer (1969). The Smoot Formation is classified as a minor aquifer in the Wyoming is composed of interbedded red mudstone and Water Framework Plan (WWC Engineering siltstone (Oriel and Platt, 1980). The Smoot and others, 2007, Figure 4-9) (pls. 5 and 6). Formation is absent in some local areas and is Because lithologic characteristics of sandstones about 200-ft thick when combined with the in the Cloverly Formation likely are similar in all underlying Draney Limestone (Oriel and Platt, Wyoming structural basins, classification of the 1980). lithostratigraphic unit as an aquifer was tentatively retained herein for the Snake/Salt River Basin (pls. The Draney Limestone of the Gannett Group 5 and 6). Cox (1976) noted that sandstone in the consists of dark to medium gray limestone, unit probably would not yield more than a few weathering light gray, very fine-crystalline to gallons per minute per well. No data were located aphanitic limestone interbedded with dark gray describing the physical and chemical hydrogeologic calcareous shale and siltstone (Lines and Glass characteristics of the lithostratigraphic unit in the 1975; Oriel and Platt, 1980; Rubey and others, Snake/Salt River Basin. 1980). The unit is about 200-ft thick when combined with the overlying Smoot Formation. 7.3.24 Gannett aquifer and confining unit The Bechler Conglomerate of the Gannett Group is composed of red, red-gray, purple, and purple- The physical and chemical characteristics of the gray, calcareous mudstone and siltstone, which Gannett aquifer and confining unit in the Snake/ becomes increasingly sandstone and chert-pebble Salt River Basin are described in this section of the conglomerate towards the west (Lines and Glass report. 1975; Oriel and Platt, 1980; Rubey and others, 1980). A few thin limestone interbeds occur locally. Physical characteristics The formation is about 1,300-ft thick.
The Gannett aquifer and confining unit is The Peterson Limestone of the Gannett Group composed of the Lower Cretaceous Gannett consists of light to medium gray and pastel- Group (pl. 4). The Gannett Group consists of colored, weathering very light gray, very fine- red sandy mudstone, sandstone, and chert-pebble crystalline limestone and pastel-colored calcareous conglomerate. Some thin limestone and dark gray mudstone (Lines and Glass 1975; Oriel and Platt, shale are present in the upper part of the unit, and 1980; Rubey and others, 1980). The unit is about the lower part is more conglomeratic. Reported 230-ft thick. thicknesses vary. Thickness of the Gannett Group decreases from about 2,953 ft in Idaho to about The basal Ephraim Conglomerate of the Gannett 787 ft in Wyoming (Oriel and Platt, 1980). Group is composed of brick-red, red, orange-red, and maroon mudstone and siltstone; light gray, In some areas, the Gannett Group is mapped red, tan, and brown, crossbedded, coarse-grained as separate formations or groups of formations. calcareous to quartzitic sandstone; and red to The Gannett Group was described in detail brown, chert-pebble conglomerate. Thickness of
7-165 the Ephraim Conglomerate decreases eastward as a marginal aquifer (WWC Engineering and from about 3,300 ft in Idaho to about 490 ft in others, 2007, Figure 4-9) (pl. 4). Wyoming (Lines and Glass 1975; Oriel and Platt, 1980; Rubey and others, 1980; M’Gonigle and Because the unit has low overall permeability, Dover, 1992). but has distinct zones and formations of higher permeability with potential to yield water to Permeability in the Gannett Group likely is small wells, the Gannett Group was classified as both on a regional scale, and thus, in most areas the an aquifer and confining unit herein (pl. 4). Few unit is capable of yielding only small quantities hydrogeologic data describing the Gannett aquifer of water locally. However, more permeable water- and confining unit in the Snake/Salt River Basin bearing parts of the Gannett Group capable of are available, but spring-discharge and well-yield yielding larger quantities of water are present in the measurements inventoried as part of this study are conglomeratic formations (Bechler and Ephraim shown on plate 3. Conglomerates) and in areas where fractures and solution openings (secondary permeability) are Chemical characteristics present (Robinove and Berry, 1963; Lines and Glass, 1975, Sheet 1; Ahern and others, 1981, The chemical characteristics of groundwater from Table IV-1). In addition, sandstone beds in the the Gannett aquifer and confining unit in the lower part of the Gannett Group also may be Snake/Salt River Basin are described in this section permeable and water-bearing (Ahern and others, of the report. Groundwater quality of the Gannett 1981, Table IV-1). The Wyoming Water Planning aquifer and confining unit is described in terms Program (1972, Table III-2) speculated that the of a water’s suitability for domestic, irrigation, Smoot Formation and Ephraim Conglomerate and livestock use, on the basis of USEPA and might be poor to fair aquifers; the Draney WDEQ standards (table 5-2), and groundwater- Limestone might be a poor aquifer (?); the Bechler quality sample summary statistics tabulated by Conglomerate might be a poor aquifer; and the hydrogeologic unit as quantile values (appendix Peterson Limestone might be a fair to poor aquifer E–5). (?) in the Snake/Salt River Basin (pl. 4). Ahern and others (1981, Figure II-7) classified the Gannett Overthrust Belt Group as a series of "discontinuous aquifers with The chemical composition of groundwater in local confining units" in the Overthrust Belt and the Gannett aquifer and confining unit in the the adjacent Green River Basin (pl. 4). Glover Overthrust Belt (OTB) was characterized and the (1990) considered the Ephraim Conglomerate of quality evaluated on the basis of environmental the Gannett Group (identified as a conglomerate water samples from three springs and one well. near the base of the Gannett Group) to be a minor Individual constituents are listed in appendix aquifer in the Evanston area in the Bear River E–5. Major-ion composition in relation to TDS valley in the Overthrust Belt to the south of the for springs issuing from the Gannett aquifer and Snake/Salt River Basin. He also noted that aquifers confining unit is shown on a trilinear diagram in the Gannett Group were hydraulically isolated (appendix F–5, diagram E). TDS concentrations from the overlying Evanston aquifer (Hams indicated that all waters were fresh (TDS Fork Conglomerate Member of the Evanston concentrations less than or equal to 999 mg/L) Formation), Wasatch aquifer, and Bear River (appendix E–5; appendix F–5, diagram E). The alluvial aquifer. TriHydro Corporation (1993b, TDS concentrations for the springs ranged from p. II-3) reported that the Ephraim Conglomerate 141 to 228 mg/L, with a median of 208 mg/L. The produced about 10 gal/min during drilling of TDS concentration for the well was 318 mg/L. a test boring at the Spring Creek anticline near Cokeville in the Bear River Basin to the south of On the basis of the characteristics and constituents the Snake/Salt River Basin. In the Wyoming Water analyzed for, the quality of water from springs Framework Plan, the Gannett Group was classified issuing from the Gannett aquifer and confining
7-166 unit in the OTB was suitable for most uses. No a few gallons per minute per well in northwestern characteristics or constituents approached or Wyoming. No data were located in the Snake/Salt exceeded applicable USEPA or State of Wyoming River Basin describing the physical and chemical domestic, agriculture, or livestock water-quality characteristics of the hydrogeologic unit. standards. 7.3.26 Ellis Group On the basis of the characteristics and constituents analyzed for, the quality of water in the one well In the Yellowstone Volcanic Area in the Snake/ sample completed in the Gannett aquifer and Salt River Basin, the Middle Jurassic Ellis Group confining unit in the OTB was suitable for most is composed of three different formations—the uses. One characteristic (pH) had a value outside Swift, Rierdon, and Sawtooth Formations (Love the range for USEPA aesthetic standards for and Christiansen, 1985, Sheet 2) (pl. 1; pl. 6). The domestic use and WDEQ livestock-use standards Swift Formation consists of calcareous, glauconitic (above upper SMCL and WDEQ Class III limit sandstone and sandy limestone. The Rierdon of 8.5). No characteristics or constituents had Formation consists of mudstone, siltstone, shale, concentrations that exceeded State of Wyoming and basal limestone. The Sawtooth Formation agricultural standards. consists of redbeds and limestone. No data were located describing the physical and chemical 7.3.25 Morrison confining unit characteristics of the Ellis Group in the Snake/Salt River Basin. The Upper Jurassic Morrison Formation comprises the Morrison confining unit in the Snake/ 7.3.27 Sundance aquifer Salt River Basin (pls. 5 and 6). The Morrison Formation consists of buff and gray sandstone The Middle and Upper Jurassic Sundance interbedded with red, green, and gray siltstone and Formation comprises the Sundance aquifer in claystone (Love and others, 1992). Thickness of the Snake/Salt River Basin (pls. 5 and 6). The the formation ranges from 185 to 250 ft (Love and formation consists of two lithologic units in the others, 1992). Snake/Salt River Basin. The upper unit consists of glauconitic gray, buff, and green very calcareous The Morrison Formation is classified as a confining sandstone with a few thin shale beds and very unit, an aquifer, or both, by previous investigators fossiliferous limestone beds (Love and others, in the adjacent Wind River and Bighorn Basins 1992). Thickness of the upper unit ranges from 75 east of the Snake/Salt River Basin (Bartos and to 140 ft. The lower unit consists of gray calcareous others, 2012, and references therein), and southeast plastic to splintery shale, clayey limestone, hard in the Green River Basin (Bartos and Hallberg, oolitic limestone, and one or more zones of 2010, and references therein). The Wyoming Water red, soft, plastic shale (Love and others, 1992). Planning Program (1972, Table III-2) speculated The lower unit is marine in origin and is highly that the Morrison Formation was probably a poor fossiliferous. Thickness of the lower unit ranges aquifer in the Snake/Salt River Basin (pls. 5 and from 400 to 550 ft. 6). The Morrison Formation is classified as a minor aquifer in the Wyoming Water Framework Plan Cox (1976, Sheet 1) speculated that the unit (WWC Engineering and others, 2007, Figure 4-9) may yield a few gallons per minute per well from (pls. 5 and 6). Because lithologic characteristics sandstone and from fractures and solution channels of the Morrison Formation generally are similar in limestone. No data were located in the Snake/ in all Wyoming structural basins, classification of Salt River Basin describing the physical and the lithostratigraphic unit as a confining unit was chemical characteristics of the hydrogeologic unit. tentatively retained herein for the Snake/Salt River Basin (pls. 5 and 6). Cox (1976, Sheet 1) noted that the unit probably would not yield more than
7-167 7.3.28 Stump Formation composed of green-gray to olive-green, soft, flaky to fissile claystone with minor thin interbeds of The physical and chemical characteristics of the sandstone and oolitic, fossiliferous limestone. The Stump Formation in the Snake/Salt River Basin are lower lithologic unit is composed of green-gray to described in this section of the report. brown-gray, glauconitic, thin- to thick-bedded, ripple-marked, crossbedded, fine- to very fine- Physical characteristics grained sandstone (some silty and medium-grained sandstone). The Upper to Middle Jurassic Stump Formation (pl. 4) consists of interbedded light to dark Little information is available describing the green, green-gray, glauconitic, fine-grained hydrogeologic characteristics of the Stump sandstone, siltstone, and limestone (Lines and Formation. Robinove and Berry (1963, Plate 1) Glass, 1975; Oriel and Platt, 1980; Rubey and speculated that the Stump Formation was likely to others, 1980; M’Gonigle and Dover, 1992; Dover yield small quantities of groundwater to wells in and M’Gonigle, 1993). Pipiringos and Imlay the Bear River valley in the Overthrust Belt south (1979) divided the Stump Formation into two of the Snake/Salt River Basin. The Wyoming Water members—the Upper Jurassic Redwater Member Planning Program (1972, Table III-2) speculated and the Middle Jurassic Curtis Member (individual that the Stump Formation was a fair to poor (?) members not shown on Plate 4). The Stump aquifer in the Snake/Salt River Basin (pl. 4). Lines Formation ranges in thickness from 92 ft to at and Glass (1975, Sheet 1) noted that rocks in the least 400 ft in the Overthrust Belt area, and thins Stump Formation in the Overthrust Belt were irregularly to the north and east from the thickest relatively impermeable and in most areas were section in southeastern Idaho (Pipiringos and probably capable of yielding only small quantities Imlay, 1979; Oriel and Platt, 1980; Rubey and of water. Ahern and others (1981, Figure II-7, others, 1980; M’Gonigle and Dover, 1992; Dover Table IV-1) classified the Stump Formation as a and M’Gonigle, 1993). The upper member of the confining unit [aquitard] or poor aquifer (pl. 4). Stump Formation is similar to the silty to sandy Few hydrogeologic data are available describing facies of the Redwater Member of the Sundance the Stump Formation, but well-yield and spring- Formation eastward in Wyoming, whereas the discharge measurements inventoried for the lower member is similar to the Curtis Formation lithostratigraphic unit in the Snake/Salt River Basin in the San Rafael Swell area of central Utah are summarized in plate 3. (Pipiringos and Imlay, 1979). Chemical characteristics The Redwater Member of the Stump Formation consists of two lithologic units (Pipiringos The chemical characteristics of groundwater from and Imlay, 1979). The upper lithologic unit the Stump Formation in the Snake/Salt River is composed of gray, green-gray, nearly white, Basin are described in this section of the report. glauconitic, thin- to thick-bedded, crossbedded Groundwater quality of the Stump Formation sandstone with minor interbeds of sandy siltstone, is described in terms of a water’s suitability for clayey siltstone, and oolitic, sandy limestone, which domestic, irrigation, and livestock use, on the basis locally contains chert pebbles, belemnite fossils, of USEPA and WDEQ standards (table 5-2), and and ammonite fossils. The lower lithologic unit groundwater-quality sample summary statistics is composed of yellow-gray to brown, glauconitic tabulated by hydrogeologic unit as quantile values siltstone and claystone, which is locally sandy and (appendices E–3 and E–5). contains belemnite fossils. Jackson Hole The Curtis Member of the Stump Formation The chemical composition of the Stump Formation consists of two lithologic units (Pipiringos in Jackson Hole (JH) was characterized and the and Imlay, 1979). The upper lithologic unit is quality evaluated on the basis of one environmental
7-168 water sample from one spring. Individual Creek Limestone (pl. 4). constituents are listed in appendix E–3. The TDS concentration (245 mg/L) indicated that the water Little information is available describing the was fresh (concentration less than or equal to hydrogeologic characteristics of the Preuss 999 mg/L) (appendix E–3). On the basis of the Sandstone or Redbeds. Robinove and Berry (1963, characteristics and constituents analyzed for in the Plate 1) speculated that the Preuss Sandstone or one spring sample, the quality of water from the Redbeds were likely to yield small quantities of Stump Formation in JH was suitable for most uses. groundwater to wells in the Bear River valley in No characteristics or constituents approached or the Overthrust Belt to the south of the Snake/ exceeded applicable USEPA or State of Wyoming Salt River Basin,. The Wyoming Water Planning domestic, agriculture, or livestock water-quality Program (1972, Table III-2) speculated that standards. the Preuss Sandstone or Redbeds likely were a poor aquifer (?) in the Snake/Salt River Basin Overthrust Belt (pl. 4). Lines and Glass (1975, Sheet 1) noted The chemical composition of groundwater in the that rocks in the Preuss Sandstone or Redbeds Stump Formation in the Overthrust Belt (OTB) were relatively impermeable and in most areas was characterized and the quality evaluated on were probably capable of yielding only small the basis of one environmental water sample quantities of water. Ahern and others (1981, from one spring. Individual constituents are Figure II-7, Table IV-1) classified the formation listed in appendix E–5. The TDS concentration as a confining unit [aquitard] or poor aquifer (pl. (241 mg/L) indicated that the water was fresh 4). No data were located describing the physical (concentration less than or equal to 999 mg/L) and chemical hydrogeologic characteristics of the (appendix E–5). On the basis of the characteristics lithostratigraphic unit in the Snake/Salt River and constituents analyzed for in the one spring Basin. sample, the quality of water from the Stump Formation in the OTB was suitable for most uses. In outcrop and shallow groundwater areas, bedded No characteristics or constituents approached or halite (rock salt) in the lower part of the formation exceeded applicable USEPA or State of Wyoming has been removed by dissolution (Imlay, 1952). In domestic, agriculture, or livestock water-quality areas where evaporite beds have been removed by standards. dissolution, breccia zones and collapse structures may have formed and consequently, may have 7.3.29 Preuss Sandstone or Redbeds increased permeability.
