By W.G. Batten and R.A. Lidwin
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U.S. GEOLOGICAL SURVEY
Water-Resources Investigations Report 95-4207
Prepared in cooperation with the
BAD RIVER CHIPPEWA INDIAN TRIBE OF WISCONSIN
- Purpose and scope
- Identification of data-collection sites
- Description of study area
- Geologic setting
- Ground water
- Occurrence and flow
- Aquifer characteristics of sand and gravel deposits
- Aquifer characteristics of Precambrian sandstone
- Surface water
- Selected references
Water-level and construction data for wells within the Bad River Indian Reservation Physical and chemical characteristics of water from wells and springs within the Bad River Indian Reservation Trace-constituent analyses of water from wells and springs within the Bad River Indian Reservation Physical and chemical characteristics of water from streams within the Bad River Indian Reservation Physical and chemical characteristics of water and bottom material in lakes and sloughs within the Bad River Indian Reservation
Multiply By To obtain foot (ft) 0.3048 meter mile (mi) 1.609 kilometer acre .004047 square kilometer square mile (mi2) 2.590 square kilometer inch per year 25.40 millimeter per year foot per day (ft/d) .3048 meter per day foot per mile (ft/mi) 0.1894 meter per kilometer gallon per minute (gal/min) 0.06309 liter per second cubic foot per second (ft3/s) 0.02832 cubic meter per secondTemperature, in degrees Fahrenheit (F) can be converted to degree Celsius (C) by use of the following equation:
Sea level: In this report "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)-a geodetic datum derived from a general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929.
Abbreviated water-quality units used in this report: Chemical concentrations and water temperature are given in metric units. Chemical concentration is given in milligrams per liter (mg/L) or micrograms per liter (mg/L). Milligrams per liter is a unit expressing the concentration of chemical constituents in solution as weight (milligrams) of solute per unit volume (liter) of water. One thousand micrograms per liter is equivalent to one milligram per liter. For concentrations less than 7,000 mg/L, the numerical value is the same as for concentrations in parts per million.
Specific conductance of water is expressed in microsiemens per centimeter at 25 degrees Celsius (mS/cm). This unit is equivalent to micromhos per centimeter at 25 degrees Celsius (mmho/cm), formerly used by the U.S. Geological Survey.
U.S. GEOLOGICAL SURVEY
Gordon P. Eaton, Director
For additional information write to: Copies of this report can be purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Earth Science Information Center 6417 Normandy Lane Open-File Reports Section Madison, WI 53719 Box 25286, MS 517 Denver Federal Center Denver, CO 80225
Water-resources data were collected in the Bad River Indian Reservation of northern Wiscon sin from 1983 through 1987. Some data are interpreted to describe ground-water flow, ground water quality, streamflow, and surface-water qual ity. Data also are presented in tables and appen dixes for baseline reference.
Precambrian sandstone and basalt underlie varying thicknesses of sandy till, outwash sand and gravel, and clay deposited in glacial meltwater lakes. The thickness of glacial deposits generally ranges from 100 to 300 ft but reaches a known thickness of almost 1,000 ft on the east-central edge of the Reservation. Sand and gravel deposits are generally buried beneath 50 to 150 ft of glacial lake clays and silts throughout most of the Reser vation. These buried sand and gravel deposits lie directly on Precambrian sandstone of unknown thickness in the northern half of the Reservation. The sand and gravel deposits and the sandstone form a single aquifer system confined by the over lying clay deposits. In and near the village of Odanah, numerous wells finished in either the sand and gravel or in the sandstone flow above land surface.
Estimates of the horizontal hydraulic con ductivity of the sand and gravel based on 30 spe cific-capacity tests range from about 2 to 700 ft per day with a median value of about 80 ft per day. Horizontal hydraulic conductivity estimates for the sandstone range from about 1 to 360 ft per day with a median of about 2 ft per day. These esti mates are based on 42 specific-capacity tests of wells open only to the upper 20 to 60 ft of sand stone. The horizontal hydraulic conductivity of the sandstone appears to decrease with depth; highest estimates were determined for wells open only to the upper 20 ft of sandstone.
