Hydraulic Properties of Mt. Simon 

Aquifer, Prairie Island Indian 

Community, Southeastern Minnesota, 

2001

By T.A. Winterstein

Water-Resources Investigations Report 02-4263

Prepared in cooperation with the Prairie Island Indian Community
U.S. DEPARTMENT OF THE INTERIOR

Gale A. Norton, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

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.

Mound View, Minnesota, 2002

For additional information write to:

U.S. Geological Survey

District Chief

2280 Woodale Drive

Mounds View, MN 55112

Copies of this report can be purchased from:

U.S. Geological Survey

Branch of Information Services

Box 25286, MS 517

Federal Center

Denver, CO 80225

Information regarding the USGS is available on the Internet via the World Wide Web. 

You may connect to the USGS Home Page using the Universal Resource Locator (URL) at 

http://wwwrvares.er.usgs.gov. 

You may also connect to the Minnesota District Home Page at 

http://mn.water.usgs.gov/.

For more information on all USGS reports and 

products (including maps, images, and computerized data), call 1-888-ASK-USGS

Water-Resources Investigations Report 02-4263
iii

Contents

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

Introduction........................................................................................................................................................... 1

Hydrogeologic Setting ...................................................................................................................................................................... 3

Aquifer-test design ............................................................................................................................................................................. 3

Aquifer-test analysis and hydraulic properties ..........................................................................................................................6

Summary ............................................................................................................................................................................................. 10

References Cited ............................................................................................................................................................................... 11

Supplemental Information.............................................................................................................................................................. 12

Illustrations

Figure 1. Map showing locations of study area, water-supply and observation wells, Prairie Island Indian Community, 

Minnesota ................................................................................................................................................................................. 2

Figure 2. Schematic and showing lithology at Water-Supply Well No. 3 and observation well and generalized geologic section, 

Prairie Island Indian Community, Minnesota........................................................................................................................... 4

Fiugres 3–5. Log-log scale showing:

3. Measured water levels in Water-Supply Well No. 3 and the observation well, Prairie Island Indian Community,

 Minnesota, September 10-11, 2001 .................................................................................................................................... 6

4.The fitted Hantush type curve and measured water levels in Water-Supply Well No. 3 and the observation well, 

Prairie Island Indian Community, Minnesota, September 10-11, 2001............................................................................... 9

5. The fitted Theis type curve and measured water levels in Water-Supply Well No. 3 and the observation well, 

Prairie Island Indian Community, Minnesota, September 10-11, 2001............................................................................. 10

Tables

Table 1. Stratigraphy at Water-Supply Well No. 3 and the observation well, Prairie Island Indian Community, Minnesota................. 5

Table 2. Measured water levels in Water-Supply Well No. 3, Prairie Island Indian Community, Minnesota, 

September 10-11, 2001............................................................................................................................................................... 7

Table 3. Selected measured water levels in the observation well, Prairie Island Indian Community, Minnesota,

 September 10-11, 2001.............................................................................................................................................................. 8

Conversion Factors

Foot (ft) 0.3048 meter

Foot per day (ft/d) 0.0348 meter per day

Foot squared per day (ft2/d) 0.09290 meter squared per day

Gallon(gal) 3.785 liter

Pound (lb) 0.4536 kilogram

Sea level: Vertical coordinate information is referenced to the North American Vertical Datum of 1988.
iv
1

	





















ABSTRACT

An aquifer test of the Mt. Simon aquifer was conducted at the northern end of the Prairie Island Indian Community, in cooperation with the Prairie Island Indian Community, September 10-11, 2001 to determine hydraulic 

properties. Two wells at the northern end of Prairie Island were used in the aquifer test. A production well, 

Water-Supply Well No. 3, completed in the Mt. Simon aquifer, was pumped for 24 hours at 1,530 gal/min. Drawdown and recovery water levels were measured in the pumped well and in an observation well located 458 ft 

from the pumped well that was open to the Mt. Simon aquifer. Recovery water levels were measured in both 

wells for 10 hours after pumping ceased at Water-Supply Well No. 3.