The Middle Jurassic Preuss Sandstone or Redbeds 7.3.30 Twin Creek aquifer (plate 4) consists of interbedded purple, maroon, dull red, purple-gray, and red-gray, siltstone, sandy The physical and chemical characteristics of the siltstone, silty claystone, and claystone with minor Twin Creek aquifer in the Snake/Salt River Basin interbedded halite (rock salt), alum, and gypsum are described in this section of the report. locally present in irregular zones (Lines and Glass, 1975, Sheet 1; Oriel and Platt, 1980; Rubey and Physical characteristics others, 1980; M’Gonigle and Dover, 1992; Dover and M’Gonigle, 1993). Beds of red, gray, and tan, The Twin Creek aquifer is composed of the Middle fine-grained, thin-bedded and regular-bedded Jurassic Twin Creek Limestone (pl. 4). The Twin sandstone also are present. Formation thickness Creek Limestone consists of green-gray argillaceous decreases eastward from about 1,640 ft in Idaho to (shaly) limestone and calcareous siltstone. 360 ft in Wyoming (Lines and Glass, 1975, Sheet Thickness of the formation decreases eastward 1; Oriel and Platt, 1980; Rubey and others, 1980). from about 3,300 ft in Idaho to about 440 ft in The Preuss Sandstone or Redbeds are overlain by Wyoming (Imlay, 1967; Lines and Glass 1975; the Stump Formation and underlain by the Twin Oriel and Platt, 1980; Rubey and others, 1980;
7-169 M’Gonigle and Dover, 1992). The formation is Limestone consists of gray, compact, dense, brittle, as much as 2,900-ft thick above and to the west medium- to thin-bedded limestone, which forms of the Absaroka thrust fault (WSGS Plate 1?). prominent cliffs and ridges. The basal unit of the Thickness of the Twin Creek Limestone below Watton Canyon Member generally is massive and and to the east of the Absaroka thrust fault in the oolitic, and some oolitic limestone interbeds occur Kemmerer area in the Bear River Basin south of throughout the unit. The upper part of the Watton the Snake/Salt River Basin ranges from 800 to Canyon Member grades upward into the shaly, 1,000 ft (M’Gonigle and Dover, 1992). The Twin soft basal limestone of the overlying Leeds Creek Creek Limestone was deposited in a Jurassic seaway Member and contains pelecypod fossils. Thickness marine environment, as reflected by the presence of of the Watton Canyon Member decreases eastward pelecypod fossils such as Gryphaea (Imlay, 1967). from about 400 to 60 ft (Imlay, 1967). Imlay (1967) defined and described seven members of the Twin Creek Formation in the Overthrust The Boundary Ridge Member of the Twin Creek Belt of Wyoming-Idaho-Utah. These members are, Limestone consists of red, green, and yellow, soft from youngest (top) to oldest (bottom): Giraffe siltstone with interbedded silty to sandy or oolitic Creek Member, Leeds Creek Member, Watton limestone. The Boundary Ridge Member grades Canyon Member, Boundary Ridge Member, Rich eastward into red, gypsiferous, soft siltstone and Member, Sliderock Member, and Gypsum Spring claystone, and grades westward into cliff-forming, Member (individual members not shown on Plate oolitic to dense limestone with minor interbedded 4). red siltstone. The Boundary Ridge Member is overlain by the cliff-forming, basal limestone of The Giraffe Creek Member of the Twin Creek the Watton Canyon Member. Thickness decreases Limestone consists of yellow-gray, green-gray, eastward from about 285 to 30 ft (Imlay, 1967). and pink-gray, silty to sandy, ripple-marked, thin-bedded limestone and sandstone with minor The Rich Member of the Twin Creek Limestone thick interbeds of oolitic sandy limestone. Sand consists of gray, shaly limestone that is very soft at and glauconite content increases to the west, and the base; clay content increases to the north, and the Giraffe Creek Member of the Twin Creek the upper part grades into the basal hard sandy Limestone grades upward into red, soft siltstone limestone or red, soft siltstone of the Boundary at the base of the Preuss Sandstone or Redbeds. Ridge Member of the Twin Creek Limestone. Thickness decreases eastward and northward from Pelecypod and cephalopod fossils are present. 295 to 25 ft (Imlay, 1967). Thickness of the Rich Member decreases eastward from 500 to 40 ft (Imlay, 1967). The Leeds Creek Member of the Twin Creek Limestone consists of light gray, dense, shaly, soft The Sliderock Member of the Twin Creek limestone, which weathers into slender splinters, Limestone consists of gray-black, medium- to and minor interbeds of oolitic silty or sandy, ripple- thin-bedded limestone with oolitic basal beds, and marked limestone. Clay content increases to the commonly forms a low ridge between adjacent northeast in Idaho and Wyoming and to the south members. Pelecypod and cephalopod fossils are in Utah. The Leeds Creek Member is the least present. Thickness of the Sliderock Member resistant member of the Twin Creek Limestone decreases eastward from 285 to 20 ft (Imlay, and commonly forms valleys in outcrop areas. The 1967). Leeds Creek Member of the Twin Creek Limestone grades upward into the harder, silty to sandy, basal The Gypsum Spring Member of the Twin Creek limestone of the overlying Giraffe Creek Member. Limestone consists of red to yellow, soft siltstone Thickness decreases eastward from about 1,600 to and claystone, interbedded with brecciated, vuggy, 260 ft (Imlay, 1967). or chert-bearing limestone. In Wyoming, a basal unit of brecciated limestone is present and grades The Watton Canyon Member of the Twin Creek eastward into thick, massive gypsum deposits.
7-170 The chert-bearing limestone thickens westward with, and "drain into" the underlying Nugget from a few feet thick in Wyoming to a thick, cliff- aquifer. Clarey (2011) speculated that groundwater forming unit in Idaho. Locally, the top bed of the from the Gypsum Spring Member in areas where Gypsum Spring Member is a green tuff. Thickness gypsum deposits are present may have the potential of the Gypsum Spring Member decreases eastward for calcium-sulfate-type waters and large TDS from 400 to 12 ft (Imlay, 1967). In some areas of concentrations. Wyoming, including parts of the Snake/Salt River Basin, the Gypsum Spring Member of the Twin Chemical characteristics Creek Limestone has been elevated to formation rank and is referred to as the Gypsum Spring The chemical characteristics of groundwater from Formation (Love and others, 1993). the Twin Creek aquifer in the Snake/Salt River Basin are described in this section of the report. The Twin Creek Limestone is classified as Groundwater quality of the Twin Creek aquifer an aquifer or potential aquifer by previous is described in terms of a water’s suitability for investigators and that classification is retained domestic, irrigation, and livestock use, on the basis herein (pl. 4). Robinove and Berry (1963, Plate of USEPA and WDEQ standards (table 5-2), and 1) speculated that the Twin Creek Limestone was groundwater-quality sample summary statistics likely to yield small quantities of groundwater to tabulated by hydrogeologic unit as quantile values wells in the Bear River valley in the Overthrust (appendices E–2, E–5, and E–6). Belt to the south of the Snake/Salt River Basin. The Wyoming Water Planning Program (1972, Table Northern Ranges III-2) speculated that the Twin Creek Limestone The chemical composition of the Twin Creek was a poor aquifer (?) in the Snake/Salt River Basin aquifer in the Northern Ranges (NR) was (pl. 4). Lines and Glass (1975, Sheet 1) noted that characterized and the quality evaluated on the permeability in the upper part of the Twin Creek basis of one environmental water sample from Limestone likely was low compared to the lower one spring. Individual constituents are listed part and thus, the formation likely would yield in appendix E–2. The TDS concentration small quantities of water to wells completed in (256 mg/L) indicated that the water was fresh the upper part of the unit. The investigators noted (concentration less than or equal to 999 mg/L) that limestone in the lower part of the Twin Creek (appendix E–2). On the basis of the characteristics Limestone is brecciated and honeycombed; thus, and constituents analyzed for in the one spring wells completed in the lower part of the formation sample, the quality of water from the Twin Creek were more likely to yield moderate quantities of aquifer in the NR was suitable for most uses. water (Lines and Glass, 1975, Sheet 1). In the No characteristics or constituents approached or Wyoming Water Framework Plan, the Twin Creek exceeded applicable USEPA or State of Wyoming Limestone was classified as a minor aquifer (WWC domestic, agriculture, or livestock water-quality Engineering and others, 2007, Figure 4-9) (pl. standards. 4). Hydrogeologic data describing the Twin Creek aquifer, including spring-discharge measurements Overthrust Belt and other hydraulic properties, are summarized on The chemical composition of groundwater in the pl. 3. Twin Creek aquifer in the Overthrust Belt (OTB) was characterized and the quality evaluated on The Twin Creek aquifer likely is in hydraulic the basis of environmental water samples from as connection with the underlying Nugget aquifer many as 10 springs. Summary statistics calculated (Lines and Glass, 1975, Sheet 1; Ahern and others, for available constituents are listed in appendix 1981). In fact, Lines and Glass (1975, Sheet 1) E–5. Major-ion composition in relation to TDS noted that few springs issue from the lower part concentrations for springs issuing from the Twin of the Twin Creek Limestone, possibly because Creek aquifer is shown on a trilinear diagram the overlying unit may be in hydraulic connection (appendix F–5, diagram F). TDS concentrations
7-171 indicated that all waters were fresh (TDS Physical characteristics concentrations less than or equal to 999 mg/L) (appendix E–5; appendix F–5, diagram F). The The Gypsum Spring confining unit is composed TDS concentrations for the springs ranged from of the Middle Jurassic Gypsum Spring Formation 133 to 326 mg/L, with a median of 219 mg/L. (pls. 5 and 6). The Gypsum Spring Formation On the basis of the characteristics and constituents consists of dark-red soft shale, underlain by and analyzed for in the spring samples, the quality of interbedded with slabby gray dolomite and white water from the Twin Creek aquifer in the OTB gypsum. In most outcrop areas, gypsum in the was suitable for most uses. No characteristics or formation has been leached, leaving lithified constituents approached or exceeded applicable carbonate breccia that forms rounded cliffs (Love USEPA or State of Wyoming domestic, agriculture, and others, 1992). Thickness of the formation or livestock water-quality standards. ranges from 50 to 150 ft, depending on amount of leaching of gypsum (Love and others, 1992). Star Valley The chemical composition of the Twin Creek The Gypsum Spring Formation is classified as aquifer in the Star Valley (SV) was characterized a confining unit, aquifer, or both by previous and the quality evaluated on the basis of one investigators in the adjacent Wind River and environmental water sample from one spring. Bighorn Basins east of the Snake/Salt River Basin Individual constituents are listed in appendix E–6. (Bartos and others, 2012, and references therein), The TDS concentration (614 mg/L) indicated that and southeast in the Green River Basin (Bartos waters were fresh (TDS concentrations less than or and Hallberg, 2010, and references therein). equal to 999 mg/L) (appendix E–6). The Wyoming Water Planning Program (1972, Table III-2) speculated that the Gypsum Spring Concentrations of some properties and Formation was a poor aquifer in the Snake/Salt constituents in water from a spring issuing from River Basin (pls. 5 and 6). The Gypsum Spring the Twin Creek aquifer in the SV approached or Formation was classified as a marginal aquifer in exceeded applicable USEPA or State of Wyoming the Wyoming Water Framework Plan (WWC water-quality standards and could limit suitability Engineering and others, 2007, Figure 4-9) (pls. for some uses. Most environmental waters were 5 and 6). Because of lithologic characteristics of suitable for domestic use, as no concentrations the Gypsum Spring Formation in the study area of constituents exceeded health-based standards. (described above), the lithostratigraphic unit was Concentrations of one characteristic and one tentatively classified as a confining unit in the constituent exceeded USEPA aesthetic standards Snake/Salt River Basin (pls. 5 and 6). One spring for domestic use: TDS (exceeded SMCL limit of discharge was inventoried as part of this study for 500 mg/L) and sulfate (exceeded SMCL of 250 the Gypsum Spring confining unit in the Snake/ mg/L). One constituent in the spring approached Salt River Basin (pl. 3). or exceeded applicable State of Wyoming standards for agricultural-use standards: sulfate (exceeded Chemical characteristics WDEQ Class II standard of 200 mg/L). No characteristics or constituents approached or The chemical characteristics of groundwater from exceeded applicable State of Wyoming livestock the Gypsum Spring confining unit in the Snake/ water-quality standards. Salt River Basin are described in this section of the report. Groundwater quality of the Gypsum Spring 7.3.31 Gypsum Spring confining unit confining unit is described in terms of a water’s suitability for domestic, irrigation, and livestock The physical and chemical characteristics of the use, on the basis of USEPA and WDEQ standards Gypsum Spring confining unit in the Snake/Salt (table 5-2), and groundwater-quality sample River Basin are described in this section of the summary statistics tabulated by hydrogeologic unit report. as quantile values (appendix E–2).
7-172 Northern Ranges Gros Ventre Ranges) ranges from about 100 to 400 The chemical composition of the Gypsum Spring ft (Pampeyan and others, 1967; Oriel and Moore, confining unit in the Northern Ranges (NR) was 1985; Love and others, 1992; Love, 2001a,b,c). characterized and the quality evaluated on the Reported maximum thickness of the Nugget basis of one environmental water sample from Sandstone in the Overthrust Belt ranges from one spring. Individual constituents are listed in about 250 to 984 ft (Jobin, 1965, 1972; Pampeyan appendix E–2. The TDS concentration (2,190 and others, 1967; Schroeder, 1969, 1972, 1973, mg/L) indicated that the water was slightly saline 1974, 1976, 1979, 1981; Albee, 1968, 1973; (TDS concentration ranging from1,000 to 2,999 Albee and Cullins, 1975; Oriel and Platt, 1980; mg/L) (appendix E–2). Schroeder and others, 1981; Love and others, 1992; Love, 2003c). Concentrations of some properties and constituents in water from the spring issuing from the Gypsum The Nugget Sandstone is classified as an aquifer Spring confining unit in the NR approached or by all investigators and that classification is exceeded applicable USEPA or State of Wyoming retained herein (pls. 4, 5, and 6). Robinove and water-quality standards and could limit suitability Berry (1963, Plate 1) speculated that the Nugget for some uses. Most environmental waters were Sandstone was likely to yield small quantities of suitable for domestic use, as no concentrations groundwater to wells in the Bear River valley in of constituents exceeded health-based standards. the Overthrust Belt to the south of the Snake/ Concentrations of one characteristic and one Salt River Basin. The Wyoming Water Planning constituent exceeded USEPA aesthetic standards Program (1972, Table III-2) speculated that for domestic use and State of Wyoming standards the Nugget aquifer was a fair to good aquifer for agricultural use: TDS (exceeded SMCL limit in the Snake/Salt River Basin (pls. 4, 5, and 6). of 500 mg/L and WDEQ Class II standard of Lines and Glass (1975, Sheet 1) considered the 2,000 mg/L) and sulfate (exceeded SMCL of 250 Nugget Sandstone to be the "best aquifer" in mg/L and WDEQ Class II standard of 200 mg/L). their "hydrogeologic division 4" (identified as No characteristics or constituents approached or being composed of Jurassic- and Cretaceous-age exceeded applicable State of Wyoming livestock sandstone and limestone and shown on pls. 4 and water-quality standards. 5) in the Overthrust Belt. The investigators (Lines and Glass, 1975, Sheet 1) reported that the Nugget 7.3.32 Nugget aquifer aquifer was capable of yielding moderate to large quantities of water where "outcrop or recharge The physical and chemical characteristics of the areas are large, where bedding is continuous and Nugget aquifer in the Snake/Salt River Basin are not offset by faults, and in topographic lows described in this section of the report. where large thickness of sandstone is saturated." Furthermore, the investigators (Lines and Glass, Physical characteristics 1975, Sheet 1) noted that few springs issue from the lower part of the Twin Creek Limestone, The Nugget aquifer is composed of the Triassic (?) possibly because the overlying unit may be in to Jurassic (?) Nugget Sandstone (pls. 4, 5, and hydraulic connection with, and "drain into" the 6). The Nugget Sandstone consists of tan to pink, underlying Nugget aquifer. Springs commonly crossbedded, well-sorted, quartz-rich sandstone issue from the Nugget aquifer in the Overthrust (Lines and Glass, 1975, Sheet 1; Oriel and Platt, Belt (Lines and Glass, 1975, Sheet 1) (also see pl. 1980; Rubey and others, 1980; Love and others, 3). In the Wyoming Water Framework Plan, the 1992). The Nugget Sandstone has been interpreted Nugget Sandstone was classified as a major aquifer as deposited as an eolian (wind-blown) sand dune (WWC Engineering and others, 2007, Figure 4-9) sequence from a desert or a beach environment. (pls. 4, 5, and 6). Spring-discharge and well-yield Reported maximum thickness of the Nugget measurements for the Nugget aquifer in the Snake/ Sandstone in the Northern Ranges (Teton and Salt River Basin inventoried as part of this study
7-173 are summarized in plate 3. many as 10 springs and 1 well. Summary statistics calculated for available constituents are listed in Ahern and others (1981, Figure II-7, and Table appendix E–5. Major-ion composition in relation IV-1) classified the Nugget Sandstone as a to TDS concentrations for springs issuing from major aquifer in the Overthrust Belt and the the Nugget aquifer is shown on a trilinear diagram adjacent Green River Basin (pls. 4 and 5). The (appendix F–5, diagram G). TDS concentrations Nugget aquifer was considered to be part of an indicated that all waters were fresh (TDS aquifer system, identified as the Nugget aquifer concentrations less than or equal to 999 mg/L) system, composed of the overlying Twin Creek (appendix E–5; appendix F–5, diagram G). The Limestone and the underlying Ankareh Formation TDS concentrations in the spring samples ranged and Thaynes Limestone in the Overthrust Belt from 30.0 to 388 mg/L, with a median of 106 (pl. 4). The investigators noted that porosity mg/L. The TDS concentration in the well sample and permeability in the Nugget aquifer were was 269 mg/L. On the basis of the characteristics "good," especially in the crossbedded upper part. and constituents analyzed for, the quality of water The investigators also speculated that smaller from the Nugget aquifer in the OTB was suitable transmissivities for the Nugget aquifer in the for most uses. No characteristics or constituents adjacent Green River Basin may be attributable to approached or exceeded applicable USEPA or State increased lithostatic pressure (deeper burial) and of Wyoming domestic, agriculture, or livestock decreased fracture occurrence. water-quality standards.
