Water Quality of Selected Springs

and Public-Supply Wells,

Pine Ridge Indian Reservation,

South Dakota, 1992-97

Water-Resources Investigations Report 99-4063

Prepared in cooperation with the Oglala Sioux Tribe

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

U.S. Geological Survey

Water Quality of Selected Springs

and Public-Supply Wells,

Pine Ridge Indian Reservation,

South Dakota, 1992-97

By Allen J. Heakin

Water-Resources Investigations Report 99-4063

Prepared in cooperation with the Oglala Sioux Tribe
U.S. Department of the Interior

Bruce Babbitt, Secretary

U.S. Geological Survey

Charles G. Groat, Director

The use of firm, trade, and brand names in this report is for identification purposes only and

does not constitute endorsement by the U.S. Geological Survey.

Rapid City, South Dakota: 2000

For additional information write to:

District Chief

U.S. Geological Survey

1608 Mt. View Road

Rapid City, SD 57702

Copies of this report can be purchased from:

U.S. Geological Survey

Branch of Information Services

Box 25286

Denver, CO 80225-0286
Contents III

CONTENTS

Abstract.................................................................................................................................................................................. 1

Introduction ........................................................................................................................................................................... 2

Purpose and Scope....................................................................................................................................................... 4

Previous Investigations ................................................................................................................................................ 4

Description of Study Area ........................................................................................................................................... 4

Physiography and Climate................................................................................................................................. 4

Geology ............................................................................................................................................................. 5

Hydrology.......................................................................................................................................................... 5

Public Water-Supply Systems............................................................................................................................ 9

Water-Quality Sampling Locations and Methods.................................................................................................................. 9

Location of Springs and Wells..................................................................................................................................... 9

Sampling Methods....................................................................................................................................................... 13

Quality Assurance........................................................................................................................................................ 15

Blank Samples ................................................................................................................................................... 15

Duplicate Samples ............................................................................................................................................. 17

Standard Reference Samples ............................................................................................................................. 21

Summary of Quality-Assurance Data................................................................................................................ 21

Water-Quality Data And Analysis for Selected Springs and Wells....................................................................................... 23

Springs......................................................................................................................................................................... 23

Public-Supply Wells .................................................................................................................................................... 35

Summary and Conclusions .................................................................................................................................................... 39

References ............................................................................................................................................................................. 40

Supplemental Data................................................................................................................................................................. 43

ILLUSTRATIONS

1. Map showing location of study area ........................................................................................................................... 3

2. Map showing generalized geology of the study area.................................................................................................. 8

3. Map showing location of springs and public-supply wells sampled for this study .................................................... 11

4. Site-location diagram.................................................................................................................................................. 14

5. Hydrographs for selected springs ............................................................................................................................... 30

6. Trilinear diagrams showing proportional concentrations of major ions in ground-water

samples from selected springs and wells .................................................................................................................... 32

TABLES

1. Generalized stratigraphic column showing selected geologic units and characteristics......................................... 6

2. Spring sites for which data are presented................................................................................................................ 10

3. Public-supply wells for which data are presented................................................................................................... 12

4. Quality-assurance results of blank samples ............................................................................................................ 16

5. Chemical and radionuclide analyses of duplicate field samples for springs and public-supply wells.................... 18

6. Precision of chemical analyses of duplicate field samples for springs and public-supply wells ............................ 20

7. Quality-assurance results for standard reference samples M-116 and T-99 submitted during

public-supply well sampling program..................................................................................................................... 22

8. Water-quality criteria, standards, or recommended limits for selected properties or constituents ......................... 24

9. Statistical summary of chemical analyses of spring-water samples collected September 1992

through March 1997................................................................................................................................................ 28

10. Comparison of water-quality data for selected springs to U.S. Environmental Protection Agency

drinking-water standards......................................................................................................................................... 33
IV Contents

TABLES—Continued

11. Tritium and pesticide analyses for selected springs................................................................................................ 34

12. Comparison of water-quality data for selected public-supply wells to U.S. Environmental

Protection Agency drinking-water standards.......................................................................................................... 36

13. Spring water-quality data........................................................................................................................................ 45

14. Public-supply well water-quality data .................................................................................................................... 53

ABBREVIATED UNITS USED IN THIS REPORT AND VERTICAL DATUM

mi2 square miles

ft feet

mi miles

in. inches

ft3/s cubic feet per second

gal/min gallons per minute

gal/d gallons per day

gal/hr gallons per hour

° F degrees Fahrenheit

μg/L micrograms per liter

mg/L milligrams per liter

μS/cm microsiemens per centimeter at 25 degrees Celsius

mL milliliters

col/100 mL colonies per 100 milliliters

pCi/L picocuries per liter

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.
Abstract 1

Water Quality of Selected Springs and Public-Supply 

Wells, Pine Ridge Indian Reservation,

South Dakota, 1992-97

By Allen J. Heakin

ABSTRACT

This report presents results of a waterquality study for the Pine Ridge Indian Reservation, South Dakota. The study was a cooperative 

effort between the U.S. Geological Survey and the 

Water Resources Department of the Oglala Sioux 

Tribe. 

Discharge and water-quality data were 

collected during 1992-97 for 14 contact springs 

located in the northwestern part of the Reservation. Data were collected to evaluate potential 

alternative sources of water supply for the village 

of Red Shirt, which currently obtains water of 

marginal quality from a well completed in the 

Inyan Kara aquifer. During 1995-97, waterquality data also were collected for 44 publicsupply wells that serve about one-half of the 

Reservation’s population. Quality-assurance 

sampling was used to evaluate the precision and 

accuracy of environmental samples.

Ten of the springs sampled contact the 

White River Group, and four contact the Pierre 

Shale. Springs contacting the White River Group 

range from calcium bicarbonate to sodium bicarbonate water types. Two springs contacting the 

Pierre Shale have water types similar to this; however, sulfate is the dominant anion for the other 

two springs. In general, springs contacting the 

White River Group are shown to have better 

potential as alternative sources of water supply for 

the village of Red Shirt than springs contacting the 

Pierre Shale.

Nine of the springs with better water quality 

were sampled repeatedly; however, only minor 

variability in water quality was identified. Six of 

these nine springs, of which five contact the White 

River Group, probably have the best potential for 

use as water supplies. Discharge from any of these 

six springs probably would provide adequate 

water supply for Red Shirt during most periods, 

based on a limited number of discharge measurements collected. Concentrations of lead exceeded 

the U.S. Environmental Protection Agency 

(USEPA) action level of 15 μg/L for three of these 

six springs. Five of these six springs also had 

arsenic concentrations that exceeded 10 μg/L, 

which could be problematic if the current maximum contaminant level (MCL) is lowered. 

Blending of water from one or more springs with 

water from the existing Inyan Kara well may be an 

option to address concerns regarding both quantity 

and quality of existing and potential sources.

All nine springs that were sampled for indicator bacteria had positive detections on one or 

more occasions during presumptive tests. 

Although USEPA standards for bacteria apply 

only to public-water supplies, local residents using 

spring water for domestic purposes need to be 

aware of the potential health risks associated with 

consuming untreated water.

One spring contacting the White River 

Group and two springs contacting the Pierre Shale 

exceeded 15 pCi/L for gross alpha; these values do 

not necessarily constitute exceedances of the 

MCL, which excludes radioactivity contributed by 
2 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

uranium and radon. Additional sampling using 

different analysis techniques would be needed to 

conclusively determine if any samples exceeded 

this MCL. Nine springs were sampled for selected 

pesticides and tritium. The pesticides atrazine, 

carbaryl, and 2,4-D were not detected in any of the 

samples. The nine springs were analyzed for 

tritium in order to generally assess the age of the 

water and to determine if concentrations exceeded 

the MCL established for gross beta-particle 

activity. Tritium results indicated two springs are 

composed primarily of water recharged prior to 

atmospheric testing of nuclear bombs and two 

other springs have a relatively large percentage of 

test-era water. The remaining five springs had 

tritium values that indicated some percentage of 

test-era water; however, additional sampling 

would be needed to determine whether water is 

predominantly pre- or post-bomb age.

Of the 44 public-supply wells sampled, 42 

are completed in the Arikaree aquifer, one is completed in an alluvial aquifer, and one is completed 

in the Inyan Kara aquifer. Water from the alluvial 

well is a sodium bicarbonate water type, water 

from Arikaree aquifer ranges from calcium bicarbonate to sodium bicarbonate types, and water 

from the Inyan Kara well is a calcium sulfate 

bicarbonate type. Of the 44 wells sampled, 28 

(64 percent) tested positive for indicator bacteria 

in presumptive tests. Because these were single 

samples that generally were collected upstream 

from chemical treatment feeders, positive detections do not necessarily constitute exceedances of 

drinking-water standards.

A single sample from an Arikaree well 

exceeded the MCL for arsenic of 50 μg/L. 

Arsenic exceeded 10 μg/L for six additional 

Arikaree wells and for the alluvial well and the 

Inyan Kara well, which could be problematic if the 

current MCL is lowered. The alluvial well also 

exceeded the secondary maximum contaminant 

level (SMCL) for dissolved solids, which is nonenforceable, and the action level for lead. The 

Inyan Kara well exceeded the SMCL’s for iron and 

for manganese and the MCL of 5 pCi/L for 

radium-226 and 228 combined. Several Arikaree 

wells exceeded SMCL’s for either pH, sulfate, dissolved solids, iron, or manganese. One Arikaree 

well exceeded the MCL of 4.0 mg/L for fluoride 

and another exceeded the MCL of 10 mg/L for 

nitrite plus nitrate.

Ten Arikaree wells equalled or exceeded 

15 pCi/L for gross alpha; however, these values do 

not necessarily constitute exceedances of the 

MCL, which excludes radioactivity contributed by 

uranium and radon. Additional sampling using 

different analysis techniques would be needed to 

conclusively determine if any samples exceeded 

this MCL.

Eight wells, all from the Arikaree aquifer, 

equalled or exceeded the proposed MCL of 

20 μg/L for uranium and 33 wells (75 percent) 

equalled or exceeded one-half of the proposed 

MCL. Although this standard has only been proposed, additional information regarding the extent 

of elevated uranium concentrations in the Arikaree 

aquifer, and the geochemical processes involved, 

may be beneficial. It was determined from 

analyses of uranium isotope data for five wells that 

the source of elevated uranium concentrations is 

naturally occurring, rather than anthropogenic.

INTRODUCTION

The Pine Ridge Indian Reservation is located in 

south-central South Dakota. The village of Red Shirt is 

located in the northwestern part of Shannon County 

(fig. 1). The sole source of public water supply for the 

village is from a well drilled about 2,600-ft deep, completed in the Inyan Kara aquifer. Water from the well 

is geothermally heated, highly mineralized, and 

because it exceeds several U.S. Environmental Protection Agency (USEPA) standards, cannot be used for 

drinking purposes without costly pretreatment.

Throughout the rest of the Reservation, wells 

completed in the Arikaree aquifer are the primary 

source of public supply. Concentrations of several 

constituents such as bacteria, sulfate, nitrate, arsenic, 

and selenium have been reported to exceed USEPA 

drinking-water standards in various public-supply 

wells.
Introduction 3

43o

43o30'

43o45'

43o15'

102o

101o30

102o30'

103o

R. 48 W. R. 47 W. R. 46 W. R. 45 W. R. 44 W. R. 43 W. R. 42 W. R. 41 W.

R. 40 W.

R. 39 W. R. 38 W. R. 37 W.

R. 36 W. 

T. 35 N.

T. 36 N.

Potato

Creek

27

73

73

44

44

2

27

27

33

28

41

41

32

18

18

18

87

COUNTY

Badlands

National

Park

SOUTH DAKOTA

DAWES COUNTY SHERIDAN COUNTY

PENNINGTON COUNTY

JACKSON COUNTY

FALL RIVER COUNTY

CUSTER 

SHANNON COUNTY

SOUTH DAKOTA

NEBRASKA

Kyle

Potato

Creek

Oglala

RedShirt

Rockyford

Wounded

Knee

Manderson Porcupine

Martin

Patricia

Allen

Wanblee

PineRidge

White

River

Cain

Creek

Creek Medicine Root

Porcupine

Creek

Creek

Wounded

Knee

OglalaLake

White

Clay

Creek

Cheye nne

River

White

Creek

Creek

Creek

Craven

Eagle Nest

Bear-in-the-Lodge Badlands

National

Park

Bear- in-the-Lodge Creek

Base from U.S. Geological Surveydigital data 1:100,000

Figure 1. Location of study area.

Jackson Co.

Shannon Co. Bennett Co.

SOUTH D

Study Area

BlackHills

Misso
4 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

In 1992, the U.S. Geological Survey (USGS), in 

cooperation with the Oglala Sioux Tribe, initiated a 

study to assess water quality on the Reservation. The 

two specific objectives of the study were to (1) evaluate 

the quality and quantity of water produced by springs 

located in the northwestern part of Shannon County as 

sources of an alternative water supply for the village of 

Red Shirt; and (2) evaluate the water quality of publicsupply wells located throughout the Reservation.

Purpose and Scope

The purpose of this report is to present the results 

of the study of selected springs and public-supply wells 

for the Pine Ridge Indian Reservation, South Dakota. 

Discharge and water-quality data for 14 springs located 

in the northwestern part of the Reservation and waterquality data for 44 public-supply wells are presented. 

Data for the springs were collected during 1992-97, 

and data for the wells were collected during 1995-97. 

Selected water-quality constituents include field 

parameters (specific conductance, pH, temperature, 

dissolved oxygen, acid neutralizing capacity, and 

bacterial concentration), common ions, nutrients, trace 

elements, radionuclides, and pesticides. Water-quality 

data are compared to standards and criteria for drinking 

water promulgated by the USEPA to determine if concentrations of any constituents were present at levels 

that could be harmful to humans.

Previous Investigations

Various studies describing the geology and the 

hydrology of the study area are available. Darton 

(1909) described the general surface geology, which 

was later published as part of a geologic map of South 

Dakota (Darton, 1951). Gries (1964) described the 

shallow ground-water resources, and Harksen and 

MacDonald (1969) used road logs to describe the 

surficial geology within the study area. Ellis and 

Adolphson (1971) provided an extensive description of 

the hydrogeology of the study area. They produced a 

map showing major geologic units and assessed the 

potential of these units as sources of water supply. 

Kolm and Case (1983) estimated various hydraulic 

properties of the High Plains aquifer, which includes 

the Ogallala and Arikaree aquifers, within the study 

area. Meyer (1984) summarized the water-quality data 

available in the U.S. Geological Survey National Water 

Data Storage and Retrieval System (WATSTORE). 

Heintzman (1988) completed a study that evaluated 

water quality for 39 wells distributed throughout the 

study area, and Sipe (1989) investigated the hydrogeology of part of the Arikaree aquifer near Pine Ridge. 

Greene and others (1991) performed aquifer tests and 

water-quality analyses on the Arikaree aquifer near 

Pine Ridge.

Description of Study Area

The study area (the Pine Ridge Indian Reservation) includes all of Shannon County, the portion of 

Jackson County south of the White River, and the 

portion of Bennett County north of U.S. Highway 18 

(fig. 1). The topography of the study area is diverse; in 

the northwestern part there are numerous sod-covered 

tableland features that are remnants of alluvial 

deposits. The Badlands also are in this general area and 

are characterized by stark contrasts in topography, 

ranging from low hills to sharply rising pinnacles. 

Gently rolling plains are present in the southern and 

eastern parts of the study area, but the relief is steeper 

and more broken along the Cheyenne and White Rivers 

and their tributaries. 

Land use is predominantly a mixture of cropland 

and grazing land, with the majority of grazing land 

consisting of subhumid and semi-arid grasses. Livestock production and dryland farming are the main 

agricultural enterprises on the Reservation. Livestock 

produced include cattle, horses, hogs, sheep, and 

chickens. The major crops include wheat, alfalfa, 

barley, corn, oats, rye, and sorghum (South Dakota 

Crop and Livestock Reporting Service, 1924-65). 

Physiography and Climate

The study area is located within the Great Plains 

physiographic province (Fenneman, 1946). The 

climate, which is characteristic of the northern Great 

Plains, is semi-arid with cold winters and hot summers. 

Most of the precipitation falls during the growing season between April and September. Climatological data 

for Manderson (fig. 1) indicate that May typically is the 

wettest month with an average (1961-90) of 5.9 in. of 

precipitation, and December typically is the driest 

month with an average of only 0.2 in. of precipitation 

(U.S. Department of Commerce, 1995). The average 

annual precipitation is 16 in., and the average annual 

air temperature is about 48° F, with an average of 72° F 

for July and an average of 27° F for January. 
Introduction 5

Mean annual evaporation in southern South 

Dakota averages about 60 in. (Gutentag and others, 

1984). High evaporative losses coupled with moderate 

annual precipitation result in only limited water 

available to recharge ground-water systems.

Geology

The relatively shallow (Cretaceous age and 

younger) geology of the study area is comprised of 

sedimentary rocks that have been divided into rockstratigraphic units (table 1). These include, from oldest 

to youngest, the Inyan Kara Group, the Skull Creek 

Shale, the Dakota Formation, and the Graneros Shale, 

all of Early Cretaceous age; the Greenhorn Formation, 

the Carlile Shale, the Niobrara Formation, and the 

Pierre Shale, all of Late Cretaceous age; the White 

River Group of Oligocene age; the Arikaree Formation 

of Miocene age; the Ogallala Formation of Pliocene 

age; and various deposits of Quaternary age (Harksen 

and MacDonald, 1969; Ellis and Adolphson, 1971). 

Bedrock units within the study area are of Cretaceous 

age and older. Areal extents of units occurring at the 

land surface are shown in figure 2.

The Inyan Kara Group is composed of two 

formations. These formations are, from oldest to 

youngest, the Lakota Formation and the Fall River 

Formation.

Part of the Badlands National Park is located 

within the Reservation in northern Shannon County. 

Thick deposits of clays and sands were deposited in the 

Badlands area at the end of Eocene time (Gries, 1996). 

These sedimentary clays and sands comprise the White 

River Group. The White River Group has been divided 

into the older Chadron Formation, which forms conspicuous haystack-shaped features, and the younger 

Brule Formation, which forms the steep fluted cliffs 

and bluffs typical throughout much of the Badlands.

During Oligocene time, volcanic ash became a 

significant part of the accumulating sediments. The 

ash probably resulted from volcanic activity to the west 

that was transported by winds and incorporated into the 

upper Brule Formation. Volcanic ash continued to be 

deposited in the lower Arikaree Formation until the 

middle of Miocene time (Gries, 1996).

The Arikaree Formation has been divided into 

five geologic subdivisions by Ellis and Adolphson 

(1971). These units, from oldest to youngest, have 

been designated A through E. The Rockyford Ash 

Member of the Sharps Formation corresponds to unit A 

and an unnamed member of the Sharps Formation 

corresponds to unit B. The Monroe Creek Formation is 

equivalent to unit C and the Harrison Formation is 

equivalent to unit D. The Rosebud Formation corresponds to unit E of the Arikaree Formation (Harksen 

and MacDonald, 1969).

Hydrology

Ground water from wells and springs is the predominant source of domestic supply within the study 

area. Ground water usually can be obtained from most 

of the bedrock units shown in table 1, except for the 

White River Group, Pierre Shale, the Niobrara Formation, the Carlile Shale, the Greenhorn Formation, and 

the Graneros and Skull Creek Shales. The Ogallala 

aquifer (corresponds to the Ogallala Formation) is 

present only in small parts of the study area (fig. 2). 

The Arikaree aquifer (corresponds to the Arikaree 

Formation), which is the primary source of water 

supply in the study area, is much more extensive. 

Within the study area, the potentiometric surface of the 

Arikaree aquifer is highest in the southwest corner and 

the predominant direction of ground-water flow is to 

the northeast (Kolm and Case, 1983). Ground water in 

the Arikaree aquifer generally occurs under water-table 

conditions; however, in some locations confined conditions can occur (Greene and others, 1991). Depth to 

water ranged from 26 to 134 ft below land surface in 

wells sampled for this study. In the northwestern part 

of the study area, the Arikaree Formation has been 

eroded, and there is no continuous aquifer present. 

However, permeable beds overlying less permeable 

beds of the White River Group and the Pierre Shale in 

this area have created many isolated, shallow aquifers 

that are sufficient for domestic supply.

Outcrops of the Inyan Kara Group are exposed at 

higher elevations along the eastern slope of the Black 

Hills (west of study area; fig. 1, index map). These outcrops provide areas of recharge for the aquifer. The 

Inyan Kara aquifer (corresponds to the Inyan Kara 

Group) extends eastward from the Black Hills throughout most of South Dakota. Because a large portion of 

the aquifer recharge comes from higher elevations, the 

aquifer is under high artesian pressure and numerous 

flowing wells have been completed in the Inyan Kara 

aquifer.
6 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97 Table 1. Generalized stratigraphic column showing selected geologic units and characteristics [Modified from Ellis and Adolphson, 1971] System Series Rock- stratigraphic unit Sub- divisions Thickness (feet) Lithology 

Quaternary

Holocene Flood-plain 

alluvium

0-40 Light-brown to gray clay, silt, and fine sand; discontinuous sandy and clayey gravel beds in lower part. Generally water bea

domestic and stoc

are not uniform. deposits are thin, summer or early rivers, respond raQuality of the wa

lain by Tertiary dunderlain by Cret

Holocene and 

Pleistocene

Terrace

alluvium

0-60 Light-brown clay, silt, and fine sand; thin discontinuous beds of medium to coarse gravel at or near the 

top. Clayey and sandy gravel common in the basal few feet, especially along the White River.

Water bearing wher

table of adjacent ftable is perched. those of flood-pla

Windblown 

sand deposits

0-200 Brown, unconsolidated, very fine to medium grained, 

uniform, quartz sand; characterized by dune topography and blowouts.

Water table generall

common along thcommonly more stock needs. Qua

Pleistocene Old terrace 

deposits

0-80 Brown, silty clay, sand, and gravel. Commonly, the 

silty and sandy layers are partly cemented, and the gravel and sand beds are commonly interbedded with laminated silty clay.

Generally water bea

and seeps commogenerally adequaQuality of water 

Tertiary

Pliocene Ogallala

Formation

0-200 Tan to olive, fine- to medium-grained sandstone with 

some silty clay. Upper unit of Ogallala Formation is also known as the Ash Hollow Formation and the lower unit as the Valentine Formation. 

Upper unit relatively 

locally because ounit generally waSprings and seeplying Arikaree Foquate for domestigenerally is good

Miocene Arikaree

Formation

Unit E 0-235 Light-tan to brown, interbedded calcareous sand, silt, 

and clay; contains gray to pinkish-gray tabular concretions and small light-brown and greenish clay beds.

Lack of detailed sub

impossible to detof individual unitmost common soReservation. Yieand stock needs. contact between tWhite River Grou
Introduction 7

Tertiary

Unit D 0-125 Gray, massive, poorly consolidated, fine to very fine 

sand; commonly contains layers of light-gray sandy marl, large pipey concretions, and small spherical concretions. Formation becomes silty toward the east; concretions in the lower part present only in discontinuous zones. Unit is difficult to differentiate from underlying units.

Unit C 0-90 Buff siltstone and very fine-grained sandstone; sandier 

toward east. Difficult to distinguish from overlying and underlying units.

Unit B 0-375 Pinkish-tan, poorly consolidated silt and very finegrained sand; gray, small (2-4 in.) calcareous 

concretions are common. Lenses of limestone and channel sand and gravel occur locally throughout the unit in central and western parts of the Reservation.

Unit A 0-45 White, tan, buff, and reddish-brown silty volcanic ash; 

interbedded with thin layers of silt.

Oligocene White River 

Group 

Brule

Formation

0-450 Yellow to brown, poorly consolidated siltstone and 

claystone with some beds of fine-grained sand.

Generally too imper

ground water. Qu

Chadron

Formation

0-110 Pale, gray-green bentonite clay alternating with layers 

of greenish-gray siltstone.

Generally too imper

ground water. Qu

Cretaceous

Upper

Cretaceous

Pierre Shale 0-1,200 Dark-gray marine shale and mudstone with some 

layers of bentonite.

Not a source of grou

is poor.

Niobrara

Formation

0-325 Tan to gray, highly calcareous shale. Commonly 

described by drillers as “chalk.” 

Not a source of grou

is poor.

Carlile Shale 100-325 Dark-gray marine shale and mudstone. Middle part of 

the formation is sandy and contains thin limestone ledges locally.

Not a source of grou

Greenhorn 

Formation

170-207 Tan, bluish, white, or gray calcareous shale. Marine 

origin.

Water-bearing traits 

Lower

Cretaceous

Graneros Shale 1200-330 Dark-gray non-calcareous shale. Marine origin. Nearly impermeable

unknown.

Dakota

Formation

(Dakota

Sandstone)

1155-292 Interbedded tan to white sandstone and dark-colored 

shale. Sandstone is composed of loose to wellcemented, very fine to coarse quartz sand; cement most commonly is calcium carbonate. Marine origin.

Permeable sandston

water under arteswells. The water used for irrigation 

Skull Creek 

Shale

1109-284 Dark bluish-gray shale. Marine origin. Relatively imperme

largely unknown.

Inyan Kara 

Group(undifferentiated)

1241-357 White to light-gray or tan sandstone and siltstone; 

contains beds of gray to black and reddish to buff shale. The Inyan Kara Group is sometimes divided into the Fall River and Lakota Formations. Continental to marginal marine origin.

Permeable sandston

water under arteswells. The water used for irrigation 

1Based on interpretation and projection of data from electric logs and drillers’ logs.
8 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Figure 2. Generalized geology of the study area.

G

Flood-plain alluviumTerrace alluviumWind-blown sandOld terrace deposits

Ogallala FormatioArikaree FormatioWhite River Group

QUATERNARY TERTIARY 

EXPLANATION

Base from U.S. Geological Surveydigital data 1:100,000

White

River

Cain

Creek

Creek Medicine Root

Porcupine

Creek

Creek

Wounded

Knee

OglalaLake

White

Clay

Creek

Cheye nne

River

White

Creek

Creek

Creek

Craven

Eagle Nest

Bear-in-the-Lodge

Bear- in-the-Lodge Creek

43o

43o30'

43o45'

43o15'

102o

101o30

102o30'

103o

R. 48 W. R. 47 W. R. 46 W. R. 45 W. R. 44 W. R. 43 W. R. 42 W. R. 41 W.

R. 40 W.

R. 39 W. R. 38 W. R. 37 W.

R. 36 W. 

T. 35 N.

T. 36 N.

COUNTY

DAWES COUNTY SHERIDAN COUNTY

PENNINGTON COUNTY

JACKSON COUNTY

FALL RIVER COUNTY

CUSTER 

SHANNON COUNTY

SOUTH DAKOTA

NEBRASKA

Kyle

Potato

Creek

Oglala

RedShirt

Rockyford

Wounded

Knee

Manderson Porcupine

Martin

Patricia

Allen

Wanblee

PineRidge

Potato

Creek
Water-Quality Sampling Locations and Methods 9

Springs with relatively steady flows are present 

in the northwestern part of the study area where terrace 

deposits overlie either the White River Group or the 

Pierre Shale. Some of the more productive springs 

have been developed to serve as sources for domestic 

supply or livestock watering.