Hantush and Theis methods type curves were fitted to the measured drawdown and recovery curves in the 

observation well. The results of matching the type curves to the measured data indicate that leakage is negligible 

from the overlying Eau Claire confining unit into the Mt. Simon aquifer. The transmissivity and storage coefficients for the Mt. Simon aquifer, determined by both methods, are 3, 000 ft2

/d and 3 x 10-4, respectively. The 

average hydraulic conductivity, assuming an aquifer thickness of 233 ft, is 10 ft/d. 

INTRODUCTION

The Mt. Simon aquifer is the 

major source of water for the Prairie Island Indian Community (fig. 

1). Woodward (1986) estimated 

transmissivities of 2,000-4,000 

ft2

/d for the portion of the aquifer 

in the Prairie Island area, but additional information about the 

hydraulic properties of the aquifer 

is needed. The U.S. Geological 

Survey, in cooperation with the 

Prairie Island Indian Community, 

conducted an aquifer test on September 10-11, 2001 to better define 

the hydraulic properties of the Mt. 

Simon aquifer at the northern end 

of Prairie Island. Information from 

the test will be useful to tribal officials for development of Community water-management plans, to 

non-tribal government officials for 

development of regional watermanagement plans, and to waterresource investigators for subsequent studies on the hydraulic 

properties of the aquifer. 

The propose of this report is to 

describe the aquifer-test design 

and analysis and to present the 

hydraulic properties of the Mt. 

Simon aquifer at the northern end 

of Prairie Island determined from 

the aquifer test. The test was conducted by pumping water from a 

newly completed production well 

(Water-Supply Well No. 3) in the 

Mt. Simon aquifer during a 24-

hour period and measuring the 

drawdown in one observation well 

and the pumped well. Recovery 

water levels in the observation 

well and pumped well were measured for 10 hours. The study area 

is located in southeastern Minnesota between the Mississippi and 

Vermillion Rivers about 40 miles 

southeast from the Twin Cities 

metropolitan area (fig. 1). 
2

North

Lake

Sturgeon

Lake

Clear

Lake

Larson Lake

Nelson

Lake

Upper

Clear

Lake

Mississippi

River

Vermillion

River

Spring

Banks

Lake

33 34 35 36 31 32

1 6 5 2 3 4

28 27 26 25 30

21 22 23 24

16 15 14

9 10 11

R 16 W R 15 W

T

114

N

T

113

N

DAKOTA CO.

GOODHUE CO.

DAKOTA CO.

GOODHUE CO.

WISCONSIN

MINNESOTA

Observation

well

WaterSupply

Well No. 3

44°38'

44°40'

92°44' 92°42' 92°40' 92°38'

0123 MILES

0 1 2 3 KILOMETERS

Prairie

Island

Locations of study area and water-supply and observation wells, Prairie Island Indian Community, Minnesota.

Prairie Island Indian Community

EXPLANATION

Base from Minnesota Department of Transportation digital data 1:24,000,

Base Map 97 revised 1997

Universal Transverse Mercator projection, North American Datum 1983

WISCONSIN

MINNESOTA

River

Minnesota

River

Lake Superior

94°

92°

90°

96°

48°

46°

44°

Study

Area

Location Map

Mississippi

Minneapolis St. Paul

Red Wing

Figure 1.
3

HYDROGEOLOGIC SETTING

The geologic units near WaterSupply Well No. 3 include thick 

glacial outwash and four bedrock 

units of Late Cambrian age (fig. 

2). The bedrock units are, in 

descending order, the Franconia 

Formation, the Ironton and Galesville Sandstones, the Eau Claire 

Formation, and the Mt. Simon 

Sandstone. The Mt. Simon aquifer 

consists of the Mt. Simon Sandstone. The thickness of the geologic units are listed in table 1. The 

following description of the bedrock units is from Mossler and 

Tipping (2000). 

The upper part of the Franconia 

Formation consists of sandstone 

and may be 100 ft thick in the 

southeastern part of the Twin Cities metropolitan area. The lower 

part consists of interlayered shale, 

siltstone, and lesser amounts of 

sandstone as thick as 30 ft that 

overlie sandstone interlayered with 

dolostone, also as thick as 30 ft. 

The contact with the underlying 

Ironton Sandstone is sharply 

defined, but apparently conformable. 