Ground water in the confined aquifer system is a calcium magnesium bicarbonate type with rel atively low total dissolved solids concentrations. The median total dissolved solids concentration of water from 17 sand and gravel wells is about 150 milligrams per liter and the median for water from 21 sandstone wells is about 244 milligrams per liter. High concentrations of iron and manganese were found in water from 12 of 36 sampled wells. Total recoverable concentrations of iron exceeded 500 micrograms per liter in 5 wells and concentra tions of manganese exceeded 50 micrograms per liter in 7 wells.
Streamflow has been continuously mea sured at a streamflow-gaging station in the Bad River near Odanah for much of the time since 1914. This station monitors drainage from a basin with an area of 597 square miles and the average daily discharge of the Bad River at this gaging sta tion is 622 cubic feet per second. The peak instan taneous flow at the station was 27,700 cubic feet per second on April 24, 1960 and the minimum instantaneous flow was 34 cubic feet per second on November 8, 1976.
Analysis of water samples collected at 12 sites at 10 small streams during base-flow condi tions indicate that the concentrations of common chemical constituents are similar to but lower than those found in ground water. The median concen tration of total dissolved solids was about 110 mil ligrams per liter as compared to about 155 milligrams per liter in ground-water samples from wells finished in sand and gravel.
Hydrologic and water-quality data were col lected on the Bad River Indian Reservation from 1983 through 1987 by the U.S. Geological Survey (USGS), in cooperation with the Bad River Chippewa Indian Tribe of Wisconsin. These baseline hydrologic and water-quality data will be used by tribal planners and leaders to manage and protect the water resources of the Reservation.
This report summarizes ground- and surface water data collected during the study. Ground-water and streamflow data have been analyzed and inter preted; surface-water quality data are presented in tab ular form with minimal interpretation and discussion. Data from seismic-refraction survey lines and drillers' well-construction reports were used to compile maps of the altitude of the bedrock surface, the thickness of gla cial deposits, and the potentiometric surface of the con fined ground-water-flow system. These data also were used to construct an idealized geologic section and a conceptual model of the ground-water-flow system. Selected well-construction data were analyzed to esti mate the hydraulic properties of the sand and gravel and sandstone aquifers that make up the confined ground-water-flow system. Water samples from wells, streams, lakes, and sloughs were analyzed for major ions and trace metals. Streamflow data were analyzed to determine flow-duration, flood, and low-flow fre quency characteristics of the Bad River near Odanah.
Each surface-water data-collection site and well mentioned in this report and shown on plate 1 has a unique identification number. The system for assigning these identification numbers is based on the geographic location of the surface-water sites and wells. There are two groups of surface-water data-collection sites: streamflow-gaging stations and sites used for collect ing surface-water (and bottom material) quality samples. Each streamflow-gaging station has a "down stream order number" that consists of seven or eight digits, with the number increasing in the "downstream" direction within a given stream basin. Each surface water quality sampling site has a unique fifteen-digit identification number that combines the (approximate) latitude and longitude of the site plus a two-digit sequence number which further distinguishes each site.
Wells and springs also are identified by a unique 15-digit number that is a combination of the site's lati tude and longitude and a two-digit sequence number. The sequence number distinguishes sites located less than about 100 ft from each other with the same latitude and longitude. Each well is also identified by a local number in addition to the identification number. The local number consists of an abbreviation for the county name; the township, range and section; and a four-digit sequence number assigned to the well. For example, well AS-46/03W/20-0221 is located in Ashland County (AS), township 46 north, range 3 west, section 20; its sequence number is 0221. The local number is used in the appendixes in this report. Only the last two or three digits of the four-digit sequence number are used to identify wells and springs on plate 1.