The Cheyenne and White Rivers are the major 

rivers present within the study area (fig. 1). The headwaters of the Cheyenne River are in eastern Wyoming, 

from where the river flows southeast around the Black 

Hills and enters Angostura Reservoir in southwestern 

South Dakota. It then flows northeast forming the 

northwestern boundary of the Reservation, and 

continues flowing northeast to its confluence with the 

Missouri River.

The headwaters of the White River are in northwestern Nebraska, from where the river flows northeast 

and enters South Dakota about 15 mi southwest of 

Oglala. Upstream of Oglala, contributions from 

ground-water discharge maintain flow in the river. 

Downstream of Oglala, the White River flows through 

the Badlands and then continues to its confluence with 

the Missouri River. Because the Badlands contain 

highly erodible soils, they serve as a primary source of 

sediment load in the river. Most of the smaller tributaries to the White River flow from south to north and are 

intermittent, flowing mainly in response to precipitation. However, short reaches of Bear-in-the-Lodge, 

Porcupine, Wounded Knee, and White Clay Creeks 

sustain some flow throughout most of the year because 

either discharge from springs supplements runoff or 

their streambeds intercept the water table (Ellis and 

Adolphson, 1971).

Public Water-Supply Systems

Two Tribal departments are responsible for 

maintaining the Reservation’s public water-supply 

systems: the Oglala Sioux Tribe Water and Sewer 

Department and the Oglala Sioux Rural Water Department. The Oglala Sioux Water and Sewer Department 

operates and maintains about 20 wells, 15 pump 

houses, and 14 mi of water mains that serve about 

5,300 people in 12 communities (U.S. Public Health 

Service, 1996). The Oglala Sioux Rural Water Department operates and maintains about 19 wells, 11 pump 

houses, and 130 mi of water mains that serve about 

4,000 people in five communities.

On October 24, 1988, Congress enacted Public 

Law 100-516, which authorized the construction of a 

rural water-supply and distribution system named Mni 

Wiconi that would pump water from the Missouri 

River through about 4,000 mi of pipeline to serve 

water-poor areas of southwestern South Dakota. The 

Reservation is included in the area to be served by Mni 

Wiconi. The project is expected to take 10 years to 

complete and cost about $260 million, making it the 

Nation’s largest rural water-supply system. Water from 

some of the Tribe’s existing public-supply wells and 

possibly from additional new public-supply wells also 

will be used to augment the supply.

WATER-QUALITY SAMPLING

LOCATIONS AND METHODS

Samples were collected from 14 springs (table 2) 

located in northwestern Shannon County (fig. 3). Nine 

of these springs were sampled five times to evaluate 

temporal changes in water quality. Springs typically 

are found where the land surface has been deeply 

eroded and intercepts local water tables. Consequently, 

most springs are located on the flanks of tablelands and 

can be easily distinguished by abundant brush thickets 

or cedar groves in areas that would otherwise lack such 

vegetation. The largest yielding springs are located at 

the stratigraphic contact between deposits of Quaternary-age windblown sand or old terrace gravel and 

underlying relatively impermeable clays of the White 

River Group or the Pierre Shale. Springs were selected 

for sampling based on discharge and proximity to the 

village of Red Shirt.

Samples were collected from 44 public-supply 

wells (table 3). Forty-two of the 44 public-supply 

wells sampled for this study were completed in the 

Arikaree aquifer, one was completed in an alluvial 

aquifer, and one was completed in the Inyan Kara 

aquifer (fig. 3).

Location of Springs and Wells

Two methods are used to locate sampling sites 

that appear in the water-quality tables in this report. 

The first method is the station identification number. 

This unique number is based on the international 

system of latitude and longitude. The number is composed of 15 digits. The first six digits denote the 

degrees, minutes, and seconds of latitude north of the 

equator. The next seven digits denote the degrees, 

minutes and seconds of longitude west of the prime 

(Greenwich) meridian. The last two digits are used to 

distinguish between multiple sites located at the same 

latitude and longitude. 
10 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97 Table 2. Spring sites for which data are presented [Site number refers to spring location in fig. 3] Site number Station identification number Local number Spring name County Sampling date or period Num

of samp

1S1 432750102484701 40N46W18BBAD South Hubner Shannon 09-29-92 1 1S2 432853102365501 41N44W31CBCC Old Road Shannon 09-23-92 to

03-26-97

5 

1S3 433301102430501 41N45W 6DDCC Red Shirt Table Shannon 09-21-92 1 

S4 433105102391401 41N45W23BBCB Cuny Cafe Shannon 09-25-92 to

03-24-97

5 

S5 433052102372401 41N45W24ACCA South Corral Shannon 09-22-92 to

03-24-97

5 

1S6 433022102401001 41N45W27BBAA Davey Cuny Shannon 09-30-92 to

03-25-97

5 

S7 433252102484201 41N46W 9BBCA Blackfeather Shannon 10-01-92 to

03-26-97

5 

1S8 433226102441601 41N46W12DACD Duhamill Shannon 09-21-92 to

03-25-97

5 

1S9 433035102441701 41N46W24DCBA Mill’s East Shannon 10-08-92 to

03-25-97

5 

1S10 433218102573801 41N47W 7DCBA Rapp North Shannon 11-04-92 1 

S11 433113102530501 41N47W23BAAC Slide Shannon 09-18-92 1 S12 433822102164601 42N42W 2DACA Heathershaw Shannon 11-12-92 to

03-27-97

5 

S13 433852102524501 42N47W 2ACAA Red Shirt Table N/E Shannon 09-30-92 1 

1S14 433524102585401 42N48W25ABCC Knupe North Shannon 11-05-92 to

03-26-97

5 

1Indicates developed spring.
Water-Quality Sampling Locations and Methods 11 43o

43o30'

43o45'

43o15'

102o

101o30'

102o30'

103o

R. 48 W. R. 47 W. R. 46 W. R. 45 W. R. 44 W. R. 43 W. R. 42 W. R. 41 W.

R. 40 W.

R. 39 W. R. 38 W. R. 37 W.

R. 36 W.

R. 3

T. 35 N.

T. 36 N.

27

73

73

44

44

2

27

27

33

28

41

41

32

18

18

18

87

COUNTY

DAWES COUNTY SHERIDAN COUNTY

PENNINGTON COUNTY

J

JACKSON COUNTY

B

FALL RIVER COUNTY

CUSTER 

SHANNON COUNTY

SOUTH D SOUTH DAKOTA

NEBRASKA

Kyle

Potato

Creek

Oglala

RedShirt

Rockyford

Wounded

Knee

Manderson Porcupine

Martin

Patricia

Allen

Wanblee

PineRidge

White

River

Cain

Creek

Creek Medicine Root

Porcupine

Creek

Creek

Wounded

Knee

OglalaLake

White

Clay

Creek

Cheye nne

River

White

Creek

Creek

Creek

Creek

Pass

Craven

Eagle Nest

Bear-in-the-Lodge Badlands

National

Park

Bear- in-the-Lodge Creek

Potato

S1 S2

Creek

S3

S4

S5

S6

S7

S8

S9

S12

S3

S11

383044

S10

S11

S13

S14

44

39

40

41

42

43

21,22

23 24

25 26

27

28

29

30

31

32 3334

35 36

37

1

2

3,4

6

7 8

9

10

11

13,14

15 16 17

18

19 20 12

5

38

Base from U.S. Geological Surveydigital data 1:100,000

Figure 3. Location of springs and public-supply wells sampled for this study.

EXPLANATION

TABLELANDSSPRING CONTACTING THE WHITE RIVER GROUP--Number indicates site numberSPRING CONTACTING THE PIERRE SHALE-- Number indicates site number

WELL COMP Number inWELL COMP Number inWELL COMP Number in
12 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 3. Public-supply wells for which data are presented

[Site number refers to well location in fig. 3; ---, no data]

Site

number

Station 

identification

number

Local

number County Datesampled

Depth

of well

(feet)

Aquifer

1 430223102084901 35N41W 4DA Shannon 09-26-96 120 Arikaree

2 430140102324101 35N44W 7ACBB Shannon 08-29-96 374 Arikaree

3 430125102324001 35N44W 7ACCD Shannon 08-21-96 455 Arikaree

4 430125102324002 35N44W 7DBAB Shannon 08-20-96 520 Arikaree

5 430056102261501 35N44W13AADB Shannon 06-26-97 280 Arikaree

6 430157102333801 35N45W 1DCDA Shannon 08-22-96 284 Arikaree

7 430122102342801 35N45W11DAAC Shannon 07-08-97 168 Arikaree

8 430129102333101 35N45W12ACCA Shannon 09-05-96 --- Arikaree

9 430141102343701 35N45W12BDDB Shannon 12-07-95 340 Arikaree

10 430120102341601 35N45W12CCCA Shannon 09-09-96 303 Arikaree

11 430738102055901 36N41W 1BBCB Shannon 07-17-97 375 Arikaree

12 430247102273201 36N44W35DDCD Shannon 07-23-97 --- Arikaree

13 430706102382802 36N45W 5DCAC Shannon 09-19-96 --- Arikaree

14 430703102383101 36N45W 5DCCA Shannon 09-25-96 --- Arikaree

15 430709102382801 36N45W 5DCCB Shannon 09-18-96 320 Arikaree

16 430726102391202 36N45W 6DAA Shannon 09-12-96 300 Arikaree

17 430742102394301 36N45W 6DAAC Shannon 09-17-96 71 Arikaree

18 430531102354101 36N45W15DDAB Shannon 07-08-97 130 Arikaree

19 430439102350701 36N45W23CDBD Shannon 09-03-96 180 Arikaree

20 430439102350702 36N45W23DCBC Shannon 09-03-96 100 Arikaree

21 430928102225102 37N43W26CADD Shannon 11-30-95 187 Arikaree

22 430929102225301 37N43W26CDAA Shannon 11-30-95 187 Arikaree

23 431703101560801 38N39W10CBCC Bennett 11-08-95 205 Arikaree

24 431625101551201 38N39W15AACA Bennett 11-08-95 --- Arikaree

25 431526102202601 38N42W30ABAC Shannon 11-29-95 454 Arikaree

26 431442102201601 38N42W30ABBB Shannon 09-24-96 300 Arikaree

27 431440102202801 38N42W30ADBD Shannon 11-29-95 526 Arikaree

28 431405102282901 38N44W25DBDC Shannon 12-06-95 --- Arikaree

29 431351102280601 38N44W25DDCD Shannon 07-09-97 --- Arikaree

30 432336102240401 39N43W 3BBAA Shannon 11-28-95 --- Arikaree

31 431907102223501 39N43W36BCCC Shannon 11-28-95 180 Arikaree

32 432523102101801 40N41W21DADD Shannon 06-30-97 --- Arikaree

33 432518102102801 40N41W21DDAC Shannon 06-30-97 110 Arikaree

34 432538102102001 40N41W21DDDA Shannon 11-09-95 --- Arikaree

35 432513102100501 40N41W22CCCB Shannon 07-01-97 93 Arikaree

36 432507102100701 40N41W28AAAA Shannon 07-01-97 121 Arikaree

37 432731102261101 40N43W 8CCAC Shannon 12-05-95 60 Arikaree

38 433157101593001 41N39W17BADB Jackson 10-19-95 68 Alluvium

39 433456101332001 42N36W25CACC Jackson 07-22-97 --- Arikaree

40 433400101390001 42N36W31CBDB Jackson 10-18-95 184 Arikaree

41 433357101392301 42N36W31CCAD Jackson 07-16-97 124 Arikaree

42 433328101392801 42N36W31CCDA Jackson 07-16-97 200 Arikaree

43 433422101390301 42N37W36ADDA Jackson 10-18-95 106 Arikaree

44 433740102532001 43N47W27CDA Shannon 06-25-97 2,640 Inyan Kara
Water-Quality Sampling Locations and Methods 13

The second method is the local number and is 

based on the Federal system of land subdivision (township, range, and section) (fig. 4). The first number of a 

site designation indicates the township and is followed 

by "N" or "S" (for north or south); the second number 

indicates the range and is followed by "E" or "W" (for 

east or west); the third number represents the section 

and it may be followed with up to four uppercase 

letters. An increasing number of letters following the 

section number indicates the degree of accuracy with 

which the site has been located. The first letter after 

the section number represents the 160-acre tract, the 

second the 40-acre tract, the third the 10-acre tract and 

the fourth the 2.5-acre tract in which the site is located. 

The letters A, B, C, and D are assigned in a counterclockwise direction, beginning in the northeast corner 

of each tract. A number following the last uppercase 

letter is sometimes used to distinguish between 

multiple sites in the same tract. The well number 

38N44W25DDCD, shown in figure 4, indicates the 

well is located in the SE1/4 of the SW1/4 of the SE1/4 

of the SE1/4 of section 25 in township 38 north and 

range 44 west.

Sampling Methods

Water-quality samples were collected from 

springs and public-supply wells according to methods 

recommended by the USGS. Samples collected prior 

to 1994 generally followed methods presented in Wood 

(1976). Samples collected and processed during 1994 

and thereafter generally followed methods described 

by Horowitz and others (1994). Field measurements of 

specific conductance, pH, temperature, dissolved oxygen, and acid neutralizing capacity were recorded at all 

sampling sites. The term acid neutralizing capacity 

(ANC) is applied to the acid neutralizing capacity of 

solutes plus particulates in a water sample, reported in 

equivalents, and normally titrated on an unfiltered sample. Samples were processed and preserved according 

to Horowitz and others (1994), then kept chilled until 

received at the laboratory.

Fourteen springs were sampled during 1992-97, 

of which eight were developed for domestic supply or 

stock watering, and six were undeveloped (table 2). 

Developed springs generally consist of a pipe pushed 

horizontally into a hillside until a flow of spring water 

is intercepted. Discharge is then routed to a house or to 

a tank for livestock. Spring discharge can be accurately 

determined by measuring the rate of water flowing 

from the pipe. Samples from developed springs were 

collected using a separate, precleaned 8-L churn splitter at each site. Prior to sampling, each churn splitter 

was cleaned and double bagged as needed to prevent 

contamination. Churn splitters were opened only for 

rinsing and sample collection, and were then covered to 

avoid contamination. Quality-assurance procedures 

used for sample collection and processing are 

described by Horowitz and others (1994). Powder-free 

vinyl gloves were worn throughout the sample collection and processing procedure to reduce the potential 

for sample contamination. 

Discharge was measured from undeveloped 

springs with a portable flume. Grab samples were 

collected because limited width and depth made collection of integrated cross-sectional samples impractical. 

Aliquots of spring water were carefully collected in 

precleaned 8-L churn splitters and covered.

A flow-through chamber was used to obtain field 

measurements for wells so that contact with the atmosphere was limited. Samples were collected after a 

minimum of three casing volumes were evacuated 

from the well and after field measurements stabilized 

(Wood, 1976).

To reduce the potential for external contamination, most of the public-supply well samples were 

collected from sampling ports located upstream of any 

chemical treatment feeders. However, workable sampling ports were not available upstream of chemical 

feeders for sites 6, 11, and 12; thus, samples for these 

three sites were collected downstream of treatment. 

Tygon tubing was used to connect the flow-through 

chamber to the sampling ports. Sample bottles were 

filled from a valve located upstream from the flowthrough chamber. The tygon tubing, flow-through 

chamber, and associated plumbing were field rinsed 

several times with deionized water between sampling 

sites.

Samples from springs and wells were analyzed 

for common ions, nutrients, trace elements, and radionuclides by the USGS National Water Quality Laboratory (NWQL) using analytical methods described by 

Fishman and Friedman (1989) and Fishman (1993). 

Pesticide samples were collected from nine springs and 

analyzed at the local USGS office laboratory by the 

enzyme-linked immunoassay method developed by 

Ohmicron Environmental Diagnostics, Newtown, 

Pennsylvania. Bacteria samples were processed in the 

field and analyzed at the local USGS office laboratory, 

generally following the procedures described by 

Britton and Greeson (1987) and by Myers and 

Sylvester (1997).
14 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Figure 4. Site-location diagram. The local number consists of the township number, followed by "N," the range number

followed by "W," and the section number followed by a maximum of four uppercase letters that indicate, respectively, the

160-, 40-, 10-, and 2 1/2-acre tract in which the well is located. These letters are assigned in a counterclockwise direction

beginning with "A" in the northeast quarter. A serial number following the last letter is used to distinguish between wells

in the same 2 1/2-acre tract.

25

A B

C D

A B

C D

A

B

C D

C

D

A

B

Well

38N44W25DDCD

1 2

3

4

5

6

12

11

10

9

8

7

13

14

15

16

17

24

23

22

21

20

19

36

26

27

28

29

30

18

35

34

33

32

31

R. 44W.

T. 38 N.

R. 48 W. R. 47 W. R. 46 W.

R. 45 W. R. 44 W. R. 43 W.

R. 42 W. R. 41 W.

R. 40 W. R. 39 W. R. 38 W. R. 37 W. R. 36 W. R. 35 W. R. 34 W. R. 33 W.

T. 35 N.

T. 37 N.

T. 38 N.

T. 39 N.

T. 40 N.

T. 41 N.

T. 42 N.

T. 43 N.

T. 44 N.

T. 36 N.

SHANNON CO

JACKSON CO

BENNETT CO

SOUTH DAKOTA

NEBRASKA
Water-Quality Sampling Locations and Methods 15

To avoid any cross contamination between wells, 

raw water samples for the determination of indicator 

bacteria concentrations were collected directly into 

sterilized glass jars. The samples were kept on ice until 

they were processed, then placed in portable incubators 

and held at the required temperature for the specified 

time until the colonies were counted. Presumptive 

analysis was used as a screening method in order to 

generally assess the types of indicator bacteria present. 

Additional conformation procedures are usually 

required to quantify the presence of indicator bacteria 

for regulatory purposes. Kits for the presumptive 

analysis of fecal coliform and fecal streptococcus bacteria were obtained from the USGS Quality of Water 

Services Unit (QWSU) in Ocala, Florida. The bacteria 

kits that QWSU supply must pass quality-assurance 

tests performed by the NWQL (Horowitz and others, 

1994). PourRite1

 ampules of M-ColiBlue241 agar 

broth were used for the presumptive analysis of total 

coliform and E. coli bacteria. This agar was chosen 

because it can be used to simultaneously analyze for 

total coliforms and E. coli. Total coliform colonies are 

determined by counting both blue and red colonies on 

each plate, while E. coli are determined by counting 

only blue colonies. All media were used prior to the 

expiration date. 

Quality Assurance

Quality-assurance samples were used to evaluate 

the precision and accuracy of the analysis of environmental samples. The quality-assurance samples 

included blanks, duplicate field samples, and standard 

reference samples (SRS’s) that were submitted as blind 

samples to the laboratory and analyzed concurrently 

with the environmental samples.

Blank Samples

Blank samples, consisting of equipment and 

field blanks, were collected and analyzed to identify 

the presence and magnitude of contamination that 

could potentially bias analytical results. Equipment 

blanks are samples of ultrapure deionized water that are 

certified trace-element free and processed through the 

sampling equipment used to collect water-quality 

samples. Equipment blanks are processed through the 

sampling equipment in a laboratory or some other controlled environment so that any contamination attributable to the equipment can be isolated and identified. 

Field blanks are samples of ultrapure deionized water 

that are processed through the sampling equipment at a 

sample-collection site and represent actual field conditions and are used to identify contamination attributable to the equipment or contamination introduced 

during sample collection and processing in the field.

One equipment blank and one field blank were 

collected during the sampling program, and the results 

are presented in table 4. Low-level analyses were 

performed on the equipment blank; thus, minimum 

reporting levels (MRL’s) for many constituents were 

lower than for the field blank, which was analyzed at 

the same limits as environmental samples. In the 

equipment blank, silica and boron were present at 

detectable concentrations. Silica was reported at 

0.3 mg/L and boron at 9.1 μg/L. Lot numbers provided 

by the manufacturers of the blank water, as well as the 

filters used to process the equipment blank, were 

checked and the statements of analyses indicated that 

silica was present at 0.04 mg/L in the water and at less 

than 0.02 mg/L in the filtrate from the capsule filters, 

which indicates that the source of silica detected in the 

equipment blank probably is due to contamination. 

Boron was present at 10 μg/L in the blank water, and at 

less than 2.0 μg/L in the filtrate from the capsule filters, 

indicating that source of boron detected in the equipment blank was from the blank water and possibly from 

the filter as well. The equipment blank was processed 

in the laboratory, and it is possible that the source of 

some of the silica and boron contamination could be 

contact with a glass beaker, considering that laboratory 

glass beakers often are made with borosilicate glass.

The results of the field-blank sample, collected 

after the equipment blank, show a silica value at the 

minimum reporting level of 0.01 mg/L and a boron 

value below the minimum reporting level of 10 μg/L. 

Field-blank-sample results indicate that external contamination did not substantially contribute to concentrations of silica and boron detected in the waterquality samples presented in this report. This conclusion also is supported by the water-quality data for 

silica and boron because the minimum value reported 

for all environmental samples collected was 8.2 mg/L 

for silica and 20 μg/L for boron.

1M-ColiBlue24 and PourRite are trademarks of the Hach 

Company, Loveland, Colorado.
16 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 4. Quality-assurance results of blank samples

[μS/cm, microsiemens per centimeter at 25°Celsius; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data; <, less than]

Constituent and reporting unit Equipment blank

4-12-95

Field blank

4-24-95

Specific conductance, lab (μS/cm) 1.4 1.4

pH, lab (standard units) -- 7.2

Calcium, dissolved (mg/L as Ca) 0.01 <0.02

Magnesium, dissolved (mg/L as Mg) 0.01 <0.01

Sodium, dissolved (mg/L as Na) <0.03 <0.2

Potassium, dissolved (mg/L as K) -- <0.1

Sulfate, dissolved (mg/L as SO4) -- <0.1

Chloride, dissolved (mg/L as Cl) -- <0.1

Fluoride, dissolved (mg/L as F) -- <0.1

Silica, dissolved (mg/L as SiO2) 0.3 0.01

Nitrogen, ammonia dissolved (mg/L) -- <0.01

Nitrogen, ammonia + organic dissolved (mg/L as N) -- <0.2

Nitrogen, nitrite dissolved (mg/L as N) -- <0.01

Nitrogen, nitrite plus nitrate, dissolved (mg/L as N) -- <0.05

Phosphorus, dissolved (mg/L as P) -- <0.01

Phosphorus ortho, dissolved (mg/L as P) -- <0.01

Arsenic, dissolved (μg/L as As) -- <1

Barium, dissolved (μg/L as Ba) <0.2 <2

Beryllium, dissolved (μg/L as Be) <0.2 <0.5

Boron, dissolved (μg/L as B) 9.1 <10

Cadmium, dissolved (μg/L as Cd) <0.3 1

Cadmium, water unfiltered total (μg/L as Cd) -- <1

Chromium, dissolved (μg/L as Cr) <0.2 <5

Cobalt, dissolved (μg/L as Co) <0.2 <3

Copper, dissolved (μg/L as Cu) <0.2 <10

Iron, dissolved (μg/L as Fe) <3 <3

Lead, dissolved (μg/L as Pb) <0.3 <10

Lithium, dissolved (μg/L as Li) -- <4

Manganese, dissolved (μg/L as Mn) <0.1 1

Mercury, dissolved (μg/L as Hg) -- <0.1

Molybdenum, dissolved (μg/L as Mo) <0.2 <10

Nickel, dissolved (μg/L as Ni) <0.5 10

Selenium, dissolved (μg/L as Se) -- <1

Silver, dissolved (μg/L as Ag) <0.2 <1

Thallium, dissolved (μg/L as Tl) <0.1 <0.5

Strontium, dissolved (μg/L as Sr) <0.1 <0.5

Vanadium, dissolved (μg/L as V) -- <6

Zinc, dissolved (μg/L as Zn) <0.5 <3
Water-Quality Sampling Locations and Methods 17

Three constituents (cadmium, manganese, and 

nickel) were present at detectable concentrations in the 

field blank. Cadmium and manganese were both 

present at 1.0 μg/L, and nickel was present at 10 μg/L. 

The corresponding minimum reporting levels for 

cadmium, manganese, and nickel were 1.0, 1.0, and 

10 μg/L, respectively. Statements of analyses provided 

for the blank water, as well as filters used to process the 

field blank, indicated that they were not the source of 

the contamination. It is therefore possible that contamination could account for detectable concentrations of 

these three constituents, which were present at or near 

the minimum reporting level in the environmental 

samples. 

The effectiveness of sterilization techniques 

used during collection and processing of bacterial 

samples was monitored by filtering an aliquot of sterile 

phosphate buffer as a blank between sampling sites. 

The filter was then placed on the respective agar media 

and incubated to determine if characteristic bacteria 

colonies developed. Bacteria colonies developed on 

one blank collected between spring sites; no bacteria 

colonies developed on blanks collected during the 

public-supply well sampling.

Duplicate Samples

Duplicate field samples consist of splits from the 

same sample aliquot that are collected in a manner such 

that the samples are assumed to be essentially identical 

in composition. These samples are used to estimate 

variability in the sample-collection and analysis 

process. 

A data-quality objective for precision of duplicate field samples was established at a maximum 

relative standard deviation of 20 percent. The establishment of a data-quality objective provides a tool for 

assessing the reliability of sampling and analytical 

methods, as well as a method for identifying and 

qualifying questionable data. Comparisons of qualityassurance data to the data-quality objective are used to 

evaluate whether sampling and analytical methods 

have consistently produced data that are representative 

of existing environmental conditions.

The precision of the analytical results for a 

specific constituent can be determined by calculating a 

standard deviation from the differences of pairs of the 

duplicate measurements. The standard deviation is 

estimated by the following equation (Taylor, 1987):

where:

S = standard deviation of the difference in concentration between duplicate analyses;

d = difference in concentration between each 

pair of duplicate analyses; and

k = number of pairs of duplicate analyses.

Precision also can be expressed as a relative 

standard deviation (RSD), in percent, for a specific 

constituent. The RSD is calculated from the standard 

deviation and the mean concentration of all duplicate 

analyses as given in the following equation (Taylor, 

1987):

where:

RSD = relative standard deviation, in percent;

S = standard deviation; and

x = mean of all duplicate concentrations.

Chemical analyses of duplicate field samples for 

springs and public-supply wells (table 5) were combined to provide the paired sets of data used to calculate 

precision. Results of precision calculations are 

provided in table 6.

Many reported concentrations were less than the 

MRL. For these “censored” values, an estimated value 

of one-half the MRL was substituted into precision 

calculations. 

Radionuclide analyses presented in table 5 

include precision estimates for each analysis. The term 

2 sigma refers to the 2 sigma precision estimate 

(2SPE), which is a measure of the uncertainty of the 

reported concentration. Generally, there is about 

95 percent certainty that the true concentration for a 

sample is within the range of the reported value plus or 

minus 2SPE, with the lower part of that range bounded 

by zero.

