GROUND-WATER RESOURCE S of BENSON and PIERCE COUNTIES

GROUND-WATER RESOURCE S

BENSON AND PIERCE COUNTIES ,

NORTH DAKOTA

P. G. RANDICH

U.S. Geological Survey

COUNTY GROUND-WATER STUDIES 18 — PART II I North Dakota State Water Commission Vernon Fahy, State Enginee r

BULLETIN 59 — PART II I North Dakota Geological Survey Edwin A . Noble, State Geologist

Prepared by the United States Geological Survey i n cooperation with the North Dakota State Wate r Commission, North Dakota Geological Survey , Benson County Water Management District, an d Pierce County Water Management Distric t

1977

CONTENTS

Page

ABSTRACT 1 INTRODUCTION 2 Purpose of investigation 2 Physiography and drainage 2 Climate 2 Population and economy 4 Data numbering system 5 Previous investigations 5 Acknowledgments 7

HYDROGEOLOGIC SETTING 7 Preglacial rocks 7 Glacial deposits 8

AVAILABILITY AND QUALITY OF GROUND WATER 12 General concepts 12 Ground water in the preglacial rocks 16 Dakota aquifer 16 Pierre aquifer 16 Fox Hills aquifer 16 Ground water in the glacial deposits 18 Buried-valley aquifers 20 New Rockford aquifer 21 Spiritwood aquifer system 31 Spiritwood aquifer system near Warwick 31 Spiritwood aquifer system near Minnewaukan 32 Kilgore aquifer 37 Buried-outwash aquifers 40 Maddock aquifer 40 Leeds aquifer 41 Surficial-outwash aquifers 44 Warwick aquifer 44 Esmond aquifer 52 Pleasant Lake aquifer 56 Tokio aquifer 60 Minor glacial-drift aquifers 60 Lake Souris deposits 62 Ice-contact deposits 62 Till and associated sand and grave l deposits 66 iii Page

UTILIZATION OF GROUND-WATER RESOURCES 66 Farm supplies 66 Public supplies 67

SUMMARY AND CONCLUSIONS 68

SELECTED REFERENCES 7 1

GLOSSARY OF SELECTED TERMS 75

ILLUSTRATIONS

Plate 1. Bedrock topography map (in pocket)

2. Availability of ground water from majo r glacial-drift aquifers (in pocket)

3. Geologic sections of major glacial-drift aquifers (in pocket)

Figure 1. Map showing physiographic and drainage - basin divisions in North Dakota an d location of report area 3

2. Diagram showing system of numbering dat a sites 6

3. Map showing bedrock formations and thicknes s of glacial drift : 9

4. Map showing generalized surficial geolog y and locations of buried valleys 10

5. Diagram showing classification of wate r for irrigation use 15

6. Map showing depth to the top of the Dakot a aquifer 17

7. Hydrograph showing water-level fluctuation s in a shallow well tapping the Fox Hill s aquifer, and precipitation at Rugby 19 iv Page

8. Hydrographs showing water-level fluctuation s in deep wells tapping the Fox Hills aquifer, and precipitation at Rugby 20

9. Graph showing particle-size distributio n curves for samples from the eastern part of the New Rockford aquifer 22

10. Graph showing particle-size distribution curves for samples from the western part of the New Rockford aquifer 23

11. Map showing locations of wells in the Ne w Rockford aquifer, and drawdown caused by aquifer test near Selz 25

12. Hydrograph showing water-level trends in the New Rockford aquifer 26

13. Graph showing type-curve calculation o f transmissivity (T) and storage coefficien t (S)., well 151-72-25BBC, New Rockford aquifer test (1969) 27

14. Graph showing straight-line solution of transmissivity (T) and storage coefficient (S), New Rockford aquifer test (1969) 28

15. Hydrographs showing monthly water-level fluctuations in shallow aquifers overlyin g the New Rockford aquifer, and preciptatio n at Balta 29

16. Hydrograph showing water-level fluctuations in the New Rockford aquifer showing long - term increase in storage 30

17. Graph showing particle-size distributio n curves for samples from the Spiritwood aquifer system near Warwick 33

18. Hydrographs showing water-level fluctuation s in the Spiritwood aquifer system near Warwick, and precipitation at Warwick 34 v Page 19. Graph showing particle-size distributio n curves for samples from the upper sediment s of the Spiritwood aquifer system near Minnewaukan 35

20. Graph showing particle-size distributio n curves for samples from the lower sediments of the Spiritwood aquifer system near Minnewaukan 36

21. Hydrographs showing water-level fluctuation s in the Spiritwood aquifer system nea r Minnewaukan, and precipitation at Maddock 38

22. Hydrograph showing water-level fluctuation s in the Spiritwood aquifer system nea r Minnewaukan showing a gradual increas e in storage 39

23. Hydrographs showing water-level fluctuation s in the Maddock aquifer (151-69-15AAA) and in overlying glacial-drift deposits (151 - 69-10DAA), and precipitation at Maddock 41

24. Graph showing particle-size distributio n curves for samples from the Leeds aquifer 42

25. Hydrograph showing water-level fluctuation s in the southwestern part of the Leeds aquifer , and precipitation at Leeds 43