Clarey (2011) noted that the upper part of the 7.3.33 Chugwater aquifer and confining Nugget Sandstone in some areas of the Overthrust unit Belt has calcite (calcium carbonate) cement with slightly increased permeability, and that the lower The physical and chemical characteristics of the part of the formation has siliceous (quartz) cement Chugwater aquifer and confining unit in the with decreased permeability. The investigator Snake/Salt River Basin are described in this section reported that this "dual cementation feature" of of the report. the Nugget Sandstone has been observed in an oilfield production well located to the northeast of Physical characteristics Evanston in Uinta County, Wyoming. The Chugwater aquifer and confining unit is Chemical characteristics composed of the Upper and Lower Triassic- age Chugwater Formation (pls. 5 and 6). The The chemical characteristics of groundwater Chugwater Formation is composed of four from the Nugget aquifer in the Snake/Salt River members (Love and others, 1992) (individual Basin are described in this section of the report. members not shown on Plates 5 and 6). The Groundwater quality of the Nugget aquifer is uppermost unit, the Popo Agie Member, consists described in terms of a water’s suitability for of ocher and purple claystone, red shale, lenticular domestic, irrigation, and livestock use, on the basis purple limestone-pellet conglomerate, and red of USEPA and WDEQ standards (table 5-2), and siltstone, ranging in thickness from 75 to 300 groundwater-quality sample summary statistics ft. The next lower unit, the Crow Mountain tabulated by hydrogeologic unit as quantile values Sandstone Member, consists of red to salmon-pink (appendix E–5). soft porous sandstone containing large rounded quartz grains in a finer matrix, ranging in thickness Overthrust Belt from 50 to 100 ft. The next lower unit, the Alcova The chemical composition of groundwater in the Limestone Member, consists of gray and purple Nugget aquifer in the Overthrust Belt (OTB) thin-bedded hard limestone and dolomite with was characterized and the quality evaluated on interbeds of white gypsum, ranging in thickness the basis of environmental water samples from as from 10 to 60 ft. The lowermost unit is the Red
7-174 Peak Member, which consists of red gypsiferous is described in terms of a water’s suitability for siltstone and very fine grained sandstone domestic, irrigation, and livestock use, on the basis containing some red shale partings, ranging in of USEPA and WDEQ standards (table 5-2), and thickness from 800 to 1,275 ft. groundwater-quality sample summary statistics tabulated by hydrogeologic unit as quantile values The Chugwater Formation is classified as a (appendix E–2). confining unit, an aquifer, or both, by previous investigators (pls. 5 and 6). The Wyoming Water Northern Ranges Planning Program (1972, Table III-2) speculated The chemical composition of the Chugwater that the Chugwater Formation was probably a fair aquifer and confining unit in the Northern Ranges to poor aquifer (?) in the Snake/Salt River Basin (NR) was characterized and the quality evaluated (pls. 5 and 6). In the eastern Gros Ventre Range, on the basis of environmental water samples from the Chugwater Formation was combined by Mills two wells. Individual constituents are listed in (1989) and Mills and Huntoon (1989) with the appendix E–2. The TDS concentrations (153 and underlying Dinwoody and Phosphoria Formations 1,340 mg/L) indicated that the waters were fresh into a single confining unit that overlies and and slightly saline (TDS concentrations less than confines the underlying Tensleep aquifer (pl. 5). In or equal to 999 mg/L, and TDS concentrations the adjacent Wind River and Bighorn Basins east greater than or equal to 1,000 and less than or of the Snake/Salt River Basin (Bartos and others, equal to 2,999 mg/L, respectively). 2012, and references therein), and southeast in the Green River Basin (Bartos and Hallberg, 2010, and Concentrations of some properties and constituents references therein), the Chugwater Formation was in water from the Chugwater aquifer and confining classified as both aquifer and confining unit (pls. unit in the NR approached or exceeded applicable 5 and 6). The Chugwater Formation is classified as USEPA or State of Wyoming water-quality either a marginal aquifer or major aquitard in the standards and could limit suitability for some Wyoming Water Framework Plan, depending upon uses. No concentrations of constituents exceeded area of occurrence (WWC Engineering and others, health-based standards. Concentrations of one 2007, Figure 4-9) (pls. 5 and 6). Because lithologic characteristic and one constituent exceeded USEPA characteristics of the Chugwater Formation aesthetic standards for domestic use: TDS (1 of 2 generally are similar in all Wyoming structural samples exceeded SMCL limit of 500 mg/L) and basins, classification of the lithostratigraphic unit as sulfate (1 of 2 samples exceeded SMCL of 250 both an aquifer and confining unit was tentatively mg/L). One constituent approached or exceeded retained herein for the Snake/Salt River Basin applicable State of Wyoming standards for (pls. 5 and 6). Cox (1976, Sheet 1) noted that agricultural-use standards: sulfate (1 of 2 samples the unit probably would not yield more than a exceeded WDEQ Class II standard of 200 mg/L). few gallons per minute per well in northwestern No characteristics or constituents approached or Wyoming. Few hydrogeologic data are available exceeded applicable State of Wyoming livestock describing the Chugwater aquifer and confining water-quality standards. unit in the Snake/Salt River Basin, but two well- yield measurements were inventoried as part of this 7.3.34 Ankareh aquifer study and are presented on plate 3. The physical and chemical characteristics of the Chemical characteristics Ankareh aquifer in the Snake/Salt River Basin are described in this section of the report. The chemical characteristics of groundwater from the Chugwater aquifer and confining unit Physical characteristics in the Snake/Salt River Basin are described in this section of the report. Groundwater quality The Ankareh aquifer is composed of the Upper of the Chugwater aquifer and confining unit Triassic Ankareh Formation (pl. 4). The Ankareh
7-175 Formation consists of red and maroon shale and Basin are described in this section of the report. pale purple limestone with minor white to red, Groundwater quality of the Ankareh aquifer fine-grained, quartz-rich sandstone; thickness of is described in terms of a water’s suitability for the formation increases eastward from about 460 domestic, irrigation, and livestock use, on the basis ft in Idaho to about 920 ft in Wyoming (Lines of USEPA and WDEQ standards (table 5-2), and and Glass, 1975, Sheet 1; Oriel and Platt, 1980; groundwater-quality sample summary statistics M’Gonigle and Dover, 1992). In central Wyoming, tabulated by hydrogeologic unit as quantile values the Ankareh Formation is the stratigraphic (appendices E–2 and E–5). equivalent of the upper part of the Chugwater Group or Formation (including the Red Peak Northern Ranges Member, Alcova Limestone Member, unnamed The chemical composition of the Ankareh aquifer redbeds of interbedded siltstone and sandstone, in the Northern Ranges (NR) was characterized and Popo Agie Member of the Chugwater Group and the quality evaluated on the basis of one or Formation) (Kummel, 1954). The sandstone environmental water sample from one spring. may correlate westward to the Timothy Sandstone Individual constituents are listed in appendix E–2. Member of the Thaynes Limestone, and the The TDS concentration (256 mg/L) indicated limestone may correlate westward to the Portneuf that the water was fresh (TDS concentration less Limestone Member of the Thaynes Limestone than or equal to 999 mg/L) (appendix E–2). On (Kummel, 1954). Redbeds present below the thin the basis of the characteristics and constituents limestone or sandstone in the Ankareh Formation analyzed for in the one spring sample, the quality may correlate westward to the Lanes Tongue of the of water from the Ankareh aquifer in the NR Ankareh Formation (Kummel, 1954). was suitable for most uses. No characteristics or Previous investigators have defined the Ankareh constituents approached or exceeded applicable Formation as an aquifer, and that definition is USEPA or State of Wyoming domestic, agriculture, tentatively retained herein (pl. 4). Robinove and or livestock water-quality standards. Berry (1963, Plate 1) speculated that the Ankareh Formation was likely to yield small quantities Overthrust Belt of groundwater to wells in the Bear River valley The chemical composition of groundwater in the to the south of the Snake/Salt River Basin. The Ankareh aquifer in the Overthrust Belt (OTB) was Wyoming Water Planning Program (1972, Table characterized and the quality evaluated on the basis III-2) speculated that the Ankareh Formation was of environmental water samples from as many as probably a poor aquifer in the Snake/Salt River two springs. Individual constituents are listed in Basin (pl. 4). Lines and Glass (1975, Sheet 1) appendix E–5. The TDS concentrations (263 and noted that rocks in the Ankareh Formation were 364 mg/L) indicated that waters were fresh (TDS relatively impermeable in most areas, but that concentrations less than or equal to 999 mg/L) the unit was probably capable of yielding small (appendix E–5). On the basis of the characteristics quantities of water locally. Ahern and others (1981, and constituents analyzed for in the spring Figure II-7, and Table IV-1) defined the Ankareh samples, the quality of water from the Ankareh Formation as a minor aquifer or minor regional aquifer in the OTB was suitable for most uses. aquifer (locally confining) in the Overthrust Belt No characteristics or constituents approached or (pl. 4). Spring-discharge measurements for the exceeded applicable USEPA or State of Wyoming Ankareh aquifer in the Snake/Salt River Basin domestic, agriculture, or livestock water-quality inventoried as part of this study are summarized in standards. plate 3. 7.3.35 Thaynes aquifer Chemical characteristics The physical and chemical characteristics of the The chemical characteristics of groundwater Thaynes aquifer in the Snake/Salt River Basin are from the Ankareh aquifer in the Snake/Salt River described in this section of the report.
7-176 Physical characteristics member of the Thaynes Limestone is composed of dark gray, silty limestone. The lower limestone The Thaynes aquifer is composed of saturated and member of Thaynes Limestone consists of gray- permeable parts of the Upper and Lower Triassic blue to gray (weathers gray), massive limestone Thaynes Limestone (pl. 4). The Thaynes Limestone with cephalopod fossils. consists of gray limestone and brown-weathering, gray, calcareous siltstone with abundant dark Previous investigators generally have defined gray shale and abundant limestone in the lower the Thaynes Limestone as an aquifer and that part of the formation (Lines and Glass, 1975; definition is retained herein (plate 4). Robinove Oriel and Platt, 1980; M’Gonigle and Dover, and Berry (1963, Plate 1) speculated that the 1992). Thickness of the Thaynes Limestone in the Thaynes Limestone was likely to yield small Overthrust Belt ranges from about 250 to 1,640 ft quantities of groundwater to wells in the Bear (Jobin, 1965, 1972; Pampeyan and others, 1967; River valley to the south of the Snake/Salt River Albee, 1968, 1973; Schroeder, 1969, 1973, 1979, Basin. Lines and Glass (1975, Sheet 1) considered 1981, 1987; Albee and Cullins, 1975; Oriel and the Thaynes Limestone to be the "best aquifer" Platt, 1980; Schroeder and others, 1981; Oriel and in their "hydrogeologic division 3" (identified Moore, 1985; Lageson, 1986; Love and others, as being composed of Triassic and Permian 1992). Thickness of the Thaynes Limestone in the siltstones and limestones and shown on plate 4) Teton Range ranges from about 110 to 1,640 ft in the Overthrust Belt. Ahern and others (1981, (Pampeyan and others, 1967; Oriel and Moore, Figure II-7, and Table IV-1) defined the Thaynes 1985). Limestone as a major aquifer or regional aquifer in the Overthrust Belt. In contrast to these previous Kummel (1954) defined several members of the investigators, the Wyoming Water Planning Thaynes Limestone and the interfingering Ankareh Program (1972, Table III-2) speculated that the Formation, which the investigator considered a Thaynes Limestone was a confining unit in the member of the Thaynes Limestone (individual Snake/Salt River Basin (pl. 4). Limestone in the members not shown on Plate 4). The Timothy Thaynes aquifer likely yields moderate quantities Sandstone Member is the uppermost member of of water to wells; yields are greatest in areas with the Thaynes Limestone and is missing at some bedding-plane partings and where secondary locations. The Timothy Sandstone Member permeability in the form of fractures or solution consists of red siltstone, shale, and sandstone at openings, or both, has developed (Lines and Glass, Hot Springs along Indian Creek in southeastern 1975, Sheet 1; Ahern and others, 1981, Figure II- Idaho and rapidly thins eastward into Wyoming. In 7, and Table IV-1). Spring-discharge measurements adjacent Idaho, the Timothy Sandstone Member and other hydraulic properties for the Thaynes was removed by Trimble (1982) as a member aquifer in the Snake/Salt River Basin inventoried as of the Thaynes Limestone and was elevated to part of this study are summarized in plate 3. formation rank because of its "nonmarine origin." The Portneuf Limestone Member of the Thaynes Chemical characteristics Limestone consists of olive-gray, massive limestone and olive-light tan calcareous siltstone. The Lanes The chemical characteristics of groundwater Tongue of the Thaynes Limestone consists of from the Thaynes aquifer in the Snake/Salt River red, interbedded shale and siltstone. The redbeds Basin are described in this section of the report. member is similar to the overlying Ankareh Groundwater quality of the Thaynes aquifer is Formation. The upper calcareous siltstone member described in terms of a water’s suitability for consists of light tan, thin- to massively-bedded, domestic, irrigation, and livestock use, on the basis silty limestone and calcareous siltstone. The middle of USEPA and WDEQ standards (table 5-2), and shale member of the Thaynes Limestone consists of groundwater-quality sample summary statistics black shale and shaly limestone with cephalopod, tabulated by hydrogeologic unit as quantile values ammonite, and pelecypod fossils. The lower shale (appendix E–5).