The data-quality objective (maximum RSD) of 

20 percent for the precision of field duplicates was 

exceeded for five of the constituents (beryllium, iron, 

molybdenum, zinc, and radium-226) in table 6. The 

high RSD for two constituents (beryllium and molybdenum) resulted from a single sample for each constituent for which a detectable concentration was reported 

(table 5). Similarly, reported values for zinc and 

radium-226 were near the MRL. Iron was the only 

constituent for which a particularly large discrepancy 

was identified; however, poor precision of this relatively low concentration for iron is of small 

consequence. Thus, although the data-quality objective was not met for all constituents, the problems are 

S considered very minor. Σd

2

2k = ---------

RSD S

x = -- × ( ) 100
18 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 5. Chemical and radionuclide analyses of duplicate field samples for springs and public-supply wells

[μS/cm, microsiemens per centimeter at 25°Celsius; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data; <, less than]

Constituent and reporting unit

Site S9

(spring)

10-08-92

Site 7

(well)

07-28-97

Site 29

(well)

07-09-97

Sample Duplicate Sample Duplicate Sample Duplicate

Specific conductance, lab (μS/cm) 511 511 542 542 661 658

pH, lab (standard units) 8.3 8.3 7.9 7.2 7.3 7.1

ANC, lab (mg/L as CaCO3) 201 201 262 250 276 276

Calcium, dissolved (mg/L as Ca) 27 27 58 56 81 81

Magnesium, dissolved (mg/L as Mg) 3 3 7.9 7.7 8.7 8.6

Sodium, dissolved (mg/L as Na) 74 75 44 44 49 48

Potassium, dissolved (mg/L as K) 11 13 -- -- 12 12

Sulfate, dissolved (mg/L as SO4) 34 34 23 23 80 80

Chloride, dissolved (mg/L as Cl) 11 11 8.1 8.1 5.1 5.2

Fluoride, dissolved (mg/L as F) 0.3 0.3 0.3 0.3 0.3 0.3

Silica, dissolved (mg/L as SiO2) 56 56 54 53 57 56

Solids, dissolved (mg/L) 357 347 374 371 480 481

Nitrogen, ammonia dissolved (mg/L) -- -- 0.2 0.2 <0.015 <0.015

Nitrogen ammonia + organic, dissolved (mg/L) -- -- -- -- <0.2 <0.2

Nitrogen, nitrite plus nitrate, dissolved

(mg/L as N)

-- -- 3 3 0.6 0.7

Phosphorus, dissolved (mg/L as P) -- -- 0.1 0.1 0.04 0.04

Arsenic, dissolved (μg/L as As) 10 10 11 15 4.7 4.8

Barium, dissolved (μg/L as Ba) 52 51 260 270 49 47

Beryllium, dissolved (μg/L as Be) <0.5 <0.5 <0.5 1.4 <0.5 <0.5

Boron, dissolved (μg/L as B) 170 180 130 130 77 74

Cadmium, dissolved (μg/L as Cd) <1 <1 <1 <1 <1 <1

Cadmium, water unfiltered total (μg/L as Cd) <1 <1 -- -- <1 <1

Chromium, dissolved (μg/L as Cr) <5 <5 <5 <5 <5 <5

Cobalt, dissolved (μg/L as Co) <3 <3 <3 <3 <3 <3

Copper, dissolved (μg/L as Cu) <10 <10 <10 <10 <10 <10

Iron, dissolved (μg/L as Fe) 3 4 33 11 <3 <3

Lead, dissolved (μg/L as Pb) <10 <10 <10 <10 <10 <10

Lithium, dissolved (μg/L as Li) 36 37 18 24 45 44

Manganese, dissolved (μg/L as Mn) <1 1 75 67 <1 <1
Water-Quality Sampling Locations and Methods 19

Mercury, dissolved (μg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Molybdenum, dissolved (μg/L) <10 <10 <10 10 <10 <10

Nickel, dissolved (μg/L as Ni) <10 <10 <10 <10 <10 <10

Selenium, dissolved (μg/L as Se) 11 10 3 4 2.1 1.8

Silver, dissolved (μg/L as Ag) <1 <1 <1 <1 <1 <1

Strontium, dissolved (μg/L as Sr) 360 360 420 460 850 829

Thallium, dissolved (μg/L as Tl) -- -- -- -- <0.5 <0.5

Vanadium, dissolved (μg/L as V) 9 9 10 12 <6 6.6

Zinc, dissolved (μg/L as Zn) 3 <3 <3 9 <3 5.1

Gross alpha, dissolved (μg/L as U) 13.5 13.9 12 15 -- --

Alpha count, 2 sigma precision estimate, 

dissolved (pCi/L as U)

2.8 3.1 5.3 6.3 -- --

Gross alpha radio, dissolved (pCi/L as Th-230) 9.2 9.9 8.3 11 18.8 16.5

Alpha count, 2 sigma precision estimate 

dissolved (pCi/L as Th-230)

1.9 2.0 3.7 4.4 5.7 5.3

Gross beta, dissolved (pCi/L as Cs-137) 8.8 8.9 24 21 21.2 21.3

Beta, 2 sigma precision estimate dissolved 

(pCi/L as Cs-137)

0.8 1.3 3.4 3.2 4.8 4.8

Gross beta, dissolved (pCi/L as Sr90/Y90) -- -- 18 16 -- --

Beta, 2 sigma precision estimate dissolved 

(pCi/L as Sr90/Y90)

-- -- 2.6 2.4 -- --

Ra-226, dissolved (pCi/L) -- -- 0.1 0.2 0.03 0.03

Ra-226, dissolved 2 sigma precision estimate 

(pCi/L)

-- -- 0.1 0.1 0.04 0.04

Uranium, dissolved (μg/L as U) -- -- 10 12 18.4 19.6

Uranium, dissolved 2 sigma precision estimate 

(μg/L)

-- -- 3.0 3.5 5.2 5.5

Table 5. Chemical and radionuclide analyses of duplicate field samples for springs and public-supply wells–Continued

[μS/cm, microsiemens per centimeter at 25°Celsius; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data; <, less than]

Constituent and reporting unit

Site S9

(spring)

10-08-92

Site 7

(well)

07-28-97

Site 29

(well)

07-09-97

Sample Duplicate Sample Duplicate Sample Duplicate
20 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 6. Precision of chemical analyses of duplicate field samples for springs and public-supply wells

[Units in micrograms per liter except where indicated. μS/cm, microsiemens per centimeter at 25°Celsius; mg/L, milligrams per liter;

pCi/L, picocuries per liter]

Constituent and reporting unit

Minimum

reporting

level

Number of

duplicate

pairs

Standard

deviation

Relative standard 

deviation

(percent)

Specific conductance (μS/cm) 1 3 1.2 0.2

pH (standard units) 0.1 3 0.3 3.9

Acid neutralizing capacity (mg/L as CaCO3) 1 3 4.9 2.0

Calcium, dissolved (mg/L) 0.1 3 0.8 1.5

Magnesium, dissolved (mg/L) 0.1 3 0.09 1.4

Sodium, dissolved (mg/L) 0.1 3 0.6 1.0

Potassium, dissolved (mg/L) 0.1 2 1.0 8.3

Sulfate, dissolved (mg/L) 0.1 3 0.0 0.0

Chloride, dissolved (mg/L) 0.1 3 0.04 0.5

Fluoride, dissolved (mg/L) 0.1 3 0.0 0.0

Silica, dissolved (mg/L) 0.1 3 0.6 1.1

Solids, dissolved (mg/L) 1 3 4.3 1.1

Nitrogen, ammonia, dissolved (mg/L) 0.02 2 0.0 0.0

Nitrogen, nitrite plus nitrate, dissolved (mg/L as N) 0.005 2 0.05 2.7

Phosphorus, dissolved (mg/L) 0.001 2 0.0 0.0

Arsenic, dissolved 1 3 1.6 18

Barium, dissolved 1 3 4.2 3.4

Beryllium, dissolved 0.5 3 0.50 106

Boron, dissolved 10 3 4.3 3.4

Cadmium, water unfiltered total 1 2 0.0 0.0

Cadmium, dissolved 1 3 0.0 0.0

Chromium, dissolved 5 3 0.0 0.0

Cobalt, dissolved 3 3 0.0 0.0

Copper, dissolved 10 3 0.0 0.0

Iron, dissolved 3 3 9.0 100

Lead, dissolved 10 3 0.0 0.0

Lithium, dissolved 6 3 2.5 7.4

Manganese, dissolved 1 3 3.3 14

Mercury, dissolved 0.1 3 0.0 0.0

Molybdenum, dissolved 10 3 2.0 35

Nickel, dissolved 10 3 0.0 0.0

Selenium, dissolved 1 3 0.6 11

Silver, dissolved 1 3 0.0 0.0

Thallium, dissolved 0.5 1 0.0 0.0

Strontium, dissolved 1 3 18 3.4

Vanadium, dissolved 6 3 1.6 20

Zinc, dissolved 3 3 3.4 96

Gross alpha, dissolved, as uranium natural 3 2 1.5 11

Gross alpha radioactivity, dissolved, as Th-230, pCi/L 3 3 1.5 12

Gross beta, dissolved, pCi/L as Cs-137 4 3 1.2 6.9

Gross beta, dissolved, pCi/L as Sr/Y-90 4 1 1.4 8.3

Radium-226, dissolved, pCi/L 0.1 2 0.05 55

Uranium, natural, dissolved 1 2 1.2 7.8
Water-Quality Sampling Locations and Methods 21

Standard Reference Samples

Two standard reference samples (SRS’s), which 

consisted of standard reference water provided by the 

NWQL, were submitted as quality-assurance samples. 

The SRS’s are sample lots that are prepared by the 

NWQL as part of a USGS interlaboratory evaluation 

program (Farrar and Long, 1996) and are available for 

quality-assurance purposes. Analyses performed by 

numerous laboratories are used to determine the most 

probable value (MPV) for selected analytes in an SRS. 

The MPV represents the median (midpoint) value 

established for a constituent. An F-pseudosigma value, 

which is a measure of variability similar to a standard 

deviation, also is determined for each analyte from 

results reported by participating laboratories.

Two SRS’s were prepared as quality-assurance 

samples by pouring directly into sample bottles that 

had been rinsed with SRS water. SRS M-116 (mainly 

for major constituents) was submitted on December 11, 

1995, and SRS T-99 (mainly for trace constituents) was 

submitted on September 6, 1996. Analytical results are 

presented in table 7, along with a comparison to the 

MPV and an "acceptable" analytical range, which is the 

MPV plus or minus two times the F-pseudosigma 

value. The MPV’s and F-pseudosigma values were 

provided by Keith R. Long and Jerry W. Farrar (U.S. 

Geological Survey, written commun., 1991). The 

MPV data, acceptable F-pseudosigma ranges, and 

results of SRS’s submitted as blind samples to the 

NWQL are summarized in table 7.

The SRS M-116 was analyzed for seven constituents. The only constituent that exceeded the established acceptable range was sulfate. Because sulfate 

only narrowly exceeded the acceptable range, and 

because the analyses of sulfate in duplicate field 

samples were in perfect agreement, the exceedance was 

not considered to be a problem in the analysis of 

environmental samples.

The SRS T-99 was analyzed for 22 constituents 

with established MPV’s and F-pseudosigma ranges. 

Seven constituents (cadmium, cobalt, copper, lead, 

molybdenum, silver, and zinc) had values that fell outside of their established acceptable ranges, indicating 

the analytical variability associated with these constituents. Chronic problems with NWQL analyses for a 

limited number of constituents, primarily in ranges 

near the MRL’s, have been identified based largely on 

data collected by the NWQL Blind Sample Program. 

To address these problems, the NWQL raised the 

minimum reporting levels effective December 15, 

1997, for six of the seven constituents, and for several 

others routinely analyzed by inductively coupled 

plasma-atomic emission spectroscopy (ICP-AES). 

(U.S. Geological Survey, National Water Quality 

Laboratory Technical Memorandum 98.05, dated 

Dec. 9, 1997). Had the newly established minimum 

reporting levels been in effect at the time SRS T-99 was 

analyzed, lead and molybdenum would have had 

acceptable F-pseudosigma ranges. Because the SRS 

data presented in this report for cadmium, cobalt, 

copper, lead, molybdenum, silver, and zinc failed to 

meet the required standards for precision, the data 

presented for environmental samples for these seven 

constituents should be used cautiously.

Summary of Quality-Assurance Data

The quality-assurance samples analyzed for this 

report included equipment blanks, field blanks, fieldduplicate samples, and SRS’s. Although a number of 

minor analytical problems were identified, none of the 

problems posed any real difficulty with respect to the 

interpretation of the environmental data sets. This is 

because most of the minor problems would be significant only if analyses for selected constituents were of 

particular importance, near the MRL’s. If this were the 

case, low-level analytical methods would have been 

used.

The analysis of the equipment blank shows that 

silica and boron were both present at detectable concentrations but did not have an appreciable effect on the 

environmental samples. The analysis of the field blank 

shows that cadmium, manganese, and nickel were 

present at detectable concentrations. Therefore, detections of cadmium and manganese in the environmental 

samples at concentrations near the minimum reporting 

level could have resulted from sample contamination. 

Nickel was not detected in any of the environmental 

samples analyzed, and therefore was not affected.

Results from the analysis of field-duplicate 

samples show that precision data for beryllium, iron, 

molybdenum, zinc, and radium-226 fail to meet the 

established data-quality objectives. Because beryllium 

was only detected in a single environmental sample, its 

failure to meet the established data-quality objective 

did not negatively affect the beryllium data. The 

reason radium-226 failed to meet the established dataquality objective probably resulted from the generally 

low concentrations detected in the randomly selected 

field-duplicate samples.
22 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 7. Quality-assurance results for standard reference samples M-116 and T-99 submitted during public-supply well 

sampling program

[Units in micrograms per liter except where indicated. SRS, standard reference sample; NWQL, USGS National Water Quality Laboratory; MPV, most 

probable value; μS/cm, microsiemens per centimeter at 25°Celsius; mg/L, milligrams per liter; --, no data; <, less than]

Constituent and 

reporting unit

SRS M-116 SRS T-99

MPV Acceptable 

range1

NWQL 

reported 

value

(4-1-96)

Within 

acceptable 

range?

MPV Acceptable 

range1

NWQL 

reported

value

(10-29-96)

Within 

acceptable 

range?

Specific conductance

(μS/cm)

1,477 1,373-1,581 1,460 Yes -- -- -- --

pH (standard units) 2.7 2.5-2.9 2.7 Yes -- -- -- --

Calcium (mg/L) -- -- -- -- 202 172-232 200 Yes

Magnesium (mg/L) -- -- -- -- 113 99-127 110 Yes

Sodium (mg/L) -- -- -- -- 323 289-357 310 Yes

Potassium (mg/L) 4.9 4.3-5.5 5.1 Yes 5.2 3.6-6.8 5.0 Yes

Sulfate (mg/L 97 85-109 110 No -- -- -- --

Chloride (mg/L) 208 192-224 210 Yes -- -- -- --

Fluoride (mg/L) 0.7 0.5-0.9 0.5 Yes -- -- -- --

Silica (mg/L) -- -- -- -- 10.9 9.5-12.3 10 Yes

Arsenic -- -- -- -- 5.8 2-9.6 8.0 Yes

Barium -- -- -- -- 19.6 <2-40 23 Yes

Boron 136 88-184 130 Yes 495 455-535 498 Yes

Cadmium -- -- -- -- 4.7 1.7-7.7 15 No

Chromium -- -- -- -- 16.3 3.3-29.3 27 Yes

Cobalt -- -- -- -- 2.1 <3-4.1 12 No

Copper -- -- -- -- 27.9 18.7-37.1 40 No

Iron -- -- -- -- 137 79-195 130 Yes

Lead -- -- -- -- 4.7 <10-11.5 40 No

Lithium -- -- -- -- 176 134-218 170 Yes

Manganese -- -- -- -- 82 54-110 84 Yes

Molybdenum -- -- -- -- 13.1 8.3-17.9 40 No

Nickel -- -- -- -- 16.5 <10-50.1 40 Yes

Silver -- -- -- -- 3 <1-6 7 No

Strontium -- -- -- -- 3,900 3,500-4,300 3,900 Yes

Vanadium -- -- -- -- 11.8 <6-24 24 Yes

Zinc -- -- -- -- 36 21.4-50.6 120 No

1Acceptable range established as MPV plus or minus 2 times F-pseudosigma values.
Water-Quality Data and Analysis for Selected Springs and Wells 23

The analysis of SRS’s show that cadmium, 

cobalt, copper, lead, molybdenum, silver, and zinc 

exceeded the established acceptable ranges. Because 

copper was only detected in a single environmental 

sample, its failure to fall within the established acceptable range did not negatively affect the copper data.

The results of four meticulous quality-assurance 

methods applied to nearly 50 constituents analyzed for 

this study show that data reported for six (cadmium, 

cobalt, iron, manganese, silver and zinc) exceeded the 

established acceptable criteria and there is no clear 

explanation. Subsequently, even though most of these 

trace metal constituents appear at or near the minimum 

reporting level in the environmental samples analyzed, 

the results for these six constituents should be used 

cautiously. The quality-assurance methods used for 

this study also show that for most constituents of concern, specifically for most of those regulated by the 

Safe Drinking Water Act, the data are highly reliable.

WATER-QUALITY DATA AND ANALYSIS 

FOR SELECTED SPRINGS AND WELLS

Water-quality data were collected during 

1992-97 for 14 springs and 44 public-supply wells. 

Analytical results of sampling for field parameters, 

common ions, nutrients, trace elements, radionuclides, 

and pesticides are discussed in the following sections.

Water-quality data also are compared to USEPA 

criteria and standards for drinking water (table 8). Two 

types of standards are typically used to assess the suitability of water for human consumption. A secondary 

maximum contaminant level (SMCL) represents a 

recommended level for a constituent and is considered 

to be a nonenforceable guideline that is usually related 

to the aesthetic quality of water. The second type of 

standard is the maximum contaminant level (MCL), 

which represents the maximum permissible level of a 

contaminant allowed in water that is delivered to any 

user of a public-supply system. MCL’s are enforceable 

standards under the Safe Drinking Water Act.

The USGS typically analyzes ground-water 

samples for dissolved constituent concentrations, 

which means the water sample has been passed through 

a filter with an average mesh size of 0.45 microns. 

Drinking-water standards established by the USEPA 

are based on total constituent concentrations, which 

refer to the combined concentration of both dissolved 

and suspended phases of the water sample. Therefore, 

results reported by the USGS as dissolved constituent 

concentrations may be less than those obtained for 

similar samples analyzed for total constituent 

concentrations.

Springs

Fourteen springs were initially sampled in 1992, 

during the reconnaissance phase of the study. After the 

initial sampling, nine of these springs were sampled 

four more times between 1994 and 1997. Waterquality data for all spring samples are presented in 

table 13 in the Supplemental Data section at the end of 

this report. Median values for the nine springs that 

were sampled multiple times are presented in table 9.

Discharge measurements generally were made at 

the time that water-quality samples were collected from 

springs. Additional discharge measurements were 

made at six of the springs (S4-S9) to evaluate 

variability in spring discharge. Hydrographs are shown 

in figure 5 for all springs at which multiple discharge 

measurements were made. Most of the springs show 

very little variability in discharge. The largest 

variability in discharge was for Cuny Cafe Spring (S4), 

which ranged from about 0.05 to 0.39 ft3/s (fig. 5).

Several long-time residents of the area have 

reported that even during periods of drought conditions, most of the more consistent springs have maintained enough flow for livestock watering. Severe 

drought conditions occurred during the late 1980’s, a 

few years prior to initiation of the sampling for this 

study. None of the springs sampled were reported dry 

during the late 1980’s; thus, it is likely that most of 

these springs maintained some flow during that period. 

It is not possible to make estimates of discharge during 

that period; however, flow for some of the springs may 

have been less than the minimum values shown in 

figure 5. All discharge measurements shown in 

figure 5 are rounded to the nearest 0.01 ft3/s; thus, 

actual discharges for some of the measurements shown 

are somewhat less than 0.01 ft3

/s.

The village of Red Shirt includes 12 houses and 

a Shannon County School, with an estimated population of about 80 people while the school is in session 

(U.S. Public Health Service, 1996). Assuming an 

average use of 80 gal/d per person, a spring would need 

to supply about 6,400 gal/d to meet demand. A discharge of 0.01 ft3/s is equal to about 4.5 gal/min or 

about 6,460 gal/d. Thus, a single spring discharging 

0.01 ft3/s might only minimally meet the present public 

water-supply needs of the village of Red Shirt during 

periods of average demand. Blending water from 

springs and the existing well completed in the Inyan 

Kara aquifer may be a possible alternative for meeting 

the public water-supply needs of the village of Red 

Shirt.
24 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 8. Water-quality criteria, standards, or recommended limits for selected properties or constituents

[Modified from Howells, 1979. All concentrations are from U.S. Environmental Protection Agency (1996) unless noted. MCL, maximum contaminant 

level; SMCL, secondary maximum contaminant level; mL, milliliters; mg/L, milligrams per liter; μg/L, micrograms per liter; pCi/L, picocuries per liter;

--, no limit established]

Constituent

or property Limit Significance

Specific conductance -- A measure of the ability of water to conduct an electrical current; varies with temperature. 

Magnitude depends on concentration, kind, and degree of ionization of dissolved constituents; can be used to determine the approximate concentration of dissolved solids. 

Values are reported in microsiemens per centimeter at 25° Celsius.

pH 6.5-8.5 units

SMCL

A measure of the hydrogen ion concentration; pH of 7.0 indicates a neutral solution, pH 

values smaller than 7.0 indicate acidity, pH values larger than 7.0 indicate alkalinity. 

Water generally becomes more corrosive with decreasing pH; however, excessively 

alkaline water also may be corrosive.

Acid neutralizing 

capacity (ANC)

-- A measure of the capacity of unfiltered water to neutralize acid. In almost all natural waters 

ANC is produced by the dissolved carbon dioxide species, bicarbonate and carbonate. 

Typically expressed as mg/L CaCO3.

E. coli bacteria presence/absence

MCL1

Indicator bacteria used to assess the quality of water. E. coli strictly inhabit the gastrointestinal tract of humans and warm-blooded animals. Its presence in water is direct evidence 

of fecal contamination and the possible presence of disease-causing organisms. Disease 

symptoms may include gastroenteritis, fever, and diarrhea.

Total coliform bacteria presence/absence

MCL1 Indicator bacteria used to assess the quality of water. They are not typically disease causing, 

but are correlated to the presence of several water-borne disease-causing organisms. May 

result from the intestinal tract of humans and warm-blooded animals or from other 

sources. The presence of indicator bacteria is used to assess the sanitary quality of water 

for consumption.

Fecal coliform bacteria presence/absence

MCL1 Indicator bacteria used to assess the quality of water. They are not typically disease causing, 

but are correlated to the presence of several waterborne disease-causing organisms. 

Generally found in the intestinal tract of humans and warm-blooded animals, presence in 

water indicates fecal pollution.

Fecal streptococci

bacteria

-- Indicator bacteria used to assess the quality of water. They are not typically disease causing, 

but are correlated to the presence of several waterborne disease-causing organisms. 

Generally found in the intestinal tract of humans and warm-blooded animals, presence in 

water indicates fecal pollution.

Hardness (mg/L as 

CaCO3)

-- Related to the soap-consuming characteristics of water; results in formation of scum when 

soap is added. May cause deposition of scale in boilers, water heaters, and pipes. Hardness contributed by calcium and magnesium, bicarbonate and carbonate mineral species 

in water is called carbonate hardness; hardness in excess of this concentration is called 

noncarbonate hardness. Water that has a hardness less than 61 mg/L is considered soft; 

61-120 mg/L, moderately hard; 121-180 mg/L, hard; and more than 180 mg/L, very hard 

(Heath, 1983).

Calcium plus 

magnesium

-- Cause most of the hardness and scale-forming properties of water (see hardness).

Sodium plus 

potassium

-- Large concentrations may limit use of water for irrigation and industrial use and, in combination with chloride, give water a salty taste. Abnormally large concentrations may 

indicate natural brines, industrial brines, or sewage.

Sodium-adsorption

ratio (SAR)

A ratio used to express the relative activity of sodium ions in exchange reactions with soil. 

Important in irrigation water; the greater the SAR, the less suitable the water for 

irrigation.

Bicarbonate -- In combination with calcium and magnesium forms carbonate hardness.
Water-Quality Data and Analysis for Selected Springs and Wells 25

Sulfate 250 mg/L

SMCL

Sulfates of calcium and magnesium form hard scale. Large concentrations of sulfate have a 

laxative effect on some people and, in combination with other ions, give water a bitter 

taste.

Chloride 250 mg/L

SMCL

Large concentrations increase the corrosiveness of water and, in combination with sodium, 

give water a salty taste.

Fluoride 4.0 mg/L

MCL

2.0 mg/L

SMCL

Reduces incidence of tooth decay when optimum fluoride concentrations present in water 

consumed by children during the period of tooth calcification. Potential health effects of 

long-term exposure to elevated fluoride concentrations include dental and skeletal fluorosis (U.S. Environmental Protection Agency, 1994).

Silica (as SiO2) -- Forms hard scale in pipes and boilers and may form deposits on blades of steam turbines. 

Inhibits deterioration of zeolite-type water softeners.

Dissolved solids 500 mg/L

SMCL

The total of all dissolved mineral constituents, usually expressed in milligrams per liter. 

The concentration of dissolved solids may affect the taste of water. Water that contains 

more than 1,000 mg/L is unsuitable for many industrial uses. Some dissolved mineral 

matter is desirable; otherwise the water would have no taste. The dissolved solids concentration commonly is called the water’s salinity and is classified as follows: fresh, 

0-1,000 mg/L; slightly saline, 1,000-3,000 mg/L; moderately saline, 3,000-10,000 mg/L; 

very saline, 10,000-35,000 mg/L; and briny, more than 35,000 mg/L (Heath, 1983).

Nitrite (mg/L as N) 1.0 mg/L

MCL

An acute health concern at certain levels of exposure. Nitrite may originate in water from 

fertilizers and is found in sewage and wastes from humans and farm animals. Concentrations greater than 1.0 mg/L, as nitrogen, may be injurious when used in feeding infants.

Nitrite plus nitrate 

(mg/L as N)

10 mg/L

MCL

Concentrations greater than local background levels may indicate pollution by feedlot 

runoff, sewage, or fertilizers. Concentrations greater than 10 mg/L, as nitrogen, may be 

injurious when used in feeding infants.

Phosphorus,

orthophosphate

-- Dense agal blooms or rapid plant growth can occur in waters rich in phosphorus. A limiting 

nutrient for eutrophication because it is typically in shortest supply. Sources are human 

and animal wastes and fertilizers.

Arsenic 250 μg/L

MCL

No known necessary role in human or animal diet, but is toxic. A cumulative poison that is 

slowly excreted. Can cause nasal ulcers; damage to the kidneys, liver, and intestinal 

walls; and death. Recently suspected to be a carcinogen (U.S. Environmental Protection 

Agency, written commun., 1998).

Barium 2,000 μg/L

MCL

Toxic; used in rat poison. In moderate to large concentrations can cause death; smaller 

concentrations cause damage to the heart, blood vessels, and nerves.

Beryllium 4 μg/L

MCL

Toxic, suspected human carcinogen and poison. Potential human health effects include eye, 

lung, liver, spleen, and heart damage.

Boron -- Essential to plant growth, but may be toxic to crops when present in excessive concentrations in irrigation water. Sensitive plants show damage when irrigation water contains 

more than 670 μg/L and even tolerant plants may be damaged when boron exceeds 

2,000 μg/L. The recommended limit is 750 μg/L for long-term irrigation on sensitive 

crops (U.S. Environmental Protection Agency, 1986).

Cadmium 5 μg/L

MCL

A cumulative poison; very toxic. Not known to be either biologically essential or beneficial. 

Believed to promote renal arterial hypertension. Elevated concentrations may cause liver 

and kidney damage, or even anemia, retarded growth, and death.

Chromium 100 μg/L

MCL

No known necessary role in human or animal diet. In the hexavalent form is toxic, leading 

to intestinal damage and to nephritis.