26. Hydrograph showing water-level fluctuations in the central part of the Leeds aquifer 44

27. Graph showing particle-size distributio n curves for samples from the Warwic k aquifer 46

28. Graph showing water-level drawdown an d recovery in the Warwick aquifer caused by pumping well 151-63-25ADB1 for 3.13 days (1969) 48

29. Hydrograph showing long-term water-level trends in the Warwick aquifer near the city of Devils Lake (Ramsey County) well field, and precipitation at Warwick 49 vi Page

30. Hydrograph showing seasonal change i n storage in a relatively unused part o f the Warwick aquifer 50

31. Hydrographs showing water-level fluctuation s in the Warwick aquifer, stage changes in Shinbone Lake, and precipitation at Warwick 51

32. Graph showing particle-size distributio n curves for samples from the southern par t of the Esmond aquifer 53

33. Graph showing particle-size distributio n curves for samples from the northern part of the Esmond aquifer 54

34. Hydrographs showing water-level fluctuation s in the Esmond aquifer, and precipitation at Balta 55

35. Graph showing particle-size distribution curves for samples from the Pleasant Lak e aquifer 57

36. Hydrograph of water-level fluctuation s in the central part of the Pleasant Lak e aquifer showing an increase in ground-wate r storage, and precipitation at Rugby 58

37. Hydrograph showing water-level fluctuations in the Pleasant Lake aquifer affected by pu:mpage for the city of Rugby 59 38. Hydrographs showing water-level fluctuation s in the Tokio aquifer, discharge of Big Coulee, and precipitation at Warwick 61

39. Graph showing particle-size distribution curves for samples from Lake Souris glacial deposits 63

40. Hydrographs showing water-level fluctuations in Lak 3 Souris glacial deposits, an d precipi:ation at Balta 64

vii Page

41 . Hydrographs showing water-level fluctuation s in ice-contact deposits, and precipitation at Leeds 65

TABLE S

Table 1. Major chemical constituents in water — thei r sources, effects upon usability, an d recommended concentration limits 14

2. Summary of data obtained from pumping tests in the Warwick aquifer 47

SELECTED FACTORS FOR CONVERTING ENGLISH UNIT S TO INTERNATIONAL SYSTEM (SI) OF METRIC UNIT S

A dual system of measurements — English units and the International System (SI) of metric units — is given in this report . SI is a consistent system of units adopted by the Eleventh General Conference on Weights and Measures in 1960. Selected factors for converting English units to SI unit s are given below.

Multiply English units By To obtain SI units Acres 0.4047 hectares (ha) Acre-feet 1,233 cubic metres (m 3) 1.233x10'6 cubic kilometres (km 3) Feet .3048 metres (m) Feet per day (ft/d) .3048 metres per day (m/d ) Feet per mile (ft/mi) .18943 metres per kilometre (m/kn Feet squared per day .0929 metres squared per day (ft2/d) (m2/d) Gallons 3.785 litres Gallons per day (gal/d) 3.785x10' 3 cubic metres per day (m3/d) Gallons per minute (gal/min) .06309 litres per second (Us ) Gallons per minute per .2070 litres per second per metre fool: [(gal/min)/ft] [(Us)/m] Inches 25. 4 millimetres (mm ) .0254 metres (m) Miles 1.609 kilometres (km ) Miles per hour .44704 metres per second (m/s) Million gallons (Mgal) 3,785 cubic metres (m3) Million gallons per day 3,785 cubic metres per day (Mgal/d) (m3/d) Square miles (m 2) 2 .590 square kilometres (km 2)

ix GROUND-WATER RESOURCES O F BENSON AND PIERCE COUNTIES, NORTH DAKOT A

By P. G. Randich

ABSTRACT

Ground water is obtainable in Benson and Pierce Counties from aquifer s in preglacial rocks of Cretaceous age and from aquifers in glacial drift o f Pleistocene age. Aquifers in the preglacial rocks are more widely distributed , but those in the drift provide higher yields to wells and better quality water . Aquifers in the preglacial rocks occur in the Dakota Group and the Pierr e and Fox Hills Formations. The Dakota underlies the entire area at depth s between 1,400 and 2,200 feet (430 and 670 metres) below land surface . The Dakota aquifer is capable of yielding large quantities of water, but th e water contains about 4,000 milligrams per litre dissolved solids . Flowing wells are obtainable in places . The Pierre Formation is an aquifer where it is fractured and directl y underlies glacial drift, mainly in Benson County . The Fox Hills Formation is restricted to the western part of the area. Only small quantities of wate r are generally obtainable from the Pierre and Fox Hills, although in place s the Fox Hills may yield as much as 100 gallons per minute (6 .3 litres pe r second) to individual wells . Water from both aquifers is soft and contains high concentrations of sodium . Nine major aquifers were identified in the glacial-drift deposits . These are classified into buried-valley, buried-outwash, and surficial-outwash aquifers. The aquifers contain a total of nearly 1 .8 million acre-feet (2 .2 cubic kilometres) of available ground water. They have been named the New Rockford, Spi:ritwood, Kilgore, Maddock, Leeds, Warwick, Esmond, Pleasan t Lake, and Tokio aquifers. The largest and potentially most productive aquife r is the New Rockford, which underlies about 80 square miles (210 squar e kilometres) in southwestern Benson and Pierce Counties . A well in th e aquifer was test pumped for 5 days at a rate of 1,420 gallons per minute (90 litres per second) in order to determine the hydraulic properties of the aquifer. The New Rockford aquifer is tapped by only a few small-capacity wells . It should yield as much as 1,500 gallons per minute (95 litres per second) to properly constructed wells located in the central part . The glacial-drift aquifers yield water that differs considerably in chemica l quality, depending on aquifer depth and position in the ground-water flow system, but the water is satisfactory for most uses . About 3.2 million gallons per day (12,100 cubic metres per day) of groun d water is pumped for municipal, domestic, and livestock uses in the two - county area.