The Bad River Indian Reservation encompasses about 195 mi2 in northeastern Ashland County in north-central Wisconsin (fig. 1). The Reservation also includes a 9-mi2 area in northwestern Iron County and a small, 196-acre parcel of land on the northeastern tip of Madeline Island (fig. 1) in Lake Superior. The parcel on Madeline Island is not included in the present study.
Lowlands in the northern two-thirds of the Res ervation contain many wetlands. This part of the Res ervation slopes at a rate of about 10 to 15 ft/mi to Lake Superior, which has a mean elevation of 602 ft above sea level. A 20-mi2 area of marshes and sloughs bor ders Lake Superior at the mouths of the Bad and Kak agon Rivers (pl. 1). Uplands in the southeastern part of the Reservation rise over 500 ft above the lowlands to more than 1,250 ft above sea level.
Approximately 85 percent of the Reservation is covered by second-growth forest of aspen and white birch. Northern hardwoods and white pine cover the few upland areas. Swamp and marsh vegetation cover the wetlands along Lake Superior (U.S. Department of Housing and Urban Development, 1976). Virtually no agricultural crops are grown on the poorly drained clay soils that cover most of the land.
Precambrian basalt and sandstone bedrock underlies the entire Reservation. A sequence of dark colored volcanic basalt lava flows, sometimes referred to as "traprock," underlies the topographic high in the extreme southeastern corner of the Reservation (fig. 2). The Oronto Group, a sequence of sandstone with some shale and conglomerate (Mudrey and others, 1982), underlies most of the Reservation (fig. 2). The young est of the bedrock units is called the Bayfield Group. This unit consists of nearly flat-lying sandstone and is found in the northwestern part of the Reservation (fig. 2). The contact between the Bayfield and Oronto Groups is somewhat uncertain. The basalt lava flows are about 1 to 1.5 billion years old and the youngest rocks in the Bayfield Group are just under 1 billion years old (Mudrey and others, 1982).
Drillers' geologic logs, outcrop locations, and seismic-refraction data were analyzed to determine the altitude of the bedrock surface in feet above sea level. Plate 2 is a contour map of the bedrock surface from a plot of these data. The shape and location of contour lines are inferred in large areas of the Reservation inte rior where few data are available. The bedrock surface ranges from a known altitude of about 1,150 ft above sea level in the extreme southeastern corner of the Res ervation (pl. 2) to about 20 ft below sea level deter mined from a seismic-refraction survey line just east of the Reservation boundary in section 31 of T47N, R1W, about 1 mi southeast of the settlement at Birch Ridge (pl. 2). Two community-supply wells at Birch Ridge also penetrate more than 950 ft of glacial material that overlies sandstone bedrock. This bedrock low extends from the Birch Ridge area to the southwest as a bedrock valley, or more likely as a structural trough formed by folding of the bedrock layers (M.G. Mudrey, Wiscon sin Geological and Natural History Survey, oral com mun., 1989). Another broad but shallower bedrock trough appears to underlie the central part of the Reser vation and trends from the southwest to the northeast with bedrock altitudes ranging from 300 to 400 ft above sea level (pl. 2).
Wisconsin stage glacial deposits directly overlie Precambrian bedrock throughout most of the Reserva tion. The glacial deposits in the Lake Superior region of northern Wisconsin that includes the Bad River Indian Reservation have been described by Clayton (1984). Clayton (1984) identifies glacial deposits within the Reservation as part of the Miller Creek For mation (fig. 3) deposited approximately 9,500 to 11,500 years ago, or as part of the Copper Falls Forma tion, deposited earlier than 11,500 years ago. Deposits of the Miller Creek Formation overlie the Copper Falls Formation throughout most of the Reservation (fig. 3).
The Miller Creek Formation consists of two types of deposits: (1) clayey till that was reworked by glacial-meltwater lake-wave action, and (2) offshore clay and silt deposited by turbidity currents flowing into glacial lakes (Clayton, 1984). The offshore clay and silt which covers most of the lowland along Lake Superior is locally referred to as the "red clay." This material underlies Quaternary alluvial sand and gravel deposited along major streams and underlies recent organic deposits in wetland areas.