7-177 Overthrust Belt Little information is available describing the The chemical composition of groundwater in the hydrogeologic characteristics of the Woodside Thaynes aquifer in the Overthrust Belt (OTB) Shale. Robinove and Berry (1963, Plate 1) was characterized and the quality evaluated on speculated that the Woodside Shale was likely to the basis of environmental water samples from as yield small quantities of groundwater to wells in many as six springs. Summary statistics calculated the Bear River valley to the south of the Snake/ for available constituents are listed in appendix Salt River Basin. The Wyoming Water Planning E–5. Major-ion composition in relation to TDS Program (1972, Table III-2) speculated that the concentrations for the six springs is shown on a Woodside Shale was a poor aquifer in the Snake/ trilinear diagram (appendix F–5, diagram H). Salt River Basin (pl. 4). Lines and Glass (1975, TDS concentrations indicated that all waters Sheet 1) noted that rocks in the Woodside Shale were fresh (TDS concentrations less than or were relatively impermeable in the Overthrust equal to 999 mg/L) (appendix E–5; Appendix Belt and in most areas were probably capable of F–5, diagram H). The TDS concentrations yielding only small quantities of water. Ahern and for the springs ranged from 89.0 to 281 mg/L, others (1981, Figure II-7) classified the formation with a median of 186 mg/L. On the basis of the as an aquitard (confining unit and that definition is characteristics and constituents analyzed for in tentatively retained herein (pl. 4). the spring samples, the quality of water from the Thaynes aquifer in the OTB was suitable for most Chemical characteristics uses. No characteristics or constituents approached or exceeded applicable USEPA or State of The chemical characteristics of groundwater from Wyoming domestic, agriculture, or livestock water- the Woodside confining unit in the Snake/Salt quality standards. River Basin are described in this section of the report. Groundwater quality of the Woodside 7.3.36 Woodside confining unit confining unit is described in terms of a water’s suitability for domestic, irrigation, and livestock The physical and chemical characteristics of the use, on the basis of USEPA and WDEQ standards Woodside confining unit in the Snake/Salt River (table 5-2), and groundwater-quality sample Basin are described in this section of the report. summary statistics tabulated by hydrogeologic unit as quantile values (appendix E–5). Physical characteristics Overthrust Belt The Woodside confining unit is composed of The chemical composition of groundwater in the the Lower Triassic Woodside Shale (pl. 4). The Woodside confining unit in the Overthrust Belt Woodside Shale consists of interbedded red (OTB) was characterized and the quality evaluated siltstone and shale with minor sandstone and gray on the basis of environmental water samples from limestone interbeds; thickness increases eastward as many as two springs. Individual constituents across the Overthrust Belt from about 390 ft in are listed in appendix E–5. Specific conductance Idaho to about 650 ft in Wyoming (Kummel, measurements (230 and 460 microsiemens per 1954; Lines and Glass, 1975, Sheet 1; Oriel and centimeter at 25 degrees Celsius) indicated that Platt, 1980; M’Gonigle and Dover, 1992). The both waters were fresh (specific conductance Woodside Formation overlies the Dinwoody measurements equivalent to TDS concentrations Formation and is overlain by the Thaynes less than or equal to 999 mg/L) (appendix Limestone in the Overthrust Belt in the Snake/ E–5). On the basis of the few characteristics and Salt River Basin (pl. 4). The upper part of the constituents analyzed for in the spring samples, Woodside Shale is stratigraphically equivalent to the quality of water from the Woodside confining the Red Peak Member of the Chugwater Group or unit in the OTB was suitable for most uses. No Formation (Kummel, 1954). characteristics or constituents approached or exceeded applicable USEPA or State of Wyoming
7-178 domestic, agriculture, or livestock water-quality Engineering and others, 2007, Figure 4-9) (pls. standards. 4, 5, and 6). Because the unit has low overall permeability, but with distinct zones of higher 7.3.37 Dinwoody aquifer and confining permeability with potential to yield water to wells, unit the Dinwoody Formation was classified as both an aquifer and confining unit herein (pls. 4, 5, and The physical and chemical characteristics of the 6). Few hydrogeologic data are available describing Dinwoody aquifer and confining unit in the Snake/ the Dinwoody aquifer and confining unit in the Salt River Basin are described in this section of the Snake/Salt River Basin, but two spring-discharge report. measurements were inventoried as part of this study and are listed on plate 3. Physical characteristics Chemical characteristics The Dinwoody aquifer and confining unit is composed of the Lower Triassic Dinwoody The chemical characteristics of groundwater Formation (pls. 4, 5, and 6). The Dinwoody from the Dinwoody aquifer and confining unit Formation consists of basal, middle, and upper in the Snake/Salt River Basin are described in units (Kummel, 1954). In Wyoming, the basal and this section of the report. Groundwater quality middle units thin eastward from the Overthrust of the Dinwoody aquifer and confining unit Belt to zero thickness. The 100- to 300-ft thick is described in terms of a water’s suitability for upper unit consists of interbedded, tan, calcareous domestic, irrigation, and livestock use, on the basis siltstone, gray silty limestone, gray crystalline of USEPA and WDEQ standards (table 5-2), and limestone, and a few shale beds. The 25- to 350- groundwater-quality sample summary statistics ft thick middle unit of the Dinwoody Formation tabulated by hydrogeologic unit as quantile values consists of interbedded, gray silty limestone, gray (appendices E–2 and E–6). crystalline limestone, and olive-light tan to gray shale beds. The 50- to 175-ft thick basal unit of the Northern Ranges Dinwoody Formation consists of light tan to tan, The chemical composition of the Dinwoody silty limestone and calcareous siltstone. aquifer and confining unit in the Northern Ranges (NR) was characterized and the quality evaluated Permeability in the Dinwoody aquifer and on the basis of one environmental water sample confining unit likely is small on a regional scale, from one spring. Individual constituents are listed and thus, in most areas the unit probably is capable in appendix E–2. The TDS concentration (262 of yielding only small quantities of water from mg/L) indicated that the water was fresh (TDS permeable zones where fractures and secondary concentration less than or equal to 999 mg/L) permeability are present (Lines and Glass, 1975, (appendix E–2). On the basis of the characteristics Sheet 1; Ahern and others, 1981, Table IV-1). and constituents analyzed for in the one spring Ahern and others (1981, Figure II-7, and Table sample, the quality of water from the Dinwoody IV-1) classified the Dinwoody Formation as an aquifer and confining unit in the NR was suitable aquitard (confining unit) with locally productive for most uses. No characteristics or constituents permeable zones in the Overthrust Belt and the approached or exceeded applicable USEPA or State adjacent Green River Basin (Plates 4 and 5). The of Wyoming domestic, agriculture, or livestock investigators (Ahern and others, 1981, Table IV- water-quality standards. 1) noted that the most productive parts of the Dinwoody Formation were in areas where fractures Star Valley were present and in interbedded sandstones in The chemical composition of the Dinwoody the upper part of the formation. In the Wyoming aquifer and confining unit in Star Valley (SV) was Water Framework Plan, the Dinwoody Formation characterized and the quality evaluated on the was classified as a marginal aquifer (WWDC basis of one environmental water sample from
7-179 one hot spring. Individual constituents are listed hydrogeologic units are accessible in or very close in appendix E–6. The TDS concentration (5,250 to these outcrop areas. Depending on location and mg/L) indicated that the water was moderately depth, wells completed in Paleozoic hydrogeologic saline (TDS concentration ranging from 3,000 to units produce highly variable quantities and quality 9,999 mg/L) (appendix E–6). of water. The highly complex structural features of the Overthrust Belt require site-specific geologic Concentrations of some properties and constituents and hydrogeologic investigation to characterize in water from the hot spring issuing from the and develop groundwater resources from Paleozoic Dinwoody aquifer and confining unit in SV hydrogeologic units. approached or exceeded applicable USEPA or State of Wyoming water-quality standards and could Relatively few water wells are completed in limit suitability for most uses. Concentrations of Paleozoic aquifers in the Snake/Salt River Basin, lead exceeded the USEPA action level of 15 µg/L. with most along mountain-basin margins where Concentrations of one characteristic and two they crop out and are directly exposed at land constituents exceeded USEPA aesthetic standards surface or immediately downgradient in adjacent for domestic use: TDS (exceeded SMCL limit of bordering basins where they occur at shallow 500 mg/L), chloride (exceeded SMCL limit of depths below younger hydrogeologic units. In 250 mg/L), and sulfate (exceeded SMCL of 250 these areas, waters are relatively fresh and suitable mg/L). Two characteristics and three constituents for most uses. However, permeability decreases approached or exceeded applicable State of and groundwater quality deteriorates rapidly Wyoming standards for agricultural use: SAR downgradient from outcrop areas along the basin (exceeded WDEQ Class II standard of 8), TDS margins. Much of the water used from Paleozoic (exceeded WDEQ Class II standard of 2,000 aquifers in the Snake/Salt River Basin is obtained mg/L), boron (exceeded WDEQ Class II standard from springs rather than wells (for example, Star of 750 µg/L), chloride (exceeded WDEQ Class Valley area); many of these springs have moderate II standard of 100 mg/L), and sulfate (exceeded to large yields (greater than 100 gal/min). WDEQ Class II standard of 200 mg/L). One characteristic and one constituent approached or Paleozoic aquifers produce water from bedrock exceeded applicable State of Wyoming livestock composed primarily of carbonate rocks [for water-quality standards: TDS (exceeded WDEQ example, limestone (rock composed of the mineral Class III standard of 2,000 mg/L) and lead calcite) and dolostone (rock composed of the (exceeded WDEQ Class III standard of 100 mineral dolomite)] and siliciclastic rocks (for µg/L). example, sandstone) deposited primarily in marine environments. Primary porosity and intergranular 7.4 Paleozoic hydrogeologic units permeability are much greater in the sandstones than in the carbonates, where primary permeability Paleozoic hydrogeologic units (aquifers and is very low. Carbonate aquifers generally may be confining units) are described in this section of utilized only in areas where substantial secondary the report. Lithostratigraphic units of Permian, permeability has developed. Permeability of the Pennsylvanian, Mississippian, Devonian, siliciclastic and carbonate rocks composing the Ordovician, and Cambrian age compose the Paleozoic hydrogeologic units may be enhanced Paleozoic hydrogeologic units (aquifers and by bedding-plane partings, faults, fractures, and confining units) in the Snake/Salt River Basin solution openings where the rocks have been (pls. 4, 5, and 6). Paleozoic hydrogeologic units structurally deformed by folding and faulting underlie Cenozoic and Mesozoic hydrogeologic in the Overthrust Belt. In fact, development of units in the Snake/Salt River Basin, except in secondary permeability, such as fractures, faults, areas where structural deformation has uplifted and solution openings, in Paleozoic hydrogeologic and exposed the Paleozoic units in the mountains units usually is required for siting and construction and highlands of the Overthrust Belt. Paleozoic of high yielding springs and wells.
7-180 Because data from wells are not available for Physical characteristics many Paleozoic hydrogeologic units in the Snake/ Salt River Basin, interpretations of the water- The Phosphoria aquifer and confining unit is bearing properties of some units herein are based composed of the Permian Phosphoria Formation on the physical and chemical hydrogeologic (pls. 4, 5, and 6). The Phosphoria aquifer and characteristics of the same or similar units in other confining unit is overlain by the Dinwoody parts of Wyoming. Permeability and groundwater aquifer and confining unit and underlain by the circulation in Paleozoic hydrogeologic units has Wells or Tensleep aquifer in most of the Snake/ been studied at many locations in Wyoming, Salt River Basin (pls. 4, 5, and 6). The Phosphoria and they are controlled by lithology, sedimentary Formation consists of an upper part of dark to structure and depositional environment, and light gray, cherty shale and sandstone, and a lower tectonic structures such as folds and faults (for part of brown-weathering, dark, phosphatic shale example, Lundy, 1978; Huntoon and Lundy, 1979; and limestone (Rubey and others, 1980; Love and Thompson, 1979; Eisen and others, 1980; Richter, others, 1992). 1981; Western Water Consultants, Inc., 1982, The formation is divided into two members at 1993, 1995; Cooley, 1984, 1986; Davis, 1984; some locations (individual members not shown Huntoon, 1985, 1993; Jarvis, 1986; Spencer, 1986; on Plates 4, 5 and 6). The Rex Chert Member Mills, 1989; Mills and Huntoon, 1989; Wiersma, is composed of dark gray siltstone, black, thin- 1989; Blanchard, 1990; Blanchard and others, bedded chert and limestone, and a few thin beds of 1990; Younus, 1992; Johnson and Huntoon, 1994; phosphate rock in the upper part. Resistant ledges Stacy, 1994; Stacy and Huntoon, 1994; Garland, of gray, cherty, dolomitic limestone and some 1996). Except near outcrops, where water-table bedded chert are present in the middle and lower (unconfined) conditions may be encountered, part of the Rex Chert Member (Rubey and others, groundwater in Paleozoic hydrogeologic units is 1980). The Meade Peak Member consists of dark generally semiconfined or confined. gray, non-resistant, and brown phosphatic siltstone and cherty siltstone, gray dolomite, several blue Recharge to Paleozoic hydrogeologic units beds of phosphorite, and one bed of vanadium- generally occurs where the units crop out, although bearing carbonaceous siltstone (Rubey and others, severing by faults near recharge areas may disrupt 1980). downgradient aquifer continuity and prevent much of this recharge from entering the aquifers Phosphoria Formation thickness varies by downgradient from outcrop areas. Near recharge geographic area in the Snake/Salt River Basin. areas, water in these hydrogeologic units can be Thickness of the Phosphoria Formation decreases relatively fresh and may be suitable for most uses. eastward in the Overthrust Belt and ranges from This is where springs are developed and most wells about 180 to 361 ft (Love and Love, 1978; Oriel are completed. Elsewhere, and with increasing and Platt, 1980; Oriel and Moore, 1985; Rubey depth and as the water moves away from the and others, 1980; Love and others, 1992; Love outcrop, the water can have high TDS, limiting the and Love, 2000). Thickness of the Phosphoria use of water for most purposes. Formation in the Teton Range ranges from 180 to 220 ft (Love, 1974a,b, 2003a; Christiansen 7.4.1 Phosphoria aquifer and confining and others, 1978; Oriel and Moore, 1985; Love unit and Love, 2000). Thickness of the Phosphoria Formation in the Gros Ventre Range ranges from The physical and chemical characteristics of the about 180 to about 235 ft (Love and Love, 1978, Phosphoria aquifer and confining unit in the 2000; Oriel and Platt, 1980; Rubey and others, Snake/Salt River Basin are described in this section 1980; Love and others, 1992; Love, 2001b,c; Love of the report. and Reed, 2001a).
7-181 The Phosphoria Formation is classified as an Northern Ranges aquifer, confining unit, or both by previous The chemical composition of the Phosphoria investigators (pls. 4, 5, and 6). Robinove and aquifer and confining unit in the Northern Ranges Berry (1963, p. V18) identified the Phosphoria (NR) was characterized and the quality evaluated Formation and the underlying Wells Formation on the basis of environmental water samples from as potential Paleozoic aquifers in the Bear River three springs. Individual constituents are listed in valley to the south of the Snake/Salt River Basin; appendix E–2. Major-ion composition in relation the investigators noted that both formations "may to TDS concentrations for springs issuing from the be expected to yield small to moderate amounts Phosphoria aquifer and confining unit is shown of water to wells." Primary permeability in the on a trilinear diagram (appendix F–2, diagram Phosphoria aquifer likely is small, and in most E). The TDS concentrations for the springs ranged areas the unit probably is capable of yielding only from 95.4 to 164 mg/L, with a median of 119 "small quantities" of water (Lines and Glass, 1975, mg/L, indicating that the waters were fresh (TDS Sheet 1). However, in areas where fractures are concentrations less than or equal to 999 mg/L) present and secondary permeability is developed, (appendix E–2; appendix F–2, diagram E). On the aquifer is capable of yielding "moderate the basis of the characteristics and constituents quantities" of water (Lines and Glass, 1975, Sheet analyzed for in the spring samples, the quality of 1). Ahern and others (1981, Figure II-7, and Table water from the Phosphoria aquifer and confining IV-1) classified the Phosphoria Formation as a unit in the NR was suitable for most uses. No locally confining minor aquifer in the Overthrust characteristics or constituents approached or Belt and adjacent Green River Basin (pls. 4 and 5). exceeded applicable USEPA or State of Wyoming The investigators (Ahern and others, 1981, Table domestic, agriculture, or livestock water-quality IV-1) noted that the most productive parts of the standards. Phosphoria Formation were in areas where fractures were present and in interbedded sandstones Overthrust Belt in the upper part of the formation. In the The chemical composition of groundwater in Wyoming Water Framework Plan, the Phosphoria the Phosphoria aquifer and confining unit in Formation was classified as a minor aquifer (WWC the Overthrust Belt (OTB) was characterized Engineering and others, 2007, Figure 4-9) (pls. and the quality evaluated on the basis of one 4, 5, and 6). Hydrogeologic data describing the environmental water sample from one spring. Phosphoria aquifer and confining unit, including Individual constituents are listed in appendix spring-discharge and well-yield measurements and E–5. The specific conductance measured in the other hydraulic properties, are summarized on spring (320 microsiemens per centimeter at 25 plate 3. degrees Celsius) indicated that the water was fresh (measured specific conductance equivalent to TDS Chemical characteristics concentration less than or equal to 999 mg/L) (appendix E–5). On the basis of the characteristics The chemical characteristics of groundwater and constituents analyzed for in the spring sample, from the Phosphoria aquifer and confining unit the quality of water from the Phosphoria aquifer in the Snake/Salt River Basin are described in and confining unit in the OTB was suitable for this section of the report. Groundwater quality most uses. No characteristics or constituents of the Phosphoria aquifer and confining unit approached or exceeded applicable USEPA or State is described in terms of a water’s suitability for of Wyoming domestic, agriculture, or livestock domestic, irrigation, and livestock use, on the basis water-quality standards. of USEPA and WDEQ standards (table 5-2), and groundwater-quality sample summary statistics 7.4.2 Quadrant Sandstone tabulated by hydrogeologic unit as quantile values (appendices E–2 and E–5). Within the Snake/Salt River Basin, the Pennsylvanian Quadrant Sandstone (also known