1 INTRODUCTION

The present study of ground-water resources in Benson and Pierce Coun- ties (fig. 1) was made cooperatively by the U .S. Geological Survey, the North Dakota State Water Commission, the North Dakota Geological Survey, and the Benson and Pierce Counties Water Management Districts .

Purpose of Investigation

This investigation was one of a series of studies to obtain information o n the ground-water resources in North Dakota . The purpose of the study wa s to determine the general quantity and quality of ground water available fo r municipal, domestic, livestock, industrial, and irrigation uses . Accordingly, the report contains descriptions of the location, areal extent, thickness , and nature of the major aquifers ; estimates of the quantities of water store d in these aquifers ; estimates of the potential yields of wells tapping the aquifers; and descriptions of the chemical quality of the ground water .

Physiography and Drainage

Benson and Pierce Counties have an area of 2,512 mil (6,506 km2) in north-central North Dakota; they are within the Drift Prairie section of th e Central Lowland physiographic province . The area is generally of moderate to low relief. Total relief is about 460 feet (140 m) — ranging from about 1,400 feet (426 m) above msl (mean sea level) on the Sheyenne River at the south boundary of Benson County to 1,865 feet (568 m) near Harlow in north-central Benson County . The promi- nent land features are glacial in origin — moraines, ice-contact features, lake plains, and outwash plains . Drainage is fairly well developed in some parts of the counties, but poorl y developed in others . Drainage to the east consists of the Sheyenne Rive r and its tributaries (Red River of the North basin), and to the west consist s of intermittent streams of the Souris River basin (fig. 1). The Devils Lake basin lies between the basins of the Red and Souris Rivers . Because there has been no outflow from the Devils Lake basin in historic time, it is generally regarded as a closed basin . The basin divides generally coincide with the crests of major end moraines . The land surface contains numerous undrained depressions, commonl y referred to as sloughs or prairie potholes . Although each depression represents a small closed basin, some fill up and spill over — especially during rapid spring thaws that follow winters of above normal snowpack .

Climate

Benson and Pierce Counties are in a region of cool-temperature continen- tal climate. The mean annual temperature at Maddock in Benson Count y ranges from 36°F (2.2°C) to 39.5°F (4.2°C). The mean monthly temperature ranges from 5.3°F (-14 .8°C) in January to 69.6°F (20.9°C) in July (National 2

A J I \

ss,( \~~ (

46°

104° 102° 100° "' MODIFIED FROM FENNEMAN, 1946 5 0 5 10 20 30 40 MILE S 10 0 10 30 50 KILOMETRE S FIGURE 1.-Physiographic and drainage-basin divisions in North Dakota and location of report area . Weather Service, 1931-68). The mean monthly temperature at Maddock is 26°F (3.3°C) for the period November through March, and 62°F (16.7°C) for the period June through August . The prevailing wind is from the northwest, except June through August when southeast winds predominate . The average wind velocity is about 10 miles per hour (4 m/s) . Wind velocity is greates t in the spring and least in the fall. The mean annual precipitation is 16 .5 inches (420 mm) at Maddock and 15.7 inches (400 mm) at Rugby (Pierce County). More than 75 percent of the precipitation occurs during the growing season from April through Septem- ber. The mean annual snowfall in the area is generally between 34 and 3 8 inches (86,0 and 970 mm). The driest period of the year is November throug h February when about 0 .5 inch (13 mm) of moisture is received each mont h as snow. The mean annual evaporation from lake surfaces in the area is abou t 30 inches (760 mm). Frost accumulates 4 to 6 feet (1 to 2 m) below land surface in most parts of the area. Spring thaw usually starts in March, causing most of the pea k flows in streams to occur in April.