The Ironton and Galesville 

Sandstones consist of sandstone 

interlayered with scattered thin 

beds of shale. Although separated 

by a disconformity, the two sandstones cannot be distinguished 

with certainty where geologic control consists of drill cuttings alone. 

The Eau Claire Formation can 

be divided into three intervals. The 

upper one-third to one-fourth of 

the formation is sandstone interlayered with scattered thin partings 

of shale. The middle one-fourth to 

one-third of the formation consists 

of siltstone, sandstone, and shale. 

The basal one-third to one-half of 

the formation consists of sandstone and siltstone. The Eau Claire 

Formation has a conformable contact with the underlying Mt. Simon 

Sandstone. 

The upper one-fifth of the Mt. 

Simon Sandstone consists of 

medium to thick, locally crossstratified beds of fine- to mediumgrained, moderately-sorted to 

well-sorted quartz sandstone interlayered with thin beds of graygreen shale, very fine-grained feldspathic sandstone and siltstone, 

and fine- to coarse-grained, silty, 

poorly-sorted, thick-bedded to 

massive quartzose to feldspathic 

sandstone.

The middle one-third to twofifths of the Mt. Simon Sandstone 

consists of thick, crudely planar or 

cross-stratified beds of fine- to 

coarse-grained, moderately-sorted 

quartz sandstone interlayered with 

thin to very thick (as thick as 8 ft) 

beds of very fine-grained to finegrained, well-sorted, feldspathic 

sandstone. The feldspathic sandstone is, in turn, interlayered with 

thin beds of green-gray, silty shale. 

Granule-sized grains of quartz or, 

rarely, intraclasts of siltstone and 

very fine-grained sandstone define 

the lower parts of the thick, 

coarser-grained sandstone beds. 

The lower one-half of the Mt. 

Simon Sandstone consists of 

medium to thick cross-stratified 

beds of medium- to very coarsegrained, moderately sorted to wellsorted quartz sandstone. The interval contains thin intercalated 

lenses of granule- to pebble-sized 

quartz and scattered thin beds of 

light-gray siltstone and red-brown 

to pale-red to green-gray shale. A 

basal conglomerate as thick as 6 ft 

marks the base of the Mt. Simon 

Sandstone. 

Sufficient amounts of borehole 

and well data are not available to 

describe the geologic units underlying the Mt. Simon Sandstone in 

the Prairie Island area (Bruce 

Bloomgren, Minnesota Geological Survey, oral commun., 2001). 

In some areas of the MinneapolisSt. Paul metropolitan area the Mt. 

Simon Sandstone overlies the 

crystalline bedrock of Proterozoic 

age, in other areas the Mt. Simon 

Sandstone overlies the Hinckley 

Sandstone, the Fond du Lac Formation, or the Solor Church Formation of middle Proterozoic age 

(Bruce Bloomgren, Minnesota 

Geological Survey, oral commun., 

2001). Samples from a few deep 

water-supply wells that penetrated 

the entire thickness of the Mt. 

Simon Sandstone beneath the city 

of Red Wing, located about 12 

miles southwest of Prairie Island, 

indicate that the rocks underlying 

the Mt. Simon Sandstone are the 

Hinckley Sandstone or the Fond 

du Lac Formation (Runkel, 1998). 

AQUIFER-TEST DESIGN

Two wells were used in the 

aquifer test (fig. 1). The pumped 

well, Water-Supply Well No. 3, is 

cased from land surface to a depth 

of 480 ft and is open to the Mt. 

Simon aquifer from a depth of 480 
4

ALTITUDE, IN FEET

ABOVE SEA LEVEL

SW NE Vermillion River Lake

Sturgeon Lake

Mississippi River

Prairie Island

MINNESOTA WISCONSIN

Lithology at Water-Supply Well No. 3 and the observation well and generalized geologic-section, Prairie Island Indian

Community, Minnesota.

VERTICAL EXAGGERATION 10 X From Cowdery, 1999.