The Copper Falls Formation consists of sandy till and sandy outwash deposited by glacial meltwater. These deposits underlie the Miller Creek Formation throughout most of the Reservation (fig. 3). The Miller Creek Formation is absent in the extreme southeastern corner of the Reservation where the Copper Falls For mation extends from land surface to volcanic bedrock (fig. 3). Glacial deposits older than the Copper Falls Formation may be present where the thickness of gla cial deposits exceeds 300 ft or more.
Glacial deposits overlie sandstone bedrock in the northern half of the Reservation (fig. 4). The thickness of glacial deposits differs greatly throughout the Reser vation. Average thickness ranges from 200 to 400 ft but attain a maximum thickness of the glacial deposit is about 1,000 ft in the center of the bedrock trough along the east edge of the Reservation (fig. 4). Glacial depos its are less than 100 ft thick in the upland area in the southeastern and west-central part of the Reservation. Sandstone bedrock crops out along the Bad River in sections 35 and 36 of T47N, R3W (pl. 2). The thickness of glacial deposits is estimated in many areas of the Reservation where no data are available.
All water used by Reservation residents is supplied by wells that pump water from saturated sand and gravel deposits or Precambrian sandstone. The occur rence and availability of this ground water is deter mined by the hydraulic properties of these deposits.
Ground-water occurrence and flow can best be described by referring to the geohydrologic section shown in figure 3. The shaded zones represent the two ground-water-flow systems. The shallow system repre sents flow that takes place at shallow depths (probably less than 50 ft in most areas). Flow paths, indicated by small arrows, within this shallow system tend to be short. Flow begins as precipitation infiltrates the soil and moves downward through vertical cracks (frac tures) in the generally clayey Miller Creek Formation. Flow is horizontal through thin sand or silty layers interlayered in the clay in this shallow system. Some water flows in the clay itself at the microscopic level. However, the velocity or flow rate of water in the clay is probably on the order of 1 in/yr or less. Ground water in this shallow system generally flows from topo graphic highs toward the nearest stream or wetland where the water seeps (discharges) into the surface water body. The level below land surface in this shal low system where all openings between individual sand grains or clay particles are completely saturated is called the water table (fig. 3);; the shallow system can be referred to as a water-table system.
The shallow system is separated from the deep system by a layer of massive clay in the Miller Creek Formation that probably ranges from about 50 to 150 ft in thickness (fig. 3). The clay at this depth does not con tain channels created by plant roots or by the chemical or physical breakdown of clay material by infiltrating precipitation. Therefore, this clay is not able to conduct water unlike the near-surface clay deposits that com prise the shallow (water-table) system. As a result, the channel-free clay acts as a layer that retards the vertical flow of water and confines the deep ground-water-flow system.
The deep ground-water-flow system is referred to as a confined or artesian aquifer system. In this deep system (fig. 3), ground water flows through both the permeable Precambrian sandstone and sand deposits of the Copper Falls Formation. The deep system is a large regional flow system, as indicated by the long arrows in figure 3. Water in this system comes from precipitation and snowmelt infiltrating the sandy Copper Falls For mations (fig. 3) in the upland area in the southeastern part of the Reservation and in uplands south of the Res ervation (not shown). Ground water generally flows northward within these deposits toward Lake Superior (fig. 3) and becomes confined where the thickness of the overlying clay layer of the Miller Creek Formation is great enough to retard vertical movement. In upland areas, the deep system is not confined by overlying clay, and flow of the ground water is similar to that in the shallow system, where the ground water flows along short paths from topographically high areas toward nearby headwaters of streams. However, some of the ground water in these upland areas does not dis charge to streams; instead, it flows along extended flow paths under the confining clay layer, as shown by the long arrows in figure 3.
As water moves northward under the clay, the hydraulic head or pressure on water in the deep flow system can cause the water level in a well open only to this flow system to rise above the top of the system. The imaginary surface representing the water levels in these wells is commonly called the potentiometric surface of the ground-water-flow system. The altitude of the potentiometric surface is shown in figure 5.