7-182 as the Quadrant Quartzite) is present only in Chugwater Formations) and from below by the the Yellowstone Volcanic Area (pl. 1; pl. 6), and Amsden confining unit composed of the Amsden consists of well-bedded white to pink, fine-to Formation (Mills, 1989; Mills and Huntoon, medium-grained quartzite (Mallory, 1967). The 1989) (pl. 5). In addition, the Tensleep aquifer in Quadrant Sandstone is laterally equivalent to the eastern Gros Ventre Range also is composed the Tensleep Sandstone. No data were located of hydraulically connected lower sandstones in describing the physical and chemical hydrogeologic the overlying Phosphoria Formation (Mills, 1989; characteristics of the lithostratigraphic unit in the Mills and Huntoon, 1989) (pl. 5). Snake/Salt River Basin. The Tensleep Sandstone is classified as an aquifer 7.4.3 Tensleep aquifer by all investigators and that definition is retained herein (pls. 5 and 6). The Wyoming Water The physical and chemical characteristics of the Planning Program (1972, Table III-2) speculated Tensleep aquifer in the Snake/Salt River Basin are that the Tensleep Sandstone was a poor to good described in this section of the report. aquifer in the Snake/Salt River Basin (pls. 5 and 6). Ahern and others (1981, Figure II-7, and Table Physical characteristics IV-1) classified the Tensleep Sandstone and the equivalent Wells Formation as major aquifers in the The Tensleep aquifer is composed of saturated Overthrust Belt and adjacent Green River Basin and permeable parts of the Middle to Upper (pls. 4 and 5). The investigators also considered Pennsylvanian to Permian Tensleep Sandstone (pls. the Wells/Tensleep aquifer to be part of a larger 5 and 6). The Tensleep Sandstone consists of light- regional Paleozoic aquifer system composed of gray, weathering yellowish brown, fine-grained hard many different hydrogeologic units (pls. 4 and brittle sandstone; some zones are quartzitic (Love 5). Mills (1989) and Mills and Huntoon (1989) and others, 1992). The middle and lower parts classified the formation as an aquifer in the eastern of the formation contain many beds of gray, hard Gros Ventre Range (pl. 5). In the Wyoming fine-grained limestone and dolomite. The Tensleep Water Framework Plan, the Wells Formation was Sandstone is transitional with the underlying classified as a major aquifer (WWC Engineering Amsden Formation. The Tensleep Sandstone and others, 2007, Figure 4-9) (pl. 4). is stratigraphically equivalent to the Wells Formation—the lithostratigraphic unit is identified Lines and Glass (1975, Sheet 1) noted that as the Wells Formation south and west of the sandstone beds composing the Tensleep Sandstone Jackson thrust fault and as the Tensleep Sandstone were aquifers capable of yielding moderate to north and east of the Jackson thrust fault (Love and large quantities of water (100 gal/min or more), others, 1992). Thickness of the Tensleep Sandstone depending upon local recharge, sandstone bed ranges from about 385 to about 450 ft (Pampeyan continuity, and development of secondary and others, 1967; Schroeder, 1969, 1972, 1987; permeability from fractures. In addition, the Jobin, 1972; Love, 1974a,b, 1975b, 2001a,b,c, investigators (Lines and Glass, 1975, Sheet 1) 2003a; Christiansen and others, 1978; Love and noted that sandstone beds "on topographic Love, 1978; Oriel and Moore, 1985; Love and highs may be drained [unsaturated], especially others, 1992). if underlying limestones have extensive solution development." Several investigators (Cox, 1976; The Tensleep aquifer is overlain by the Phosphoria Mills, 1989; Mills and Huntoon, 1989) reported aquifer and confining unit and underlain by the yields as much as 100 gal/min or more to Amsden aquifer (pls. 5 and 6). In the eastern Gros individual springs in the Gros Ventre Range. Mills Ventre Range, the Tensleep aquifer is confined (1989) and Mills and Huntoon (1989) noted that from above by the Phosphoria-Dinwoody- permeability in lithologic units composing the Chugwater confining unit (composed of most of aquifer in the eastern Gros Ventre Range was both the Phosphoria Formation and the Dinwoody and primary and secondary. Permeability in sandstones
7-183 in the Tensleep aquifer was determined to be a median of 268 mg/L. On the basis of the intergranular along the backlimbs of examined characteristics and constituents analyzed for in folds, but could be secondarily enhanced due the spring samples, the quality of water from the to fractures and associated piping along the Tensleep aquifer in the NR was suitable for most forelimbs of examined folds (Mills, 1989; Mills and uses. No characteristics or constituents approached Huntoon, 1989). Primary permeability of dolomite or exceeded applicable USEPA or State of in the Tensleep aquifer was small along the Wyoming domestic, agriculture, or livestock water- forelimbs of examined folds, but was enhanced due quality standards. to fracturing and karstification along the forelimbs of examined folds. Jackson Hole The chemical composition of the Tensleep Hydrogeologic information describing the Tensleep aquifer in Jackson Hole (JH) was characterized aquifer, including well-yield and spring-discharge and the quality evaluated on the basis of one measurements and other hydraulic properties, produced water sample from one well. The TDS is summarized on plate 3. Spring-discharge concentration (1,980 mg/L) indicated that the measurements and well yields inventoried as part of water was slightly saline (TDS concentration this study (pl. 3) confirm that sandstone aquifers ranging from 1,000 to 2,999 mg/L). The pH value in the Tensleep Sandstone are capable of yielding in the produced water sample was 7.2. Measured moderate to large quantities of water (100 gal/min concentrations of cations were 468 mg/L (sodium), or more) in parts of the Snake/Salt River Basin. 190 mg/L (calcium), and 27 mg/L (magnesium). Measured concentrations of anions were 854 mg/L Chemical characteristics (sulfate), 684 mg/L (bicarbonate), and 110 mg/L (chloride). The chemical characteristics of groundwater from the Tensleep aquifer in the Snake/Salt River Concentrations of some properties and constituents Basin are described in this section of the report. in water from the Tensleep aquifer in the JH Groundwater quality of the Tensleep aquifer produced water sample approached or exceeded is described in terms of a water’s suitability for applicable USEPA or State of Wyoming water- domestic, irrigation, and livestock use, on the basis quality standards and could limit suitability for of USEPA and WDEQ standards (table 5-2), and some uses. Concentrations of one characteristic groundwater-quality sample summary statistics and one constituent exceeded USEPA aesthetic tabulated by hydrogeologic unit as quantile values standards for domestic use: TDS (exceeded SMCL (appendices E–2 and E–4). limit of 500 mg/L) and sulfate (exceeded SMCL of 250 mg/L). Two constituents in the produced Northern Ranges water sample approached or exceeded applicable The chemical composition of the Tensleep aquifer State of Wyoming standards for agricultural-use in the Northern Ranges (NR) was characterized standards: chloride (exceeded WDEQ Class II and the quality evaluated on the basis of standard of 100 mg/L) and sulfate (exceeded environmental water sample from as many as six WDEQ Class II standard of 200 mg/L). No springs. Summary statistics calculated for available characteristics or constituents approached or constituents are listed in appendix E–2. Major-ion exceeded applicable State of Wyoming livestock composition in relation to TDS concentrations water-quality standards. for springs issuing from the Tensleep aquifer is shown on a trilinear diagram (appendix F–2, Green River and Hoback Basins diagram F). TDS concentrations indicated that The chemical composition of the Tensleep aquifer the water was fresh (TDS concentrations less than in the Green River and Hoback Basins (GH) was or equal to 999 mg/L) (appendix E–2; appendix characterized and the quality evaluated on the F–2, diagram F). The TDS concentrations for basis of one environmental water sample from one the springs ranged from 123 to 312 mg/L, with spring. Individual constituent concentrations are
7-184 listed in appendix E–4. The TDS concentration aquifers in the Bear River valley to the south of the (303 mg/L) indicated that the water was fresh Snake/Salt River Basin in the Overthrust Belt; the (TDS concentration less than or equal to 999 investigators noted that both formations "may be mg/L) (appendix E–4). On the basis of the expected to yield small to moderate amounts of characteristics and constituents analyzed for, the water to wells." Similarly, Lines and Glass (1975, quality of water from the Tensleep aquifer in the Sheet 1) noted that sandstone beds composing GH was suitable for most uses. No characteristics the formation were aquifers capable of yielding or constituents approached or exceeded applicable moderate to large quantities of water, depending USEPA or State of Wyoming domestic, agriculture, upon local recharge, sandstone bed continuity, or livestock water-quality standards. and development of secondary permeability from fractures. In addition, the investigators (Lines and 7.4.4 Wells aquifer Glass, 1975, Sheet 1) noted that sandstone beds "on topographic highs may be drained, especially The physical and chemical characteristics of the if underlying limestones have extensive solution Wells aquifer in the Snake/Salt River Basin are development." Cox (1976, Sheet 1) speculated described in this section of the report. that sandstones in the formation might yield a few tens of gallons per minute per well. Ahern and Physical characteristics others (1981, Figure II-7, and Table IV-1) classified the Wells Formation and the equivalent Tensleep The Wells aquifer is composed of the Middle Sandstone as major aquifers in the Overthrust to Upper Pennsylvanian to Permian Wells Belt and adjacent Green River Basin (pl. 4). In Formation (pl. 4). The Wells Formation consists the Wyoming Water Framework Plan, the Wells of interbedded gray limestone and pale yellow Formation was classified as a major aquifer (WWC calcareous sandstone with minor gray dolomite Engineering and others, 2007, Figure 4-9) (pl. 4). beds; the lower part of the formation is cherty Hydrogeologic information describing the Wells (Love and others, 1992). The Wells Formation aquifer, including well-yield and spring-discharge is stratigraphically equivalent to the Tensleep measurements and other hydraulic characteristics, Sandstone—the lithostratigraphic unit is identified is summarized on plate 3. as the Wells Formation south and west of the Jackson thrust fault and as the Tensleep Sandstone Chemical characteristics north and east of the Jackson thrust fault (Love and others, 1992). Thickness of the Wells Formation The chemical characteristics of groundwater in the Overthrust Belt ranges from about 591 to from the Wells aquifer in the Snake/Salt River about 1,969 ft (Jobin, 1965, 1972; Pampeyan and Basin are described in this section of the report. others, 1967; Albee, 1968, 1973; Schroeder, 1973, Groundwater quality of the Wells aquifer is 1974, 1976, 1979, 1981, 1987; Love and Love, described in terms of a water’s suitability for 1978; Oriel and Platt, 1980; Oriel and Moore, domestic, irrigation, and livestock use, on the basis 1985; Schroeder and others, 1981; Love and of USEPA and WDEQ standards (table 5-2), and others, 1992). groundwater-quality sample summary statistics tabulated by hydrogeologic unit as quantile values The Wells Formation is classified as an aquifer by (appendix E–5). most investigators and that definition is retained herein (pl. 4). Berry (1955) identified the Wells Overthrust Belt Formation (referred to as the Tensleep Sandstone) The chemical composition of groundwater in as a potential aquifer (pl. 4) in the Cokeville area the Wells aquifer in the Overthrust Belt (OTB) to the south of the Snake/Salt River Basin in the was characterized and the quality evaluated on Overthrust Belt. Robinove and Berry (1963, p. the basis of environmental water samples from as V18) identified the Wells Formation and overlying many as 12 springs and 1 well. Summary statistics Phosphoria Formation as potential Paleozoic calculated for available constituents are listed in
7-185 appendix E–5. Major ion composition in relation Reed, 2000, 2001a,b; Love, 2001a,c, 2003c; to TDS for springs issuing from the Wells aquifer Love and others, 1992). Thickness of the Amsden is shown on a trilinear diagram (appendix F–5, Formation in the Teton Range ranges from 230 to diagram I). TDS concentrations indicated that all 700 ft (Schroeder, 1972; Love, 1974a,b, 2003a; waters were fresh (TDS concentrations less than Christiansen and others, 1978; Oriel and Moore, or equal to 999 mg/L) (appendix E–5; appendix 1985). Thickness of the Amsden Formation in the F–5, diagram I). The TDS concentrations for Overthrust Belt ranges from about 328 to about the springs ranged from 114 to 239 mg/L, with 700 ft (Oriel and Platt, 1980; Love and others, a median of 171 mg/L. The TDS concentration 1992). for the well was 317 mg/L. On the basis of the characteristics and constituents analyzed for, the The Amsden Formation in the Snake/Salt River quality of water from the Wells aquifer in the OTB Basin is classified as either an aquifer or confining was suitable for most uses. No characteristics or unit by previous investigators, depending upon constituents approached or exceeded applicable the physical characteristics of the unit in the USEPA or State of Wyoming domestic, agriculture, area examined (pls. 4, 5, and 6). The Wyoming or livestock water-quality standards. Water Planning Program (1972, Table III-2) speculated that the Amsden Formation was a 7.4.5 Amsden aquifer fair to poor aquifer in the Snake/Salt River Basin (pls. 4, 5, and 6). Lines and Glass (1975, Sheet The physical and chemical characteristics of the 1) noted that small quantities of water might be Amsden aquifer in the Snake/Salt River Basin are available from cherty limestone in the formation described in this section of the report. in the Overthrust Belt, but "on topographic highs, the Amsden Formation is probably well- Physical characteristics drained, especially if underlying limestones have extensive solution development." Ahern and others The Amsden aquifer is composed of saturated and (1981, Figure II-7, and Table IV-1) classified the permeable parts of the Upper Mississippian to formation as a minor locally confining aquifer Pennsylvanian Amsden Formation (pls. 4, 5, and in the Overthrust Belt and adjacent Green 6). The Amsden Formation consists of red and gray River Basin (pls. 4 and 5). The investigators cherty limestone and yellow siltstone, sandstone, also considered the Amsden aquifer to be part and conglomerate (Mallory, 1967; Lines and Glass of a larger regional Paleozoic aquifer system 1975; Oriel and Platt, 1980; Rubey and others, composed of many different hydrogeologic units 1980; Love and others, 1992; and M’Gonigle and (pls. 4 and 5). In the eastern Gros Ventre Range Dover, 1992). The Amsden Formation overlies and the Salt River Range, general permeability the Madison Group or Limestone north and of the shale and limestone composing much of east of the Jackson thrust fault and is overlain by the Amsden Formation is small enough that the the stratigraphically equivalent Wells Formation lithostratigraphic unit is considered a confining south and west of the Jackson thrust fault. The unit that overlies the Madison aquifer, and Amsden Formation has as many as three members underlies the Tensleep aquifer (Mills, 1989; Mills in the Snake/Salt River Basin: Ranchester and Huntoon, 1989; Blanchard, 1990; Blanchard Limestone Member (Pennsylvanian); Horseshoe and others, 1990) (pls. 4 and 5). However, the Shale Member (Upper Mississippian to Lower investigators noted that sandstones in the Amsden Pennsylvanian); and Darwin Sandstone Limestone Formation were permeable and that sandstone Member (Upper Mississippian) (Mallory, 1967). permeability was intergranular. In the Wyoming Water Framework Plan, the Amsden Formation Thickness of the Amsden Formation varies by was classified as a marginal aquifer throughout geographic area in the Snake/Salt River Basin. Wyoming (WWC Engineering and others, 2007, Thickness of the Amsden Formation in the Gros Figure 4-9) (pls. 4, 5, and 6). Previous studies Ventre Range is about 400 to 450 ft (Love and of the Amsden Formation in the adjacent Green
7-186 River Basin and surrounding areas have classified water sample from one well. Individual the formation as an aquifer (Ahern and others, constituents are listed in appendix E–3. The TDS 1981; Geldon, 2003; Bartos and Hallberg, 2010, concentration (327 mg/L) indicated that the water and references therein). In the upper Colorado was fresh (TDS concentrations less than or equal River Basin and adjacent areas (including Green to 999 mg/L) (appendix E–3). On the basis of the River Basin and parts of the Overthrust Belt), characteristics and constituents analyzed for in the Geldon (2003) classified the Ranchester Limestone one sample, the quality of water from the Amsden and the Darwin Sandstone Members as aquifers aquifer in JH was suitable for most uses, although and the Horseshoe Shale Member as a confining the concentration of one constituent exceeded unit (see Bartos and Hallberg, 2010, Figure 5-4). health-based standards: radon (the 1 sample Hydrogeologic information describing the Amsden analyzed for this constituent exceeded the proposed aquifer, including well-yield and spring-discharge USEPA MCL of 300 pCi/L, but did not exceed measurements and other hydraulic properties, is the AMCL of 4,000 pCi/L). No characteristics or summarized on plate 3. constituents approached or exceeded applicable State of Wyoming agriculture or livestock water- Chemical characteristics quality standards.
The chemical characteristics of groundwater Overthrust Belt from the Amsden aquifer in the Snake/Salt River The chemical composition of groundwater in the Basin are described in this section of the report. Amsden aquifer in the Overthrust Belt (OTB) was Groundwater quality of the Amsden aquifer is characterized and the quality evaluated on the basis described in terms of a water’s suitability for of environmental water samples from three springs. domestic, irrigation, and livestock use, on the basis Individual constituents are listed in appendix of USEPA and WDEQ standards (table 5-2), and E–5. Major ion composition in relation to TDS groundwater-quality sample summary statistics for springs issuing from the Amsden aquifer is tabulated by hydrogeologic unit as quantile values shown on a trilinear diagram (appendix F–5, (appendices E–2, E–3, and E–5). diagram J). TDS concentrations indicated that all waters were fresh (TDS concentrations less than Northern Ranges or equal to 999 mg/L) (appendix E–5; appendix The chemical composition of the Amsden aquifer F–5, diagram J). The TDS concentrations for in the Northern Ranges (NR) was characterized the springs ranged from 119 to 178 mg/L, with and the quality evaluated on the basis of one a median of 138 mg/L. On the basis of the environmental water sample from one spring. characteristics and constituents analyzed for, the Individual constituents are listed in appendix E–2. quality of water from the Amsden aquifer in the The TDS concentration (56.3 mg/L) indicated OTB was suitable for most uses. No characteristics that the water was fresh (TDS concentration less or constituents approached or exceeded applicable than or equal to 999 mg/L) (appendix E–2). On USEPA or State of Wyoming domestic, agriculture, the basis of the characteristics and constituents or livestock water-quality standards. analyzed for in the one spring sample, the quality of water from the Amsden aquifer in the NR 7.4.6 Madison aquifer was suitable for most uses. No characteristics or constituents approached or exceeded applicable The physical and chemical characteristics of the USEPA or State of Wyoming domestic, agriculture, Madison aquifer in the Snake/Salt River Basin are or livestock water-quality standards. described in this section of the report.