Population and Economy

The population of North Dakota has decreased about 2.3 percent durin g the period 1960-70 (U .S. Bureau of the Census, 1971) . Comparatively, the population in'Benson and Pierce Counties has declined 13 and 14 percent , respectively, for the same period . Population figures and percentage o f change for the two-county area are as follow :

1960 1970 Percentage of population population change Benson County 9,435 8,245 -13 Brinsmade 110 36 -67 Esmond 420 416 — 1 Knox 122 104 -15 Leeds 797 626 -22 Maddock 740 708 — 4 Minnewaukan' 420 496 +18 Oberon 248 151 -39 Warwick 204 168 -18 York 148 102 -31 Pierce County 7,394 6,323 -14 Balta 165 133 -19 Barton 80 34 -58 Rugby' 2,972 2,889 — 3 Wolford 136 81. -40

'County seat . 4 The 1970 census figures show that about 66 percent of the Benson Count y residents and about 50 percent of the Pierce County residents live in rura l areas. The economy is based mainly on diversified dryland farming and stoc k raising, with wheat, barley, flax, alfalfa, and hay as the main crops . Recrea- tional activities in the Devils Lake area help broaden the economic base of the counties.

Data Numbering Syste m

The wells, test holes, and other data-collection points mentioned in thi s report are numbered according to a system based on the location in th e public land classification of the U.S. Bureau of Land Management . The system is illustrated in figure 2. The first numeral denotes the township north o f a base line, the second numeral denotes the range west of the fifth principal meridian, and the third numeral denotes the section in which the well i s located. The letters A, B, C, and D designate, respectively, the northeast , northwest, southwest, and southeast quarter section, quarter-quarter section , and quarter-quarter-quarter section (10-acre or 4-ha tract) . For example, well 154-72-15DAA is in the NEY4NE'SE% sec . 15, T. 154 N., R. 72 W. Consecutive terminal numerals are added if more than one well is recorde d within a 10-acre tract.

Previous Investigation s

The first worker concerned with the geology of the area was Warren Up - ham (1895), whose study results are published in his classic report on glacia l Lake Agassiz. Simpson (1929) prepared the first areal report on the ground- water resources of the counties . His report contains brief discussions of the geology, ground-water resources, public water systems, and quality of groun d water. Abbott and Voedisch (1938) listed chemical constituents of a fe w ground-water samples from the area. Detailed geologic studies have been completed for the Flora quadrangle (Branch, 1947), Oberon quadrangl e (Tetrick, 1949), and Tokio quadrangle (Easker, 1949) . Aronow and others (1953) described the geology and ground-water resources of the Minnewauka n area in Benson County . Swenson and Colby (1955) studied the chemica l quality of surface water in the Devils Lake region. Robinove and other s (1958) included the area in a statewide report on principal saline-water aquifers. Brookhart and Powell (1961) described the ground-water resources near Maddock in ]Benson County. Randich and Bradley (1962) described the ground-water :resources in the vicinity of Leeds in Benson County . The North Dakota State Department of Health (1964) included chemical analyses fro m the area in a study of municipal water supplies in North Dakota . Paulson and Akin (1964) described the ground-water resources of the Devils Lak e region. Their report contains geohydrologic interpretation and a large volum e of data. Froelich (1965) reported on a ground-water survey of the Rugby area. His report contains geohydrologic interpretation of a 120-mi2 (311-km2) area in Pierce County . Mitten and others (1968) prepared a supplemental 5 FIGURE 2.-System of numbering data sites . 6 report to Swenson and Colby's work (1955) on the chemical quality of surface waters in the Devils Lake basin. Randich (1972) prepared a hydrologic atlas outlining the general ground-water availability in Benson and Pierc e Counties.

Acknowledgement s

Appreciation is expressed to the residents and officials of Benson an d Pierce Counties. Their ready cooperation made it possible to complete th e study without unnecessary delays. C . E . Naplin, R. W. Schmid, M . O. Lindvig, L . L. Froelich, David Ripley, and L . M . Knutson of the North Dakota State Water Commission provided most of the test-drilling and aquifer-test data. T. F. Freers and C. G. Carlson of the North Dakota Geo- logical Survey mapped the surface geology and provided auger test-hole data . Recognition is due Chevron Oil Co., C. A. Simpson and Son Drilling Co . , and Frederickson's, Inc ., for contributing drillers logs of seismograph hole s and water wells, and for participation during aquifer tests .

HYDROGEOLOGIC SETTIN G

Preglacial Rocks

Benson and Pierce Counties are on the eastern flank of the Willisto n basin. The floor of the basin is formed of crystalline metamorphic and igneous rocks of Precambrian age. The overlying preglacial sedimentary rocks range in thickness from about 4,000 to 6,000 feet (1,220 to 1,830 m), and in ag e from Ordovician to Cretaceous . Rocks of pre-Cretaceous age generally are to o deeply buried and contain water too highly mineralized to be of economi c importance . Rocks of Cretaceous age contain major aquifers, but an under - standing of their stratigraphic framework is essential to the interpretatio n of their ground-water potential. In ascending order, the rocks of Cretaceous age can be divided into th e Dakota, Colorado, and Montana Groups . ' The Dakota Group of Lower Cretaceous age has been further divided int o the Lakota, Fuson, Fall River, Skull Creek, Newcastle, and Mowry Forma- tions (Hansen, 1955). However, the Dakota has not been subdivided in the study area. -Interpretation of 30 oil-test logs shows that the Dakota Grou p averages about 300 feet (90 m) in thickness and contains two sandstone intervals that are important aquifers. These intervals probably are equivalent to the La1cbta and Newcastle Formations ; which consist primarily of loosely cemented quartz sandstone and siltstone separated by about 200 feet (60 m ) of thinly bedded shale and siltstone .