Table 8. Water-quality criteria, standards, or recommended limits for selected properties or constituents–Continued

[Modified from Howells, 1979. All concentrations are from U.S. Environmental Protection Agency (1996) unless noted. MCL, maximum contaminant 

level; SMCL, secondary maximum contaminant level; mL, milliliters; mg/L, milligrams per liter; μg/L, micrograms per liter; pCi/L, picocuries per liter;

--, no limit established]

Constituent

or property Limit Significance
26 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Cobalt -- Importance to human nutrition is not known but the element is essential in plant and animal 

nutrition. Concentrations of cobalt in the Earth’s crust are generally very low. Uncontaminated natural water should generally contain no more than a few micrograms per liter 

of cobalt (Hem, 1989, p. 139).

Copper 1,300 μg/L

(action level)

Essential to metabolism; copper deficiency in infants and young animals results in nutritional anemia. Large concentrations of copper are toxic and may cause liver damage. 

Moderate levels of copper (near the action level) can cause gastro-intestinal distress. If 

more than 10 percent of samples at the tap of a public water system exceed 15 μg/L, the 

USEPA requires treatment to control corrosion of plumbing materials in the system (U.S. 

Environmental Protection Agency, 1991).

Iron 300 μg/L

SMCL

Forms rust-colored sediment; stains laundry, utensils, and fixtures reddish brown. Objectionable for food and beverage processing. Can promote growth of certain kinds of 

bacteria that clog pipes and well openings.

Lead 15 μg/L

(action level)

A cumulative poison, toxic in small concentrations. Can cause lethargy, loss of appetite, 

constipation, anemia, abdominal pain, gradual paralysis in the muscles, and death. If 

more than 10 percent of samples of a public supply exceed 15 μg/L, the USEPA recommends treatment to remove lead and monitoring of the water supply for lead content (U.S. 

Environmental Protection Agency, 1991).

Lithium -- Reported as probably beneficial in small concentrations (250-1,250 μg/L). Reportedly may 

help strengthen the cell wall and improve resistance to genetic damage and to disease. 

Lithium salts are used to treat certain types of psychosis.

Manganese 50 μg/L

SMCL

Causes gray or black stains on porcelain, enamel, and fabrics. Can promote growth of 

certain kinds of bacteria that clog pipes and wells.

Mercury 2 μg/L

MCL

No known essential or beneficial role in human or animal nutrition. Liquid metallic 

mercury and elemental mercury dissolved in water are comparatively nontoxic, but some 

mercury compounds, such as mercuric chloride and alkyl mercury, are very toxic. 

Elemental mercury is readily alkylated, particularly to methyl mercury, and concentrated 

by biological activity. Potential health effects of exposure to some mercury compounds 

in water include severe kidney and nervous system disorders (U.S. Environmental 

Protection Agency, 1994).

Molybdenum -- In minute concentrations, appears to be an essential nutrient for both plants and animals, but 

in large concentrations may be toxic.

Nickel -- Very toxic to some plants and animals. Toxicity for humans is believed to be minimal.

Selenium 50 μg/L

MCL

Essential to human and animal nutrition in minute concentrations, but even a moderate 

excess may be harmful or potentially toxic if ingested for a long time (Callahan and 

others, 1979). Potential human health effects of exposure to elevated selenium concentrations include liver damage (U.S. Environmental Protection Agency, 1994).

Silver 100 μg/L

SMCL

Causes permanent bluish darkening of the eyes and skin (argyria). Where found in water is 

almost always from pollution or by intentional addition. Silver salts are used in some 

countries to sterilize water supplies. Toxic in large concentrations.

Strontium -- Importance in human and animal nutrition is not known, but believed to be essential. 

Toxicity believed minimal—no more than that of calcium.

Thallium 2 μg/L

MCL

Toxic; used as rat and insect poison. Potential human health effects of exposure to thallium 

include eye, central nervous system, liver, and kidney damage. Oral ingestion may be 

fatal.

Table 8. Water-quality criteria, standards, or recommended limits for selected properties or constituents–Continued

[Modified from Howells, 1979. All concentrations are from U.S. Environmental Protection Agency (1996) unless noted. MCL, maximum contaminant 

level; SMCL, secondary maximum contaminant level; mL, milliliters; mg/L, milligrams per liter; μg/L, micrograms per liter; pCi/L, picocuries per liter;

--, no limit established]

Constituent

or property Limit Significance
Water-Quality Data and Analysis for Selected Springs and Wells 27

Vanadium -- Not known to be essential to human or animal nutrition, but believed to be beneficial in trace 

concentrations. May be an essential trace element for all green plants. Large 

concentrations may be toxic.

Zinc 5,000 μg/L

SMCL

Essential and beneficial in metabolism; its deficiency in young children or animals will 

retard growth and may decrease general body resistance to disease. Seems to have no ill 

effects even in fairly large concentrations (20,000-40,000 mg/L), but can impart a 

metallic taste or milky appearance to water. Zinc in drinking water commonly is derived 

from galvanized coatings of piping.

Gross alphaparticle activity15 pCi/L

MCL

The measure of alpha-particle radiation present in a sample. A limit is placed on gross 

alpha-particle activity because it is impractical at the present time to identify all alphaparticle-emitting radionuclides due to analytical costs. Gross alpha-particle activity is a 

radiological hazard. The 15 pCi/L standard also includes radium-226, a known carcinogen, but excludes any uranium or radon that may be present in the sample.

Radium-226 & 228 

combined

5 pCi/L

MCL

Radium locates primarily in bone, however, inhalation or ingestion may result in lung 

cancer. Radium-226 is a highly radioactive alkaline-earth metal that omits alpha-particle 

radiation. It is the longest lived of the four naturally occurring isotopes of radium and is a 

disintegration product of uranium-238. Concentrations of radium in most natural waters 

are usually less than 1.0 pCi/L (Hem, 1985, p. 149).

Strontium-90 Gross betaparticle activity,

man-made

(4 millirem/yr)

MCL

Strontium-90 is one of 12 unstable isotopes of strontium known to exist. It is a product of 

nuclear fallout and is known to cause adverse human health affects. Strontium-90 is a 

bone seeker and a relatively long-lived beta emitter with a half-life of 28 years. The 

USEPA has calculated that an average annual concentration of 8 pCi/L will produce a 

total body or organ dose of 4 millirem/yr (U.S. Environmental Protection Agency, 1997).

Thorium-230 Gross alphaparticle activity,

15 pCi/L

MCL

Thorium-230 is a product of natural radioactive decay when uranium-234 emits alphaparticle radiation. Thorium-230 also is a radiological hazard because it is part of the 

uranium-238 decay series and emits alpha-particle radiation through its own natural 

decay to become radium-226. The half-life of thorium-230 is about 80,000 years.

Tritium (3H) Gross betaparticle activity,

man-made

(4 millirem/yr)

MCL

Tritium occurs naturally in the atmosphere but is present largely as a result of testing thermonuclear bombs between 1952-69. It can be incorporated into water molecules that 

reach the Earth’s surface as precipitation. Tritium emits low energy beta particles and is 

relatively short-lived with a half-life of about 12.3 years. The USEPA has calculated that 

a concentration of 20,000 pCi/L will produce a total body or organ dose of 4 millirem/yr 

(U.S. Environmental Protection Agency, 1997).

Uranium 20 μg/L

proposed

MCL

Uranium is a chemical and a radiological hazard and carcinogen. It omits alpha-particle 

radiation through natural decay. It is a hard, heavy, malleable metal that can be present in 

several oxidation states. Generally, the more oxidized states are more soluble. Uranium238 and uranium-235, which occur naturally, account for most of the radioactivity in 

water. Uranium concentrations range between 0.1 and 10 μg/L in most natural waters.

1

USEPA’s policy (U.S. Environmental Protection Agency, 1997, p. 360-361) is that a single positive sample is not an exceedance of the MCL but 

dictates further monitoring for conformation. Successive positive results may constitute an exceedance of the MCL. 2While the drinking water MCL currently remains at 50 μg/L, USEPA is reviewing the standard to have a new MCL set by January 2001; public 

water suppliers should be concerned about any source-water concentration exceeding 10 μg/L (U.S. Environmental Protection Agency, written commun., 

1998).

Table 8. Water-quality criteria, standards, or recommended limits for selected properties or constituents–Continued

[Modified from Howells, 1979. All concentrations are from U.S. Environmental Protection Agency (1996) unless noted. MCL, maximum contaminant 

level; SMCL, secondary maximum contaminant level; mL, milliliters; mg/L, milligrams per liter; μg/L, micrograms per liter; pCi/L, picocuries per liter;

--, no limit established]

Constituent

or property Limit Significance
28 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 9. Statistical summary of chemical analyses of spring-water samples collected September 1992 through

March 1997

[Site number refers to spring location in fig. 3. Data reported in micrograms per liter except where indicated. ft3/s, cubic feet per second; mg/L, milligrams 

per liter; μS/cm, microsiemens per centimeter at 25°Celsius; pCi/L, picocuries per liter; <, less than minimum reporting level]

Property or

dissolved constituent

Median values for selected springs sampled multiple times

Site numbers

S2 S4 S5 S6 S7 S8 S9 S12 S14

Discharge (ft3/s) 0.01 0.19 0.07 0.02 0.12 0.03 0.02 0.07 0.01

Specific conductance, field (μS/cm) 494 504 370 520 542 621 512 431 534

pH, field (standard units) 7.5 7.9 8.1 7.8 8.2 7.7 8.3 8.4 8.1

Oxygen, dissolved (mg/L) 5.7 7.8 8.1 8.3 7.6 8.4 9.2 7.5 9.9

Acid neutralizing capacity, field, as 

CaCO3 (mg/L)

 223 249 176 219 278 214 214 217 231

Hardness, total as CaCO3 (mg/L) 120 185 165 110 180 87 82 135 195

Solids, residue at 180°C 327 325 249 335 378 423 335 282 324

Solids, sum of constituents 325 330 252 347 390 419 364 300 321

Calcium (mg/L) 45 60 54 34 59 28 27 46 58

Magnesium (mg/L) 2.3 8.1 7.2 5.9 7.5 4.0 3.0 5.2 11

Sodium (mg/L) 61 36 9.5 64 48 96 73 34 37

Potassium (mg/L) 6.6 9.9 6.4 11 13 11 13 11 6.0

Bicarbonate, HCO3 (mg/L) 273 321 214 268 339 243 254 277 279

Sulfate (mg/L) 18 7.4 7.6 31 23 66 35 10 45

Chloride (mg/L) 1.7 3.5 0.9 9.7 14 24 11 2.0 5.4

Fluoride (mg/L) 0.2 0.3 0.3 0.3 0.3 0.2 0.3 0.3 0.4

Silica (mg/L) 41 47 49 51 54 59 57 46 18

Nitrite (mg/L as N) <0.01 <0.01 0.02 <0.01 0.02 <0.01 <0.01 <0.01 <0.01

Nitrogen, nitrite plus nitrate

(mg/L as N)

 5.0 0.09 2.4 2.4 2.8 4.0 4.0 1.2 <0.05

Phosphorus, orthophosphate (mg/L) 0.07 <0.01 0.02 0.04 0.04 0.01 <0.01 0.03 <0.01

Arsenic 4.0 8.0 8.5 16 14 17 9.0 6.0 <1.0

Barium 150 260 270 70 210 84 46 175 150

Beryllium <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

Boron 80 75 30 145 130 220 175 55 60

Cadmium <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0

Chromium <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0

Cobalt <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0

Copper <10 <10 <10 <10 <10 <10 <10 <10 <10
Water-Quality Data and Analysis for Selected Springs and Wells 29

Iron 13.2 104 60 <3.0 28 <3.0 <3.0 15 22

Lead <10 <10 <10 <10 <10 <10 <10 <10 <10

Lithium 27 22 14 25 27 48 36 26 28

Manganese 11.2 21 16 <1.0 59 <1.0 <1.0 5.0 3.0

Mercury <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Molybdenum <10 <10 <10 <10 <10 15 <10 <10 <10

Nickel <10 <10 <10 <10 <10 <10 <10 <10 <10

Selenium 2.0 <1.0 1.0 11 3.5 26 10 6.0 3.0

Silver <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0

Strontium 180 445 340 315 435 310 360 500 480

Thallium <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5

Vanadium <6.0 <6.0 7.5 11 8.0 7.0 9.0 6.0 <6.0

Zinc 14.0 <3.0 <3.0 13.2 <3.0 11.2 <3.0 <3.0 <3.0

Gross alpha as uranium natural 7.8 6.4 5.1 11.5 12 22 15.5 8.0 11.2

Gross alpha (pCi/L) as Th-230 5.7 4.4 3.8 8.1 8.5 17 10.1 5.9 8.1

Gross beta (pCi/L) as Cs-137 9.5 10.2 4.1 12 18 15.5 13.4 15.7 11

Radium-226 (pCi/L) 0.2 <0.1 <0.1 0.1 <0.1 0.1 <0.1 0.2 0.2

Uranium 7.1 3.3 2.1 11.0 10 13 9.6 7.2 7.0

Tritium (pCi/L) 100 32 110 9.3 28 2.9 18 25 40

1

The data set contained reported concentrations for some determinations that were less than the MRL. For these “censored” values, an estimated 

value of one-half the MRL was substituted to calculate the median.

Table 9. Statistical summary of chemical analyses of spring-water samples collected September 1992 through

March 1997–Continued

[Site number refers to spring location in fig. 3. Data reported in micrograms per liter except where indicated. ft3/s, cubic feet per second; mg/L, milligrams 

per liter; μS/cm, microsiemens per centimeter at 25°Celsius; pCi/L, picocuries per liter; <, less than minimum reporting level]

Property or

dissolved constituent

Median values for selected springs sampled multiple times

Site numbers

S2 S4 S5 S6 S7 S8 S9 S12 S14
30 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

0.001

1

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

Site S4

Site S5

Site S6

0.001

1

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

Site S7

Site S8

Site S9

1992 1993 1994 1995 1996 1997

0.001

1

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5 Site S2

Site S12

Site S14

DISCHARGE, IN CUBIC FEET PER SECOND

Figure 5. Hydrographs for selected springs (site number and spring location shown in fig. 3).
Water-Quality Data and Analysis for Selected Springs and Wells 31

Concentrations of most constituents for most of 

the nine springs with multiple samples have relatively 

small variability (table 13). Concentrations of some 

trace elements have somewhat larger variability than 

concentrations of common ions for some springs. Concentrations of many dissolved constituents frequently 

are inversely related to discharge in surface streams 

and rivers (Hem, 1985). Variability in discharge for the 

springs with multiple samples was shown to be relatively small (fig. 5), and no relations between discharge 

and constituent concentrations were apparent.

Ten of the springs sampled contact the White 

River Group and four contact the Pierre Shale (table 2). 

Major-ion data for all samples collected from all 14 

springs are presented graphically on trilinear diagrams 

(fig. 6) using a method developed by Piper (1944). 

Concentrations of the major dissolved ionic constituents are determined in milliquivalents per liter and 

expressed as percentages of the total anions and cations 

present in the water sample. This allows for further 

classification into different water types based on the 

relative proportion of anions and cations present. For 

example, the springs contacting the White River Group 

range from calcium bicarbonate to sodium bicarbonate 

water types. Two of the springs (S11 and S14) contacting the Pierre Shale have similar water types; however, 

sulfate is the dominant anion for springs S10 and S13. 

Once a water has been classified as a particular water 

type, it can be used to associate different water sources 

with a particular water type. Additional information on 

how trilinear diagrams can be used to classify water 

into different types can be found in Freeze and Cherry 

(1979, p. 245-247) and in Back (1966).

Water-quality criteria, standards, and recommended limits for community drinking water, promulgated by the USEPA, are presented in table 8. The 

analytical results for the spring water samples 

(table 13) were compared to the standards in table 8 to 

determine if concentrations of any constituents were 

present at levels that could be harmful to humans. 

Water-quality constituents that equalled or exceeded 

the USEPA drinking-water standards in at least one 

sample from the springs are summarized in table 10.

Two springs contacting the White River Group 

and one spring contacting the Pierre Shale exceeded the 

upper recommended level of pH 8.5 established by the 

USEPA (table 10). Recommended levels, or SMCL’s, 

are nonenforceable guidelines that typically are related 

to aesthetic qualities such as taste, odor, or color.

Five springs (sites S1, S3, S10, S11, and S13) 

were not sampled for indicator bacteria; however, 

water from the remaining nine springs produced positive results for presumptive tests for the presence of 

E. coli, total coliform, fecal coliform, and fecal streptococci bacteria one or more times (tables 10 and 13). 

Whereas these fecal-indicator bacteria typically are not 

disease causing, they indicate the possible presence of 

pathogenic organisms. Furthermore, the presence of 

E. coli in water is direct evidence of fecal contamination from warm-blooded animals (Dufour, 1977).

A likely source of bacteria is livestock and other 

animals that may water at the springs. Although the 

USEPA standards apply only to public suppliers, local 

residents should be aware of the potential health risks 

of bacterial contamination associated with the consumption of water from springs and other untreated 

sources.

No springs contacting the White River Group 

equalled or exceeded the SMCL of 250 mg/L established for sulfate (table 10); however, two springs contacting the Pierre Shale had dissolved sulfate values 

that exceeded the SMCL. No springs contacting the 

White River Group equalled or exceeded the MCL of 

4.0 mg/L established for fluoride; however, one spring 

contacting the Pierre Shale exceeded the MCL. One 

spring contacting the White River Group exceeded the 

SMCL of 500 mg/L for dissolved solids; however, two 

springs contacting the Pierre Shale had values that 

exceeded the SMCL. No springs exceeded the MCL of 

50 μg/L for arsenic; however, dissolved arsenic 

exceeded 10 μg/L for seven of the springs contacting 

the White River Group. The MCL for arsenic may be 

changed to 10 μg/L (table 8), following a review by 

USEPA (U.S. Environmental Protection Agency, 

written commun., 1998). No springs contacting the 

White River Group equalled or exceeded the SMCL of 

300 μg/L for iron; however, two springs contacting the 

Pierre Shale exceeded the SMCL for iron.

Three springs contacting the White River Group 

and one spring contacting the Pierre Shale exceeded the 

action level of 15 μg/L for lead. Two springs 

contacting the Pierre Shale had censored values of less 

than 30 μg/L for lead (S10 and S13). Both samples 

contacting the Pierre Shale had high values for specific 

conductance that required a three-fold dilution of the 

sample prior to analysis. This caused the reporting 

level for lead to be changed from 10 to 30 μg/L (the 

reporting level multiplied times the dilution factor). It 

is therefore not possible to ascertain if these samples 

exceeded the 15 μg/L action level established for lead. 

Although the precision data for lead showed no 

problems for field duplicate samples, the analysis of 

the SRS’s submitted to the NWQL did indicate 

unacceptable analytical variability. Lead concentrations reported for all environmental samples should 

therefore be interpreted cautiously.
32 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Figure 6. Trilinear diagrams showing proportional concentrations of major ions in ground-water samples from

selected springs and wells.

Calcium + Magnesium

Sulfate

Sodium + Potassium

Chloride + Fluoride + Nitrate + Sulfate

Bicarbonate + Carbonate

Magnesium

Calcium Chloride + Fluoride + Nitrate

80

60

40

20

80

80

60

40

20

20

20

406080

40

60

80

60

40

20

20

80

6040

20

40

60

80

80

60

40

20

SPRINGS CONTACTING WHITE RIVER GROUP

Calcium + Magnesium

Sulfate

Sodium + Potassium

Chloride + Fluoride + Nitrate + Sulfate

Bicarbonate + Carbonate

Magnesium

Calcium Chloride + Fluoride + Nitrate

80

60

40

20

80

80

60

40

20

20

20

40

60

80

40

60

80

60

40

20

20

80

6040

20

40

60

80

80

60

40

20

SPRINGS CONTACTING PIERRE SHALE

Calcium + Magnesium

Sulfate

Sodium + Potassium

Chloride + Fluoride + Nitrate + Sulfate

Bicarbonate + Carbonate

Magnesium

Calcium Chloride + Fluoride + Nitrate

80

60

40

20

80

80

60

40

20

20

20

40

60

80

40

60

80

60

40

20

20

80

60

40

20

40

60

80

80

60

40

20

ALLUVIAL WELL

Calcium + Magnesium

Sulfate

Sodium + Potassium

Chloride + Fluoride + Nitrate + Sulfate

Bicarbonate + Carbonate

Magnesium

Calcium Chloride + Fluoride + Nitrate

80

60

40

20

80

80

60

40

20

20

20

40

60

80

40

60

80

60

40

20

20

80

60

4020

40

60

80

80

60

40

20

INYAN KARA WELL

Calcium + Magnesium

Sulfate

Sodium + Potassium

Chloride + Fluoride + Nitrate + Sulfate

Bicarbonate + Carbonate

Magnesium

Calcium Chloride + Fluoride + Nitrate

80

60

40

20

80

80

60

40

20

20

20

40

60

80

40

60

80

60

40

20

20

80

60

40

20

40

60

80

80

60

40

20

ARIKAREE WELLS

NOTE: Concentrations expressed as percentages of total

anions and cations present in the water sample.
Water-Quality Data and Analysis for Selected Springs and Wells 33

Table 10. Comparison of water-quality data for selected springs to U.S. Environmental Protection Agency drinking-water 

standards

[Site number refers to spring location in fig. 3; SMCL, secondary maximum contaminant level; MCL, maximum contaminant level]

Site

number

Spring

name

Confining

unit

Constituents of

concern1

Type of standard

equalled or

exceeded1

S1 South Hubner White River Group Solids

Arsenic

SMCL

(

2)

S2 Old Road White River Group Bacteria Presence3

S3 Red Shirt Table White River Group Arsenic (

2

)

S4 Cuny Cafe White River Group pH

Bacteria

Arsenic

Lead

SMCL

Presence3

(

2

)

Action level

S5 South Corral White River Group Bacteria

Lead

Presence3

Action level

S6 Davey Cuny White River Group Arsenic

Bacteria

(

2)

Presence3

S7 Blackfeather White River Group Arsenic

Bacteria

(

2

)

Presence3

S8 Duhamill White River Group Arsenic

Bacteria

(

2)

Presence3

S9 Mill’s East White River Group Arsenic

Bacteria

Lead

(

2)

Presence3

Action level

S10 Rapp North Pierre Shale Sulfate

Fluoride

Solids

Iron

SMCL

MCL

SMCL

SMCL

S11 Slide Pierre Shale Iron SMCL

S12 Heathershaw White River Group pH

Bacteria

SMCL

Presence3

S13 Red Shirt Table N/E Pierre Shale Sulfate

Solids

SMCL

SMCL

S14 Knupe North Pierre Shale pH

Bacteria

Lead

SMCL

Presence3

Action level

1

USEPA standards apply to total constituents; however, analyses performed were for dissolved constituents. 2

Current MCL of 50 μg/L not exceeded; however, USEPA is reviewing the standard to have a new MCL set by January 2001; public water suppliers 

should be concerned about any source-water concentrations exceeding 10 μg/L (U.S. Environmental Protection Agency, written commun., 1998). 3

USEPA’s policy (U.S. Environmental Protection Agency, 1997, p. 360-361) is that a single positive sample is not an exceedance of the MCL but 

dictates further monitoring for conformation. Successive positive results may constitute an exceedance of the MCL.
34 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

One spring contacting the White River Group 

and two springs contacting the Pierre Shale exceeded 

15 pCi/L for gross alpha. Because the USEPA standard 

for gross alpha includes radium-226 but excludes any 

uranium or radon present in a sample, it is not possible 

to conclusively determine if any of these samples 

exceed the MCL. This is because the units used to 

present results for gross alpha and uranium were 

different. Therefore, additional samples could be collected at sites where gross alpha equalled or exceeded 

15 pCi/L. The new samples could be analyzed for 

gross alpha, 234U, 235U, 238U, and radon in picocuries 

per liter so that the radioactivity contributed by 

uranium and radon can be subtracted. The resulting 

“adjusted” gross alpha values could then be appropriately compared to the MCL.

Nine springs were analyzed for tritium to 

generally assess the age of the water and to determine 

if concentrations exceeded the MCL established for 

gross beta-particle activity. Results of tritium analyses 

are presented in table 11. Although tritium occurs 

naturally, large amounts of manmade tritium were 

introduced into the atmosphere during the era of largescale testing of thermonuclear bombs between 1952 

and 1969 (Freeze and Cherry, 1979). Payne (1972) 

estimated that prior to atmospheric testing in 1952, the 

natural content of precipitation was in the range of 5 to 

20 TU [one TU (tritium unit) = one tritium atom per 

1,018 hydrogen atoms]. Between 1953 and 1962, 

monthly tritium values in precipitation at Ottawa, 

Canada, generally increased. During 1963, monthly 

tritium values in precipitation peaked at about 

1,400 TU. Since 1963, monthly tritium values in 

precipitation generally have decreased (Freeze and 

Cherry, 1979). Because the half-life of tritium is 

12.3 years, ground water that was recharged prior to 

1953 would have tritium concentrations about 2 to 

4 TU, or less. Ground water that contains tritium at 

concentrations greater than about 30 TU probably has 

a relatively large percentage of water that was 

recharged during the bomb-testing era. Ground water 

that contains intermediate concentrations of tritium 

probably result from bomb-testing era water mixed 

with pre- or post-bomb water.

The USGS reports tritium values in picocuries 

per liter, which can be converted to tritium units by 

dividing picocuries per liter by 3.24. Tritium values for 

the nine springs ranged from 0.9 to 33.9 TU. Two 

springs (S6 and S8) had values less than 4 TU and 

probably are composed primarily of pre-bomb water 

indicating a relatively long travel time from areas of 

recharge to areas of discharge. Two springs (S2 

and S5) had values greater than 30 TU and probably 

consist of a relatively large percentage of test-era water. 

The remaining five springs (S4, S7, S9, S12, and S14) 

had values that ranged from 5.5 to 12 TU and probably 

have some test-era water. Additional study would be 

required to determine if the tritium values for these five 

springs fall on the increasing or decreasing side of the 

1963 tritium peak.

Table 11. Tritium and pesticide analyses for selected springs

[Site number refers to spring location in fig. 3. Data reported in micrograms per liter except as indicated; pCi/L, picocuries per liter; <, less than]

Site

number

Date

sampled

Tritium

total

(pCi/L)

(07000)

Tritium

2 sigma

water, whole,

total

(pCi/L)

(75985)

Tritium

total

(tritium units1)

Atrazine Carbaryl 2,4-D

S2 3-26-97 100 5.8 30.9 <0.1 <0.4 <1.0

S4 3-24-97 32 3.2 9.9 <0.1 <0.4 <1.0

S5 3-24-97 110 9.6 33.9 <0.1 <0.4 <1.0

S6 3-25-97 9.3 1.0 2.9 <0.1 <0.4 <1.0

S7 3-26-97 28 1.9 8.6 <0.1 <0.4 <1.0

S8 3-25-97 2.9 1.0 .9 <0.1 <0.4 <1.0

S9 3-25-97 18 1.3 5.5 <0.1 <0.4 <1.0

S12 3-27-97 25 2.6 8.6 <0.1 <0.4 <1.0

S14 3-26-97 40 2.6 12.3 <0.1 <0.4 <1.0

1pCi/L divided by 3.24 equals tritium units.
Water-Quality Data and Analysis for Selected Springs and Wells 35

Pesticide samples were collected from nine 

springs and analyzed at the local USGS office laboratory by the enzyme-linked immunoassay method 

(table 11). Analysis of atrazine, carbaryl, and 2,4-D 

(the most commonly used pesticides in the area) were 

all below minimum reporting levels of 0.1, 0.4, and 

1.0 μg/L, respectively.