The relation between the water-table and the potentiometric surface is important for understanding the overall flow system. This relation depends on the hydraulic gradient. The hydraulic gradient is simply the difference or change in the hydraulic (pressure) head over the distance from one point in the ground water system to another point in the system. Where the water table is above the potentiometric surface, some water flows downward from the shallow system through any confining clay and into the deep system, because ground water flows from areas of high hydrau lic (pressure) head toward areas of low hydraulic head.
In the lowland area near Lake Superior, the hydraulic gradient is reversed. The hydraulic head in the confined (deep) system is greater than in the shal low water table system. This is evidenced by water lev els in a number of domestic wells open to sandstone or sand and gravel in the deep system near the village of Odanah. Water levels in these wells are above the land surface, which causes the well to flow.
Wells finished either in the sand and gravel deposits, or in sandstone, appear capable of producing yields for domestic purposes in those few areas of the Reservation where well data are available. Drillers report well yields of about 5 to 20 gal/min for domestic supply, and about 25 to 90 gal/min for community-supply wells. Yields larger than those reported are possible depending on lithology and location.
Drillers' specific-capacity data were analyzed using a procedure developed by Bradbury and Roths child (1985) to estimate the horizontal hydraulic con ductivity of the sand and gravel deposits in the Copper Falls Formation. Horizontal hydraulic conductivity indicates the ability of an aquifer (in this case, the sand and gravel deposits) to transmit water. It is defined as the volume of water that will move in a unit of time under a unit hydraulic gradient at unit kinematic vis cosity through a unit area at right angles to the direction of ground-water flow. Generally, horizontal hydraulic conductivity is directly proportional to well yield.
The horizontal hydraulic conductivity of the sand and gravel deposits estimated from drillers' spe cific-capacity tests ranges from about 2 to 700 ft/d. The median value is about 80 ft/d, which is indicative of a clean, somewhat compacted sand. These values are within the wide range of hydraulic-conductivity values given by Freeze and Cherry (1979, p. 29) for silty sand and clean sand.
Specific-capacity data were analyzed to estimate the horizontal hydraulic conductivity of the sandstone. Hydraulic-conductivity values range from less than 1 to about 360 ft/d. The median value for the 42 wells is about 2 ft/d. According to Freeze and Cherry (1979, p. 29), this median value is at the upper end of the range of hydraulic conductivity for sandstone. Two factors may account for the apparent large values of horizontal hydraulic conductivity. First, most of these wells are only open to the upper 10 to 50 ft of sandstone. Second, the upper sandstone generally is fractured or broken up by weathering. Water can move at a faster rate through these openings than it can through unfractured rock. The 10 largest horizontal hydraulic-conductivity val ues were determined for wells open to an average of just 18 ft in the upper part of the sandstone. The 10 smallest values were determined for wells that are open to an average of about 60 ft of sandstone. This indicates that the horizontal hydraulic conductivity in the sand stone tends to decrease with depth.
A total of 21 water samples were collected from 17 wells finished in sand and gravel deposits, and sin gle samples were collected from each of 21 wells fin ished in Precambrian sandstone wells. Most of these samples (36 of 42) were collected from 1983 through 1987 to characterize recent ground-water quality on the Bad River Indian Reservation.