Jackson Hole Physical characteristics The chemical composition of the Amsden aquifer in Jackson Hole (JH) was characterized and the The Lower to Upper Mississippian Madison quality evaluated on the basis of one environmental Limestone is a thick sequence of carbonate rocks
7-187 [limestone (carbonate rock composed of the (pl. 3), as well as in many other areas of Wyoming mineral calcite) and dolostone (carbonate rock (for example, Bartos and others, 2012, and composed of the mineral dolomite)] that consists references therein). of two parts—an upper part of light- to dark-gray, thick-bedded to massive limestone, and a lower In areas where secondary permeability is developed, part of dark gray, thin-bedded limestone and springs issuing from and wells completed in the dolomite (Lines and Glass, 1975; Oriel and Platt, Madison aquifer may yield several hundred gallons 1980; Love and others, 1992). In the vicinity of per minute (Lines and Glass, 1975; Cox, 1976; Grand Teton National Park, thin lenses of brown Huntoon and Coogan, 1987; Mills, 1989; Mills cherty dolomite are present near the base and and Huntoon, 1989; Blanchard, 1990; Blanchard lenses of black chert are common (Love and others, and others, 1990; Sunrise Engineering, 2003, 1992). Thickness of the Madison Limestone in the 2009) (pl. 3). Some of these springs issuing from Gros Ventre and Teton Ranges ranges from about the Madison aquifer are used to provide water for 1,100 to 1,500 ft (Love and Love, 1978; Oriel and public-supply purposes in the Snake/Salt River Platt, 1980; Love and others, 1992). Thickness Basin [notably, Periodic Spring is used to provide of the Madison Group or Limestone in the a substantial amount of the water supply for the Overthrust Belt ranges from about 800 to about city of Afton (Huntoon and Coogan, 1987, and 1,800 ft (Oriel and Platt, 1980; Schroeder, 1974, references therein; Forsgren Associates, 1990; 1976, 1979, 1981, 1987; Schroeder and others, Sunrise Engineering, 2009)]. Fracturing of rocks 1981; Lageson, 1986). composing the Madison Group or Limestone (and other Paleozoic hydrogeologic units) generally Saturated and permeable parts of the Madison occurs in areas of structural deformation such as Group or Limestone compose the Madison near faults and on the limbs of folds (Lines and aquifer. The Madison Group or Limestone in the Glass, 1975; Cox, 1976; Mills, 1989; Mills and Snake/Salt River Basin is classified as an aquifer Huntoon, 1989; Blanchard, 1990; Blanchard and by all previous investigators (pls. 4, 5, and 6). others, 1990; Rendezvous Engineering, PC, and The Madison aquifer is overlain by the Amsden Hinckley Consulting, 2009). Solution openings aquifer and underlain by the Darby aquifer (pls. generally develop in outcrop areas or near land 4, 5, and 6). In the eastern Gros Ventre Range and surface where recharging waters containing carbon the Salt River Range, the Madison aquifer is part dioxide dissolve parts of the aquifer until eventually of different aquifer systems composed of other discharging from the aquifer (Lines and Glass, Paleozoic aquifers with varying degrees of hydraulic 1975; Cox, 1976; Huntoon and Coogan, 1987; connection (Mills, 1989; Mills and Huntoon, Mills, 1989; Mills and Huntoon, 1989; Blanchard, 1989; Blanchard, 1990; Blanchard and others, 1990; Blanchard and others, 1990). Fracturing and 1990) (pls. 4 and 5). faulting provides a pathway for vertical movement of groundwater between different Paleozoic aquifers Primary permeability (intergranular or (including the Madison aquifer) at some locations intercrystalline) of the Madison Group or in the Snake/Salt River Basin (Mills, 1989; Mills Limestone generally is low, and large volumes and Huntoon, 1989). of the formation are composed of relatively impermeable rocks (for example, Mills, 1989; Mills In the Snake/Salt River Basin, much of the water and Huntoon, 1989). The availability of water discharged from the Madison aquifer and other from the Madison aquifer depends substantially Paleozoic aquifers is through a few large springs on the development of secondary permeability, where there has been selective enlargement of primarily fractures and karstic features such as solution openings and a concentration of flow solution openings. Where permeability has been in a few of the larger openings (Lines and Glass, enhanced by fracturing and solution openings, the 1975; Cox, 1976; Huntoon and Coogan, 1987; Madison Group or Limestone is one of the most Mills, 1989; Mills and Huntoon, 1989; Blanchard, productive aquifers in the Snake/Salt River Basin 1990; Blanchard and others, 1990). Outcrops
7-188 on topographic highs commonly are unsaturated (appendices E–1 to E–6). (drained) to depths of several hundred feet. Lines and Glass (1976, Sheet 1) noted that wells that Yellowstone Volcanic Area penetrated "water-bearing solution channels" The chemical composition of the Madison aquifer were likely to "yield much more water than wells in the Yellowstone Volcanic Area (YVA) was that do not penetrate the major conduits." Unlike characterized and the quality evaluated on the basis limestones in other Paleozoic hydrogeologic of environmental water samples from one spring units of the Snake/Salt River Basin, outcrops of and two wells. Individual constituents are listed the Madison Group or Limestone have ancient in appendix E–1. TDS concentrations indicated karstic features such as solution openings that that all waters were fresh (TDS concentrations less probably developed before and during deposition than or equal to 999 mg/L) (appendix E–1). The of the overlying Amsden Formation (Lines and TDS concentration in the spring was 245 mg/L. Glass, 1975; Mills, 1989; Mills and Huntoon, The TDS concentrations for the wells were 128 1989). Consequently, solution permeability in and 138 mg/L. On the basis of the characteristics the Madison aquifer probably is present at greater and constituents analyzed for in the spring and well depths below the present land surface than in other samples, the quality of water from the Madison Paleozoic hydrogeologic units. aquifer in the YVA was suitable for most uses. No characteristics or constituents approached or Recharge to the Madison aquifer is from direct exceeded applicable USEPA or State of Wyoming infiltration of precipitation (snowmelt and rain), domestic, agriculture, or livestock water-quality snowmelt runoff, lakes, and ephemeral and standards. perennial streamflow losses on outcrops (Lines and Glass, 1975; Cox, 1976; Huntoon and The chemical composition of Madison aquifer in Coogan, 1987; Mills, 1989; Mills and Huntoon, the YVA also was characterized and the quality 1989; Blanchard, 1990; Blanchard and others, evaluated on the basis of environmental water 1990). This recharge may be enhanced in areas samples from as many as three hot springs. where fractures occur along the axes of anticlines Individual constituents are listed in appendix or in karstified areas (Huntoon and Coogan, E–1. Major ion composition in relation to TDS 1987; Mills, 1989; Mills and Huntoon, 1989; for the three hot springs issuing from the Madison Blanchard, 1990; Blanchard and others, 1990). aquifer in the YVA is shown on a trilinear diagram Discharge from the Madison aquifer occurs from (appendix F–1, diagram G). TDS concentrations withdrawals by pumped wells and naturally by indicated that waters ranged from slightly saline (2 evapotranspiration, gaining streams, seeps, and of 3 samples, TDS concentrations between 1,000 spring flows. Hydrogeologic data describing the to 2,999 mg/L) to fresh (1 of 3 samples, TDS Madison aquifer, including well-yield and spring- concentration less than or equal to 999 mg/L) discharge measurements and other hydraulic (appendix E–1; appendix F–1, diagram G). TDS properties, is summarized on plate 3. concentrations for the hot springs ranged from 695 to 1,960 mg/L, with a median of 1,550 mg/L. Chemical characteristics Concentrations of some properties and constituents The chemical composition of groundwater in in water from the three hot springs issuing from the Madison aquifer in the Snake/Salt River the Madison aquifer in the YVA approached or Basin is described in this section of the report. exceeded applicable USEPA or State of Wyoming Groundwater quality of the Madison aquifer water-quality standards and could limit suitability is described in terms of a water’s suitability for for some uses. Concentrations of two constituents domestic, irrigation, and livestock use, on the basis exceeded health-based standards: boron (all 3 of USEPA and WDEQ standards (table 5-2), and samples exceeded the WDEQ Class II standard of groundwater-quality sample summary statistics 750 µg/L) and fluoride (1 of 3 samples exceeded tabulated by hydrogeologic unit as quantile values the USEPA MCL of 4 mg/L). Concentrations of
7-189 one characteristic and two constituents exceeded Jackson Hole USEPA aesthetic standards for domestic use: TDS The chemical composition of the Madison aquifer (all 3 samples exceeded the SMCL of 500 mg/L), in Jackson Hole (JH) was characterized and the fluoride (all 3 samples exceeded the SMCL of 2 quality evaluated on the basis of environmental mg/L), and sulfate (2 of 3 samples exceeded the water samples from as many as six springs and one SMCL of 250 mg/L). well. Summary statistics calculated for available constituents are listed in appendix E–3. Major Concentrations of some characteristics and ion composition in relation to TDS for the springs constituents in water from the three hot springs issuing from the Madison aquifer in JH is shown issuing from the Madison aquifer in the YVA on a trilinear diagram (appendix F–3, diagram exceeded State of Wyoming standards for I). TDS concentrations indicated that all waters agricultural and livestock use. Three constituents were fresh (TDS concentrations less than or were measured at concentrations greater than equal to 999 mg/L) (appendix E–3; Appendix agricultural-use standards: boron (all 3 samples F–3, diagram I). The TDS concentrations for exceeded the WDEQ Class II standard of 750 the springs ranged from 127 to 588 mg/L, with a µg/L), chloride (all 3 samples exceeded the WDEQ median of 273 mg/L. The TDS concentration in Class II standard of 100 mg/L), and sulfate (2 of the well was 262 mg/L. 3 samples exceeded the WDEQ Class II standard of 200 mg/L). No characteristics or constituents Concentrations of some properties and constituents approached or exceeded applicable State of in water from the Madison aquifer in JH Wyoming livestock water-quality standards. approached or exceeded applicable USEPA or State of Wyoming water-quality standards and could Northern Ranges limit suitability for some uses. Concentrations of The chemical composition of the Madison aquifer one characteristic and one constituent in one of in the Northern Ranges (NR) was characterized the six spring samples exceeded USEPA aesthetic and the quality evaluated on the basis of standards for domestic use: TDS (exceeded SMCL environmental water samples from as many as five limit of 500 mg/L) and sulfate (exceeded SMCL springs and one cave. Summary statistics calculated of 250 mg/L). One constituent in one of the six for available constituents in the five springs and spring samples approached or exceeded applicable one cave sample are listed in appendix E–2 (one State of Wyoming standards for agricultural- cave sample grouped with five spring samples for use standards: sulfate (exceeded WDEQ Class summary purposes in appendix E–2). Major ion II standard of 200 mg/L). No characteristics or composition in relation to TDS for the springs constituents approached or exceeded applicable issuing from the Madison aquifer in the NR is State of Wyoming livestock water-quality shown on a trilinear diagram (appendix F–2, standards. diagram G). TDS concentrations indicated that all waters were fresh (TDS concentrations less than On the basis of the characteristics and constituents or equal to 999 mg/L) (appendix E–2; appendix analyzed for, the quality of water from the Madison F–2, diagram G). The TDS concentrations aquifer in wells and springs in JH was suitable for for the springs and cave ranged from 31.5 to most uses, as no concentrations of constituents 106 mg/L, with a median of 89.0 mg/L. The exceeded health-based standards. No characteristics TDS concentration in water issuing from the or constituents in the well sample approached or cave was less than 83 mg/L. On the basis of the exceeded applicable USEPA or State of Wyoming characteristics and constituents analyzed for, the domestic, agriculture, or livestock water-quality quality of water from the Madison aquifer in the standards. NR was suitable for most uses. No characteristics or constituents approached or exceeded applicable Green River and Hoback Basins USEPA or State of Wyoming domestic, agriculture, The chemical composition of the Madison aquifer or livestock water-quality standards. in the Green River and Hoback Basins (GH) was
7-190 characterized and the quality evaluated on the exceeded applicable USEPA or State of Wyoming basis of environmental water samples from two water-quality standards and could limit suitability springs. Individual constituent concentrations are for some uses. Most environmental waters were listed in appendix E–4. The TDS concentrations suitable for domestic use, as no concentrations (94.6 and 102 mg/L) indicated that all waters were of constituents exceeded health-based standards. fresh (TDS concentrations less than or equal to Concentrations of one characteristic and one 999 mg/L) (appendix E–4). On the basis of the constituent exceeded USEPA aesthetic standards characteristics and constituents analyzed for, the for domestic use in one of the two well samples quality of water from the Madison aquifer in the and in the hot spring sample: TDS (exceeded the GH was suitable for most uses. No characteristics SMCL of 500 mg/L) and sulfate (exceeded the or constituents approached or exceeded applicable SMCL of 250 mg/L). One constituent approached USEPA or State of Wyoming domestic, agriculture, or exceeded applicable State of Wyoming standards or livestock water-quality standards. for agricultural-use standards in one of the two well samples and in the hot spring sample: Overthrust Belt sulfate (exceeded the WDEQ Class II standard The chemical composition of groundwater in the of 200 mg/L). No characteristics or constituents Madison aquifer in the Overthrust Belt (OTB) approached or exceeded applicable State of was characterized and the quality evaluated on the Wyoming livestock water-quality standards in basis of environmental water samples from as many samples from the two wells or the hot spring. as 18 springs, 2 wells, and 1 hot spring. Summary statistics calculated for available constituents are The chemical composition of the Madison listed in appendix E–5. Major ion composition aquifer in the OTB also was characterized in relation to TDS for the 18 springs issuing from and the quality evaluated on the basis of one the Madison aquifer in the OTB is shown on a produced water sample from one well. The TDS trilinear diagram (appendix F–5, diagram K). concentration (5,600 mg/L) indicated that the TDS concentrations indicated that waters in all water was moderately saline (TDS concentration 18 springs (appendix F–5, diagram K) and one ranging from 3,000 to 9,999 mg/L). The pH of two wells were fresh (TDS concentrations less value in the produced water sample was 8.5. than or equal to 999 mg/L), and waters from the Measured concentrations of cations were 1,780 hot spring and one of two wells were slightly saline mg/L (sodium), 151 mg/L (calcium), 54 mg/L (TDS concentrations ranging from 1,000 to 2,999 (magnesium), and 25 mg/L (potassium). Measured mg/L) (appendix E–5). The TDS concentrations concentrations of anions were 2,200 mg/L for the 18 springs ranged from 89.0 to 319 (sulfate), 1,870 mg/L (bicarbonate), and 440 mg/L mg/L, with a median of 194 mg/L. The TDS (chloride). concentrations for the wells were 110 and 1,150 mg/L. The TDS concentration in the hot spring Concentrations of some properties and constituents was 1,160 mg/L. in the produced water sample from the Madison aquifer in the OTB approached or exceeded On the basis of the characteristics and constituents applicable USEPA or State of Wyoming water- analyzed for in the 18 spring samples, the quality quality standards and could limit suitability for of water from the Madison aquifer in the OTB most uses. Concentrations of one characteristic was suitable for most uses. No characteristics or and two constituents exceeded USEPA aesthetic constituents approached or exceeded applicable standards for domestic use and State of Wyoming USEPA or State of Wyoming domestic, agriculture, standards for agricultural use: TDS (exceeded or livestock water-quality standards. SMCL limit of 500 mg/L and WDEQ Class II standard of 2,000 mg/L), chloride (exceeded Concentrations of some properties and constituents SMCL of 250 mg/L and WDEQ Class II standard in water from the two wells and the hot spring in of 100 mg/L), and sulfate (exceeded SMCL of the Madison aquifer in the OTB approached or 250 mg/L and WDEQ Class II standard of 200
7-191 mg/L). One characteristic approached or exceeded in the Yellowstone Volcanic area (pl. 1; pl. 6) applicable State of Wyoming livestock water- and consists of pink, yellow, and green, dolomitic quality standards: TDS (exceeded WDEQ Class III siltstone and shale (Love and Christiansen, 1985, standard of 5,000 mg/L). Sheet 2). Within the Snake/Salt River Basin, the Upper Devonian Jefferson Formation also is Star Valley present only in the Yellowstone Volcanic Area (pl. The chemical composition of the Madison aquifer 1; pl. 6) and consists of massive siliceous dolomite in Star Valley (SV) was characterized and the and limestone (Love and Christiansen, 1985, quality evaluated on the basis of environmental Sheet 2). Cox (1976, Sheet 1) speculated that wells water samples from as many as six wells. Summary completed in either formation probably would statistics calculated for available constituents are not yield more than a few gallons per minute. listed in appendix E–6. Major ion composition No data were located describing the physical and in relation to TDS for the wells in the Madison chemical hydrogeologic characteristics of either aquifer in the SV is shown on a trilinear diagram lithostratigraphic unit in the Snake/Salt River (appendix F–6, diagram C). TDS concentrations Basin. indicated that all waters were fresh (TDS concentrations less than or equal to 999 mg/L) 7.4.8 Darby aquifer (appendix E–6). TDS concentrations for the wells ranged from 244 to 349 mg/L, with a median of The physical and chemical characteristics of the 311 mg/L. On the basis of the characteristics and Darby aquifer in the Snake/Salt River Basin are constituents analyzed for, the quality of water from described in this section of the report. the Madison aquifer in SV was suitable for most uses. No characteristics or constituents approached Physical characteristics or exceeded applicable USEPA or State of Wyoming domestic, agriculture, or livestock water- The Darby aquifer is composed of saturated and quality standards. permeable parts of the Upper Devonian to Lower Mississippian Darby Formation (pls. 4, 5, and 6). The chemical composition of a Paleozoic The Darby Formation consists of an upper part limestone (may be Madison aquifer) underlying of dull-yellow, gray, pink, and black thin-bedded the Salt Lake Formation in Star Valley (SV) was dolomitic siltstone and shale, and a lower part of characterized and the quality evaluated on the basis brown, vuggy, siliceous, brittle dolomite containing of environmental water samples from as many sparse thin limestone beds and thin sandstone beds as two wells. Individual constituents are listed (Love and others, 1992). in appendix E–6. The TDS concentration (169 mg/L) from one well indicated that the water was Thickness of the Darby Formation varies by fresh (TDS concentration less than or equal to geographic area in the Snake/Salt River Basin. 999 mg/L) (appendix E–6). On the basis of the Thickness of the Darby Formation in the Gros characteristics and constituents analyzed for, the Ventre Range ranges from about 285 to 450 ft quality of water from a Paleozoic limestone aquifer (Love and others, 1992). Thickness of the Darby in SV was suitable for most uses. No characteristics Formation in Jackson Hole is about 250 ft (Love, or constituents approached or exceeded applicable 2003b). Thickness of the Darby Formation in USEPA or State of Wyoming domestic, agriculture, the Teton Range ranges from about 250 to 450 or livestock water-quality standards. ft (Pampeyan and others, 1967; Schroeder, 1969, 1972; Christiansen and others, 1978; Love and 7.4.7 Three Forks and Jefferson others, 1992). Thickness of the Darby Formation Formations in the Overthrust Belt ranges from about 285 to 700 ft (Pampeyan and others, 1967; Schroeder, Within the Snake/Salt River Basin, the Upper 1969, 1972, 1973, 1974, 1976, 1981, 1987; Jobin, Devonian Three Forks Formation is present only 1972; Albee, 1973; Albee and Cullins, 1975; Oriel
7-192 and Platt, 1980; Schroeder and others, 1981; Chemical characteristics Lageson, 1986; Love and others, 1992; Love and Love, 2000; Love, 2003c). The chemical composition of groundwater in the Darby aquifer in the Snake/Salt River The Darby Formation in the Snake/Salt River Basin Basin is described in this section of the report. is classified as an aquifer by previous investigators Groundwater quality of the Darby aquifer is (pls. 4, 5, and 6). The Wyoming Water Planning described in terms of a water’s suitability for Program (1972, Table III-2) speculated that the domestic, irrigation, and livestock use, on the basis Darby Formation was a fair to poor aquifer in the of USEPA and WDEQ standards (table 5-2), and Snake/Salt River Basin (pls. 4, 5, and 6). Lines and groundwater-quality sample summary statistics Glass (1976, Sheet 1) speculated that the Darby tabulated by hydrogeologic unit as quantile values Formation probably would not yield more than a (appendices E–1 and E–5). few gallons per minute per well. Ahern and others (1981, Figure II-7, and Table IV-1) classified the Yellowstone Volcanic Area formation as a major aquifer in the Overthrust The chemical composition of the Darby aquifer Belt and adjacent Green River Basin (pls. 4 and in the Yellowstone Volcanic Area (YVA) was 5). The investigators also considered the Darby characterized and the quality evaluated on the basis aquifer to be part of a larger regional Paleozoic of one environmental water sample from one well. aquifer system composed of many different Individual constituents are listed in appendix E–1. Paleozoic hydrogeologic units (pls. 4 and 5). In The TDS concentration (183 mg/L) indicated the eastern Gros Ventre Range and the Salt River that the water was fresh (TDS concentration less Range, the Darby Formation is classified as an than or equal to 999 mg/L) (appendix E–1). On aquifer and is considered part of an aquifer system the basis of the characteristics and constituents composed of other Paleozoic hydrogeologic units analyzed for, the quality of water from the Darby with varying amounts of hydraulic connection aquifer in the YVA was suitable for most uses. (pls. 4 and 5). In the Wyoming Water Framework No characteristics or constituents approached or Plan, the Darby Formation was classified as a exceeded applicable USEPA or State of Wyoming major aquifer throughout Wyoming (WWC domestic, agriculture, or livestock water-quality Engineering and others, 2007, Figure 4-9) (pls. standards. 4, 5, and 6). Previous studies of the Darby Formation in the adjacent Green River Basin and Overthrust Belt surrounding areas have classified the formation as The chemical composition of groundwater in an aquifer or confining unit (Ahern and others, the Darby aquifer in the Overthrust Belt (OTB) 1981; Geldon, 2003; Bartos and Hallberg, 2010, was characterized and the quality evaluated on and references therein). In the upper Colorado the basis of environmental water samples from as River Basin and adjacent areas (including Green many as four springs. Summary statistics calculated River Basin, and parts of the Overthrust Belt), for available constituents are listed in appendix Geldon (2003) classified the Darby Formation as E–5. Major ion composition in relation to TDS a regional confining unit (see Bartos and Hallberg, for springs issuing from the Darby aquifer in the 2010, Figure 5-4). In the Wind River and Bighorn OTB is shown on a trilinear diagram (appendix Basins east of the Snake/Salt River Basin, the F–5, diagram L). TDS concentrations indicated Darby Formation was classified as an aquifer (pl. 6) that waters from two of the four springs were fresh (Bartos and others, 2012, and references therein). (TDS concentrations less than or equal to 999 Permeability of the dolomite that comprises much mg/L), and waters from the other two springs were of the Darby Formation in the eastern Gros Ventre slightly saline (TDS concentrations ranging from Range primarily is intercrystalline (Mills, 1989; 1,000 to 2,999 mg/L) (appendix E–5; appendix Mills and Huntoon, 1989). Spring-discharge F–5, diagram L). The TDS concentrations for the measurements for the Darby aquifer in the Snake/ springs ranged from 134 to 1,330 mg/L, with a Salt River Basin are summarized on plate 3. median of 719 mg/L.