In general, springs contacting the White River 

Group are shown to have better potential as alternative 

sources of water supply for the village of Red Shirt than 

springs contacting the Pierre Shale. All of the springs 

sampled that contact the Pierre Shale exceeded 

SMCL’s for one or more constituents. In addition, 

discharge from most of the springs contacting the 

Pierre Shale, considered individually, probably would 

not provide an adequate supply of water.

Nine of the springs with better water quality 

were sampled repeatedly, of which six (sites S4-S9) 

were subsequently selected for additional discharge 

measurements. These six springs, of which five contact the White River Group, probably have the best 

potential for use as water supplies. Discharge from any 

of these six springs probably would supply adequate 

yield for Red Shirt during most periods, based on the 

limited number of discharge measurements. Concentrations of lead exceeded the USEPA action level of 

15 μg/L for three of these six springs; however, results 

may be unreliable because of analytical uncertainty. 

Additional sampling using low-level analysis could 

accurately quantify lead concentrations in these 

springs. Five of these six springs also had arsenic 

concentrations that exceeded 10 μg/L, which could be 

problematic if the current MCL is lowered (U.S. 

Environmental Protection Agency, written commun., 

1998).

Blending of water from one or more springs with 

water from the existing well completed in the Inyan 

Kara aquifer may be an option for providing additional 

water supply for Red Shirt. Blending could be used to 

address concerns regarding both quantity and quality of 

existing and potential sources.

Public-Supply Wells

Forty-four public-supply wells were sampled 

during 1995-97. Water-quality data are presented in 

table 14 in the Supplemental Data section. Forty-two 

of the wells sampled were completed in the Arikaree 

aquifer, one was completed in an alluvial aquifer, and 

one was completed in the Inyan Kara aquifer (table 3). 

Water from the alluvial well is a sodium bicarbonate 

water type, and water from the Inyan Kara well is a 

calcium sulfate bicarbonate water type (fig. 6). Water 

from the Arikaree aquifer ranges from calcium bicarbonate to sodium bicarbonate water types. Waterquality constituents that equalled or exceeded USEPA 

drinking-water standards for selected public-supply 

wells are summarized in table 12.

Positive detections for indicator bacteria were 

common, with samples from the alluvial well, Inyan 

Kara well, and 26 of the Arikaree wells testing positive. 

In all, 28 of 44 (64 percent) of the wells sampled tested 

positive for the presence of bacteria. Of the 44 wells 

sampled, 13 (29 percent) tested positive for E. coli

bacteria, 27 (61 percent) tested positive for total 

coliform bacteria, 9 (20 percent) tested positive for 

fecal coliform bacteria, and 12 (27 percent) tested 

positive for fecal streptococci bacteria.

Most of the bacteria samples, with the exception 

of sites 6, 11, and 12, were collected from sampling 

ports located upstream of chemical treatment feeders, 

as described in the section titled "Sampling Methods." 

Thus, bacterial detections do not necessarily constitute 

exceedances of drinking-water standards, which apply 

to successive positive detections using colony confirmation methods for treated water (table 8). However, 

16 percent of the wells sampled (sites 1, 13, 14, 15, 17, 

39, and 42) simultaneously tested positive for total 

coliform, fecal coliform, and fecal streptococci 

bacteria. Even though this study used only presumptive tests to determine bacterial concentration, the fact 

that some wells tested positive for several different 

types of indicator bacteria may be viewed as strong 

evidence of fecal contamination in water samples 

collected from those wells. Occurrences of bacteria in 

well water can be transient, with bacterial detections 

occurring sporadically. Additional information 

regarding results of samples of treated water from 

selected public-supply wells that have been collected 

and analyzed for bacteria and other constituents are 

available from the U.S. Public Health Service (1996).

It is not possible to determine the sources of the 

indicator bacteria from the reconnaissance-level sampling that was performed. Many possible bacterial 

sources exist, including introduction of bacteria into 

well casings by insects or rodents; water moving downward along the borehole annulus outside the casing; 

and water moving through the aquifer media to the 

well. Widespread bacterial contamination could occur 

from leaking sewage lagoons or surface streams that 

have numerous potential bacterial sources. Additional 

studies would be necessary to evaluate potential 

sources of bacteria to individual wells.
36 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 12. Comparison of water-quality data for selected public-supply wells to U.S. Environmental Protection Agency 

drinking-water standards

[Site number refers to well location in fig. 3; SMCL, secondary maximum contaminant level; MCL, maximum contaminant level; --, none of the

constituents analyzed equalled or exceeded standards]

Site

number

Community or facility

served/well identifier Aquifer Constituentsof concern1

Type of

standard

equalled or

exceeded1

1 Wakpamni Arikaree Bacteria

Arsenic

Presence2

(

3)

2 Pine Ridge/Pine Ridge Water and Sewer Arikaree -- --

3 Pine Ridge/New Hospital No.1 Arikaree Nitrite plus nitrate

Bacteria

MCL

Presence2

4 Pine Ridge/New Hospital No.2 Arikaree -- --

5 Wolf Creek Arikaree Bacteria Presence2

6 Pine Ridge/Old Hospital No.6 Arikaree -- --

7 Pine Ridge/ No.12 Arikaree Solids SMCL

8 Pine Ridge/Baker’s Hill Arikaree Bacteria Presence2

9 Pine Ridge/ PWS-7 Arikaree pH SMCL

10 Pine Ridge/OCS Campus Arikaree Sulfate

Bacteria

Uranium

Solids

SMCL

Presence2

Proposed MCL

SMCL

11 Batesland Arikaree Bacteria Presence2

12 Wolf Creek School Arikaree Bacteria Presence2

13 Oglala/PWS-2C Arikaree Bacteria Presence2

14 Oglala/PWS-2D Arikaree Bacteria

Arsenic

Presence2

(

3)

15 Oglala/PWS-5 Arikaree Bacteria

Arsenic

Presence2

(

3)

16 Oglala/PWS-4 Arikaree Bacteria Presence2

17 Oglala/PWS-7C Arikaree Bacteria Presence2

18 Calico Arikaree Bacteria Presence2

19 Red Cloud School/ Main Arikaree Arsenic (

3)

20 Red Cloud School/ North East Arikaree -- --

21 Wounded Knee Housing Authority/No.2 Arikaree -- --

22 Wounded Knee Housing Authority/No.1 Arikaree Bacteria Presence2

23 American Horse School Arikaree -- --

24 Allen Housing Authority Arikaree -- --

25 Porcupine School Arikaree Bacteria (

4

)

26 Our Lady of Lourdes School Arikaree Bacteria

Uranium

Presence2

Proposed MCL

27 Porcupine Arikaree Fluoride

Uranium

MCL

Proposed MCL

28 Manderson Housing Authority Arikaree Bacteria

Uranium

Presence2

Proposed MCL

29 Wounded Knee School Arikaree -- --
Water-Quality Data and Analysis for Selected Springs and Wells 37

30 Sharp’s Housing Authority Arikaree Arsenic

Solids

Uranium

(

3)

SMCL

Proposed MCL

31 Evergreen Housing Authority Arikaree Bacteria

Uranium

Presence2

Proposed MCL

32 Kyle/No.5 Arikaree Bacteria Presence2

33 Kyle/No.2 Arikaree Bacteria Presence2

34 Kyle/BIA No. 1 Arikaree -- --

35 Kyle/No.1 Arikaree Bacteria Presence2

36 Kyle/No.3 Arikaree Bacteria Presence2

37 Rockyford School/Jim Hart Arikaree Bacteria

Solids

Arsenic

Uranium

Presence2

SMCL

MCL

Proposed MCL

38 Potato Creek Housing Authority Alluvium Bacteria

Solids

Arsenic

Lead

Presence2

SMCL

(

3)

Action level

39 Wanblee East Housing Authority Arikaree Bacteria

Arsenic

Presence2

(

3)

40 Wanblee Housing Authority Arikaree Uranium Proposed MCL

41 Wanblee North Housing Authority Arikaree Bacteria Presence2

42 Wanblee West Housing Authority Arikaree Bacteria Presence2

43 Crazy Horse School Arikaree -- --

44 Red Shirt Inyan Kara Bacteria

Arsenic

Iron

Manganese

Ra-226

Presence2

(

3)

SMCL

SMCL

MCL

1

USEPA standards apply to total constituents; however, analyses performed were for dissolved constituents. 2

USEPA’s policy (U.S. Environmental Protection Agency, 1997, p. 360-361) is that a single positive sample is not an exceedance of the MCL but 

dictates further monitoring for conformation. Successive positive results may constitute an exceedance of the MCL. 3

Current MCL of 50 μg/L not exceeded; however, USEPA is reviewing the standard to have a new MCL set by January 2001; public water suppliers 

should be concerned about any source-water concentrations exceeding 10 μg/L (U.S. Environmental Protection Agency, written commun., 1998). 4Only fecal streptococcus bacteria were detected, and they are not regulated under USEPA’s total coliform rule.

Table 12. Comparison of water-quality data for selected public-supply wells to U.S. Environmental Protection Agency 

drinking-water standards–Continued

[Site number refers to well location in fig. 3; SMCL, secondary maximum contaminant level; MCL, maximum contaminant level; --, none of the

constituents analyzed equalled or exceeded standards]

Site

number

Community or facility

served/well identifier Aquifer Constituents

of concern1

Type of

standard

equalled or

exceeded1
38 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Other investigators have reported similar problems with respect to bacterial contamination. Heintzman (1988) sampled 39 wells in the Arikaree aquifer 

on the western part of the Reservation, with 51 percent 

of the wells sampled testing positive for either fecal 

coliform or fecal streptococcus bacteria. Whereas 

Heintzman’s (1988) results showed higher percentages 

of detections for fecal coliform and fecal streptococcus 

bacteria than this study, he sampled only private wells 

that typically were shallow. Heintzman (1988) 

suggested on-site wastewater disposal systems such as 

septic tanks or pit privies as likely sources of bacteria 

for the shallow wells considered.

Only one well exceeded the MCL for arsenic of 

50 μg/L. This was site number 37, which is completed 

in the Arikaree aquifer. Six additional wells in the 

Arikaree aquifer, as well as the alluvial well (site 

number 38) and the Inyan Kara well (site number 44), 

had dissolved arsenic concentrations that equalled or 

exceeded 10 μg/L. The MCL for arsenic may be 

changed to 10 μg/L, following a review by USEPA 

(U.S. Environmental Protection Agency, written 

commun., 1998).

The sample collected from the alluvial well also 

exceeded the SMCL of 500 mg/L for dissolved solids 

and the action level of 15 μg/L for lead. Although 

concentrations of lead in blanks and duplicate samples 

showed no contamination, SRS’s submitted to the 

NWQL indicated unacceptable levels of analytical 

variability for lead. Therefore, lead values presented in 

this report for all environmental samples should be 

interpreted cautiously.

The sample collected from the Inyan Kara well 

exceeded the SMCL of 300 μg/L for iron and the 

SMCL of 50 μg/L for manganese. Although all 44 

wells were analyzed for radium-226, only water from 

the Inyan Kara aquifer exceeded the MCL of 5 pCi/L 

for radium-226 and 228 combined.

One sample collected from an Arikaree well 

exceeded the SMCL for pH of 8.5. One sample 

exceeded the SMCL of 250 mg/L for sulfate, four 

samples exceeded the SMCL of 500 mg/L for dissolved solids, one sample exceeded the MCL of 

4.0 mg/L for fluoride, and one sample exceeded the 

action level of 15 μg/L for lead.

One sample collected from an Arikaree well 

equalled the MCL of 10 mg/L for dissolved NO2

(nitrite) plus NO3 (nitrate). Nitrate values for all 

samples from the Arikaree aquifer ranged from 0.3 to 

10.0 mg/L and had a median value of 1.3 mg/L. 

Mueller and Helsel (1996) compiled nitrate values 

from 1,100 public-supply wells located throughout the 

country and determined the median value was less than 

0.2 mg/L (42 of the 44 public-supply wells sampled for 

this study exceeded this value). They also determined 

that natural concentrations of nitrate in ground water 

generally are less than 2 mg/L (7 of the 44 publicsupply wells sampled exceeded this value). Concentrations of dissolved NO2 plus NO3 above 2 mg/L may 

indicate that the ground water has been affected by 

sources of contamination such as feedlot runoff, 

sewage, or fertilizers. More information would be 

needed to determine if nitrate concentrations above 

2 mg/L found in some of the public-supply wells on the 

Reservation are natural or result from anthropogenic 

sources.

Carter (1997) reported similar nitrate concentrations in 14 domestic and 18 observation wells completed in the Arikaree aquifer located on the Rosebud 

Indian Reservation, which is east of the study area. 

Concentrations of dissolved NO2 plus NO3 ranged 

from <0.005 to 4.0 mg/L with a median value of 

1.1 mg/L.

Ten of the 44 (23 percent) samples equalled or 

exceeded 15 pCi/L for gross-alpha radioactivity. Sites 

exceeding 15 pCi/L could be resampled and analyzed 

for gross alpha, 234U, 235U, 238U, and radon in picocuries per liter, so that the radioactivity contributed by 

uranium and radon can be subtracted. The “adjusted” 

gross alpha values could then be compared to the MCL. 

Of the 44 wells sampled, 8 (18 percent) equalled or 

exceeded the proposed MCL of 20 μg/L for uranium, 

and 33 (75 percent) equalled or exceeded one-half of 

the proposed MCL. 

Reasons for the elevated concentrations of dissolved uranium in the Arikaree aquifer are not completely understood. Dunham (1961) investigated the 

occurrence of uranium contained in Cretaceous shales 

in an area extending from northern Nebraska into 

southern Shannon County in South Dakota. Dunham 

(1961) hypothesized that downward-moving water 

may have leached uranium from volcanic ash deposited 

during Miocene and Oligocene time. Additional 

studies would be needed to better understand the 

geochemical processes responsible for elevated 

uranium concentrations.

Five samples collected for dissolved uranium 

also were analyzed for the isotopes of uranium (234U, 

235U, and 238U). The uranium isotope data for sites 27, 

28, 30, 31, and 37 are presented in table 14 in the 

Supplemental Data section. The composition of 
Summary and Conclusions 39

natural uranium is about 99.3 percent 238U and 

0.7 percent 235U (Magill and others, 1995). Weapons 

grade uranium is enriched with 235U until its composition is about 93.5 percent 235U and 6.5 percent 238U. If 

the uranium present in water samples collected from 

the five wells was from a nuclear weapon, elevated 

235U values would have been detected, considering that 

the half-life of 235U is 7.04 x 108 years. However, 

analyses of uranium isotopes indicate a natural distribution of 234U, 235U, and 238U, with 235U present only 

at background levels, suggesting that the uranium 

source is natural.

A method that compares the activity ratio 

between 235U and 238U also was used to determine the 

source of uranium detected in water samples collected 

from the five wells. The activity ratio between 

235U/238U has been determined to be about 0.046 in 

naturally occurring uranium (Tom Kraemer, U.S. 

Geological Survey, written commun., 1998). Dividing 

the 235U concentrations obtained for the five water 

samples by their corresponding 238U concentrations 

should result in a value less than about 0.046 if the 

uranium detected is naturally occurring. The 

235U/238U ratios were less than 0.046 for sites 27, 28, 

30, and 31; however, the ratio is slightly larger than 

0.046 for site 37. Considering the variability (2 sigma 

values) associated with the 235U and 238U values 

(table 14), the ratio for site 37 might also be less than 

0.046. Thus, it is concluded that the uranium source is 

naturally occurring for all of the samples.

SUMMARY AND CONCLUSIONS

Discharge and water-quality data were collected 

during 1992-97 for 14 contact springs located in the 

northwestern part of the Reservation. Data were collected to evaluate potential alternative sources of water 

supply for the village of Red Shirt, which currently 

obtains water of marginal quality from a well completed in the Inyan Kara aquifer. During 1995-97, 

water-quality data also were collected for 44 publicsupply wells that currently serve as the primary source 

of water for about one-half of the Reservation’s 

population. Quality-assurance sampling was used to 

evaluate the precision and accuracy of environmental 

samples.

Ten of the springs sampled contact the White 

River Group, and four contact the Pierre Shale. Springs 

contacting the White River Group range from calcium 

bicarbonate to sodium bicarbonate water types. Two 

springs contacting the Pierre Shale have water types 

similar to this; however, sulfate is the dominant anion 

for the other two springs.

In general, springs contacting the White River 

Group are shown to have better potential as alternative 

sources of water supply for the village of Red Shirt than 

springs contacting the Pierre Shale. All of the springs 

sampled that contact the Pierre Shale exceeded 

SMCL’s for one or more constituents. In addition, 

discharge from most of these springs probably would 

not provide an adequate supply of water.

Nine of the springs with better water quality 

were sampled repeatedly; however, only minor variability in water quality was identified. Six of these nine 

springs were subsequently selected for additional discharge measurements. These six springs, of which five 

contact the White River Group, probably have the best 

potential for use as water supplies. Discharge from any 

of these six springs probably would supply adequate 

discharge for Red Shirt during most periods, based on 

the limited number of discharge measurements. Concentrations of lead exceeded the USEPA action level of 

15 μg/L for three of these six springs; however, results 

may be unreliable because of analytical uncertainty. 

Additional sampling using low-level analysis would be 

required to accurately quantify lead concentrations in 

these springs. Five of these six springs also had arsenic 

concentrations that exceeded 10 μg/L, which could be 

problematic if the current MCL is lowered. Blending 

of water from one or more springs with water from the 

existing Inyan Kara well may be an option for 

providing additional water supply for Red Shirt. 

Blending could be used to address concerns regarding 

both quantity and quality of existing and potential 

sources.

The nine springs with multiple samples included 

analyses for various indicator bacteria; the other five 

springs were not sampled for the presence of bacteria. 

All nine springs that were sampled for bacteria had 

positive detections for presumptive tests on one or 

more occasions. Although USEPA standards for 

bacteria apply only to public-water supplies, local residents using spring water for domestic purposes should 

be aware of the potential health risks associated with 

consuming untreated water.

One spring contacting the White River Group 

and two springs contacting the Pierre Shale exceeded 

15 pCi/L for gross alpha. Because the USEPA standard 

for gross alpha includes radium-226 but excludes any 

uranium or radon present in a sample, it is not possible 

to conclusively determine if any of these samples 
40 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

exceed the MCL. This is because different units are 

used to present results for gross alpha and uranium in 

this report. Thus, for samples where gross alpha 

exceeds 15 pCi/L, accurate comparison to the MCL 

would require additional sampling with analyses for 

234U, 235U, 238U, and radon in picocuries per liter. 

Then, radioactivity contributed by uranium and radon 

could be subtracted.

Nine springs were sampled for selected pesticides and tritium. The pesticides atrazine, carbaryl, 

and 2,4-D were not detected in any of the samples. 

Tritium results for two springs showed that they were 

probably composed primarily of water recharged prior 

to atmospheric testing of nuclear bombs. Results for 

two other springs indicated a relatively large percentage of test-era water. The remaining five springs had 

tritium values that indicated some percentage of testera water; however, additional sampling would be 

needed to determine whether water is predominantly 

pre- or post-bomb age.

During 1995-97, water-quality data were 

collected for 44 public-supply wells in the study area. 

Forty-two of these wells were completed in the 

Arikaree aquifer, one was completed in an alluvial 

aquifer, and one was completed in the Inyan Kara 

aquifer. Water from the alluvial aquifer is a sodium 

bicarbonate water type, water from Arikaree aquifer 

ranges from calcium bicarbonate to sodium bicarbonate types, and water from the Inyan Kara aquifer is a 

calcium sulfate bicarbonate type.

Of the 44 wells sampled, 28 (64 percent) tested 

positive for indicator bacteria during presumptive tests. 

Because these were single samples that generally were 

collected upstream from chemical treatment feeders, 

positive detections do not necessarily constitute 

exceedances of drinking-water standards. However, 

16 percent of the wells sampled (sites 1, 13, 14, 15, 17, 

39, and 42) simultaneously tested positive for total 

coliform, fecal coliform, and fecal streptococci bacteria, which provides strong evidence of fecal contamination at these sites even though only presumptive tests 

were used for this study.

A single sample from an Arikaree well exceeded 

the MCL for arsenic of 50 μg/L. Arsenic exceeded 

10 μg/L for six additional Arikaree wells and for the 

alluvial well and the Inyan Kara well, which could be 

problematic if the current MCL is lowered. The alluvial well also exceeded the SMCL for dissolved solids 

and the action level for lead. The Inyan Kara well 

exceeded the SMCL’s for iron and for manganese and 

the MCL of 5 pCi/L for radium-226 and 228 combined. 

Several Arikaree wells exceeded SMCL’s for either 

pH, sulfate, dissolved solids, iron, or manganese.

One Arikaree well exceeded the MCL of 

4.0 mg/L for fluoride and another exceeded the MCL 

of 10 mg/L for nitrite plus nitrate. Seven of the wells 

sampled exceeded natural concentrations for nitrate 

(generally less than 2 mg/L) for ground water, which 

sometimes is used as an indicator of possible contamination from various sources. More information would 

be needed to determine sources of nitrate in the 

Arikaree aquifer.

Ten Arikaree wells equalled or exceeded 

15 pCi/L for gross alpha; however, these values do not 

necessarily constitute exceedances of the MCL, which 

excludes radioactivity contributed by uranium and 

radon, as discussed above. Additional sampling would 

be needed to conclusively determine if samples 

exceeded the MCL.

Eight of the wells (18 percent), all from the 

Arikaree aquifer, equalled or exceeded the proposed 

MCL of 20 μg/L for uranium. In all, 33 wells 

(75 percent) equalled or exceeded one-half of the 

proposed MCL. Although the standard for uranium has 

only been proposed, additional information regarding 

the extent of elevated uranium concentrations in the 

Arikaree aquifer, and the geochemical processes 

involved, may be beneficial. It was determined from 

analyses of uranium isotope data for five wells that the 

source of elevated uranium concentrations is naturally 

occurring, rather than anthropogenic.

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Kolm, K.E., and Case, H.L., 1983, A two-dimensional, 

finite-difference model of the High Plains aquifer in 

South Dakota: U.S. Geological Survey WaterResources Investigations Report 83-4175, 34 p.

Magill, J., Matzke, Hj, Nicolaou, G., Peerani, P., van Geel, J., 

1995, A once through scheme for weapons grade Pu 

disposition in LWR’s—Proliferation and criticality 

aspects: Technical Committee Meeting on the 

Recycling of Plutonium and Uranium in Water Reactor 

Fuel, Newby Birdge, Windemere, U.K., p. 3-7.

Meyer, M.J., 1984, Evaluation of the ground water resources 

of western South Dakota, Task 5; Water quality suitability by aquifer for drinking, irrigation, livestock 

watering, and industrial use: U.S. Army Corps of 

Engineers, Contract No. DACW45-80-0-0185, v. 2, 

append. 1-5.

Mueller, D.K., and Helsel, D.R., 1996, Nutrients in the 

Nation’s waters: Too much of a good thing?: U.S. 

Geological Survey Circular 1136, 24 p.

Myers, D.N., and Sylvester, M.A., 1997, Fecal indicator 

bacteria, in Myers, D.N., and Wilde, F.D., eds., 

National field manual for the collection of water-quality 

data: U.S. Geological Survey Techniques of WaterResources Investigations, book 9, chap. A7, p. 3-38.
42 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Payne, B.R., 1972, Isotope hydrology: Advances in Hydroscience, v. 8, p. 95-138.

Piper, A.M., 1944, A graphic procedure in the geochemical 

interpretation of water analyses: American 

Geophysical Union Transactions, v. 25, p. 914-923.

Sipe, Darrel D., 1989, Hydrogeology of part of the Arikaree 

aquifer near Pine Ridge, South Dakota: Rapid City, 

South Dakota School of Mines and Technology, 

unpublished M.S. thesis, 103 p.

South Dakota Crop and Livestock Reporting Service, 

1924-65, South Dakota agriculture statistics (published 

annually).

Taylor, J.K., 1987, Quality assurance of chemical measurements: Chelsea, Mich., Lewis Publishers, 328 p.

U.S. Department of Commerce, 1995, Climatological data 

annual summary for South Dakota: v. 100, no. 13.

U.S. Environmental Protection Agency, 1986, Quality 

criteria for water (updated May 1986), Update No. 2: 

Washington, D.C., Office of Water Regulations and 

Standards, EPA 440/5-86-001, 398 p.

———1991, Lead and copper rule fact sheet: U.S. 

Environmental Protection Agency, Office of Water, 

EPA 570/9-91-400, 2 p.

———1994, National primary drinking water standards: 

U.S. Environmental Protection Agency, Office of 

Water, EPA 810-F-94-001A, 4 p.

———1996, Drinking water regulations and health 

advisories: Washington, D.C., Office of Water, 

February 1996, EPA 822-R-96-001.

———1997, National primary drinking water regulations, 

Code of Federal regulations 40, parts 141 and 143, 

revised July 1, 1997, p. 288-476.

U.S. Public Health Service, 1996, Comprehensive survey of 

community sanitation facilities, Pine Ridge Indian 

Reservation, July 1996: Department of Health and 

Human Services, [195] p.