Concentrations of dissolved constituents most commonly found in Wisconsin ground water are sum marized in table 1 for wells on the Bad River Indian Reservation. The principal dissolved constituents are calcium, magnesium, and bicarbonate. Median values of most constituents shown in table 1 are similar for water from both sand and gravel deposits and Precam brian sandstone. Exceptions are the somewhat larger median concentrations of sodium, sulfate, and chloride and somewhat smaller concentrations of manganese in water from wells finished in Precambrian sandstone (table 1). In general, the similarity in composition of water from both units is reasonable because sand and gravel wells derive water from deposits that lie directly on the Precambrian sandstone. Together, these two units make up the deep ground-water-flow system pre viously discussed and shown in figure 3. Median con centrations of constituents shown in table 1 are similar to those reported by Kammerer (1984) for a large area of northern Wisconsin that includes the Reservation. Median values reported by Kammerer for selected con stituents are shown in parentheses in table 1. Median concentrations of sulfate, chloride, and dissolved solids in wells finished in sand and gravel in the larger area are 7.2, 2.5, and 150 mg/L, respectively (Kammerer, 1984, p. 38-39). Median concentrations of the same three constituents in Reservation sand and gravel wells are 6.6, 2.7, and 155 mg/L, respectively (table 1). Median concentrations of sulfate, chloride, and dis solved solids in water from wells finished in Precam brian sandstone in the larger area are 22, 16, and 244 mg/L, respectively. These median values are almost identical to those of Reservation well water, with the exception of dissolved-solids concentrations in water from Precambrian sandstone wells. The median con centration of dissolved solids in Precambrian sand stone wells on the Reservation is only 157 mg/L.
Water samples were analyzed for many constitu ents that have maximum permissible and recom mended concentrations specified in Wisconsin's drinking-water standards for public-water supplies (Wisconsin Department of Natural Resources, 1978). Wisconsin's drinking-water standards are summarized in table 2. Analyses of ground-water samples collected during this study indicate no health-related problems from inorganic constituents. This is best shown by comparing analysis results in appendixes 2 and 3 to the drinking-water standards in table 2. The trace metal lead exceeded the primary health standard of 50 mg/L (table 2) in water from two wells. Water from these wells, AS-38 and AS-288 in appendix 3, had lead con centrations of 64 and 98 mg/L, respectively. Well AS 38 is an old unused well; AS-288 is an active domestic supply well. Water from well AS-38 also had a zinc concentration of 11,000 mg/L, which exceeds the aes thetic standard of 5,000 mg/L. The source of these met als may be dissolution of these metals in the plumbing pipes. Metals may dissolve in well water in contact with pipes for long periods of time while the well is unused.
The predominant ground-water-quality problem on the Reservation is large concentrations of iron and manganese. Concentrations of these metals that exceed the Wisconsin secondary (aesthetic) drinking-water standards may cause objectionable taste and staining of laundry and plumbing fixtures. Dissolved and total recoverable (dissolved plus particulate) concentrations were determined in water from 36 wells on the Reser vation (appendix 3). Water samples from 5 wells had total-recoverable iron concentrations that exceeded 500 mg/L, and 8 water samples from 7 wells exceeded the secondary drinking-water standard of 50 mg/L for total-recoverable manganese. Kammerer (1984) found that one-fourth to one-half of all water samples col lected from wells in northern Wisconsin, including the Reservation, had iron and manganese concentrations that exceeded Wisconsin's drinking-water standards.
Streamflow has been measured continuously at one of two gaging stations on the Bad River for much of the period from 1914 to the present. The principal station, the Bad River near Odanah (station number 04027000), is located about 8 mi south of the village of Odanah (pl. 1). This station has a drainage basin of 597 mi2; about 55 mi2 of this area lies within the Reserva tion. Streamflow was measured at this station from 1914 through 1922 and from 1948 through the present. This station was discontinued, and streamflow was measured as the Bad River at Odanah (station number 04027595) from 1978 through 1988 to include more of the total Bad River basin. The drainage area at this sta tion is 990 mi2, which includes about 140 mi2 of Reser vation land. Operation of this station (Bad River at Odanah) was discontinued after 1987 because backwa ter effects from nearby Lake Superior caused the streamflow record to be unsatisfactory. Operation of the gaging station was returned to the original location (Bad River near Odanah) in 1987.
The average daily discharge for the Bad River near Odanah (location number 04027000) for the period of record ending September, 1988 is 622 ft3/s. The maximum instantaneous discharge ever recorded was 27,700 ft3/s on April 24, 1960. The peak flow of this same flood downstream at the Bad River at Odanah (station number 04027595) was estimated to be 45,600 ft3/s as determined indirectly from high-water marks. The minimum instantaneous discharge for the Bad River near Odanah was 34 ft3/s on November 8, 1976, during fall freezeup.