7-193 Concentrations of some properties and 1986; Love and others, 1992; Love and Love, constituents in water from springs issuing from 2000; Love, 2003c). the Darby aquifer in the OTB approached or exceeded applicable USEPA or State of Wyoming The Bighorn Dolomite is classified as an aquifer water-quality standards and could limit suitability by previous investigators (pls. 4, 5, and 6). The for some uses. Most environmental waters were Wyoming Water Planning Program (1972, Table suitable for domestic use, as no concentrations III-2) speculated that the Bighorn Dolomite was a of constituents exceeded health-based standards. fair to poor aquifer in the Snake/Salt River Basin Concentrations of one characteristic and one (pls. 4, 5, and 6). Ahern and others (1981, Figure constituent exceeded USEPA aesthetic standards II-7, and Table IV-1) classified the formation for domestic use in two of the four spring samples: as a major aquifer in the Overthrust Belt and TDS (exceeded the SMCL of 500 mg/L) and adjacent Green River Basin (pls. 4 and 5). The sulfate (exceeded the SMCL of 250 mg/L). One investigators also considered the Bighorn aquifer constituent (sulfate) approached or exceeded to be part of a larger regional Paleozoic aquifer the applicable State of Wyoming standard for system composed of many different Paleozoic agricultural use (two of the four springs exceeded hydrogeologic units (pls. 4 and 5). In the eastern the WDEQ Class II standard of 200 mg/L). No Gros Ventre Range and the Salt River Range, the characteristics or constituents measured in springs Bighorn Dolomite is classified as an aquifer and issuing from the Darby aquifer approached or is considered part of an aquifer system composed exceeded applicable State of Wyoming livestock of other Paleozoic hydrogeologic units with water-quality standards. varying amounts of hydraulic connection (pls. 4 and 5). In the Wyoming Water Framework Plan, 7.4.9 Bighorn aquifer the Bighorn Dolomite was classified as a major aquifer throughout Wyoming (WWC Engineering The physical and chemical characteristics of the and others, 2007, Figure 4-9) (pls. 4, 5, and 6). Bighorn aquifer in the Snake/Salt River Basin are Previous studies of the Bighorn Dolomite in the described in this section of the report. adjacent Green River Basin and surrounding areas have classified the formation as an aquifer or Physical characteristics confining unit (Ahern and others, 1981; Geldon, 2003; Bartos and Hallberg, 2010, and references The Bighorn aquifer is composed of saturated and therein). In the upper Colorado River Basin and permeable parts of the Upper Ordovician Bighorn adjacent areas (including Green River Basin, and Dolomite (pls. 4, 5, and 6). The Bighorn Dolomite parts of the Overthrust Belt), Geldon (2003) consists of gray massive dolomite and dolomitic classified the Bighorn Dolomite as a regional limestone (Love and others, 1992). Thickness confining unit (see Bartos and Hallberg, 2010, of the Bighorn Dolomite varies by geographic Figure 5-4). In the Wind River and Bighorn Basins area in the Snake/Salt River Basin. Thickness of east of the Snake/Salt River Basin, the Bighorn the Bighorn Dolomite in the Gros Ventre Range Dolomite was classified as an aquifer (pl. 6) (Bartos ranges from about 200 to 500 ft (Love and others, and others, 2012, and references therein). 1992). Thickness of the Bighorn Dolomite in the Teton Range ranges from about 400 to 440 ft Permeability of the dolomite that composes (Pampeyan and others, 1967; Schroeder, 1969, much of the Bighorn aquifer is both primary 1972; Christiansen and others, 1978; Oriel and (intercrystalline) and secondary (fractures and Moore, 1985; Love and others, 1992). Thickness solution openings) (Lines and Glass, 1975; Cox, of the Bighorn Dolomite in the Overthrust Belt 1976; Mills, 1989; Mills and Huntoon, 1989). ranges from about 400 to 820 ft (Pampeyan and Large spring discharges (100 gal/min or more) others, 1967; Schroeder, 1969, 1972, 1973, 1976, inventoried as part of this study (pl. 3) primarily 1979; Jobin, 1972; Albee and Cullins, 1975; Oriel are attributable to fractures and solution openings and Platt, 1980; Oriel and Moore, 1985; Lageson, (Lines and Glass, 1975; Cox, 1976; Mills, 1989;
7-194 Mills and Huntoon, 1989). Spring-discharge characterized and the quality evaluated on the basis measurements inventoried in the Bighorn aquifer of environmental water samples from as many as in the Snake/Salt River Basin are summarized on eight springs. Summary statistics calculated for plate 3. available constituents are listed in appendix E–5. Major ion composition in relation to TDS for Chemical characteristics springs issuing from the Bighorn aquifer in the OTB is shown on a trilinear diagram (appendix The chemical composition of groundwater in F–5, diagram M). TDS concentrations indicated the Bighorn aquifer in the Snake/Salt River that all waters were fresh (TDS concentrations Basin is described in this section of the report. less than or equal to 999 mg/L) (appendix Groundwater quality of the Bighorn aquifer is E–5; appendix F–5, diagram M). The TDS described in terms of a water’s suitability for concentrations for the springs ranged from 104 domestic, irrigation, and livestock use, on the basis to 188 mg/L, with a median of 160 mg/L. On of USEPA and WDEQ standards (table 5-2), and the basis of the characteristics and constituents groundwater-quality sample summary statistics analyzed for in the spring samples, the quality tabulated by hydrogeologic unit as quantile values of water from the Bighorn aquifer in the OTB (appendices E–2 and E–5). was suitable for most uses. No characteristics or constituents approached or exceeded applicable Northern Ranges USEPA or State of Wyoming domestic, agriculture, The chemical composition of the Bighorn aquifer or livestock water-quality standards. in the Northern Ranges (NR) was characterized and the quality evaluated on the basis of 7.4.10 Gallatin aquifer environmental water samples from as many as three springs and one well. Individual constituents The physical and chemical characteristics of the are listed in appendix E–2. Major ion composition Gallatin aquifer in the Snake/Salt River Basin are in relation to TDS for springs issuing from the described in this section of the report. Bighorn aquifer in the NR is shown on a trilinear diagram (appendix F–2, diagram H). TDS Physical characteristics concentrations indicated that the waters were fresh (TDS concentrations less than or equal to 999 The Gallatin aquifer is composed of saturated mg/L) (appendix E–2; appendix F–2, diagram and permeable parts of the Upper Cambrian H). The TDS concentrations for the springs ranged Gallatin Group or Limestone (pls. 4, 5, and from 37.1 to 107 mg/L, with a median of 96.0 6). The Gallatin Group or Limestone consists mg/L. The TDS concentration for the well was of interbedded, gray, mottled yellow and tan, 270 mg/L. On the basis of the characteristics and thin-bedded to massive limestone and dolostone constituents analyzed for, the quality of water from (dolomite); some green shale is present in the the Bighorn aquifer in the NR was suitable for middle of the formation and some conglomerate most uses. No characteristics or constituents in is present in the lower part of the formation (Lines the spring or well samples approached or exceeded and Glass 1975; Oriel and Platt, 1980; Rubey applicable USEPA standards or State of Wyoming and others, 1980; Love and others, 1992). In the domestic or livestock water-quality standards. One Yellowstone Volcanic Area and Teton and Gros characteristic in the well sample approached or Ventre Ranges, the "Gallatin" is elevated to group exceeded applicable State of Wyoming standards rank and is composed of an upper formation, the for agricultural-use standards: SAR (exceeded Snowy Range Formation, and a lower formation, WDEQ Class II standard of 8). the Pilgrim Limestone (pls. 5 and 6).
Overthrust Belt Thickness of the Gallatin Limestone varies by The chemical composition of groundwater in the geographic area in the Snake/Salt River Basin. Bighorn aquifer in the Overthrust Belt (OTB) was Thickness of the Gallatin Group or Limestone in
7-195 the Gros Ventre Range ranges from about 180 to and Hallberg, 2010, Figure 5-4). In the Wind 250 ft (Love and Love, 1978; Love and others, River and Bighorn Basins east of the Snake/Salt 1992; Love and Love, 2000; Love, 2001a,b; Love River Basin, the Gallatin Group or Limestone was and Reed, 2001a). Thickness of the Gallatin Group classified as a confining unit (pl. 6) (Bartos and or Limestone in the Teton Range ranges from others, 2012, and references therein). about 125 to 250 ft (Pampeyan and others, 1967; Schroeder, 1969, 1972; Oriel and Moore, 1985; Permeability of the dolomite that comprises Love and others, 1992; Love and Reed, 2000, much of the Gallatin aquifer is both primary 2001b; Love, 2003a). Thickness of the Gallatin (intercrystalline) and secondary (fractures and Group or Limestone in the Overthrust Belt ranges solution openings) (Lines and Glass, 1975; Cox, from about 120 to 250 ft (Pampeyan and others, 1976; Mills, 1989; Mills and Huntoon, 1989). 1967; Schroeder, 1969, 1972; Jobin, 1972; Albee Cox (1976, Sheet 1) speculated that the formation and Cullins, 1975; Oriel and Platt, 1980; Oriel might yield a few tens of gallons per minute to and Moore, 1985; Lageson, 1986; Love and others, wells. Large spring discharges (100 gal/min or 1992). more) inventoried as part of this study (pl. 3) primarily are attributable to fractures and solution The Gallatin Group or Limestone is classified as an openings (Lines and Glass, 1975; Cox, 1976; Mills, aquifer or confining unit by previous investigators 1989; Mills and Huntoon, 1989). Hydrogeologic (pls. 4, 5, and 6). The Wyoming Water Planning information describing the Gallatin aquifer in the Program (1972, Table III-2) speculated that the Snake/Salt River Basin, including well-yield and Gallatin Group or Limestone was probably a poor spring-discharge measurements and other hydraulic aquifer in the Snake/Salt River Basin (pls. 4, 5, properties, is summarized on plate 3. and 6). Ahern and others (1981, Figure II-7, and Table IV-1) classified the formation as a minor Chemical characteristics aquifer in the Overthrust Belt and adjacent Green River Basin (pls. 4 and 5). The investigators also The chemical composition of groundwater in considered the Gallatin aquifer to be part of a the Gallatin aquifer in the Snake/Salt River larger regional Paleozoic aquifer system composed Basin is described in this section of the report. of many different Paleozoic hydrogeologic units Groundwater quality of the Gallatin aquifer is (pls. 4 and 5). In the eastern Gros Ventre Range described in terms of a water’s suitability for and the Salt River Range, the Gallatin Group domestic, irrigation, and livestock use, on the basis or Limestone is classified as an aquifer and is of USEPA and WDEQ standards (table 5-2), and considered part of an aquifer system composed of groundwater-quality sample summary statistics other Paleozoic hydrogeologic units with varying tabulated by hydrogeologic unit as quantile values amounts of hydraulic connection (pls. 4 and (appendices E–2, E–3, and E–5). 5). In the Wyoming Water Framework Plan, the Gallatin Group or Limestone was classified as Northern Ranges a minor aquifer throughout Wyoming (WWC The chemical composition of the Gallatin aquifer Engineering and others, 2007, Figure 4-9) (pls. 4, in the Northern Ranges (NR) was characterized 5, and 6). Previous studies of the Gallatin Group and the quality evaluated on the basis of or Limestone in the adjacent Green River Basin environmental water samples from as many as and surrounding areas have classified the formation two springs. Individual constituents are listed in as an aquifer or confining unit (Ahern and others, appendix E–2. The TDS concentrations (75.8 and 1981; Geldon, 2003; Bartos and Hallberg, 2010, 2,480 mg/L) indicated that waters from the springs and references therein). In the upper Colorado ranged from fresh (TDS concentrations less than River Basin and adjacent areas (including Green or equal to 999 mg/L) to slightly saline (1,000 to River Basin and parts of the Overthrust Belt), 2,999 mg/L) (appendix E–2). Geldon (2003) classified the Gallatin Group or Limestone as a regional confining unit (see Bartos Concentrations of some properties and constituents
7-196 in water from the Gallatin aquifer in the NR 7.4.11 Park Shale, Meagher Limestone, approached or exceeded applicable USEPA or State and Wolsey Shale of Wyoming water-quality standards and could limit suitability for some uses. No concentrations Within the Snake/Salt River Basin, the Middle and of constituents exceeded health-based standards. Upper Cambrian Park Shale, Middle Cambrian Concentrations of one characteristic and one Meagher Limestone, and Middle Cambrian Wolsey constituent exceeded USEPA aesthetic standards Shale are present only in the Yellowstone Volcanic for domestic use and State of Wyoming standards area (pl. 1; pl. 6). The Park Shale and Wolsey for agricultural use: TDS (exceeded SMCL limit Shale consist of green micaceous shale (Love of 500 mg/L and WDEQ Class II standard of and Christiansen, 1985, Sheet 2). The Meagher 2,000 mg/L) and sulfate (exceeded SMCL of 250 Limestone consists of blue-gray and yellow mottled mg/L and WDEQ Class II standard of 200 mg/L). hard limestone (Love and Christiansen, 1985, No characteristics or constituents approached or Sheet 2). Cox (1976, Sheet 1) speculated that exceeded applicable State of Wyoming livestock wells completed in the formations probably would water-quality standards. not yield more than a few gallons per minute. No data were located describing the physical and Jackson Hole chemical hydrogeologic characteristics of the The chemical composition of the Gallatin aquifer lithostratigraphic units in the Snake/Salt River in Jackson Hole (JH) was characterized and the Basin. quality evaluated on the basis of one environmental water sample from one well. Individual 7.4.12 Gros Ventre aquifer and constituents are listed in appendix E–3. The TDS confining unit concentration (355 mg/L) indicated that the water was fresh (TDS concentration less than or equal The physical and chemical characteristics of the to 999 mg/L) (appendix E–3). On the basis of Gros Ventre aquifer and confining unit in the the characteristics and constituents analyzed for Snake/Salt River Basin are described in this section in the one sample, the quality of water from the of the report. Gallatin aquifer in JH was suitable for most uses. No characteristics or constituents approached or Physical characteristics exceeded applicable USEPA or State of Wyoming domestic, agriculture, or livestock water-quality The Middle and Upper Cambrian Gros Ventre standards. Formation (pls. 4, 5, and 6) in the Overthrust Belt is composed of gray and tan, oolitic in part, Overthrust Belt limestone with green-gray micaceous shale in the The chemical composition of groundwater in the middle of the formation (Lines and Glass, 1975; Gallatin aquifer in the Overthrust Belt (OTB) Oriel and Platt, 1980). Thickness of the Gros was characterized and the quality evaluated on Ventre Formation in the Overthrust Belt ranges the basis of one environmental water sample from from about 400 to 1,300 ft (Schroeder, 1974, one spring. Individual constituents are listed in 1981; Lines and Glass, 1975; Oriel and Platt, appendix E–5. The TDS concentration (203 1980; Lageson, 1986). mg/L) indicated that the water was fresh (TDS concentration less than or equal to 999 mg/L) In the Gros Ventre Range, the Gros Ventre (appendix E–5). On the basis of the characteristics Formation includes three members—the Park and constituents analyzed for in the spring sample, Shale, Death Canyon Limestone, and Wolsey the quality of water from the Gallatin aquifer in the Shale Members (Love and others, 1992; see Plate OTB was suitable for most uses. No characteristics 5 under Mills, 1989; Mills and Huntoon, 1989). or constituents approached or exceeded applicable The Park Shale Member consists of olive-green, USEPA or State of Wyoming domestic, agriculture, soft, flaky, micaceous shale with thin beds of flat- or livestock water-quality standards. pebble limestone conglomerate; the basal part of