Dashed where approximate

Prairie du Chien Group

(limestone)

Jordan Sandstone

Franconia Formation

(silty, shaly sandstone)

St. Lawrence Formation (sandy limestone) LS Glacial outwash Lake sediments (LS)

(mostly sand and gravel)

400

500

600

700

800

900

1,000

1,100

0

0

1

1

MILE

KILOMETER

PALEOZOIC

CAMBRIAN

FRANCONIA

FORMATION

IRONTON AND

GALESVILLE

SANDSTONES

EAU CLAIRE

FORMATION

MT SIMON

SANDSTONE

GLACIAL

OUTWASH

EON

AND

ERA

PERIOD GEOLOGIC

UNIT

GENERALIZED

LITHOLOGY

HYDROGEOLOGIC UNIT AND

WATER-BEARING CHARACTERISTICS

100

200

300

400

500

600

700

0

DEPTH BELOW LAND SURFACE, IN FEET

GLACIAL OUTWASH–Used primarily for domestic and farm

purposes on Prairie Island. The aquifer is composed of wellsorted sands and gravels that contain a few, small, local,

fine-grained lenses that are most numerous at the land and

bedrock surfaces. (Cowdery, 1999)

FRANCONIA CONFINING UNIT–Vertical hydraulic conductivity is impeded by silty or shaly beds.

IRONTON-GALESVILLE AQUIFER––Yields range from 100 to

500 gal/min.

EAU CLAIRE CONFINING UNIT–Hydraulic conductivity is

poorly known.

MOUNT SIMON AQUIFER–Well yields generally range from

200 to 700 gal/min. Locally, as much as 2,000 gal/min may be

obtained.

Depth and thickness of geologic units from geophysical log of observation well (B. Bloomgren, Minnesota Geological Survey, written commun.,

2001, water-bearing characteristics from Woodward, 1986, except where noted.

EXPLANATION OF LITHOLOGY AT WATER-SUPPLY WELL NO. 3

Glacial outwash Sandstone Silty, shale sandstone

Figure 2.
5

ft to 701 ft. The observation well is 

located 458 ft south of the WaterSupply Well No. 3 and is cased 

from land surface to a depth of 480 

ft and is open to the Mt. Simon 

aquifer from a depth of 480 ft to 

602 ft. The stratigraphy at the 

wells is shown in table 1.

Water-Supply Well No. 3 was 

pumped at 1,530 gal/min for 24 

hours. The pumping began on September 10, 2001 at 07:00. The 

pump was shut off at 07:02 September 11, 2001. The aquifer test 

ended at 17:03 September 11, 

2001. 

Water-Supply Well No. 3 was 

flowing under artesian conditions 

before the start of the test. The 

pumping rate was monitored by an 

orifice meter in the discharge line 

from the pump. Drawdown in 

Water-Supply Well No. 3 was 

measured as the depth of water 

below an initial measuring point 

on the well drilling platform at the 

well casing. Drawdown was measured with an electric tape every 5 

minutes from 07:00 to 07:30 September 10, every half hour from 

07:30 to 09:00, and every hour 

afterwards. When the pump was 

shut off, the depth to water was 

measured at intervals between 1.5 

and 5.5 minutes from 07:05 to 

07:29 September 11, 2001 and 

every half-hour thereafter to the 

end of the test. The well started 

flowing between 14:00 and 14:51 

September 11, 2001 before the end 

of the aquifer test. Water flowing 

from the well under artesian conditions was drained through a pipe 

attached to the well casing about 4 

ft below the measuring point. The 

overflow water was discharged to 

a field about 200 ft from the well. 

The drawdown and recovery water 

levels measured in Water-Supply 

Well No. 3 are shown in figure 3 

and listed in table 2. 

The observation well is under 

artesian conditions and was 

capped at the beginning of the test 

to prevent it from flowing. Drawdown below static head in the well 

was measured with a vented transducer every second and recorded 

every 90 seconds or when the pressure changed more than 0.004 

lb/ft2. Static head in the well was 

determined before the start of the 

aquifer test. Twelve minutes after 

the start of the aquifer test, when 

the water surface was below land 

surface, the valve on the cap was 

opened allowing air into the well 

to equalize the pressure above the 

water to atmospheric pressure. At 

least twice each hour the depth to 

the water was measured with a 

steel tape. The total drawdown in 

the observation well after 24 hours 

of pumping was 39.26 ft below 

static head. The water levels in the 

observation well began to recover 

about 12 minutes after pumping 

ceased at Water-Supply Well No. 