Wood, W.W., 1976, Guidelines for collection and field 

analysis of ground-water samples for selected unstable 

constituents: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 1, chap. D2, 

24 p.
SUPPLEMENTAL DATA

Supplemental Data - Table 13 45

Table 13. Spring water-quality data 

[US/CM, microsiemens per centimeter at 25°Celsius; DEG C, degrees Celsius; mm, millimeters; mg/L, milligrams per liter; UG/L, 

micrograms per liter; COL/100 ML, colonies per 100 milliliters; AC-FT, acre-feet; PCI/L, picocuries per liter; K, non-ideal 

colony count; <, less than; >, greater than; --, no data. The term non-ideal colony count is used when all filters analyzed

for a sample failed to produce colony counts in the established ideal range]

 DIS- PH BARO- OXYGEN, 

 CHARGE, SPE- WATER METRIC DIS- HARD- 

 INST. CIFIC WHOLE PRES- SOLVED NESS 

 CUBIC CON- FIELD TEMPER- TEMPER- SURE OXYGEN, (PER- TOTAL 

SITE FEET DUCT- (STAND- ATURE ATURE (MM DIS- CENT (MG/L 

NUMBER DATE PER ANCE ARD AIR WATER OF SOLVED SATUR- AS 

 SECOND (US/CM) UNITS) (DEG C) (DEG C) HG) (MG/L) ATION) CACO3)

 (00061) (00095) (00400) (00020) (00010) (00025) (00300) (00301) (00900)

S1 09-29-92 .001 819 8.1 19.0 18.0 688 6.0 70 18 

S2 09-23-92 .01 497 7.5 22.0 18.5 685 4.0 47 120 

 07-26-94 .01 494 7.1 23.0 16.5 -- 5.8 68 120 

 04-27-95 .01 493 7.6 9.0 10.0 -- 6.4 -- 110 

 06-21-95 .01 494 7.3 28.0 15.0 -- 5.7 -- 120 

 03-26-97 .01 489 7.8 -- 10.0 -- -- -- -- 

S3 09-21-92 .003 678 8.4 24.0 19.0 680 7.9 105 95 

S4 09-25-92 .05 504 7.8 17.0 15.0 673 6.5 76 180 

 07-13-94 .07 477 7.9 18.5 18.5 -- 9.0 -- 180 

 05-11-95 .16 486 8.3 16.0 14.0 668 10.0 111 190 

 08-28-95 .13 608 7.9 24.0 19.5 -- 6.7 -- 190 

 01-12-96 .30 -- -- -- -- -- -- -- -- 

 04-03-96 .17 -- -- -- -- -- -- -- -- 

 05-16-96 .17 -- -- -- -- -- -- -- -- 

 07-26-96 .22 -- -- -- -- -- -- -- -- 

 10-10-96 .26 -- -- -- -- -- -- -- -- 

 12-10-96 .39 -- -- -- -- -- -- -- -- 

 03-07-97 .30 -- -- -- -- -- -- -- -- 

 03-24-97 .30 540 8.6 -- 6.0 -- -- -- -- 

S5 09-22-92 .05 370 8.1 23.5 15.0 686 8.3 109 180 

 07-12-94 .07 377 8.0 26.0 17.0 -- 7.9 96 160 

 04-24-95 .10 360 8.4 15.0 11.0 628 9.8 108 170 

 08-28-95 .05 390 7.8 25.0 19.5 -- 7.6 -- 160 

 01-12-96 .08 -- -- -- -- -- -- -- -- 

 04-03-96 .07 -- -- -- -- -- -- -- -- 

 05-16-96 .07 -- -- -- -- -- -- -- -- 

 07-30-96 .06 -- -- -- -- -- -- -- -- 

 10-10-96 .07 -- -- -- -- -- -- -- -- 

 12-10-96 .07 -- -- -- -- -- -- -- -- 

 02-27-97 .08 -- -- -- -- -- -- -- -- 

 03-24-97 .10 330 8.1 -- 9.5 -- -- -- -- 

S6 09-30-92 .02 520 7.9 15.0 14.5 686 8.0 86 110 

 07-27-94 .02 521 7.8 20.0 13.0 -- 9.0 98 120 

 04-14-95 .01 519 7.8 15.0 11.5 688 8.6 87 110 

 07-10-95 .02 582 7.8 28.0 13.5 -- 7.4 -- 110 

 01-16-96 .01 -- -- -- -- -- -- -- -- 

 04-04-96 .01 -- -- -- -- -- -- -- -- 

 06-03-96 .01 -- -- -- -- -- -- -- -- 

 07-30-96 .02 -- -- -- -- -- -- -- -- 

 10-31-96 .02 -- -- -- -- -- -- -- -- 

 02-27-97 .02 -- -- -- -- -- -- -- -- 

 03-25-97 .01 509 7.9 -- 12.0 -- -- -- -- 

S7 10-01-92 .09 559 8.1 28.0 19.0 679 8.3 100 180 

 07-28-94 .10 542 7.9 30.0 20.0 -- 6.7 -- 180 

 05-16-95 .09 592 8.2 20.0 14.5 685 8.9 97 190 

 07-13-95 .08 510 8.3 31.0 20.0 -- 7.0 -- 170 

 01-12-96 .08 -- -- -- -- -- -- -- --

 04-04-96 .14 -- -- -- -- -- -- -- --

 06-03-96 .19 -- -- -- -- -- -- -- --

 07-31-96 .13 -- -- -- -- -- -- -- --

 10-31-96 .19 -- -- -- -- -- -- -- --

 12-10-96 .19 -- -- -- -- -- -- -- --

 02-27-97 .10 -- -- -- -- -- -- -- --

 03-26-97 .19 514 8.3 -- 9.5 -- -- -- -- 

S8 09-21-92 .02 615 7.9 21.0 14.5 680 8.1 102 87 

 07-14-94 .03 623 7.5 26.0 14.0 664 8.9 99 87 

 04-27-95 .02 626 7.7 20.0 11.0 -- 8.7 -- 84 

 06-21-95 .02 620 7.6 26.0 13.5 -- 8.2 -- 87 

 01-16-96 .01 -- -- -- -- -- -- -- -- 

 04-03-96 .04 -- -- -- -- -- -- -- -- 

 05-16-96 .03 -- -- -- -- -- -- -- -- 

 07-26-96 .03 -- -- -- -- -- -- -- -- 

 10-10-96 .03 -- -- -- -- -- -- -- -- 

 01-02-97 .06 -- -- -- -- -- -- -- -- 

 02-27-97 .06 -- -- -- -- -- -- -- -- 

 03-25-97 .06 621 8.3 -- 10.5 -- -- -- -- 

S9 10-08-92 .01 511 8.4 6.0 10.0 681 10.0 99 80 

 07-27-94 .02 512 8.2 23.0 18.0 -- 9.7 -- 86 

 05-12-95 .03 500 8.3 -- 11.0 686 8.7 88 80 

 08-29-95 .02 550 8.3 24.0 15.0 -- 8.8 -- 84 

 01-16-96 .01 -- -- -- -- -- -- -- -- 

 04-04-96 .03 -- -- -- -- -- -- -- -- 

 06-03-96 .03 -- -- -- -- -- -- -- -- 

 07-31-96 .02 -- -- -- -- -- -- -- -- 

 10-31-96 .03 -- -- -- -- -- -- -- -- 

 01-02-97 .03 -- -- -- -- -- -- -- -- 

 03-07-97 .02 -- -- -- -- -- -- -- -- 

 03-25-97 .03 521 8.4 -- 11.5 -- -- -- -- 

S10 11-04-92 .01 2680 6.8 -- 12.5 687 .1 10 1000 

S11 09-18-92 .004 518 7.3 18.0 14.5 685 .1 11 120 

S12 11-12-92 .06 423 8.4 12.0 10.0 673 8.2 82 130 

 08-02-94 .07 422 8.3 27.0 17.5 674 8.6 101 130 

 05-17-95 .05 431 8.6 15.0 14.0 -- 6.2 65 140 

 07-11-95 .08 445 8.4 28.0 17.0 -- 6.8 -- 150 

 03-27-97 .07 433 8.4 -- -- -- -- -- -- 

S13 09-30-92 .004 3440 8.6 28.0 22.0 685 -- -- 290 

S14 11-05-92 .02 534 8.0 3.5 8.0 685 8.4 79 200 

 08-03-94 .01 537 7.6 27.0 19.5 678 7.7 95 200 

 05-16-95 .01 449 8.7 21.0 22.5 685 12.1 155 150 

 07-12-95 .01 535 8.1 31.0 19.0 -- 7.5 -- 190 

 03-26-97 .01 528 8.2 -- 15.5 -- -- -- -- 
46 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 13. Spring water-quality data—Continued

 ANC1 ANC1 COLI- STREP- UNFLTRD WATER E. COLI COLI- FORM, TOCOCCI MAGNE- 

 TIT 4.5 UNFLTRD WATER FORM, FECAL, FECAL, CALCIUM SIUM, SODIUM, 

 LAB IT WHOLE TOTAL, 0.7 KF AGAR DIS- DIS- DIS- 

 SITE (MG/L FIELD TOTAL (COLS. UM-MF (COLS. SOLVED SOLVED SOLVED 

 NUMBER DATE AS MG/L AS (COL / PER (COLS./ PER (MG/L (MG/L (MG/L SODIUM

 CACO3) CACO3 100 ML) 100 ML) 100 ML) 100 ML) AS CA) AS MG) AS NA) PERCENT

 (90410) (00419) (31633) (31503) (31625) (31673) (00915) (00925) (00930) (00932)

 S1 09-29-92 423 438 -- -- -- -- 6.4 .40 190 92 

 S2 09-23-92 226 245 -- -- -- -- 45 2.3 61 50 

 07-26-94 223 223 <5 >1600 <2 68 45 2.3 60 50 

 04-27-95 224 224 <4 K7 <4 <4 42 2.2 61 52 

 06-21-95 225 216 K2 K4 K2 K14 45 2.3 61 50 

 03-26-97 -- -- -- -- -- -- -- -- -- -- 

 S3 09-21-92 281 316 -- -- -- -- 31 4.2 120 70 

 S4 09-25-92 269 236 -- -- -- -- 60 7.7 39 30 

 07-13-94 252 249 <2 >130 K360 390 58 7.6 34 28 

 05-11-95 256 250 110 250 210 K25 62 8.6 30 24 

 08-28-95 332 278 K1600 K2050 550 970 61 9.1 49 34 

 01-12-96 -- -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- -- 

 S5 09-22-92 181 192 -- -- -- -- 58 7.4 10 11 

 07-12-94 184 180 50 132 E270 >2000 54 7.1 9.4 11 

 04-24-95 174 164 -- -- -- -- 54 7.5 9.6 11 

 08-28-95 180 172 K1600 K2800 K1200 K2200 54 7.0 9.1 10 

 01-12-96 -- -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- -- 

 07-30-96 -- -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- -- 

 S6 09-30-92 220 229 -- -- -- -- 33 5.9 66 54 

 07-27-94 221 204 <2 >88 110 >4200 36 6.0 65 52 

 04-14-95 218 230 <4 >12 K4 K4 35 5.9 64 53 

 07-10-95 217 210 <1 45 <1 <1 34 5.8 62 52 

 01-16-96 -- -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- -- 

 07-03-96 -- -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- -- 

 S7 10-01-92 265 254 -- -- -- -- 60 7.8 49 35 

 07-28-94 262 287 >8000 >16000 >6000 >10000 58 7.9 44 33 

 05-16-95 272 288 K16 33 K25 170 63 7.2 53 36 

 07-13-95 251 270 2100 13900 8800 4600 55 7.1 48 36 

 01-12-96 -- -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- --

 03-26-97 -- -- -- -- -- -- -- -- -- -- 

 S8 09-21-92 199 203 -- -- -- -- 28 4.0 98 68 

 07-14-94 197 198 K2 K4 K2 <10 28 4.0 96 68 

 04-27-95 198 200 230 >230 <4 <4 27 4.0 96 68 

 06-21-95 197 198 92 312 70 70 28 4.0 97 68 

 01-16-96 -- -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- -- 

 S9 10-08-92 201 216 -- -- -- -- 27 3.0 75 63 

 07-27-94 196 204 <2 >60 44 420 29 3.1 73 61 

 05-12-95 208 224 K2 62 44 420 27 2.9 74 63 

 08-29-95 197 212 K8700 K8726 230 K46 28 3.2 73 61 

 01-16-96 -- -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- -- 

 S10 11-04-92 509 538 -- -- -- -- 280 72 300 39 

 S11 09-18-92 232 236 -- -- -- -- 42 4.7 63 50 

 S12 11-12-92 203 230 -- -- -- -- 43 5.0 33 34 

 08-02-94 209 205 920 1330 700 4900 45 5.1 33 33 

 05-17-95 214 368 K800 K2400 K1200 K2200 47 5.3 36 34 

 07-11-95 235 200 50 10850 210 690 51 5.8 38 33 

 03-27-97 -- -- -- -- -- -- -- -- -- -- 

 S13 09-30-92 561 534 -- -- -- -- 76 23 750 84 

 S14 11-05-92 237 239 -- -- -- -- 59 12 38 29 

 08-03-94 239 224 <100 >400 <50 610 59 12 37 28 

 05-16-95 178 182 200 520 300 120 42 11 37 34 

 07-12-95 237 244 90 1790 100 690 58 11 39 30 

 03-26-97 -- -- -- -- -- -- -- -- -- -- 
Supplemental Data - Table 13 47

Table 13. Spring water-quality data—Continued

 ANC1 ANC1 SOLIDS, SOLIDS, SODIUM POTAS- BICAR- CAR- CHLO- FLUO- SILICA, SUM OF RESIDUE

 AD- SIUM, BONATE BONATE SULFATE RIDE, RIDE, DIS- CONSTI- AT 180 

 SORP- DIS- IT IT DIS- DIS- DIS- SOLVED TUENTS, DEG. C

 SITE TION SOLVED FIELD FIELD SOLVED SOLVED SOLVED (MG/L DIS- DIS- 

 NUMBER DATE RATIO (MG/L MG/L AS MG/L AS (MG/L (MG/L (MG/L AS SOLVED SOLVED

 AS K) HCO3 CO3 AS SO4) AS CL) AS F) SIO2) (MG/L) (MG/L)

 (00931) (00935) (00450) (00447) (00945) (00940) (00950) (00955) (70301) (70300)

 S1 09-29-92 20 14 534 0 27 10 .50 68 579 574 

 S2 09-23-92 2 6.5 299 0 18 1.5 .20 41 323 336 

 07-26-94 2 7.1 270 0 19 1.8 .30 41 314 318 

 04-27-95 2 6.3 273 0 18 1.7 .30 38 327 310 

 06-21-95 2 6.7 263 0 17 2.0 .20 41 327 340 

 03-26-97 -- -- -- 0 -- -- -- -- -- -- 

 S3 09-21-92 5 15 321 34 49 25 .20 55 492 457 

 S4 09-25-92 1 11 337 0 7.8 3.4 .30 51 347 340 

 07-13-94 1 8.3 303 0 7.8 1.7 .30 46 314 310 

 05-11-95 .9 8.8 305 0 7.0 3.7 .40 35 307 310 

 08-28-95 2 15 339 0 5.7 14 .40 49 372 384 

 01-12-96 -- -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- 0 -- -- -- -- -- -- 

 S5 09-22-92 .3 6.6 235 0 8.5 .50 .10 50 257 255 

 07-12-94 .3 6.4 219 0 7.8 1.0 .30 49 253 256 

 04-24-95 .3 6.5 200 0 7.4 1.2 .30 47 245 242 

 08-28-95 .3 6.1 210 0 7.5 .90 .40 51 251 244 

 01-12-96 -- -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- -- 

 07-30-96 -- -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- 0 -- -- -- -- -- -- 

 S6 09-30-92 3 11 280 0 34 11 .30 50 349 321 

 07-27-94 3 11 250 0 33 9.4 .30 51 345 348 

 04-14-95 3 11 280 0 30 10 .30 51 357 338 

 07-10-95 3 11 256 0 30 9.0 .30 51 340 333 

 01-16-96 -- -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- -- 

 07-03-96 -- -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- 0 -- -- -- -- -- -- 

 S7 10-01-92 2 13 310 0 23 10 .30 54 370 378 

 07-28-94 1 16 350 0 23 8.1 .30 54 398 374 

 05-16-95 2 13 351 0 24 11 .30 50 404 394 

 07-13-95 2 13 329 0 21 7.0 .30 56 383 379 

 01-12-96 -- -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- -- 

 03-26-97 -- -- -- 0 -- -- -- -- -- -- 

 S8 09-21-92 5 10 247 0 65 28 .20 59 414 412 

 07-14-94 4 11 241 0 69 24 .30 59 411 434 

 04-27-95 5 11 244 0 67 24 .30 59 427 416 

 06-21-95 5 11 242 0 61 24 .20 61 424 430 

 01-16-96 -- -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- 0 -- -- -- -- -- -- 

 S9 10-08-92 4 13 246 0 34 11 .30 56 341 347 

 07-27-94 3 14 250 0 37 12 .20 57 367 362 

 05-12-95 4 13 273 0 29 9.1 .30 57 361 348 

 08-29-95 3 13 259 2 39 13 .30 57 374 370 

 01-16-96 -- -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- 0 -- -- -- -- -- -- 

 S10 11-04-92 4 22 661 0 1000 10 4.8 13 2030 2210 

 S11 09-18-92 2 9.7 287 0 23 19 .20 58 362 353 

 S12 11-12-92 1 11 305 15 11 2.1 .30 47 318 280 

 08-02-94 1 11 250 0 11 1.9 .20 45 282 284 

 05-17-95 1 11 449 0 9.4 2.4 .30 46 384 278 

 07-11-95 1 11 195 2 10 1.8 .40 48 268 314 

 03-27-97 -- -- -- 0 -- -- -- -- -- -- 

 S13 09-30-92 19 21 574 38 1200 110 1.4 8.2 2510 2600 

 S14 11-05-92 1 6.1 288 0 45 5.7 .40 19 328 332 

 08-03-94 1 6.0 270 0 45 5.2 .40 17 315 326 

 05-16-95 1 6.3 205 8 45 5.5 .40 14 271 262 

 07-12-95 1 5.5 298 0 43 5.0 .80 19 329 323 

 03-26-97 -- -- -- 0 -- -- -- -- -- -- 
48 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 13. Spring water-quality data—Continued

 NITRO- NITRO- NITRO- NITRO- NITRO- PHOS- 

 SOLIDS, SOLIDS, GEN, GEN, GEN, GEN, GEN, PHOS- PHORUS 

 DIS- DIS- AMMONIA AMMONIA NITRITE NO2+NO3 NITRATE PHORUS ORTHO,

 SOLVED SOLVED DIS- DIS- DIS- DIS- DIS- DIS- DIS- 

 SITE (TONS (TONS SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED 

 NUMBER DATE PER PER (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L 

 AC-FT) DAY) AS N) AS NH4) AS N) AS N) AS N) AS P) AS P) 

 (70303) (70302) (00608) (71846) (00613) (00631) (00618) (00666) (00671)

 S1 09-29-92 .78 -- -- -- -- -- -- -- -- 

 S2 09-23-92 .46 .01 -- -- -- -- -- -- -- 

 07-26-94 .43 .01 .010 .01 -- .960 -- .075 -- 

 04-27-95 .42 .01 <.015 -- <.010 5.00 -- .040 .070 

 06-21-95 .46 .01 .020 .03 <.010 5.00 -- .080 .070 

 03-26-97 -- -- -- -- -- -- -- -- -- 

 S3 09-21-92 .62 .00 -- -- -- -- -- -- -- 

 S4 09-25-92 .46 .05 -- -- -- -- -- -- -- 

 07-13-94 .42 .06 .010 .01 -- .031 -- .012 -- 

 05-11-95 .42 .13 <.015 -- <.010 .090 -- <.010 <.010 

 08-28-95 .52 .13 .040 .05 <.010 .270 -- .010 .010 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- 

 S5 09-22-92 .35 .03 -- -- -- -- -- -- -- 

 07-12-94 .35 .05 .010 .01 -- 2.10 -- .029 -- 

 04-24-95 .33 .07 <.015 -- .020 2.70 2.68 .020 .020 

 08-28-95 .33 .03 .050 .06 .030 2.40 2.37 .020 .020 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-30-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- 

 S6 09-30-92 .44 .02 -- -- -- -- -- -- -- 

 07-27-94 .47 .02 .020 .03 -- 2.10 -- .029 -- 

 04-14-95 .46 .01 .020 .03 .010 2.50 2.49 .040 .050 

 07-10-95 .45 .02 <.015 -- <.010 2.40 -- .030 .040 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-03-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S7 10-01-92 .51 .09 -- -- -- -- -- -- -- 

 07-28-94 .51 .10 .230 .30 -- 3.00 -- .090 -- 

 05-16-95 .54 .10 .020 .03 .010 1.90 1.89 .020 .020 

 07-13-95 .52 .08 .100 .13 .030 2.80 2.77 .060 .070 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-26-97 -- -- -- -- -- -- -- -- -- 

 S8 09-21-92 .56 .02 -- -- -- -- -- -- -- 

 07-14-94 .59 .04 <.010 -- -- <.050 -- .011 -- 

 04-27-95 .57 .02 <.015 -- <.010 4.00 -- <.010 .010 

 06-21-95 .58 .02 .020 .03 <.010 4.10 -- .020 .010 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S9 10-08-92 .47 .01 -- -- -- -- -- -- -- 

 07-27-94 .49 .02 .030 .04 -- 4.20 -- .007 -- 

 05-12-95 .47 .03 <.015 -- .010 3.20 3.19 <.010 .010 

 08-29-95 .50 .02 .030 .04 <.010 4.00 -- <.010 <.010 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S10 11-04-92 3.01 .06 -- -- -- -- -- -- -- 

 S11 09-18-92 .48 -- -- -- -- -- -- -- -- 

 S12 11-12-92 .38 .05 -- -- -- -- -- -- -- 

 08-02-94 .39 .05 .030 .04 -- 1.30 -- .039 -- 

 05-17-95 .38 .04 .020 .03 <.010 1.20 -- .030 .040 

 07-11-95 .43 .07 .050 .06 <.010 .740 -- .030 .030 

 03-27-97 -- -- -- -- -- -- -- -- -- 

 S13 09-30-92 3.54 -- -- -- -- -- -- -- -- 

 S14 11-05-92 .45 .02 -- -- -- -- -- -- -- 

 08-03-94 .44 .01 .030 .04 -- .013 -- .015 -- 

 05-16-95 .36 .01 <.015 -- <.010 <.050 -- .030 <.010 

 07-12-95 .44 .01 <.015 -- <.010 <.050 -- <.010 <.010 

 03-26-97 -- -- -- -- -- -- -- -- -- 
Supplemental Data - Table 13 49

Table 13. Spring water-quality data—Continued

 

 BERYL- CADMIUM CHRO- 

 ARSENIC BARIUM, LIUM, BORON, WATER CADMIUM MIUM, COBALT, COPPER,

 DIS- DIS- DIS- DIS- UNFLTRD DIS- DIS- DIS- DIS- 

 SITE SOLVED SOLVED SOLVED SOLVED TOTAL SOLVED SOLVED SOLVED SOLVED

 NUMBER DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L 

 AS AS) AS BA) AS BE) AS B) AS CD) AS CD) AS CR) AS CO) AS CU)

 (01000) (01005) (01010) (01020) (01027) (01025) (01030) (01035) (01040)

 S1 09-29-92 13 17 <.50 240 <1 <1.0 <5.0 <3.0 <10 

 S2 09-23-92 5 140 <.50 80 <1 <1.0 <5.0 <3.0 <10 

 07-26-94 4 150 <.50 80 -- <1.0 <5.0 <3.0 <10 

 04-27-95 4 150 <.50 80 <1 1.0 <5.0 <3.0 <10 

 06-21-95 5 150 <.50 70 <1 <1.0 <5.0 <3.0 <10 

 03-26-97 -- -- -- -- -- -- -- -- -- 

 S3 09-21-92 15 52 <.50 240 <1 <1.0 <5.0 <3.0 <10 

 S4 09-25-92 8 240 <.50 80 <1 <1.0 <5.0 <3.0 <10 

 07-13-94 9 250 <.50 70 -- <1.0 <5.0 <3.0 <10 

 05-11-95 8 270 <.50 70 <1 2.0 <5.0 <3.0 <10 

 08-28-95 13 310 <.50 100 <1 <1.0 <5.0 <3.0 <10 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- 

 S5 09-22-92 8 260 <.50 30 <1 <1.0 <5.0 <3.0 <10 

 07-12-94 7 280 <.50 30 -- <1.0 <5.0 <3.0 <10 

 04-24-95 9 260 <.50 20 <1 2.0 <5.0 <3.0 <10 

 08-28-95 9 300 <.50 40 <1 <1.0 <5.0 4.0 <10 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-30-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- 

 S6 09-30-92 16 69 <.50 140 <1 <1.0 <5.0 <3.0 <10 

 07-27-94 11 71 <.50 150 -- <1.0 <5.0 <3.0 <10 

 04-14-95 16 73 <.50 140 <1 <1.0 <5.0 <3.0 <10 

 07-10-95 16 70 <.50 150 <1 <1.0 <5.0 <3.0 <10 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-03-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S7 10-01-92 14 210 <.50 150 <1 <1.0 <5.0 <3.0 <10 

 07-28-94 11 260 <.50 130 -- <1.0 <5.0 <3.0 <10 

 05-16-95 15 210 <.50 130 <1 <1.0 <5.0 <3.0 <10 

 07-13-95 14 210 <.50 130 <1 <1.0 <5.0 4.0 <10 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-26-97 -- -- -- -- -- -- -- -- -- 

 S8 09-21-92 17 84 <.50 220 <1 <1.0 <5.0 <3.0 <10 

 07-14-94 19 82 <.50 230 -- <1.0 <5.0 <3.0 <10 

 04-27-95 17 86 <.50 220 <1 1.0 <5.0 <3.0 <10 

 06-21-95 17 85 <.50 210 <1 <1.0 <5.0 <3.0 <10 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S9 10-08-92 10 52 <.50 170 <1 <1.0 <5.0 <3.0 <10 

 07-27-94 8 47 <.50 170 -- <1.0 <5.0 <3.0 <10 

 05-12-95 9 45 <.50 180 <1 2.0 <5.0 <3.0 <10 

 08-29-95 12 44 <.50 180 <1 <1.0 <5.0 <3.0 <10 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S10 11-04-92 <1 22 <1.5 470 <1 <3.0 <15 <9.0 <30 

 S11 09-18-92 5 210 <.50 170 <1 <1.0 <5.0 <3.0 <10 

 S12 11-12-92 6 170 <.50 50 <1 2.0 <5.0 <3.0 <10 

 08-02-94 5 170 <.50 50 <1 <1.0 <5.0 <3.0 <10 

 05-17-95 7 180 <.50 60 <1 <1.0 <5.0 <3.0 <10 

 07-11-95 6 200 <.50 60 <1 <1.0 <5.0 <3.0 <10 

 03-27-97 -- -- -- -- -- -- -- -- -- 

 S13 09-30-92 1 18 <1.5 2800 <1 <3.0 <15 <9.0 <30 

 S14 11-05-92 1 160 <.50 60 <1 <1.0 <5.0 <3.0 <10 

 08-03-94 <1 150 <.50 50 <1 <1.0 <5.0 <3.0 <10 

 05-16-95 <1 100 <.50 60 <1 <1.0 <5.0 <3.0 <10 

 07-12-95 <1 150 <.50 80 <1 <1.0 <5.0 <3.0 <10 

 03-26-97 -- -- -- -- -- -- -- -- -- 
50 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 13. Spring water-quality data—Continued

 

 MANGA- MOLYB- SELE- 

 IRON, LEAD, LITHIUM NESE, MERCURY DENUM, NICKEL, NIUM, SILVER,

 DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- 

 SITE SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED

 NUMBER DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L 

 AS FE) AS PB) AS LI) AS MN) AS HG) AS MO) AS NI) AS SE) AS AG)

 (01046) (01049) (01130) (01056) (71890) (01060) (01065) (01145) (01075)

 S1 09-29-92 23 <10 64 <1.0 <.1 <10 <10 4 <1.0 

 S2 09-23-92 5.0 10 27 2.0 <.1 <10 <10 3 <1.0 

 07-26-94 <3.0 10 23 <1.0 <.1 <10 <10 2 <1.0 

 04-27-95 <3.0 <10 28 <1.0 <.1 <10 <10 2 2.0 

 06-21-95 5.0 <10 31 1.0 <.1 <10 <10 3 <1.0 

 03-26-97 -- -- -- -- -- -- -- -- -- 

 S3 09-21-92 270 <10 57 30 <.1 <10 <10 32 <1.0 

 S4 09-25-92 47 <10 25 27 <.1 <10 <10 <1 <1.0 

 07-13-94 89 <10 19 10 <.1 <10 <10 <1 <1.0 

 05-11-95 160 30 18 39 <.1 <10 <10 1 1.0 

 08-28-95 120 <10 26 16 <.1 10 <10 <1 <1.0 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- 

 S5 09-22-92 38 <10 12 7.0 <.1 <10 <10 2 <1.0 

 07-12-94 19 <10 17 4.0 <.1 <10 <10 1 <1.0 

 04-24-95 100 30 16 25 <.1 <10 <10 2 <1.0 

 08-28-95 83 <10 6 34 <.1 20 <10 <2 1.0 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-30-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- 