1 The stratigraphic nomenclature used in this report is that of the North Dakota Geo - logical Survey and does not necessarily follow the usage of the U.S . Geological Survey. 7 The Niobrara Formation of the Colorado Group was identified at the base of a test hole drilled into a buried valley near the southeastern corner o f Benson County . It was found to be a calcareous light-gray shale with ver y calcareous white specks (fossil fragments). Rocks in the Colorado Group are not believed to contain significant aquifers . The Pierre and Fox Hills Formations of the Montana Group directly underlie the glacial drift in most of Benson and Pierce Counties . The line of contact between the two formations trends northerly approximately through the center of the two-county area (fig . 3). The surfaces of the two formations contain numerous valleys and other erosional features (pl . 1, in pocket) carved by preglacial and interglacial streams . The bedrock topography defines the location and extent of the buried valleys and depressions containing major glacial aquifers in Benson and Pierce Counties . More detail is shown on this map than the one in Part I of this report (Carlson and Freers, 1975) becaus e the bedrock topography in most cases imposes hydraulic controls on th e glacial aquifers. These controls are confining and recharge boundaries, whic h affect potential yields and chemical quality of the ground water in the glacia l aquifers. The Pierre Formation is older than the Fox Hills and underlies it wher e both formations are present . The Pierre consists of olive-gray to grayish-blac k fissile bentonitic shale . This formation, which underlies nearly the entir e area, ranges in thickness from 0 to about 1,000 feet (300 m) . In places, where it directly underlies glacial drift, the upper 10 to 30 feet (3 to 9 m) i s fractured and generally is oxidized to a brown color . The fracturing is attributed to preglacial erosion with subsequent glacial loading, and the brown color to oxidation and hydration of iron-bearing minerals . The fractured shale forms an aquifer of considerable importance. Drilling action for the fractured zone is similar to that for a gravel . Sample returns from hydraulic-rotary drilling are chunky blocks ranging in size from 0 .5 to 2 .0 inches (13 to 51 mm). The Fox Hills Formation generally is covered by deposits of glacial drift , but crops out in isolated small exposures in the western part of the two - county area . The formation ranges in thickness from 0 to 290 feet (88 m) . It dips westward at about 10 ft/mi (1 .9 m/km). The formation outcrops are generally dark greenish gray weathering to light brown . Two samples collecte d at outcrops (153-70-36DCC and 153-72-27DAA) averaged 86 percent very fine to fine-grained sand .

Glacial Deposits

Glacial drift of Pleistocene age underlies Benson and Pierce Counties (fig . 4). The maximum known thickness of the deposits is . 382 feet (116 m), but the average (fig. 3) probably is about 100 feet (30 m) . The contact between the glacial drift and bedrock is commonly marked by a layer of boulders . In Benson and Pierce Counties, the glacial drift can be subdivided into six general types of deposits on the basis of lithology and inferred origin . These are ground moraine, end moraine, lake deposits, ice-contact deposits, buried - valley deposits, and outwash deposits (fig. 4). 8

100°IO' 100°00' 50 40 '

EXPLANATIO N

FOX HILLS FORMATIO N

PIERRE FORMATIO N •134) 122• , 14 UGBY PIE•6 C UNTY B : NS •' COUNTY NIOBRARA FORMATIO N SANT 56 LAKE i 1 200 GEOLOGIC CONTAC T EDS 9 6 • TEST HOLE -NUMBER INDICATE S THICKNESS OF GLACIAL DRIFT, I N FEE T

-200— LINE OF EQUAL GLACIAL-DRIF T 21 2 THICKNESS-INTERVAL 100 FEE T cC 166 ( .3C .5 )

N -moo '[~-1 • r4 LOK 1O 20i?:3(.2 w I - O 1 40 WARWI J 76 p~ O R .67 W. R .66W . R_65W . R.64W. R.63W . R .62W . 10 0 10 MILE S 1 r~1~51, 1n h I 10 0 10 KILOMETRE S FIGURE 3.-Bedrock formations and thickness of glacial drift .

100 0 IO'

EXPLANATIO N

GROUN D END GLACIAL LAKE ICE-CONTACT OUTWAS H MORAINE MORAINE DEPOSITS DEPOSITS DEPOSIT S

iNtr 99-'-~20 ' N COUNTY ~ i APPROXIMATE LIMIT Y 48°20' O F BURIED VALLE P.\ -GG -co l

- i CRESTS OE WELL-DEFINED RIDGE S

. OUTER LIMIT OF MAJOR GLACIAL LOB E

R .74 W .