3. The water level recovered 

30.94 ft, but was still below land 

surface, when the transducer was 

pulled after 10 hours of recovery. 

Selected water levels measured in 

the observation well are listed in 

table 3 and shown in figure 3.

Water from Water-Supply Well 

No. 3 was discharged during the 

aquifer test to a holding pond 800 

ft from the well. The water in the 

holding pond seeped into the 

ground. The surficial aquifer is 

separated by two confining units 

from the Mt. Simon aquifer. As a 

result, recharge to the Mt. Simon 

aquifer by the discharged water 

was not assumed to be a factor 

during the aquifer-test analysis. 

Table 1. Stratigraphy at Water-Supply Well No. 3 and the observation well, Prairie Island Indian Community, Minnesota

 [ft, feet; --,does not apply; >, greater than; Data from Bruce Bloomgren, Minnesota Geological Survey, written comm., 2001]

Geologic unit Hydrogeologic unit

Water-Supply Well No. 3 Observation well

Depth below land 

surface

(ft)

Thickness

(ft)

Depth below land 

surface

(ft)

Thickness

(ft)

Glacial outwash Glacial outwash aquifer 0-167 167 0-168 168

Franconia Formation Franconia Confining Unit 167-291 124 168-290 122

Ironton-Galesville Sandstones Ironton-Galesville Aquifer 291-346 55 290-345 55

Eau Claire Formation Eau Claire Confining Unit 346-468 122 345-470 125

Mt. Simon Sandstone Mt. Simon Aquifer 468-701

(bottom of hole) > 233 470-602 

(bottom of hole) > 132
6

AQUIFER-TEST ANALYSIS 

AND HYDRAULIC 

RESOURCES

For aquifer-test analyses, it was 

assumed that Water-Supply Well 

No. 3 fully penetrates the Mt. 

Simon aquifer and that the aquifer 

consists only of the Mt. Simon 

Sandstone. The Mt. Simon aquifer 

is at least 233 ft thick and WaterSupply Well No. 3 is open to 221 ft 

of the aquifer. The observation 

well partially penetrates the Mt. 

Simon aquifer for 132 ft. The 

amount of water that flowed under 

artesian conditions from WaterSupply Well No. 3 was very small 

compared to the amount of water 

pumped from the well and was 

Measured water levels in Water-Supply Well No. 3 and the observation well, Prairie Island Indian Community,

Minnesota, September 10-11, 2001

TIME FROM BEGINNING OF AQUIFER TEST, IN MINUTES

DEPTH OF WATER BELOW INITIAL MEASURING POINT OR STATIC HEAD, IN FEET

1 10 100 1,000 10,000

0.01

0.1

1

10

100

1000

Observation well measurements

Water-Supply Well No. 3 measurements

EXPLANATION

Figure 3.
7

aquifer from the overlying Eau 

Claire confining unit. 

The Theis and Hantush type 

curves were fitted simultaneously 

to the measured water levels in 

Water-Supply Well No. 3 and the 

observation well (figs. 4 and 5) to 

determine hydraulic properties of 

the Mt. Simon aquifer. The horizontal axis in the figures is time, 

in minutes, divided by the square 

of the distance of the measured 

well from the pumped well, in 

feet. The distance from the 

assumed to not significantly affect 

the aquifer test.

The computer software AQTESOLV (Hydrolsolve, 2000) was 

used to fit several type curves to the 

observed drawdown and recovery 

curves at the observation well. For 

initial analyses type curves from 

Theis (1935), Cooper and Jacob 

(1946), Hantush (1960) and Neuman and Witherspoon (1969) were 

fitted to the observed curves. Two 

type curves, Theis and Hantush, 

were selected for further analyses. 

The automatic curve fitting routine 

in AQTESOLV was used to fit the 

two type curves to the measured 

drawdown and recovery curves. 

AQTESOLV performs nonlinear 

weighted least-squared parameter 

estimation (Hydrosolve, 2000) to fit 

the type curves to the measured 

curves. AQTESOLV uses the 

method derived by Hantush (1961a, 

b) to correct for the partial penetration of the aquifer by the observation well (Hydrosolve, Inc., 2000).