 S6 09-30-92 <3.0 <10 26 <1.0 <.1 <10 <10 12 <1.0 

 07-27-94 8.0 <10 27 <1.0 <.1 <10 <10 12 <1.0 

 04-14-95 <3.0 <10 24 <1.0 <.1 <10 <10 10 <1.0 

 07-10-95 <3.0 <10 25 <1.0 <.1 <10 <10 4 <1.0 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-03-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S7 10-01-92 37 <10 27 44 <.1 <10 <10 3 <1.0 

 07-28-94 33 <10 18 75 <.1 <10 <10 3 <1.0 

 05-16-95 23 10 36 16 <.1 <10 <10 5 <1.0 

 07-13-95 22 10 27 78 <.1 <10 <10 4 <1.0 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-26-97 -- -- -- -- -- -- -- -- -- 

 S8 09-21-92 5.0 <10 49 <1.0 <.1 <10 <10 26 <1.0 

 07-14-94 <3.0 <10 47 <1.0 <.1 10 <10 24 <1.0 

 04-27-95 <3.0 <10 51 <1.0 <.1 20 <10 27 <1.0 

 06-21-95 <3.0 <10 37 1.0 <.1 20 <10 27 <1.0 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S9 10-08-92 3.0 <10 37 <1.0 <.1 <10 <10 10 <1.0 

 07-27-94 3.0 <10 30 <1.0 <.1 <10 <10 10 <1.0 

 05-12-95 <3.0 30 38 <1.0 <.1 <10 <10 6 <1.0 

 08-29-95 <3.0 <10 36 2.0 <.1 <10 <10 10 <1.0 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S10 11-04-92 390 <30 370 440 <.1 <30 <30 <1 <3.0 

 S11 09-18-92 310 <10 28 190 <.1 <10 <10 5 <1.0 

 S12 11-12-92 11 10 26 3.0 <.1 <10 <10 6 <1.0 

 08-02-94 5.0 <10 30 3.0 <.1 <10 <10 6 <1.0 

 05-17-95 20 <10 27 7.0 <.1 <10 <10 6 2.0 

 07-11-95 21 <10 24 11 <.1 <10 <10 6 <1.0 

 03-27-97 -- -- -- -- -- -- -- -- -- 

 S13 09-30-92 110 <30 250 3.0 .1 <30 <30 <1 <3.0 

 S14 11-05-92 36 <10 28 78 <.1 <10 <10 4 <1.0 

 08-03-94 7.0 10 28 1.0 <.1 <10 <10 3 <1.0 

 05-16-95 52 20 28 4.0 <.1 <10 <10 5 <1.0 

 07-12-95 9.0 <10 24 3.0 <.1 <10 <10 2 <1.0 

 03-26-97 -- -- -- -- -- -- -- -- -- 
Supplemental Data - Table 13 51

Table 13. Spring water-quality data—Continued

 GROSS

 ALPHA ALPHA GROSS ALPHA, GROSS 

 THAL- STRON- VANA- RADIO. COUNT, ALPHA, COUNT, BETA, 

 LIUM, TIUM, DIUM, ZINC, WATER 2 SIGMA DIS- 2 SIGMA DIS- 

 DIS- DIS- DIS- DIS- DISS WAT DIS SOLVED WAT DIS SOLVED

 SITE SOLVED SOLVED SOLVED SOLVED AS AS (UG/L AS (PCI/L 

 NUMBER DATE (UG/L (UG/L (UG/L (UG/L TH-230 TH-230 AS NAT U AS 

 AS TL) AS SR) AS V) AS ZN) (PCI/L) (PCI/L) U-NAT) (UG/L) CS-137)

 (01057) (01080) (01085) (01090) (04126) (75987) (80030) (75986) (03515)

 S1 09-29-92 -- 130 14 <3.0 2.6 5.2 38 7.9 18 

 S2 09-23-92 -- 180 <6 3.0 6.2 1.4 8.4 1.8 9.0 

 07-26-94 -- 170 <6 <3.0 5.2 2.9 7.3 4.0 10 

 04-27-95 <.50 180 7 6.0 -- -- -- -- -- 

 06-21-95 <.50 180 <6 <3.0 -- -- -- -- -- 

 03-26-97 -- -- -- -- -- -- -- -- -- 

 S3 09-21-92 -- 270 11 6.0 3.4 1.1 5.1 1.6 9.6 

 S4 09-25-92 -- 450 <6 4.0 5.9 1.4 8.6 1.7 9.4 

 07-13-94 -- 420 <6 <3.0 3.0 2.0 4.2 2.7 11 

 05-11-95 <.50 440 <6 <3.0 -- -- -- -- -- 

 08-28-95 <.50 470 <6 <3.0 -- -- -- -- -- 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- 

 S5 09-22-92 -- 350 8 4.0 6.0 1.7 7.8 2.2 .7 

 07-12-94 -- 350 7 <3.0 1.7 1.5 2.4 2.1 7.5 

 04-24-95 <.50 330 9 5.0 -- -- -- -- -- 

 08-28-95 <.50 330 <6 <3.0 -- -- -- -- -- 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-30-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-24-97 -- -- -- -- -- -- -- -- -- 

 S6 09-30-92 -- 320 11 11 8.1 1.6 12 2.2 11 

 07-27-94 -- 310 9 <3.0 8.2 3.8 11 5.2 14 

 04-14-95 <.50 320 11 <3.0 -- -- -- -- -- 

 07-10-95 <.50 310 12 5.0 -- -- -- -- -- 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-03-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S7 10-01-92 -- 450 <6 4.0 8.8 2.3 13 3.4 12 

 07-28-94 -- 420 10 <3.0 8.3 3.7 12 5.3 24 

 05-16-95 <.50 480 8 <3.0 -- -- -- -- -- 

 07-13-95 <.50 410 8 5.0 -- -- -- -- -- 

 01-12-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 12-10-96 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-26-97 -- -- -- -- -- -- -- -- -- 

 S8 09-21-92 -- 320 7 11 16 2.8 22 4.0 14 

 07-14-94 -- 290 6 <3.0 18 6.1 23 8.0 17 

 04-27-95 <.50 320 9 17 -- -- -- -- -- 

 06-21-95 <.50 300 7 <3.0 -- -- -- -- -- 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-03-96 -- -- -- -- -- -- -- -- -- 

 05-16-96 -- -- -- -- -- -- -- -- -- 

 07-26-96 -- -- -- -- -- -- -- -- -- 

 10-10-96 -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- 

 02-27-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S9 10-08-92 -- 360 9 <3.0 9.2 1.9 13 2.8 8.8 

 07-27-94 -- 360 7 <3.0 11 4.4 18 6.8 18 

 05-12-95 <.50 350 9 <3.0 -- -- -- -- -- 

 08-29-95 <.50 370 9 5.0 -- -- -- -- -- 

 01-16-96 -- -- -- -- -- -- -- -- -- 

 04-04-96 -- -- -- -- -- -- -- -- -- 

 06-03-96 -- -- -- -- -- -- -- -- -- 

 07-31-96 -- -- -- -- -- -- -- -- -- 

 10-31-96 -- -- -- -- -- -- -- -- -- 

 01-02-97 -- -- -- -- -- -- -- -- -- 

 03-07-97 -- -- -- -- -- -- -- -- -- 

 03-25-97 -- -- -- -- -- -- -- -- -- 

 S10 11-04-92 -- 3700 <18 16 22 9.8 29 13 22 

 S11 09-18-92 -- 260 <6 48 18 3.4 27 5.0 17 

 S12 11-12-92 -- 500 7 <3.0 5.1 2.5 6.9 3.4 16 

 08-02-94 -- 480 6 <3.0 6.8 2.9 9.1 4.0 15 

 05-17-95 <.50 500 6 <3.0 -- -- -- -- -- 

 07-11-95 <.50 520 <6 <3.0 -- -- -- -- -- 

 03-27-97 -- -- -- -- -- -- -- -- -- 

 S13 09-30-92 -- 1300 <18 <9.0 5.5 2.1 7.9 3.0 6.6 

 S14 11-05-92 -- 500 <6 6.0 9.7 3.9 14 5.5 12 

 08-03-94 -- 480 <6 <3.0 6.5 3.2 8.4 4.1 10 

 05-16-95 <.50 430 <6 4.0 -- -- -- -- -- 

 07-12-95 <.50 480 <6 <3.0 -- -- -- -- -- 

 03-26-97 -- -- -- -- -- -- -- -- -- 
52 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 13. Spring water-quality data—Continued

 BETA, GROSS BETA, RA-226,

 2 SIGMA BETA, 2 SIGMA DIS- URANIUM URANIUM

 WATER, DIS- WATER, SOLVED, RA-226 NATURAL NATURAL

 DISS, SOLVED DISS, PLAN- 2 SIGMA DIS- 2 SIGMA

 SITE AS (PCI/L AS SR90 CHET WATER, SOLVED WATER,

 NUMBER DATE CS-137 AS SR/ /Y90 COUNT DISS, (UG/L DISS,

 (PCI/L) Y-90) (PCI/L) (PCI/L) (PCI/L) AS U) (UG/L)

 (75989) (80050) (75988) (09510) (76001) (22703) (75990)

 S1 09-29-92 1.6 -- -- -- -- -- --

 S2 09-23-92 .90 -- -- -- -- -- --

 07-26-94 1.9 7.5 1.4 .2 .151 7.1 2.2

 04-27-95 -- -- -- -- -- -- --

 06-21-95 -- -- -- -- -- -- --

 03-26-97 -- -- -- -- -- -- --

 S3 09-21-92 1.2 -- -- -- -- -- --

 S4 09-25-92 .80 -- -- -- -- -- --

 07-13-94 2.0 8.4 1.5 <.1 .115 3.3 1.1

 05-11-95 -- -- -- -- -- -- --

 08-28-95 -- -- -- -- -- -- --

 01-12-96 -- -- -- -- -- -- --

 04-03-96 -- -- -- -- -- -- --

 05-16-96 -- -- -- -- -- -- --

 07-26-96 -- -- -- -- -- -- --

 10-10-96 -- -- -- -- -- -- --

 12-10-96 -- -- -- -- -- -- --

 03-07-97 -- -- -- -- -- -- --

 03-24-97 -- -- -- -- -- -- --

 S5 09-22-92 1.4 -- -- -- -- -- --

 07-12-94 1.5 5.7 1.1 <.1 .134 2.1 0.7

 04-24-95 -- -- -- -- -- -- --

 08-28-95 -- -- -- -- -- -- --

 01-12-96 -- -- -- -- -- -- --

 04-03-96 -- -- -- -- -- -- --

 05-16-96 -- -- -- -- -- -- --

 07-30-96 -- -- -- -- -- -- --

 10-10-96 -- -- -- -- -- -- --

 12-10-96 -- -- -- -- -- -- --

 02-27-97 -- -- -- -- -- -- --

 03-24-97 -- -- -- -- -- -- --

 S6 09-30-92 1.1 -- -- -- -- -- --

 07-27-94 2.4 11 1.8 .1 .125 11 3.2

 04-14-95 -- -- -- -- -- -- --

 07-10-95 -- -- -- -- -- -- --

 01-16-96 -- -- -- -- -- -- --

 04-04-96 -- -- -- -- -- -- --

 06-03-96 -- -- -- -- -- -- --

 07-03-96 -- -- -- -- -- -- --

 10-31-96 -- -- -- -- -- -- --

 02-27-97 -- -- -- -- -- -- --

 03-25-97 -- -- -- -- -- -- --

 S7 10-01-92 1.0 -- -- -- -- -- --

 07-28-94 3.5 18 2.6 .1 .129 10 3.0

 05-16-95 -- -- -- -- -- -- --

 07-13-95 -- -- -- -- -- -- --

 01-12-96 -- -- -- -- -- -- --

 04-04-96 -- -- -- -- -- -- --

 06-03-96 -- -- -- -- -- -- --

 07-31-96 -- -- -- -- -- -- --

 10-31-96 -- -- -- -- -- -- --

 12-10-96 -- -- -- -- -- -- --

 02-27-97 -- -- -- -- -- -- --

 03-26-97 -- -- -- -- -- -- --

 S8 09-21-92 1.3 -- -- -- -- -- --

 07-14-94 2.8 13 2.0 .1 .125 13 3.7

 04-27-95 -- -- -- -- -- -- --

 06-21-95 -- -- -- -- -- -- --

 01-16-96 -- -- -- -- -- -- --

 04-03-96 -- -- -- -- -- -- --

 05-16-96 -- -- -- -- -- -- --

 07-26-96 -- -- -- -- -- -- --

 10-10-96 -- -- -- -- -- -- --

 01-02-97 -- -- -- -- -- -- --

 02-27-97 -- -- -- -- -- -- --

 03-25-97 -- -- -- -- -- -- --

 S9 10-08-92 .80 -- -- -- -- -- --

 07-27-94 2.7 14 2.0 <.1 .130 9.6 2.8

 05-12-95 -- -- -- -- -- -- --

 08-29-95 -- -- -- -- -- -- --

 01-16-96 -- -- -- -- -- -- --

 04-04-96 -- -- -- -- -- -- --

 06-03-96 -- -- -- -- -- -- --

 07-31-96 -- -- -- -- -- -- --

 10-31-96 -- -- -- -- -- -- --

 01-02-97 -- -- -- -- -- -- --

 03-07-97 -- -- -- -- -- -- --

 03-25-97 -- -- -- -- -- -- --

 S10 11-04-92 9.8 -- -- -- -- -- --

 S11 09-18-92 1.4 -- -- -- -- -- --

 S12 11-12-92 2.6 -- -- -- -- -- --

 08-02-94 2.3 11 1.7 .2 .146 7.2 2.2

 05-17-95 -- -- -- -- -- -- --

 07-11-95 -- -- -- -- -- -- --

 03-27-97 -- -- -- -- -- -- --

 S13 09-30-92 .70 -- -- -- -- -- --

 S14 11-05-92 2.2 -- -- -- -- -- --

 08-03-94 1.9 7.7 1.4 .2 .167 7.0 2.1

 05-16-95 -- -- -- -- -- -- --

 07-12-95 -- -- -- -- -- -- --

 03-26-97 -- -- -- -- -- -- --

 1The term acid neutralizing capacity (ANC) is applied to the acid-neutralizing capacity of solutes

 plus particulates in a water sample, reported in equivalents, and normally titrated on an

 unfiltered sample.
Supplemental Data - Table 14 53

Table 14. Public-supply well water-quality data 

[G/M, gallons per minute; US/CM, microsiemens per centimeter at 25° Celsius; DEG C, degrees Celsius; mm, millimeters; 

mg/L, milligrams per liter; UG/L, micrograms per liter; COL/100 ML, colonies per 100 milliliters; AC-FT, acre-feet; 

PCI/L, picocuries per liter; K, non-ideal colony count; <, less than; --, no data]

 PH BARO- 

 SPE- WATER METRIC 

 DEPTH CIFIC WHOLE PRES- 

 OF CON- FIELD TEMPER- TEMPER- SURE OXYGEN,

SITE FLOW WELL, DUCT- (STAND- ATURE ATURE (MM DISNUMBER DATE RATE TOTAL ANCE ARD AIR WATER OF SOLVED

 (G/M) (FEET) (US/CM) UNITS) (DEG C) (DEG C) HG) (MG/L)

 (00059) (72008) (00095) (00400) (00020) (00010) (00025) (00300)

 1 09-26-96 -- 120.00 439 7.9 10.0 16.0 677 1.3 

 2 08-29-96 -- 374.00 432 7.4 24.0 16.0 688 3.4 

 3 08-21-96 -- 455.00 404 7.6 27.0 18.0 681 4.8 

 4 08-20-96 -- 520.00 399 7.6 28.0 18.5 683 4.8 

 5 06-26-97 30.0 280.00 295 7.5 26.0 13.0 677 7.6 

 6 08-22-96 -- 284.00 515 7.2 26.0 16.0 689 2.4 

 7 07-08-97 130 168.00 726 7.2 28.0 15.0 684 4.2 

 8 09-05-96 46.0 -- 499 7.5 29.0 17.0 678 5.0 

 9 12-07-95 -- 340.00 568 8.8 4.0 10.0 682 4.1 

10 09-09-96 60.0 303.00 1070 7.0 24.0 17.5 684 .9 

11 07-17-97 -- 375.00 410 7.6 -- 15.0 673 7.7 

12 07-23-97 -- -- 351 7.2 30.0 16.0 675 5.3 

13 09-19-96 -- -- 646 7.3 10.0 13.0 686 1.4 

14 09-25-96 -- -- 643 7.3 8.0 11.0 683 1.5 

15 09-18-96 -- 320.00 642 7.3 14.0 11.5 687 1.3 

16 09-12-96 -- 300.00 626 7.4 22.0 15.0 693 4.6 

17 09-17-96 -- 71.00 556 7.5 19.0 12.5 685 4.2 

18 07-08-97 30.0 130.00 540 7.2 -- 12.0 685 4.8 

19 09-03-96 55.0 180.00 559 7.2 24.0 13.0 683 2.6 

20 09-03-96 55.0 100.00 488 7.4 25.0 13.5 683 4.4 

21 11-30-95 -- 187.00 404 7.3 18.0 14.0 675 6.9 

22 11-30-95 -- 187.00 405 7.6 19.0 15.0 674 6.7 

23 11-08-95 -- 205.00 359 7.6 -- -- 678 7.7 

24 11-08-95 -- -- 337 7.6 -- -- 678 8.5 

25 11-29-95 20.0 454.00 504 7.3 14.0 12.0 683 5.4 

26 09-24-96 -- 300.00 561 8.2 11.0 17.0 686 5.9 

27 11-29-95 -- 526.00 708 8.3 15.0 20.5 682 3.3 

28 12-06-95 -- -- 643 7.1 2.0 12.5 692 3.9 

29 07-09-97 26.0 -- 675 7.1 30.0 12.0 686 1.2 

30 11-28-95 -- -- 981 7.6 -- 12.5 686 5.6 

31 11-28-95 -- 180.00 459 7.5 3.0 12.5 684 7.3 

32 06-30-97 80.0 -- 638 7.2 -- 11.0 686 3.6 

33 06-30-97 -- 110.00 515 7.5 -- 12.0 686 7.5 

34 11-09-95 -- -- 642 7.4 16.0 12.5 678 3.4 

35 07-01-97 65.0 93.00 600 7.3 -- 11.0 -- 5.5 

36 07-01-97 100 121.00 552 7.4 -- 12.0 682 6.6 

37 12-05-95 -- 60.00 1100 7.7 -- 11.0 677 6.8 

38 10-19-95 20.0 68.10 882 7.6 -- 12.0 685 3.5 

39 07-22-97 55.0 -- 506 7.9 31.0 12.5 693 8.9 

40 10-18-95 70.0 184.00 486 8.3 -- 13.5 675 5.6 

41 07-16-97 100 124.00 487 7.7 37.0 13.0 694 7.2 

42 07-22-97 44.0 200.00 461 7.9 30.0 13.5 688 7.1 

43 10-18-95 25.0 106.00 498 7.9 -- 14.0 677 5.4 

44 06-25-97 18.6 2640.00 667 7.0 22.0 44.0 700 .1 
54 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 14. Public-supply well water-quality data—Continued

 OXYGEN, HARD- ANC1 ANC1 COLI- STREP-

 DIS- HARD- NESS UNFLTRD WATER E. COLI COLI- FORM, TOCOCCI

 SOLVED NESS NONCARB TIT 4.5 UNFLTRD WATER FORM, FECAL, FECAL,

 (PER- TOTAL DISSOLV LAB IT WHOLE TOTAL, 0.7 KF AGAR

 SITE CENT (MG/L FLD. AS (MG/L FIELD TOTAL (COLS. UM-MF (COLS. 

 NUMBER DATE SATUR- AS CACO3 AS MG/L AS (COL / PER (COLS./ PER 

 ATION) CACO3) (MG/L) CACO3) CACO3 100 ML) 100 ML) 100 ML) 100 ML)

 (00301) (00900) (00904) (90410) (00419) (31633) (31503) (31625) (31673)

 1 09-26-96 15 97 -- 176 177 <1 58 K2 K2 

 2 08-29-96 40 150 -- 188 182 <1 <1 <1 <1 

 3 08-21-96 58 110 -- 155 152 <1 K3 <1 <1 

 4 08-20-96 58 99 -- 157 152 <1 <1 <1 <1 

 5 06-26-97 82 120 -- 137 134 K27 K27 <1 <1 

 6 08-22-96 28 210 -- 234 219 <1 <1 <1 <1 

 7 07-08-97 47 160 -- 210 211 <1 <1 <1 <1 

 8 09-05-96 59 110 -- 188 179 <1 K8 <1 <1 

 9 12-07-95 41 110 -- 194 204 <1 <1 <1 <1 

 10 09-09-96 11 410 -- 292 282 <1 73 <1 <1 

 11 07-17-97 86 150 -- 165 166 <1 K16 <1 <1 

 12 07-23-97 61 150 3 146 148 K2 K9 <1 <1 

 13 09-19-96 15 170 -- 258 253 <1 K6 K17 K1000 

 14 09-25-96 15 170 -- 258 261 <1 64 K6 K900 

 15 09-18-96 14 170 -- 258 255 <1 400 39 21 

 16 09-12-96 49 120 -- 205 200 55 96 890 <1 

 17 09-17-96 45 130 -- 204 200 <1 K16 24 K2 

 18 07-08-97 50 210 3 204 203 <1 K4 <1 <1 

 19 09-03-96 29 210 -- 222 214 <1 <1 <1 <1 

 20 09-03-96 49 180 -- 197 197 <1 <1 <1 <1 

 21 11-30-95 76 130 -- 170 165 <1 <1 <1 <1 

 22 11-30-95 75 120 -- 172 164 K10 K10 <1 <1 

 23 11-08-95 83 140 -- 172 174 <1 <1 <1 <1 

 24 11-08-95 90 140 -- 165 164 <1 <1 <1 <1 

 25 11-29-95 55 190 -- 227 228 K2 K2 <1 <1 

 26 09-24-96 69 47 -- 186 185 <1 <1 <1 240 

 27 11-29-95 41 20 -- 192 186 <1 <1 <1 <1 

 28 12-06-95 31 170 -- 243 238 K3 K3 <1 <1 

 29 07-09-97 12 240 -- 276 272 <1 <1 <1 <1 

 30 11-28-95 59 67 -- 389 390 <1 <1 <1 <1 

 31 11-28-95 77 130 -- 226 226 K6 K6 <1 <1 

 32 06-30-97 36 150 -- 311 301 <1 K11 <1 K7 

 33 06-30-97 78 86 -- 224 248 <1 K2 <1 <1 

 34 11-09-95 36 140 -- 307 316 <1 <1 <1 <1 

 35 07-01-97 -- 140 -- 289 297 K2 K12 <1 K2 

 36 07-01-97 69 92 -- 252 254 K3 K3 K4 <1 

 37 12-05-95 69 27 -- 486 500 K8 K8 <1 <1 

 38 10-19-95 36 95 -- 450 460 <1 K3 <1 <1 

 39 07-22-97 92 58 -- 187 192 K1000 K1000 K4 71 

 40 10-18-95 61 28 -- 241 245 <1 <1 <1 <1 

 41 07-16-97 75 34 -- 244 242 25 53 <1 K4 

 42 07-22-97 76 27 -- 228 227 220 220 K2 K9 

 43 10-18-95 60 72 -- 247 235 <1 <1 <1 <1 

 44 06-25-97 2 280 89 187 189 <1 270 <1 K36 
Supplemental Data - Table 14 55

Table 14. Public-supply well water-quality data—Continued

 ANC1 ANC1

 MAGNE- SODIUM POTAS- BICAR- CAR- 

 CALCIUM SIUM, SODIUM, AD- SIUM, BONATE BONATE SULFATE

 DIS- DIS- DIS- SORP- DIS- IT IT DIS- 

 SITE SOLVED SOLVED SOLVED TION SOLVED FIELD FIELD SOLVED

 NUMBER DATE (MG/L (MG/L (MG/L SODIUM RATIO (MG/L MG/L AS MG/L AS (MG/L 

 AS CA) AS MG) AS NA) PERCENT AS K) HCO3 CO3 AS SO4)

 (00915) (00925) (00930) (00932) (00931) (00935) (00450) (00447) (00945)

 1 09-26-96 24 8.8 51 51 2 9.5 216 0 47 

 2 08-29-96 49 5.9 26 25 .9 15 222 0 38 

 3 08-21-96 37 3.3 35 38 1 15 185 0 51 

 4 08-20-96 35 2.7 39 41 2 18 185 0 51 

 5 06-26-97 39 5.5 10 15 .4 6.3 164 0 10 

 6 08-22-96 67 9.5 19 16 .6 12 226 0 39 

 7 07-08-97 56 5.3 82 49 3 22 258 0 150 

 8 09-05-96 37 4.2 58 49 2 18 218 0 60 

 9 12-07-95 38 2.8 69 54 3 17 195 3 77 

 10 09-09-96 140 14 69 26 1 21 344 0 290 

 11 07-17-97 49 7.4 18 19 .6 11 202 0 27 

 12 07-23-97 49 7.2 8.0 10 .3 7.1 181 0 19 

 13 09-19-96 54 8.1 70 45 2 13 309 0 76 

 14 09-25-96 56 8.2 68 44 2 13 318 0 77 

 15 09-18-96 53 7.9 69 45 2 13 311 0 76 

 16 09-12-96 39 5.3 78 56 3 11 244 0 93 

 17 09-17-96 44 5.4 74 52 3 13 243 0 95 

 18 07-08-97 69 8.0 29 22 .9 11 240 0 67 

 19 09-03-96 68 9.3 29 22 .9 12 261 0 68 

 20 09-03-96 57 7.9 27 24 .9 11 240 0 54 

 21 11-30-95 44 5.0 29 31 1 8.0 201 0 27 

 22 11-30-95 39 4.5 35 37 1 8.9 200 0 28 

 23 11-08-95 44 7.5 12 15 .4 7.1 212 0 11 

 24 11-08-95 43 8.2 7.9 10 .3 7.3 200 0 7.3 

 25 11-29-95 58 11 29 24 .9 6.3 278 0 32 

 26 09-24-96 16 1.7 110 80 7 9.4 226 0 92 

 27 11-29-95 8.0 .090 140 90 14 12 227 0 130 

 28 12-06-95 59 5.8 62 42 2 14 290 0 80 

 29 07-09-97 81 8.6 48 29 1 12 342 0 80 

 30 11-28-95 23 2.2 200 85 11 10 476 0 110 

 31 11-28-95 37 7.9 50 45 2 6.1 276 0 14 

 32 06-30-97 55 3.5 73 48 3 15 367 0 30 

 33 06-30-97 33 .88 71 60 3 13 302 0 33 

 34 11-09-95 52 3.3 72 49 3 15 385 0 26 

 35 07-01-97 53 2.8 71 49 3 15 362 0 30 

 36 07-01-97 35 .94 78 60 4 15 310 0 34 

 37 12-05-95 9.6 .72 250 93 21 11 610 0 84 

 38 10-19-95 35 1.8 160 76 7 14 561 0 22 

 39 07-22-97 21 1.6 91 75 5 6.7 -- 0 35 

 40 10-18-95 11 .11 100 85 8 8.0 299 0 10 

 41 07-16-97 13 .12 102 83 8 8.8 296 0 14 

 42 07-22-97 11 .10 101 86 8 7.5 277 0 11 

 43 10-18-95 28 .49 83 68 4 8.8 287 0 9.0 

 44 06-25-97 74 22 23 15 .6 8.4 -- 0 160 
56 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 14. Public-supply well water-quality data—Continued