10 0 10 MILE S

10 0 10 KILOMETRE S FIGURE 4 .-Generalized surficial geology and locations of buried valleys . Ground moraines are characterized by gently rolling "swell and swale " topography of low relief. The deposits are composed chiefly of till . Generally the upper 10 to 30 feet (3 to 9 m) is yellowish-brown — caused by oxidatio n of minerals containing iron . They are most extensive in the northeastern an d central parts of the area, but widely scattered tracts exist in the souther n part also . In northeastern Benson County the deposits contain abundan t glaciofluvial sand and gravel lenses . End moraines are characterized by "knob and kettle" topography of moderate local relief and have a general linear form . These moraines mark outer positions of glacial ice sheets (fig. 4) and are composed of till and associated glaciofluvial sand and gravel. In Benson and Pierce Counties, prominen t hills are common at the junctions of end-moraine lobes. An appreciable amount of lag sand, gravel, cobbles, and boulders is common on top of thes e morainal hills . One such hill, located near Tokio in southeastern Benso n County (sec. 8, T. 151 N., R. 64 W.), is called Devils Heart Butte by loca l residents . Bedrock highs (pl. 1) in the two-county area commonly coincid e with, and perhaps contribute to, the topography and location of the end moraines (fig. 4). Lake deposits of Pleistocene age underlie the Devils Lake plain in north - eastern Benson County, and the more extensive Souris Lake plain in western Pierce County (fig. 4). These deposits consist mainly of clay, silt, and fin e sand. Some gravel is present along former shorelines . The deposits are characterized by relatively flat topography, but sand dunes have formed locally . These sand dunes are mostly subdued and stabilized by vegetation . The principal types of ice-contact features in the area are eskers, kames , crevasse fillings, and kame terraces. They were formed by glacial melt wate r flowing around, through, and beneath cavernous or fissured ice . The deposits are characterized by hilly topography and almost unpredictable lithology . The ice-contact deposits generally consist of poorly sorted and stratified sand an d gravel with varying mixtures of clay, silt, cobbles, and boulders. Buried valleys, which were part of a regional preglacial and interglacia l drainage system, underlie parts of the area (fig . 4). They are many miles in length, 1 to 7 miles (1 .6 to 11 km) wide, and 200 to nearly 400 feet (60 to 120 m) deep (pl. 1). In places these valleys underlie recognizable topographi c lows, such as ]Devils Lake and East Devils Lake in Ramsey County . However, in most places they are completely filled by glacial deposits . The buried- valley deposits consist chiefly of interbedded sand and gravel (which generall y form major aquifers) and lesser amounts of clay and silt. Massive blocks of till or bedrock locally were pushed into the deeper parts of the valleys b y advancing glaciers and form hydraulic confining barriers within the aquifers . Outwash deposits were built by streams extending beyond the ice front s (fig. 4). They are characterized by gently undulating to nearly flat topography and "consist chiefly of sand and gravel, in part interbedded with an d (or) covered by considerable amounts of clay and silt . Coarse gravel and cobbles generally are abundant near the contact of end moraines and outwash . The gravel grades to finer materials with increasing distance from the en d moraines. 11 AVAILABILITY AND QUALITY OF GROUND WATE R