The assumptions for the Hantush 

and Theis type curves and the equations defining the type curves are in 

the supplemental information section of this report. A major assumption for the Hantush type curve is 

that the Mt. Simon aquifer is leaky, 

which means that water flows from 

the overlying Eau Claire confining 

unit into the Mt. Simon aquifer 

(Hantush, 1960). The inflowing 

water comes either from storage in 

the Eau Claire confining unit or 

from the Ironton-Galesville aquifer 

that overlies the Eau Claire confining unit. The Theis type curve represents the limiting case where no 

water flows into the Mt. Simon 

Table 2. Measured water levels in Water-Supply Well No. 3, Prairie Island Indian 

Community, Minnesota, Septermber 10-11, 2001

Time since 

pumping began 

(minutes)

Depth below 

measuring 

point(feet)

Time since pumping 

began (minutes)

Depth below 

measuring 

point(feet)

0 4.371

1Well is flowing

1,080 135.77

5 83.7 1,140 136.45

10 87.82 1,200 136.78

15 96.92 1,260 137.57

20 100.68 1,320 137.65

25 101.5 1,380 138.00

30 102.49 1,440 138.43

60 109.53 1,441.752

2Pumping ceased

138.43

90 111.58 1,445.0 50.77

120 112.89 1,446.5 45.8

180 118.52 1,448.5 41.81

240 120.96 1,454.0 35.8

300 123.21 1,458.5 32.43

360 123.92 1,508 20.68

420 125.78 1,543 16.97

480 127.44 1,581 14.38

540 128.55 1,628 11.87

600 129.74 1,657 10.68

660 130.96 1,688 9.48

720 131.72 1,723 8.28

780 132.10 1,748 7.57

840 133.80 1,787 6.59

900 134.28 1,860 4.93

960 134.65 1,911 4.443

3Well is flowing

1,020 135.15
8

Table 3. Selected measured water levels in the observation well, Prairie Island 

Indian Community, Minnesota, September 10-11, 2001

Elapsed time 

from beginning of 

aquifer test

(minutes)

Depth below static 

head (feet)

Elapsed time from 

beginning of 

aquifer test

(minutes)

Depth below static 

head (feet)

0.00 0.00 200.10 21.51

1.50 0.00 224.67 22.45

2.30 0.01 251.38 23.40

2.53 0.02 282.00 24.38

2.95 0.05 320.78 25.48

3.30 0.07 353.43 26.29

3.55 0.10 403.07 27.46

3.98 0.16 452.23 28.52

4.48 0.26 506.68 29.51

5.07 0.42 568.20 30.53

5.58 0.56 635.52 31.58

6.32 0.82 711.38 32.64

7.15 1.13 796.50 33.68

7.97 1.45 892.40 34.80

8.98 1.84 1,014.00 35.98

10.12 2.27 1,135.18 37.00

11.23 2.68 1,268.13 38.06

12.68 3.19 1,417.50 39.10

14.33 3.74 1,440.25 39.26

15.87 4.25 1,462.98 32.28

17.93 4.91 1,486.12 27.46

20.12 5.53 1,509.60 24.45

22.68 6.26 1,533.45 22.26

25.40 6.97 1,557.83 20.51

28.03 7.58 1,582.60 19.07

32.07 8.44 1,607.83 17.83

35.35 9.07 1,633.43 16.74

40.38 9.96 1,659.47 15.76

44.65 10.65 1,712.88 14.07

50.28 11.45 1,740.37 13.32

56.43 12.25 1,768.38 12.62

63.27 13.06 1,796.65 11.98

71.32 13.91 1,825.25 11.38

80.17 14.73 1,854.47 10.82

90.00 15.54 1,884.27 10.29

100.82 16.34 1,914.47 9.81

112.88 17.13 1,944.70 9.39

126.53 17.92 1,975.97 9.01

142.05 18.73 2,040.47 8.32
9

pumped well for Water-Supply 

Well No. 3 was set to 1 foot for 

this analysis. The best fit for the 

Hantush type curve had a very 

small β, 1 x 10-5, indicating that 

leakage through the overlying Eau 

Claire confining unit is not significant. The fitted Hantush type curve 

is not significantly different from 

the fitted Theis type curve.The 

transmissivity and storage coefficients for the Mt. Simon aquifer, 

determined by the two methods, 

are 3,000 ft2

/d and 3 x 10-4, 

respectively. The average hydraulic conductivity is 10 ft/d, assuming an aquifer thickness of 233 ft.