Flow-duration characteristics indicate the per centage of time that a specified streamflow discharge is equaled or exceeded during the period of record. For example, table 3 shows that streamflow in the Bad River near Odanah equals or exceeds 762 ft3/s 20 per cent of the time. However, this does not mean that flow will exceed 762 ft3/s for 20 percent of each year or even within a specific 10-year period.
Knowledge of flow characteristics, particularly low flow, is useful when making decisions regarding multiple use of a stream resource. For example, knowl edge of low flow in a stream is necessary when the maintenance of fish habitat is weighed against hydro power production or against dilution of wastes. Flood and low-flow frequency characteristics were estimated from mean-daily discharge values for the period of record at Bad River near Odanah (site 04027000). The recurrence intervals were determined using a log-Pear son Type III distribution. Computed discharges with their associated recurrence intervals are shown in table 4. Table 4 shows, for example, that the average time between floods with a peak flow of 11,000 ft3/s is 5 years. The low-flow frequency values in table 4 show that the average time interval between a period of at least 7 consecutive days having a maximum discharge of 104 ft3/s is 2 years. For comparison, table 3 shows that flow equals or exceeds 104 ft3/s almost 95 percent of the time.
Water samples were collected from 12 sites on 10 streams during July and August 1983-87. These samples were collected during base-flow conditions when streamflow is derived largely from ground-water dis charge. The samples were analyzed for common inor ganic constituents, nutrients, trace metals, and organic carbon concentrations. Analysis results are shown in appendix 4.
Concentrations of common chemical constitu ents in surface water are somewhat lower than concen trations in ground water. For example, the median total-dissolved solids concentration in 19 stream-water samples is 110 mg/L and in ground-water samples from Reservation wells is about 155 mg/L.
The backwater sloughs and lakes near the mouths of the Kakagon and Bad Rivers provide habitat for extensive stands of wild rice. Wild rice depends on large nutrient concentrations in bottom material for growth. Samples of bottom material were collected at eight sites on the Kakagon slough (pl. 1) during July and August 1986 and 1987 and analyzed for concentra tions of nitrogen and phosphorus. Results of these anal yses are presented in appendix 5. Water samples also were collected from open water in two backwater lakes-Honest John Lake and the Bad River Slough and from Lake Superior (pl. 1) during July 1986. These samples were analyzed for common chemical constitu ents. Results of these three analyses (appendix 5) sug gest the dissolved-solids concentration in water from these lakes is approximately half that of ground water. This indicates that precipitation, which has a low con centration of dissolved solids, is the source of much of the water in these lakes.
Water-quality samples have been collected at the Bad River near Odanah gaging station (station number 04027000) since October 1964. In October 1974, this station became part of the U.S. Geological Survey's National Stream Quality Accounting Network (NASQAN). This nationwide program established monthly sampling at gaging stations on major rivers to provide consistent and continuous monitoring of stream-water quality. Water samples at the Bad River gaging station and other NASQAN stations are ana lyzed for common chemical constituents, nutrients, and selected trace-metal concentrations. NASQAN water quality data are available for the Bad River near Odanah gaging station for the periods October 1974 to January 1978, and from October 1987 to October 1993. The NASQAN sampling site was moved downstream to the Bad River at Odanah (station number 04027595, pl. 1) from February 1978 through September 1987, to represent a larger part of the drainage basin.
All water-quality data for these two NASQAN stations are accessible from the National Water Infor mation System (NWIS) data base at the U.S. Geologi cal Survey District office in Madison, Wis. These data also are available in annual Water Resources Data reports published by the District office in Madison, Wis.
The Bad River Indian Reservation is located along the Lake Superior shore in northwestern Wiscon sin. The area is underlain by unconsolidated glacial deposits that overlie basalt lava flows and Precambrian sandstone. Glacial deposits exceed 1,000 ft in thickness in a small area along the eastern edge of the Reserva tion. Bedrock is exposed at several locations along streambeds.