General Concepts

Part of the precipitation on the earth's surface is returned to the atmos- phere by evaporation, part runs off into streams, and the remainder infiltrates into the ground . Some of the water that enters the soil is held b y capillarity, to replace the water that was evaporated or transpired by plants during a preceding dry period. After the soil and plant requirements hav e been satisfied, any excess water will percolate downward to the saturate d zone. After the excess water enters the saturated zone, it becomes availabl e to wells. Ground water moves under the influence of gravity from areas of recharge to areas of discharge . Ground-water movement is generally very slow, pos- sibly only a few feet per year. The rate of movement is dependent upon th e hydraulic conductivity and porosity of the material through which the wate r moves and the hydraulic gradient. Gravel and well-sorted medium or coars e sand generally are highly conductive, and deposits of these materials commonly are productive aquifers . Fine-grained materials such as silt, clay, an d shale usually have low conductivity and may act as barriers that impede th e movement of ground water into or out of more conductive material. The water level in an aquifer fluctuates in response to variations in the rate of recharge and discharge . Some aquifers near or at land surface ar e recharged each spring and early summer by precipitation . Recharge to these aquifers normally is sufficient to replace losses caused by natural discharg e and by pumping of wells, although there may be several years in which net gains or losses in Around-water storage occur . Aquifers confined by thick deposits of fine-grained materials such as clay or silt are recharged very slow- ly. Replenishment of these aquifers is by seepage from the confining fine - grained materials, and laterally from unconfined areas of the aquifer . The rates of recharge may increase as heads in the aquifers are lowered by pumping. However, head declines may continue for several years before sufficien t recharge is induced to balance the rate of withdrawal . In some cases, thi s balance may never be achieved without a decrease in the rate of withdrawals . The decrease in discharge plus the increase in recharge is termed capture . In parts of Benson and Pierce Counties, surface-water bodies are in hydraulic connection with ground water in shallow aquifers . The aquifers either may receive recharge from these streams and lakes or may discharge int o them, depending on head relationships, which vary both in time and space . Ground water contains variable amounts of dissolved mineral matter . Water in the form of precipitation begins to dissolve mineral matter in th e air and continues to do so as it infiltrates the land surface and percolate s through the soil . The amount and kind of dissolved mineral matter in wate r depends upon the solubility and types of rocks and soil material encountered , the pressure and temperature of the water and rock formations, and the amount of carbon dioxide and soil acids in the water . Water that has traveled 12 a long distance from the recharge area through several types of rock formations with varying pressures and temperatures, generally is more highl y mineralized than water that has been in transit for only a short time . Numerous references are made in this report to ground-water quality types, such as sodium bicarbonate type, calcium bicarbonate type, etc . These classifications are derived from inspection of chemical analyses and represen t the predominant cation (sodium, calcium, or magnesium) and anion (bicarbonate, sulfate, or chloride) expressed in milliequivalents per litre . Results of some analyses indicate that the water is a mixed chemical type in whic h two or more cations or anions are present in nearly equal concentrations. The suitability of a water for various uses is determined largely by it s physical properties and by the kind and amount of dissolved minerals . The chemical constituents, physical properties, and indices most likely to be of concern are : iron, sulfate, nitrate, fluoride, dissolved solids, hardness, temperature, specific conductance, sodium-adsorption ratio (SAR), and percen t sodium . The source of the major chemical constituents, their effects upo n usability of the water, and the limits recommended by the U .S. Public Health Service (1962) for drinking water on interstate carriers are given in table 1 . The quality of water used for irrigation is an important factor in produc- tivity and quality of the irrigated crops . Salinity, sodium (alkali), and boron problems may result from the use of highly mineralized irrigation water. High salinity may result in the accumulation of salt in the soil to the extent that crops are injured . A sodium problem may develop if the amount of sodium in the irrigation water is high in comparison to the amount of calcium plu s magnesium. Under such conditions, the soil is poorly permeable, sticky whe n wet, and hard and difficult to till when dry . Boron is required by all crops for normal growth, but injury may result if the amount in the irrigation wate r is more than 2,000 ug/l . According to the U .S. Salinity Laboratory Staff (1954) the salinity hazar d is related to the specific conductance of the water and the sodium hazard i s related to the SAR. When judging the quality of an irrigation water according to the Salinity Laboratory Staff classification, it is assumed that the soil wil l take water readily and drain well; sufficient irrigation water will be applied to prevent salt accumulation in the root zone ; and crops of proper salt and boron tolerance will be planted. Salinity and 'sodium hazards of water from selected glacial-drift aquifers in Benson and Pierce Counties are shown in figure 5, using a classification developed by the U.S. Salinity Laboratory Staff (1954) . Most of the aquifers yield water with a low sodium hazard (Si) and a medium (C2) to high (C3 ) salinity hazard. Low-sodium water (Si) can be used for irrigation on almost all soils with little danger of the development of harmful levels of exchange - able sodium . Medium-salinity water (C2) can be used if a moderate amoun t of leaching occurs, and plants with moderate salt tolerance generally can be grown without special practices for salinity control . High-salinity water (C3 ) cannot be used on soils with restricted drainage . However, high-sodium or high-salinity waters have been used successfully for selected crops where ideal soil conditions and drainage exist .

TABLE 1 . — Major chemical constituents in water — their sources, effects upon usability, and recommended concentration limit s

(Modified after Durfor and Becker, 1964, table 2 )

U .S . Public Healt h Service (1962) recommended limits Constituents Major source Effects upon usability for drinking water

Silica Feldspars, ferromagnesia n In presence of calcium and magnesium , (SiOz) and clay minerals. silica forms a scale in boilers and o n steam turbines that retards heat trans- fer .

Iron Natural sources : amphi - If more than 100 ug/l (micrograms per 300 ugll (Fe) boles, ferromagnesia n litre) iron is present, it will precipi- minerals, ferrous and tate when exposed to air ; cause s ferric sulfides, oxides , turbidity, stains plumbing fixtures , carbonates, and cla y laundry, and cooking utensils, and minerals . Manmad e impart tastes and colors to food and sources : well casings , drinks. More than 200 ug/l is objection - pump parts, and storage able for most industrial uses. tanks .

Calcium Amphiboles, feldspars , calcium and magnesium combine wit h (Ca) gypsum, pyroxenes , bicarbonate, carbonate, sulfate, an d calcite, aragonite, Bolo- silica to form scale in heating equip- mite, and clay minerals. merit . Calcium and magnesium retar d Magnesiu m Amphiboles, olivine , the suds-forming action of soap an d (Mg) pyroxenes, dolomite, detergent. High concentrations of magnesite, and cla y magnesium have a laxative effect . minerals .

Sodium Feldspars, clay minerals, More than 50 mg/I (milligrams per (Na) and evaporites . litre) sodium and potassium with sus- Potassium Feldspars, feldspathoids , pended matter causes foaming, which (K) some micas . and cla y accelerates scale formation and corro - minerals. sion in boilers . Boron Tourmaline, biotite, an d Many plants are damaged by concen - (B) and amphiboles . trations of more than 2,000 ug/l.

Bicarbonate Upon heating of water to the boilin g (HCOa) Limestone and dolomite . point, bicarbonate is changed to steam , Carbonat e carbonate, and carbon dioxide . (COs) Carbonate combines with alkalin e earths (principally calcium and magnesium) to form scale .