The fitted Hantush type curve and measured water levels in Water-Supply Well No. 3 and the observation

well, Prairie Island Indian Community, Minnesota, September 10-11, 2001.

1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1 1.E+01 1.E+02 1.E+03 1.E+04

0.01

0.1

1

10

100

1,000

DEPTH OF WATER BELOW INITIAL MEASURING POINT OR STATIC HEAD, IN FEET

t/r , IN MINUTES PER SQUARE FOOT 2

t - the time from the beginning of the

aquifer test in minutes

r - the distance between the measured

well and the pumped well, in feet

r is 458 ft for the observation well

r is 1 ft for Water-Supply Well

No. 3

Observation well measurements

Hantush type curve ( =1x10 ) -5

Water-Supply Well No. 3 measurements

EXPLANATION



Figure 4.
10

The fitted Theis type curve and measured water levels in Water-Supply Well No. 3 and the observation well,

Prairie Island Indian Community, Minnesota, September 10-11, 2001.

1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1 1.E+01 1.E+02 1.E+03 1.E+04

0.01

0.1

1

10

100

1,000

DEPTH OF WATER BELOW INITIAL MEASURING POINT OR STATIC HEAD, IN FEET

Observation well measurements

Theis type curve

Water-Supply Well No. 3 measurements

EXPLANATION

t/r , IN MINUTES PER SQUARE FOOT 2

t - the time from the beginning of the

aquifer test in minutes

r - the distance between the measured

well and the pumped well, in feet

r is 458 ft for the observation well

r is 1 ft for Water-Supply Well

No. 3

Figure 5.

SUMMARY

An aquifer test of the Mt. Simon aquifer was conducted at the northern end of the Prairie Island Indian 

Community, in cooperation with the Prairie Island 

Indian Community, September 10-11, 2001. Two 

wells at the northern end of Prairie Island were used in 

the aquifer test. The pumped well was Water-Supply 

Well No. 3, which is completed in the Mt. Simon aquifer. The well is cased from land surface to a depth of 

480 ft and is open to the aquifer from a depth of 480 ft 

to 701 ft. The observation well is located 458 ft south 

of Water-Supply Well No. 3 and also is completed in 

the Mt. Simon aquifer. The observation well is cased 
11

REFERENCES CITED

Cooper, H.H., and Jacob, C.E., 1946, 

A generalized graphical method 

for evaluating formation constants 

and summarizing well field history: American Geophysica Union 

Transaction, v. 27, p. 526-534.

Cowdery, T.K., 1999, Water 

resources of the Prairie Island 

Indian Reservation, Minnesota, 

1994-97: U.S. Geological Survey 

Water-Resources Investigations 

Report 99-4069, 36 p.

Hantush, M.S., 1960, Modification of 

the theory of leaky aquifers: Journal of Geophysical Research, v. 

65, no. 11, p. 3713-3725.

Hantush, M.S., 1961a, Drawdown 

around a partially penetrating well: 

Journal of the Hydraulics Division, 

Proceedings of the American Society of Civil Engineering, v. 87, no. 

HY4, p. 83-98.

_____1961b, Aquifer tests on partially penetrating wells: Journal of 

the Hydraulics Division, Proceedings of the American Society of 

Civil Engineering, v. 87, no. HY5, 

p. 171-194.

Hydrosolve, 2000, AQTESOLV for 

Windows user guide: Hydrosolve, 

Inc., unpaged. 

Mossler, J.H., and Tipping, R.G., 

2000, Bedrock geology and structure of the seven-county Twin Cities Metropolitan Area, Minnesota: 

University of Minnesota, Minnesota Geological Survey Miscellaneous Map Series Map M-104, 1 

pl.

Neuman, S.P., and Witherspoon, P.A., 

1969, Theory of flow in a confined 

two aquifer system: Water 

Resources Research, v. 5., no. 4, p. 

803-816.

Runkel, A.C., 1998, Bedrock geology, 

plate 2 of Geologic atlas of 

Goodhue County, Minnesota: University of Minnesota, Minnesota 

Geological Survey County Atlas 

Series, Atlas C-12, part A, 6 pl.