All community and domestic water supplies on the Reservation are obtained from wells finished in buried glacial sand and gravel deposits or in Precam brian sandstone. Wells typically are about 150 to 250 ft deep. However, two community-supply wells along the eastern edge of the Reservation are more than 950 ft deep. The sand and gravel deposits and Precambrian sandstone that provide water to wells are buried beneath nearly impermeable glacial-lake clay deposits throughout most of the Reservation. The buried sand and gravel deposits and the upper 50 ft of Precambrian sandstone together form a confined ground-water-flow system underlying the Reservation. Several wells in and around the village of Odanah that are finished in these deposits flow above land surface as is common with wells open to aquifers in a confined ground-water system.
Drillers' specific-capacity data were used to esti mate the horizontal hydraulic conductivity of the aqui fer. The horizontal hydraulic conductivity of the sand and gravel deposits ranges from about 2 to 700 ft/d, with a median value of about 80 ft/d. Estimated hori zontal hydraulic conductivity of the Precambrian sand stone ranges from less than 1 to about 360 ft/d, with a median of about 2 ft/d. Yields of 5 to 10 gal/min for domestic supply appear to be available from sand and gravel and sandstone throughout the Reservation. Small community-supply yields of 25 to 90 gal/min appear to be available from wells finished in Precam brian sandstone.
Concentrations of dissolved chemical constitu ents in water from the sand and gravel are almost iden tical to those in water from the Precambrian sandstone. Concentrations of individual constituents, in turn, are similar to those found in these two rock types through out northern Wisconsin. The principal dissolved con stituents are calcium, magnesium, and bicarbonate; minor concentrations of sodium, sulfate, chloride, and fluoride are common. Dissolved-solids concentrations typically range from about 150 to 250 mg/L. Concen trations of dissolved iron and manganese exceed Wis consin aesthetic drinking-water standards of 300 and 50 mg/L, respectively, in about 10 to 20 percent of all ground-water samples. The largest nitrate concentra tion was about 0.30 mg/L; most nitrate concentrations (34 of 38 samples) were less than 0.10 mg/L (the Wis consin primary drinking-water standard for nitrate is 10 mg/L).
Flow-duration, flood, and low-flow frequency characteristics of the Bad River were estimated using streamflow data collected at the gaging station near Odanah. Surface-water quality in small streams and in the Bad River is similar to ground-water quality. Cal cium, magnesium, and bicarbonate are the principal dissolved constituents. However, concentrations of dis solved solids in stream water range from about 50 to 150 mg/L, somewhat less than those in ground water. NASQAN water-quality data are available for the Bad River and provide continuous baseline water-quality data since 1974.
Bradbury, K.R., and Rothschild, E.R., 1985, A computerized technique for estimating the hydraulic conductivity of aquifers from specific capacity data: Ground Water, v. 23, no. 2, p. 240-246.
Freeze, R.A., and Cherry, J.A., 1979, Groundwater: Engle wood Cliffs, N.J., Prentice-Hall, 604 p.
Clayton, Lee, 1984, Pleistocene geology of the Superior region, Wisconsin: Wisconsin Geological and Natural History Survey Information Circular 46, 40 p.
Kammerer, P.A., Jr., 1984, An overview of ground-water quality data in Wisconsin: U.S. Geological Survey Water-Resources Investigations Report 83-4239, 58 p.
Mudrey, M.G., Jr., Brown, B.A., and Greenberg, J.K., 1982, Bedrock geologic map of Wisconsin: University of Wisconsin-Extension Geological and Natural History Survey, scale 1:1,000,000, 1 sheet.
U.S. Department of Health and Human Services, Indian Health Service, 1988, Environmental health profile Bad River Reservation: 18 p.
U.S. Department of Housing and Urban Development, 1976, The overall economic development plan of the Bad River Band, Lake Superior Chippewa Indians: 15 p.
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