 SOLIDS, SOLIDS, NITRO- NITRO- NITRO-

 CHLO- FLUO- SILICA, SUM OF RESIDUE SOLIDS, GEN, GEN, GEN, 

 RIDE, RIDE, DIS- CONSTI- AT 180 DIS- AMMONIA AMMONIA NO2+NO3

 DIS- DIS- SOLVED TUENTS, DEG. C SOLVED DIS- DIS- DIS- 

 SITE SOLVED SOLVED (MG/L DIS- DIS- (TONS SOLVED SOLVED SOLVED

 NUMBER DATE (MG/L (MG/L AS SOLVED SOLVED PER (MG/L (MG/L (MG/L 

 AS CL) AS F) SIO2) (MG/L) (MG/L) AC-FT) AS N) AS NH4) AS N) 

 (00940) (00950) (00955) (70301) (70300) (70303) (00608) (71846) (00631)

 1 09-26-96 1.3 .60 71 322 314 .43 <.015 -- .420 

 2 08-29-96 3.7 .20 69 320 322 .44 <.015 -- .790 

 3 08-21-96 1.8 .30 70 349 322 .44 .020 .03 10.0 

 4 08-20-96 1.9 .30 71 314 338 .46 .020 .03 .850 

 5 06-26-97 1.7 .43 60 222 231 .31 <.015 -- 1.65 

 6 08-22-96 5.4 .20 64 330 380 .52 <.020 -- .530 

 7 07-08-97 6.9 .18 73 525 552 .75 <.015 -- 1.35 

 8 09-05-96 7.7 .30 73 372 372 .51 <.015 -- 1.30 

 9 12-07-95 6.3 1.6 73 388 428 .58 <.015 -- .920 

 10 09-09-96 5.7 .20 74 786 798 1.09 <.015 -- .300 

 11 07-17-97 9.4 .43 65 298 317 .43 <.015 -- 2.42 

 12 07-23-97 8.1 .22 60 255 274 .37 <.015 -- 1.63 

 13 09-19-96 6.1 .50 55 440 436 .59 <.015 -- 1.00 

 14 09-25-96 5.8 .50 55 446 468 .64 .020 .03 1.10 

 15 09-18-96 5.9 .50 55 438 420 .57 <.015 -- 1.00 

 16 09-12-96 5.9 .50 56 421 427 .58 <.015 -- 2.60 

 17 09-17-96 6.5 .40 59 432 436 .59 <.015 -- 3.30 

 18 07-08-97 5.0 .33 58 374 396 .54 <.015 -- 1.78 

 19 09-03-96 5.4 .30 58 383 400 .54 <.015 -- .970 

 20 09-03-96 4.3 .30 60 348 360 .49 <.015 -- 1.80 

 21 11-30-95 4.9 .40 67 291 270 .37 <.015 -- 1.40 

 22 11-30-95 3.9 .40 68 292 282 .38 <.015 -- 1.20 

 23 11-08-95 1.7 .40 60 252 236 .32 <.015 -- .720 

 24 11-08-95 1.3 .30 58 235 222 .30 <.015 -- .530 

 25 11-29-95 4.9 .40 58 342 336 .46 <.015 -- .960 

 26 09-24-96 5.4 .40 60 411 438 .60 <.015 -- 1.10 

 27 11-29-95 4.8 9.1 57 481 474 .64 <.015 -- 1.80 

 28 12-06-95 4.8 .30 63 440 438 .60 <.015 -- 1.70 

 29 07-09-97 5.2 .31 57 465 481 .65 <.015 -- .656 

 30 11-28-95 12 .50 52 652 612 .83 <.015 -- 1.70 

 31 11-28-95 4.4 .40 58 318 260 .35 <.015 -- .800 

 32 06-30-97 5.9 .31 49 415 440 .60 <.015 -- .419 

 33 06-30-97 5.5 .27 53 366 370 .50 <.015 -- 1.67 

 34 11-09-95 6.0 .30 48 414 400 .54 <.015 -- .410 

 35 07-01-97 6.2 .30 51 410 420 .57 <.015 -- .660 

 36 07-01-97 6.0 .26 53 380 402 .55 <.015 -- 1.01 

 37 12-05-95 13 .90 48 730 738 1.00 <.015 -- 2.60 

 38 10-19-95 8.3 .40 41 559 560 .76 <.015 -- .065 

 39 07-22-97 21 .44 59 359 390 .53 <.015 -- 2.61 

 40 10-18-95 3.3 .20 57 343 332 .45 <.015 -- 1.30 

 41 07-16-97 4.8 .19 54 354 376 .51 <.015 -- 2.70 

 42 07-22-97 4.6 .23 57 336 353 .48 <.015 -- 1.83 

 43 10-18-95 5.3 .90 52 336 344 .47 <.015 -- 1.60 

 44 06-25-97 2.5 .77 22 424 455 .62 .060 .08 .006 
Supplemental Data - Table 14 57

Table 14. Public-supply well water-quality data—Continued

 

 PHOS- BERYL- CADMIUM CHRO- 

 PHORUS ARSENIC BARIUM, LIUM, BORON, WATER CADMIUM MIUM, COBALT,

 DIS- DIS- DIS- DIS- DIS- UNFLTRD DIS- DIS- DIS- 

 SITE SOLVED SOLVED SOLVED SOLVED SOLVED TOTAL SOLVED SOLVED SOLVED 

 NUMBER DATE (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L 

 AS P) AS AS) AS BA) AS BE) AS B) AS CD) AS CD) AS CR) AS CO)

 (00666) (01000) (01005) (01010) (01020) (01027) (01025) (01030) (01035)

 1 09-26-96 .007 11 61 <.50 107 <1 <1.0 <5.0 <3.0 

 2 08-29-96 .006 3 69 <.50 57 <1 <1.0 8.0 <3.0 

 3 08-21-96 .007 4 63 <.50 65 <1 <1.0 5.0 <3.0 

 4 08-20-96 .004 4 60 1.0 65 <1 <1.0 6.0 <3.0 

 5 06-26-97 .007 5 143 <.50 36 <1 <1.0 <5.0 <3.0 

 6 08-22-96 .009 3 71 <.50 55 <1 <1.0 <5.0 <3.0 

 7 07-08-97 .007 4 22 <.50 158 <1 <1.0 <5.0 <3.0 

 8 09-05-96 .006 4 60 <.50 70 <1 <1.0 <5.0 <3.0 

 9 12-07-95 .011 8 28 <.50 80 <1 <1.0 <5.0 <3.0 

 10 09-09-96 .012 3 32 <.50 176 <1 <1.0 <5.0 <3.0 

 11 07-17-97 .002 6 83 <.50 53 <1 <1.0 <5.0 <3.0 

 12 07-23-97 .003 4 102 <.50 33 <1 <1.0 <5.0 <3.0 

 13 09-19-96 .074 7 64 <.50 94 <1 <1.0 5.0 <3.0 

 14 09-25-96 .077 11 65 <.50 93 <1 1.0 <5.0 <3.0 

 15 09-18-96 .070 11 65 <.50 91 <1 <1.0 <5.0 <3.0 

 16 09-12-96 .052 7 56 <.50 88 <1 <1.0 <5.0 <3.0 

 17 09-17-96 .026 7 66 <.50 87 <1 <1.0 <5.0 <3.0 

 18 07-08-97 .041 5 79 <.50 62 <1 <1.0 <5.0 <3.0 

 19 09-03-96 .052 10 87 <.50 66 <1 <1.0 <5.0 <3.0 

 20 09-03-96 .036 6 79 <.50 64 <1 <1.0 7.0 <3.0 

 21 11-30-95 .006 6 67 <.50 60 <1 <1.0 <5.0 <3.0 

 22 11-30-95 .001 6 68 <.50 70 <1 <1.0 <5.0 <3.0 

 23 11-08-95 .004 8 140 <.50 40 <1 <1.0 <5.0 <3.0 

 24 11-08-95 .005 8 130 <.50 50 <1 <1.0 <5.0 <3.0 

 25 11-29-95 .022 5 180 <.50 60 <1 <1.0 <5.0 <3.0 

 26 09-24-96 .015 8 46 <.50 169 <1 <1.0 <5.0 <3.0 

 27 11-29-95 .008 9 18 <.50 260 <1 <1.0 <5.0 <3.0 

 28 12-06-95 .022 3 35 <.50 70 <1 <1.0 <5.0 <3.0 

 29 07-09-97 .040 5 47 <.50 74 <1 <1.0 <5.0 <3.0 

 30 11-28-95 .033 21 41 <.50 300 <1 <1.0 <5.0 <3.0 

 31 11-28-95 .017 6 39 <.50 90 <1 <1.0 <5.0 <3.0 

 32 06-30-97 .027 7 79 <.50 102 <1 <1.0 <5.0 <3.0 

 33 06-30-97 .008 6 68 <.50 117 <1 <1.0 <5.0 <3.0 

 34 11-09-95 .030 6 79 <.50 100 <1 <1.0 <5.0 <3.0 

 35 07-01-97 .032 6 90 <.50 105 <1 <1.0 <5.0 <3.0 

 36 07-01-97 .008 7 61 <.50 122 <1 <1.0 <5.0 <3.0 

 37 12-05-95 .022 77 22 <.50 500 <1 <1.0 <5.0 <3.0 

 38 10-19-95 .074 13 120 <.50 250 <1 <1.0 <5.0 <3.0 

 39 07-22-97 .010 14 27 <.50 147 <1 <1.0 <5.0 <3.0 

 40 10-18-95 .009 5 10 <.50 110 <1 <1.0 <5.0 <3.0 

 41 07-16-97 .006 4 15 <.50 103 <1 1.5 <5.0 <3.0 

 42 07-22-97 .008 4 9.8 <.50 113 <1 <1.0 <5.0 <3.0 

 43 10-18-95 .029 6 26 <.50 90 <1 <1.0 <5.0 <3.0 

 44 06-25-97 .001 14 51 <.50 43 <1 <1.0 <5.0 20 
58 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 14. Public-supply well water-quality data—Continued

 

 MANGA- MOLYB- SELE- 

 COPPER, IRON, LEAD, LITHIUM NESE, MERCURY DENUM, NICKEL, NIUM, 

 DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- 

 SITE SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED

 NUMBER DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L 

 AS CU) AS FE) AS PB) AS LI) AS MN) AS HG) AS MO) AS NI) AS SE)

 (01040) (01046) (01049) (01130) (01056) (71890) (01060) (01065) (01145)

 1 09-26-96 <10 4.0 <10 24 <1.0 <.1 10 <10 5 

 2 08-29-96 <10 7.0 <10 29 <1.0 <.1 <10 <10 3 

 3 08-21-96 <10 <3.0 <10 32 <1.0 <.1 <10 <10 2 

 4 08-20-96 <10 3.0 <10 34 <1.0 <.1 <10 <10 2 

 5 06-26-97 <10 <3.0 <10 13 <1.0 <.1 <10 <10 <1 

 6 08-22-96 <10 <3.0 10 23 <1.0 <.1 10 <10 3 

 7 07-08-97 <10 8.1 <10 52 1.0 <.1 <10 <10 6 

 8 09-05-96 <10 <3.0 <10 46 <1.0 <.1 <10 <10 3 

 9 12-07-95 <10 <3.0 <10 38 <1.0 .2 <10 <10 3 

 10 09-09-96 <10 11 10 62 2.0 <.1 20 <10 16 

 11 07-17-97 <10 <3.0 <10 18 <1.0 <.1 <10 <10 <1 

 12 07-23-97 <10 <3.0 <10 13 <1.0 <.1 <10 <10 4 

 13 09-19-96 <10 <3.0 <10 42 3.0 <.1 10 <10 5 

 14 09-25-96 <10 <3.0 <10 42 4.0 <.1 <10 <10 7 

 15 09-18-96 <10 <3.0 <10 44 4.0 <.1 <10 <10 5 

 16 09-12-96 <10 <3.0 <10 39 <1.0 <.1 <10 <10 8 

 17 09-17-96 <10 <3.0 <10 41 <1.0 <.1 <10 <10 7 

 18 07-08-97 <10 <3.0 <10 35 1.5 <.1 <10 <10 3 

 19 09-03-96 <10 3.0 <10 31 <1.0 <.1 <10 <10 4 

 20 09-03-96 <10 <3.0 10 30 <1.0 <.1 <10 <10 3 

 21 11-30-95 <10 <3.0 <10 30 <1.0 <.1 <10 <10 2 

 22 11-30-95 <10 <3.0 <10 31 <1.0 <.1 <10 <10 2 

 23 11-08-95 <10 <3.0 <10 12 <1.0 <.1 <10 <10 <1 

 24 11-08-95 <10 <3.0 <10 10 <1.0 <.1 <10 <10 <1 

 25 11-29-95 <10 <3.0 <10 23 <1.0 <.1 <10 <10 2 

 26 09-24-96 <10 5.0 <10 43 <1.0 <.1 <10 <10 5 

 27 11-29-95 <10 3.0 <10 61 <1.0 <.1 10 <10 3 

 28 12-06-95 <10 <3.0 <10 48 <1.0 <.1 <10 <10 4 

 29 07-09-97 <10 <3.0 <10 44 <1.0 <.1 <10 <10 2 

 30 11-28-95 <10 <3.0 <10 50 <1.0 <.1 <10 <10 10 

 31 11-28-95 <10 4.0 <10 21 <1.0 <.1 <10 <10 2 

 32 06-30-97 <10 7.9 <10 31 <1.0 <.1 <10 <10 1 

 33 06-30-97 <10 <3.0 <10 28 <1.0 <.1 <10 <10 3 

 34 11-09-95 30 26 <10 29 <1.0 <.1 <10 <10 1 

 35 07-01-97 <10 <3.0 12 30 <1.0 <.1 14 <10 1 

 36 07-01-97 <10 13 <10 30 <1.0 <.1 <10 <10 3 

 37 12-05-95 <10 <3.0 <10 51 <1.0 <.1 20 <10 11 

 38 10-19-95 <10 <3.0 20 59 8.0 <.1 20 <10 <1 

 39 07-22-97 <10 <3.0 <10 50 1.3 <.1 <10 <10 9 

 40 10-18-95 <10 <3.0 <10 45 <1.0 <.1 <10 <10 3 

 41 07-16-97 <10 <3.0 <10 48 <1.0 <.1 <10 <10 2 

 42 07-22-97 <10 <3.0 <10 47 <1.0 <.1 <10 <10 3 

 43 10-18-95 <10 20 10 40 <1.0 <.1 <10 <10 2 

 44 06-25-97 <10 2600 <10 53 84 <.1 12 <10 <1 
Supplemental Data - Table 14 59

Table 14. Public-supply well water-quality data—Continued

 GROSS

 ALPHA ALPHA GROSS ALPHA, 

 THAL- STRON- VANA- RADIO. COUNT, ALPHA, COUNT, 

 SILVER, LIUM, TIUM, DIUM, ZINC, WATER 2 SIGMA DIS- 2 SIGMA

 DIS- DIS- DIS- DIS- DIS- DISS WAT DIS SOLVED WAT DIS

 SITE SOLVED SOLVED SOLVED SOLVED SOLVED AS AS (UG/L AS 

 NUMBER DATE (UG/L (UG/L (UG/L (UG/L (UG/L TH-230 TH-230 AS NAT U 

 AS AG) AS TL) AS SR) AS V) AS ZN) (PCI/L) (PCI/L) U-NAT) (UG/L) 

 (01075) (01057) (01080) (01085) (01090) (04126) (75987) (80030) (75986)

 1 09-26-96 <1.0 <.50 470 7 22 3.5 2.8 -- -- 

 2 08-29-96 <1.0 <.50 540 <6 8.0 6.6 3.1 -- -- 

 3 08-21-96 <1.0 <.50 470 8 7.0 3.9 2.5 -- -- 

 4 08-20-96 <1.0 <.50 420 <6 13 6.3 3.0 -- -- 

 5 06-26-97 <1.0 <.50 314 6 3.1 <3.0 2.2 -- -- 

 6 08-22-96 <1.0 <.50 610 <6 8.0 6.0 3.2 -- -- 

 7 07-08-97 <1.0 <.50 452 <6 28 22 5.8 -- -- 

 8 09-05-96 1.0 <.50 390 <6 22 6.5 3.1 -- -- 

 9 12-07-95 6.0 <.50 360 10 <3.0 6.9 3.2 9.5 4.5 

 10 09-09-96 <1.0 <.50 1100 <6 12 35 9.8 -- -- 

 11 07-17-97 <1.0 <.50 404 9 72 6.1 3.2 -- -- 

 12 07-23-97 <1.0 <.50 326 <6 161 3.3 2.5 -- -- 

 13 09-19-96 <1.0 <.50 520 16 <3.0 6.6 3.6 -- -- 

 14 09-25-96 <1.0 <.50 520 7 6.0 11 4.4 -- -- 

 15 09-18-96 <1.0 <.50 530 7 <3.0 5.6 3.4 -- -- 

 16 09-12-96 <1.0 <.50 390 13 15 9.0 3.9 -- -- 

 17 09-17-96 <1.0 <.50 510 14 9.0 8.5 3.8 -- -- 

 18 07-08-97 <1.0 <.50 675 <6 <3.0 13 4.4 -- -- 

 19 09-03-96 <1.0 <.50 630 12 13 7.0 3.4 -- -- 

 20 09-03-96 <1.0 <.50 580 9 16 12 4.3 -- -- 

 21 11-30-95 <1.0 <.50 640 6 <3.0 7.3 2.8 9.9 3.8 

 22 11-30-95 <1.0 <.50 570 7 4.0 9.1 3.3 12 4.3 

 23 11-08-95 <1.0 <.50 350 10 26 6.2 2.3 9.8 3.4 

 24 11-08-95 <1.0 <.50 310 14 <3.0 6.0 2.1 7.8 2.7 

 25 11-29-95 <1.0 <.50 700 <6 <3.0 4.6 2.2 6.4 3.0 

 26 09-24-96 <1.0 <.50 280 8 30 15 4.4 -- -- 

 27 11-29-95 <1.0 <.50 74 <6 9.0 15 5.1 21 7.4 

 28 12-06-95 <1.0 <.50 800 <6 4.0 26 6.5 37 9.2 

 29 07-09-97 <1.0 <.50 829 <7 <5.1 19 5.7 -- -- 

 30 11-28-95 <1.0 <.50 240 230 <3.0 30 9.6 41 14 

 31 11-28-95 <1.0 <.50 420 19 <3.0 12 3.7 19 5.8 

 32 06-30-97 <1.0 <.50 483 <6 <3.0 13 4.9 -- -- 

 33 06-30-97 <1.0 <.50 311 <6 <3.0 10 4.0 -- -- 

 34 11-09-95 <1.0 <.50 490 <6 3.0 10 4.1 14 5.6 

 35 07-01-97 <1.0 <.50 486 <6 <3.0 16 5.1 -- -- 

 36 07-01-97 <1.0 <.50 341 <6 <3.0 8.4 3.7 -- -- 

 37 12-05-95 <1.0 <.50 100 110 12 34 10 45 14 

 38 10-19-95 <1.0 <.50 230 <6 10 6.1 3.6 8.4 5.0 

 39 07-22-97 <1.0 <.50 114 12 63 8.9 3.7 -- -- 

 40 10-18-95 <1.0 <.50 65 7 12 13 3.7 18 5.3 

 41 07-16-97 <1.0 <.50 72 <6 3.4 16 4.6 -- -- 

 42 07-22-97 <1.0 <.50 60 6 4.5 11 4.0 -- -- 

 43 10-18-95 <1.0 <.50 120 10 130 8.8 3.4 12 4.8 

 44 06-25-97 <1.0 <.50 1280 <6 <3.0 8.4 3.8 -- -- 
60 Water Quality of Springs and Public-Supply Wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

Table 14. Public-supply well water-quality data—Continued

 GROSS BETA, GROSS BETA, RA-226, 

 BETA, 2 SIGMA BETA, 2 SIGMA DIS- 

 DIS- WATER, DIS- WATER, SOLVED, RA-226 U-238

 SOLVED DISS, SOLVED DISS, PLAN- 2 SIGMA U-238 2 SIGMA

 SITE (PCI/L AS (PCI/L AS SR90 CHET WATER, WATER, WATER

 NUMBER DATE AS CS-137 AS SR/ /Y90 COUNT DISS, DISS, DISS,

 CS-137) (PCI/L) Y-90) (PCI/L (PCI/L) (PCI/L) (PCI/L) (PCI/L)

 (03515) (75989) (80050) (75988) (09510) (76001) (22603) (75991)

 1 09-26-96 21 5.9 -- -- <.1 -- -- --

 2 08-29-96 28 6.8 -- -- <.1 -- -- --

 3 08-21-96 26 6.2 -- -- <.1 -- -- --

 4 08-20-96 25 6.0 -- -- <.1 -- -- --

 5 06-26-97 9.6 4.1 -- -- <.1 -- -- --

 6 08-22-96 24 6.8 -- -- <.1 -- -- --

 7 07-08-97 32 5.2 -- -- <.1 -- -- --

 8 09-05-96 31 7.7 -- -- <.1 -- -- --

 9 12-07-95 23 3.3 18 2.5 <.1 -- -- --

 10 09-09-96 51 13 -- -- <.1 -- -- --

 11 07-17-97 15 4.3 -- -- <.1 -- -- --

 12 07-23-97 9.2 4.1 -- -- <.1 -- -- --

 13 09-19-96 31 8.4 -- -- <.1 -- -- --

 14 09-25-96 36 10 -- -- <.1 -- -- --

 15 09-18-96 29 7.9 -- -- <.1 -- -- --

 16 09-12-96 32 8.8 -- -- <.1 -- -- --

 17 09-17-96 21 6.8 -- -- <.1 -- -- --

 18 07-08-97 16 4.5 -- -- <.1 -- -- --

 19 09-03-96 24 6.5 -- -- <.1 -- -- --

 20 09-03-96 24 6.2 -- -- <.1 -- -- --

 21 11-30-95 9.4 2.1 7.2 1.2 <.1 -- -- --

 22 11-30-95 11 2.4 8.4 1.3 <.1 -- -- --

 23 11-08-95 8.9 2.1 6.8 1.2 <.1 -- -- --

 24 11-08-95 9.5 2.1 7.2 1.2 <.1 -- -- --

 25 11-29-95 12 2.5 8.5 2.7 <.1 -- -- --

 26 09-24-96 22 5.6 -- -- <.1 -- -- --

 27 11-29-95 21 3.1 16 2.4 <.1 -- 7.5 .83

 28 12-06-95 28 3.9 21 2.9 <.1 -- 9.1 1.3

 29 07-09-97 21 4.8 -- -- <.1 -- -- --

 30 11-28-95 21 3.6 16 2.8 <.1 -- 7.4 .82

 31 11-28-95 13 2.9 9.8 3.0 <.1 -- 5.9 .65

 32 06-30-97 24 4.9 -- -- <.1 -- -- --

 33 06-30-97 20 4.6 -- -- <.1 -- -- --

 34 11-09-95 21 3.2 16 2.4 <.1 -- -- --

 35 07-01-97 23 4.8 -- -- <.1 -- -- --

 36 07-01-97 21 4.7 -- -- <.1 -- -- --

 37 12-05-95 23 4.0 18 3.0 <.1 -- 15 1.8

 38 10-19-95 18 3.3 14 2.5 <.1 -- -- --

 39 07-22-97 15 4.4 -- -- <.1 -- -- --

 40 10-18-95 13 3.2 10 2.0 <.1 -- -- --

 41 07-16-97 21 4.6 -- -- <.1 -- -- --

 42 07-22-97 14 4.3 -- -- <.1 -- -- --

 43 10-18-95 16 3.6 12 3.5 <.1 -- -- --

 44 06-25-97 9.1 4.2 -- -- 11 2.21 -- --
Supplemental Data - Table 14 61

Table 14. Public-supply well water-quality data—Continued

 URANIUM URANIUM

 U-234 U-235 NATURAL NATURAL

 U-234 2 SIGMA U-235 2 SIGMA DIS- 2 SIGMA

 SITE WATER WATER WATER WATER SOLVED WATER,

 NUMBER DATE DISS, DISS, DISS, DISS, (UG/L DISS,

 (PCI/L) (PCI/L) (PCI/L) (PCI/L) AS U) (UG/L)

 (22610) (75992) (22620) (75994) (22703) (75990)

 1 09-26-96 -- -- -- -- 6.7 2.1

 2 08-29-96 -- -- -- -- 18 5.3

 3 08-21-96 -- -- -- -- 9.6 2.8

 4 08-20-96 -- -- -- -- 10 3.1

 5 06-26-97 -- -- -- -- 3.4 1.1

 6 08-22-96 -- -- -- -- 12 3.6

 7 07-08-97 -- -- -- -- 16 4.4

 8 09-05-96 -- -- -- -- 6.8 2.0

 9 12-07-95 -- -- -- -- 18 5.3

 10 09-09-96 -- -- -- -- 59 18

 11 07-17-97 -- -- -- -- 6.0 1.8

 12 07-23-97 -- -- -- -- 5.3 1.6

 13 09-19-96 -- -- -- -- 13 3.9

 14 09-25-96 -- -- -- -- 11 3.3

 15 09-18-96 -- -- -- -- 16 4.6

 16 09-12-96 -- -- -- -- 11 3.1

 17 09-17-96 -- -- -- -- 15 4.4

 18 07-08-97 -- -- -- -- 15 4.2

 19 09-03-96 -- -- -- -- 13 3.7

 20 09-03-96 -- -- -- -- 15 4.3

 21 11-30-95 -- -- -- -- 9.4 2.8

 22 11-30-95 -- -- -- -- 6.7 2.0

 23 11-08-95 -- -- -- -- 6.1 1.8 

 24 11-08-95 -- -- -- -- 7.1 2.2 

 25 11-29-95 -- -- -- -- 11 3.3

 26 09-24-96 -- -- -- -- 31 9.1

 27 01-29-95 14 1.5 .3 .07 22 6.4

 28 12-06-95 18 2.2 .2 .14 28 8.1

 29 07-09-97 -- -- -- -- 18 5.2

 30 11-28-95 16 1.7 .3 .06 24 6.8

 31 11-28-95 11 1.1 .2 .05 20 5.9

 32 06-30-97 -- -- -- -- 13 3.8

 33 06-30-97 -- -- -- -- 12 3.3

 34 11-09-95 -- -- -- -- 16 4.8

 35 07-01-97 -- -- -- -- 10 3.0

 36 07-01-97 -- -- -- -- 11 3.1

 37 12-05-95 27 3.1 .9 .23 57 16

 38 10-19-95 -- -- -- -- 11 3.1

 39 07-22-97 -- -- -- -- 11 3.3

 40 10-18-95 -- -- -- -- 20 6.1

 41 07-16-97 -- -- -- -- 14 4.0

 42 07-22-97 -- -- -- -- 12 3.4

 43 10-18-95 -- -- -- -- 13 3.8

 44 06-25-97 -- -- -- -- <1.0 .3

 1The term acid neutralizing capacity (ANC) is applied to the acid-neutralizing capacity of

 solutes plus particulates in a water sample, reported in equivalents, and normally titrated

 on an unfiltered sample.