7-197 the unit has numerous large and small algal heads. formation as an aquitard (confining unit) in the Thickness of the Park Shale Member ranges from Overthrust Belt and adjacent Green River Basin 150 to 350 ft. The Death Canyon Limestone (pls. 4 and 5). In the upper Colorado River Basin Member consists of blue- to dark-gray, mottled and adjacent areas (including Green River Basin, brown and tan, dense, thin-bedded, cliff-forming and parts of the Overthrust Belt), Geldon (2003) limestone. The middle part of the Death Canyon classified the Gros Ventre Formation as a regional Limestone Member contains 30 ft of flaky green confining unit (see Bartos and Hallberg, 2010, shale with abundant trilobites; locally, at the base, Figure 5-4). In the Wind River and Bighorn Basins a distinctive bed of brown-weathering dolomite is east of the Snake/Salt River Basin, the Gros Ventre present. Thickness of the Death Canyon Limestone Formation was classified as a confining unit (pl. 6) Member ranges from 300 to 370 ft. The Wolsey (Bartos and others, 2012, and references therein). Shale Member consists of green to gray-green, Because the unit consists of locally permeable zones soft, highly fissile micaceous shale that is siltier interbedded with predominantly low-permeability near the base; the lower part of the unit is very lithologic units, the Gros Ventre Formation in the glauconitic and interbedded with sandstone, and Snake/Salt River Basin was classified herein as a the glauconite weathers to a red hematite color. sequence of rocks that functions as both aquifer Thickness of the Wolsey Shale Member ranges and confining unit, reflecting hydrogeologic from 100 to 130 ft. The contact between the characteristics that differ by location examined and Wolsey Shale Member and the underlying Flathead the scale of the study. Sandstone is transitional. Much of the Gros Ventre Formation consists The Gros Ventre Formation is classified as an primarily of poorly permeable rock. Permeability of aquifer or confining unit by previous investigators the Gros Ventre Formation is attributable primarily (pls. 4, 5, and 6). The Wyoming Water Planning to development of secondary permeability in Program (1972, Table III-2) speculated that the the form of fractures and solution openings in Gros Ventre Formation was a probable poor aquifer limestone that composes parts of the unit (Lines in the Snake/Salt River Basin (pls. 4, 5, and 6). In and Glass, 1975; Cox, 1976; Mills, 1989; Mills the Salt River Range, the Gros Ventre Formation and Huntoon, 1989). Cox (1976, Sheet 1) was classified as a confining unit (pl. 4) (Blanchard, speculated that the formation might yield a few 1990; Blanchard and others, 1990). In the eastern tens of gallons per minute to wells. Shale within Gros Ventre Range, the formation was classified the formation has very little permeability, and the as both aquifer and confining unit—the Wolsey lithologic units act as confining units (Lines and Shale and Park Shale Members composed primarily Glass, 1975; Cox, 1976; Mills, 1989; Mills and of shale were classified as confining units and the Huntoon, 1989). Large spring discharges (100 Death Canyon Limestone Member composed gal/min or more) inventoried as part of this study primarily of limestone was classified as an aquifer (pl. 3) are attributable to fractures and solution (pl. 5) (Mills, 1989; Mills and Huntoon, 1989). openings in limestone (Lines and Glass, 1975; Cox, In the Wyoming Water Framework Plan, the Gros 1976; Mills, 1989; Mills and Huntoon, 1989). Ventre Formation was classified as a minor aquifer Few hydrogeologic data are available describing throughout Wyoming (WWC Engineering and the Gros Ventre aquifer and confining unit in others, 2007, Figure 4-9) (pls. 4, 5, and 6). the Snake/Salt River Basin, but spring-discharge measurements are summarized on plate 3. Investigators for previous studies of the Gros Ventre Formation in areas adjacent to the Snake/ Chemical characteristics Salt River basin have classified the formation as an aquifer or confining unit (Ahern and others, 1981; The chemical composition of groundwater in the Geldon, 2003; Bartos and Hallberg, 2010, and Gros Ventre aquifer and confining unit in the references therein) (pls. 4 and 5). Ahern and others Snake/Salt River Basin are described in this section (1981, Figure II-7, and Table IV-1) classified the of the report. Groundwater quality of the Gros
7-198 Ventre aquifer and confining unit is described Overthrust Belt in terms of a water’s suitability for domestic, The chemical composition of groundwater in the irrigation, and livestock use, on the basis of Gros Ventre aquifer and confining unit in the USEPA and WDEQ standards (table 5-2), and Overthrust Belt (OTB) was characterized and the groundwater-quality sample summary statistics quality evaluated on the basis of environmental tabulated by hydrogeologic unit as quantile values water samples from two springs. Individual (appendices E–2 and E–3). constituents are listed in appendix E–5. The TDS concentrations (102 and 152 mg/L) indicated that Northern Ranges the waters were fresh (TDS concentrations less The chemical composition of the Gros Ventre than or equal to 999 mg/L) (appendix E–5). On aquifer and confining unit in the Northern Ranges the basis of the characteristics and constituents (NR) was characterized and the quality evaluated analyzed for in the spring samples, the quality of on the basis of environmental water sample from as water from the Gros Ventre aquifer and confining many as five springs. Summary statistics calculated unit in OTB was suitable for most uses. No for available constituents are listed in appendix characteristics or constituents approached or E–2. Major ion composition in relation to TDS exceeded applicable USEPA or State of Wyoming for springs issuing from the Gros Ventre aquifer domestic, agriculture, or livestock water-quality and confining unit in the NR is shown on a standards. trilinear diagram (appendix F–2, diagram I). TDS concentrations indicated that all waters were fresh 7.4.13 Flathead aquifer (TDS concentrations less than or equal to 999 mg/L) (appendix E–2; appendix F–2, diagram The physical and chemical characteristics of the I). The TDS concentrations for the springs ranged Flathead aquifer in the Snake/Salt River Basin are from 86.8 to 148 mg/L, with a median of 107 described in this section of the report. mg/L. On the basis of the characteristics and constituents analyzed for, the quality of water from Physical characteristics the Gros Ventre aquifer and confining unit in the NR was suitable for most uses. No characteristics The Flathead aquifer is composed of the Middle or constituents approached or exceeded applicable Cambrian Flathead Sandstone (pls. 4, 5, and USEPA or State of Wyoming domestic, agriculture, 6). The Flathead Sandstone consists of white to or livestock water-quality standards. pink, tan, brown, fine-grained sandstone and some lenses of coarse-grained sandstone; the Jackson Hole upper part includes some green, silty, micaceous The chemical composition of the Gros Ventre shale interbeds, and the lower part is locally aquifer and confining unit in Jackson Hole (JH) conglomeratic (Lines and Glass, 1975; Love and was characterized and the quality evaluated on others, 1992). Much of the sandstone is quartzitic. the basis of one environmental water sample from In the Gros Ventre Range, thickness of the Flathead one spring. Individual constituents are listed in Sandstone ranges from 200 to 300 ft (Schroeder, appendix E–3. The TDS concentration (308 1969, 1972, 1976; Love and Love, 1978; Love and mg/L) indicated that the water was fresh (TDS others, 1992; Love and Love, 2000; Love, 2001b; concentration less than or equal to 999 mg/L) Love and Reed, 2001a). Thickness of the Flathead (appendix E–3). On the basis of the characteristics Sandstone in the Teton Range ranges from 150 to and constituents analyzed for in the one sample, 240 ft (Pampeyan and others, 1967; Schroeder, the quality of water from the Gros Ventre aquifer 1969; Christiansen and others, 1978; Oriel and and confining unit in JH was suitable for most Moore, 1985; Love and others, 1992; Love and uses. No characteristics or constituents approached Reed, 2000; Love, 2003a). or exceeded applicable USEPA or State of Wyoming domestic, agriculture, or livestock water- Little information is available describing the quality standards. hydrogeologic characteristics of the Flathead
7-199 Sandstone in the Snake/Salt River. Cox (1976, but also noted secondary permeability development Sheet 1) speculated that the formation might along bedding-plane partings and as fractures yield a few tens of gallons per minute to wells. associated with folds; all of these investigators Because the formation was composed primarily of classified the Flathead Sandstone as an aquifer. In sandstone, Lines and Glass (1975) speculated that contrast, Boner and others (1976) and Weston the Flathead Sandstone was probably a potential Engineering, Inc. (2008) noted that the Flathead source of water in the Overthrust Belt. Sandstone in the southern Powder River Basin in northeastern Wyoming and in the northern Much of what is known about the hydrogeologic flank of the Laramie Mountains in south-central characteristics of the Flathead Sandstone is from Wyoming was well cemented and poorly sorted the Green River Basin to the east and adjacent with little primary (intergranular) permeability. areas and elsewhere in Wyoming. Ahern and others In addition, Weston Engineering, Inc. (2008, p. (1981, Figure II-7, and Table IV-1) classified the II-4) also noted that bedding-plane partings may formation as a minor aquifer in the Overthrust provide some permeability, but that silica cement Belt and adjacent Green River Basin (pls. 4 and in the formation is not readily dissolved, and that 5). In the Wyoming Water Framework Plan, the "permeability of the unit is likely to be similar to Flathead Sandstone was classified as a major aquifer that of the underlying Precambrian rocks." (WWC Engineering and others, 2007, Figure 4-9) (pls. 4, 5, and 6). Previous studies of the Chemical characteristics Flathead Sandstone in the adjacent Green River Basin and surrounding areas have classified the The chemical composition of groundwater in formation as an aquifer (Ahern and others, 1981; the Flathead aquifer in the Snake/Salt River Taylor and others, 1986; Lindner-Lunsford and Basin is described in this section of the report. others, 1989; Geldon, 2003; Bartos and Hallberg, Groundwater quality of the Flathead aquifer 2010, and references therein); classification of the is described in terms of a water’s suitability for formation as an aquifer in the Snake/Salt River domestic, irrigation, and livestock use, on the basis was tentatively retained herein (pls. 4, 5, and 6). of USEPA and WDEQ standards (table 5-2), and Few hydrogeologic data are available describing groundwater-quality sample summary statistics the Flathead aquifer in the Snake/Salt River, but tabulated by hydrogeologic unit as quantile values spring-discharge measurements are summarized on (appendix E–2). plate 3. Northern Ranges Reported descriptions of permeability of the The chemical composition of the Flathead aquifer Flathead Sandstone in Wyoming vary by in the Northern Ranges (NR) was characterized investigator and the geographic area examined. In and the quality evaluated on the basis of the Wind River Basin and Granite Mountains area environmental water samples from as many as two east of the Snake/Salt River Basin, Richter (1981, hot springs (Granite Hot Springs, about 15 miles Table IV-1) reported that porosity and permeability east-northeast of Hoback Junction). Individual is intergranular, but that secondary permeability constituents are listed in appendix E–2. The TDS is present along bedding-plane partings and as concentrations (670 to 826 mg/L) indicated that fractures associated with folds and faults; the waters were fresh (TDS concentrations less than or investigator classified the Flathead Sandstone as equal to 999 mg/L) (appendix E–2). a "major aquifer" in the Wind River Basin and adjacent Granite Mountains area east of the Snake/ Concentrations of some properties and Salt River Basin. Similarly, in the Bighorn Basin constituents in water from hot springs issuing from east of the Absaroka Range in the Snake/Salt River the Flathead aquifer in the NR approached or Basin, previous investigators (Cooley, 1984, 1986; exceeded applicable USEPA or State of Wyoming Doremus, 1986; Jarvis, 1986; Spencer, 1986) also water-quality standards and could limit suitability reported intergranular porosity and permeability for some uses. One constituent (fluoride) was
7-200 measured at concentrations greater than health- Moore, 1985; Love and others, 1992; Love and based standards (both samples exceeded the Reed, 2000; Love, 2003a). USEPA MCL of 4 mg/L). Concentrations of one characteristic and one constituent exceeded USEPA Little information is available describing the aesthetic standards for domestic use: TDS (both hydrogeologic characteristics of the Flathead samples exceeded the SMCL of 500 mg/L) and Sandstone in the Snake/Salt River. Cox (1976, fluoride (both samples exceeded the SMCL of 2 Sheet 1) speculated that the formation might mg/L). yield a few tens of gallons per minute to wells. Because the formation was composed primarily of Concentrations of some characteristics and sandstone, Lines and Glass (1975) speculated that constituents in water from hot springs issuing the Flathead Sandstone was probably a potential from the Flathead aquifer approached or exceeded source of water in the Overthrust Belt. State of Wyoming standards for agricultural and livestock use in the NR. One characteristic and one Much of what is known about the hydrogeologic constituent were measured in environmental water characteristics of the Flathead Sandstone is from samples from hot springs at concentrations greater the Green River Basin to the east and adjacent than agricultural-use standards: chloride (both areas and elsewhere in Wyoming. Ahern and others samples exceeded the WDEQ Class II standard of (1981, Figure II-7, and Table IV-1) classified the 100 mg/L) and SAR (1 of 2 samples exceeded the formation as a minor aquifer in the Overthrust WDEQ Class II standard of 8). No characteristics Belt and adjacent Green River Basin (pls. 4 and or constituents approached or exceeded applicable 5). In the Wyoming Water Framework Plan, the State of Wyoming livestock water-quality Flathead Sandstone was classified as a major aquifer standards. (WWC Engineering and others, 2007, Figure 4-9) (pls. 4, 5, and 6). Previous studies of the 7.5 Precambrian basal confining unit Flathead Sandstone in the adjacent Green River Basin and surrounding areas have classified the The physical and chemical characteristics of the formation as an aquifer (Ahern and others, 1981; Flathead aquifer in the Snake/Salt River Basin are Taylor and others, 1986; Lindner-Lunsford and described in this section of the report. others, 1989; Geldon, 2003; Bartos and Hallberg, 2010, and references therein); classification of the Physical characteristics formation as an aquifer in the Snake/Salt River was tentatively retained herein (pls. 4, 5, and 6). The Flathead aquifer is composed of the Middle Few hydrogeologic data are available describing Cambrian Flathead Sandstone (pls. 4, 5, and the Flathead aquifer in the Snake/Salt River, but 6). The Flathead Sandstone consists of white to spring-discharge measurements are summarized on pink, tan, brown, fine-grained sandstone and pl. 3. some lenses of coarse-grained sandstone; the upper part includes some green, silty, micaceous Reported descriptions of permeability of the shale interbeds, and the lower part is locally Flathead Sandstone in Wyoming vary by conglomeratic (Lines and Glass, 1975; Love and investigator and the geographic area examined. In others, 1992). Much of the sandstone is quartzitic. the Wind River Basin and Granite Mountains area In the Gros Ventre Range, thickness of the Flathead east of the Snake/Salt River Basin, Richter (1981, Sandstone ranges from 200 to 300 ft (Schroeder, Table IV-1) reported that porosity and permeability 1969, 1972, 1976; Love and Love, 1978; Love and is intergranular, but that secondary permeability others, 1992; Love and Love, 2000; Love, 2001b; is present along bedding-plane partings and as Love and Reed, 2001a). Thickness of the Flathead fractures associated with folds and faults; the Sandstone in the Teton Range ranges from 150 to investigator classified the Flathead Sandstone as 240 ft (Pampeyan and others, 1967; Schroeder, a "major aquifer" in the Wind River Basin and 1969; Christiansen and others, 1978; Oriel and adjacent Granite Mountains area east of the Snake/
7-201 Salt River Basin. Similarly, in the Bighorn Basin Concentrations of some properties and east of the Absaroka Range in the Snake/Salt River constituents in water from hot springs issuing from Basin, previous investigators (Cooley, 1984, 1986; the Flathead aquifer in the NR approached or Doremus, 1986; Jarvis, 1986; Spencer, 1986) also exceeded applicable USEPA or State of Wyoming reported intergranular porosity and permeability water-quality standards and could limit suitability but also noted secondary permeability development for some uses. One constituent (fluoride) was along bedding-plane partings and as fractures measured at concentrations greater than health- associated with folds; all of these investigators based standards (both samples exceeded the classified the Flathead Sandstone as an aquifer. In USEPA MCL of 4 mg/L). Concentrations of one contrast, Boner and others (1976) and Weston characteristic and one constituent exceeded USEPA Engineering, Inc. (2008) noted that the Flathead aesthetic standards for domestic use: TDS (both Sandstone in the southern Powder River Basin samples exceeded the SMCL of 500 mg/L) and in northeastern Wyoming and in the northern fluoride (both samples exceeded the SMCL of 2 flank of the Laramie Mountains in south-central mg/L). Wyoming was well cemented and poorly sorted with little primary (intergranular) permeability. Concentrations of some characteristics and In addition, Weston Engineering, Inc. (2008, p. constituents in water from hot springs issuing II-4) also noted that bedding-plane partings may from the Flathead aquifer approached or exceeded provide some permeability, but that silica cement State of Wyoming standards for agricultural and in the formation is not readily dissolved, and that livestock use in the NR. One characteristic and one "permeability of the unit is likely to be similar to constituent were measured in environmental water that of the underlying Precambrian rocks." samples from hot springs at concentrations greater than agricultural-use standards: chloride (both Chemical characteristics samples exceeded the WDEQ Class II standard of 100 mg/L) and SAR (1 of 2 samples exceeded the The chemical composition of groundwater in WDEQ Class II standard of 8). No characteristics the Flathead aquifer in the Snake/Salt River or constituents approached or exceeded applicable Basin is described in this section of the report. State of Wyoming livestock water-quality Groundwater quality of the Flathead aquifer standards. is described in terms of a water’s suitability for domestic, irrigation, and livestock use, on the basis of USEPA and WDEQ standards (table 5-2), and groundwater-quality sample summary statistics tabulated by hydrogeologic unit as quantile values (appendix E–2).
Northern Ranges The chemical composition of the Flathead aquifer in the Northern Ranges (NR) was characterized and the quality evaluated on the basis of environmental water samples from as many as two hot springs (Granite Hot Springs, about 15 miles east-northeast of Hoback Junction). Individual constituents are listed in appendix E–2. The TDS concentrations (670 to 826 mg/L) indicated that waters were fresh (TDS concentrations less than or equal to 999 mg/L) (appendix E–2).
7-202