Theis, C.V., 1935, The relation 

between the lowering of the piezometric surface and the rate and 

duration of discharge of a well 

using groundwater storage: American Geophysical Union Transactions, v. 16, p. 519-524. 

Woodward, D.G., 1986, Hydrogeologic framework and properties of 

regional aquifers in the Hollandale Embayment, southeastern Minnesota: U.S. Geological Survey 

Hydrologic Investigations Atlas 

HA-677, 2 pl

from the land surface to a depth of 480 ft and is open 

to the aquifer from a depth of 480 ft to 602 ft.

Water-Supply Well No. 3 was pumped at 1,530 

gal/min for 24 hours. The pumping began on September 10, 2001 at 07:00. The pump was shut off at 07:02 

September 11, 2001. The aquifer test ended at 17:03 

September 11, 2001. Drawdown and recovery water 

levels were measured in the pumped and observation 

wells. 

The Theis and Hantush type curves were fitted 

simultaneously to the measured water levels in WaterSupply Well No. 3 and the observation well. The best 

fit for the Hantush type curve had a very small β, 1 x 

10-5, indicating that leakage through the overlying 

Eau Claire confining unit was not significant. The fitted Hantush type curve was not significantly different 

from the fitted Theis type curve. The transmissivity 

and storage coefficients for the Mt. Simon aquifer, 

determined by the two methods, are 3,000 ft2/d and 3 

x 10-4, respectively. The hydraulic conductivity is 10 

ft/d, assuming an aquifer thickness of 233 ft.
12
13

SUPPLEMENTAL INFORMATION
14
15

THEIS TYPE CURVE

Assumptions (Hydrosolve, 2000)

1. Aquifer has infinite areal 

extent;

2. Aquifer is homogeneous, isotropic and of uniform thickness;

3. Pumped well is fully or partially penetrating;

4. Flow to pumped well is horizontal when pumped well is fully 

penetrating;

5. Aquifer is confined;

6. Flow is unsteady;

7. Water is released instantaneously from storage with decline 

of hydraulic head; and 

8. Diameter of pumped well is 

very small so that storage in the 

well can be neglected.

Equations for type curve 

(Hydrosolve, 2000)

1. ,

 , where w(u) is the Theis well 

function

2. 

where 

Q is pumping rate [ft3

/min];

r is radial distance [ft];

s is displacement [ft];

S is storage coefficient of the 

aquifer [dimensionless];

t is time since pumping began 

[min]; 

T is aquifer transmissivity 

[ft2

/min]; and

y is variable of integration.

HANTUSH TYPE CURVE

Assumptions (Hydrosolve, 2000)

1.Aquifer has infinite areal 

extent;

2. Aquifer is homogeneous, isotropic and of uniform thickness;

3. Aquifer potentiometric surface is initially horizontal;

4. Pumped well is fully or partially penetrating;

5. Flow to pumped well is horizontal when pumped well is fully 

penetrating;

6. Aquifer is leaky;

7. Flow is unsteady;

8. Water is released instantaneously from storage with decline 

of hydraulic head;

9. Diameter of pumped well is 

very small so that storage in the 

well can be neglected;

10. Confining unit(s) has infinite areal extent, uniform vertical 

hydraulic conductivity and storage coefficient, and uniform thickness;

11. Confining unit(s) is overlain 

or underlain by an infinite constant-head plane source; and

12. Flow in the confining 

unit(s) is vertical.

Equations (Hantush, 1960; 

Hydrosolve, 2000)

1. 

2. 

3. 

where

K’ is the vertical hydraulic conductivity of the confining unit separating the aquifers [ft/d];

S’ is the storage coefficient of 

the confining unit separating the 

aquifers [dimensionless];

b’ is the vertical thickness of 

the confining unit separating the 

aquifers [ft]; and 

all others as previously defined.

∫

∞ −

= =

u

y

w u

T

Q dy

y

e

T

Q

s ( ) 4π 4π

Tt

r S

u

4

2

=

( ) ∫

∞ −

− =

u

y

dy

y y u

u erfc

y

e

T

Q

s β

4π

Tt

r S

u

4

2

=

















′

′ ′ = b TS

r K S

4 β