Sulfat e Gypsum, anhydrite, and Combines with calcium to form scale . 250 mg/I (SOa) oxidation of sulfide More than 500 mg/I tastes bitter an d minerals . may be a laxative.

Chloride Halite and sylvite . In excess of 250 mg/I may impart salty 250 mg/I (CI) taste, greatly in excess may caus e physiological distress. Food Processing industries usually require less than 25 0 mg/I.

Fluoride Amphiboles, apatite , Optimum concentration in drinkin g Recommendedlimit s (F) fluorite, and mica. water has a beneficial effect on the depend on annua l structure and resistance to decay o f average of maximum children 's teeth . Concentrations in daily air tempera- excess of optimum may cause mottling tures . Limits range of children's teeth . from 0 .6 mg/I at32°C to 1 .7 mg/l a t 10°C .

Nitrate Nitrogenous fertilizers , More than 100 mg/I may cause a bitte r 45 mg/I (NOa) animal excrement, leg- taste and may cause physiological dis- umes, and plant debris. tress . Concentrations in excess of 45 mg/I have been reported to caus e methemoglobinemia in infants .

Dissolved Anything that is soluble . More than 500 mg/I is not desirable i f 500 m/I solids better water is available. Less than 30 0 mg/I is desirable for some manufactur - ing processes . Excessive dissolved solids restrict the use of water for irrigation .

1 4

100 2 3 4 5 6 7 8 9 1000 2 3 4 5000

2 6

2 4

22 C4 S4

3200 FI 2 8

16 o 4 C3-S3

12 p

' 8 C2-S2 °C4-S 3 t 10 o • 8 C3-S2 ° o

6 ° C4-S2

4 C2-SI ° p C3-S I 2 n , ° o p

0 • 100 250 750 225 0 CONDUCTIVITY-MICROMH OS/CM . (ECXI0 6) AT 25° C 9s 2 3 4

LOW MEDIUM HIGH VERY HIGH

SALINITY HAZARD U.S. SALINITY LABORATORY STAFF, 195 4

EXPLANATION

q NEW ROCKFORD AQUIFE R 0 MADDOCK AQUIFE R

o NEW ROCKFORD AQUIFER (WESTERN PART) A LEEDS AQUIFE R

n SPIRITWOOD AQUIFER NEAR WARWIC K • WARWICK AQUIFE R

o SPIRITWOOD AQUIFER NEAR MINNEWAUKA N • ESMOND AQUIFE R

A KILGORE AQUIFER 3 PLEASANT LAKE AQUIFE R

FIGURE 5.-Classification of water for irrigation use .

15 Ground Water in the Preglacial Rocks

Dakota Aquifer The Dakota aquifer comprises two water-bearing beds of fine- to medium - grained quartz sandstone in the Dakota Group . The upper bed average s about 100 feet (30 m) in thickness and the lower bed 50 feet (15 m) . The aquifer underlies Benson and Pierce Counties (fig . 6) at depths ranging from about 1,400 to 2,200 feet (430 to 670 m) below land surface. The potentiometric surface of the Dakota aquifer slopes eastward fro m about 1,600 feet (490 m) above msl in western Pierce County to about 1,50 0 feet (460 m) above msl in eastern Benson County . Consequently, wells will generally flow if drilled in areas where the land surface is lower than thes e altitudes. Large cones of depression caused by pumping have formed in th e potentiometric surface in areas of long-term withdrawal, such as near the cit y of Leeds . Water from the Dakota aquifer in Benson and Pierce Counties contain s about 4,000 mg/1 dissolved solids, and is a sodium sulfate or a mixed sodiu m sulfate-chloride type . This water is unsuitable for irrigation because of high dissolved solids, sodium, and boron concentrations ; however, it has been used satisfactorily for livestock and some domestic purposes without apparent ill effects. The temperature of water from flowing wells in the Dakota aquifer is about 65°F (18 .5°C). The Dakota aquifer yields as much as 100 gal/min (6 1/s) to wells in Benson and Pierce Counties . Because of its depth, mineralization, and the general availability of water in shallower aquifers, the water in the Dakota aquifer i s not extensively used . However, should an economical desalinization proces s be developed, the Dakota aquifer may be an important source of water in the future .

Pierre Aquifer Small quantities of water are generally available from fractures and silty layers in the upper part of the Pierre Formation . The fractures are mos t extensive in outcrop areas and where the formation directly underlies glacia l drift (fig. 3). Recharge to the Pierre aquifer is largely through the overlying glacia l drift. Recharge is greatest where the aquifer is overlain by permeable drift aquifers or in areas where the drift is thin . Water from the Pierre aquifer is generally of three types — sodium bicarbonate, sodium sulfate, and sodium chloride . The water generally contains high concentrations of iron and dissolved solids ; however, the water is soft and is used for domestic and livestock purposes . Well yields range from 1 to 10 gal/min (0.06 to 0.6 Us).

Fox Hills Aquifer

The Fox Hills aquifer consists of semiconsolidated sandstone in the uppe r part of the Fox Hills Formation . The lower part of the formation is mostly 16

100°IO' 100°00' 50 99°30'

EXPLANATIO N 75 5 • DATA POINT— NUMBER IS DEPTH TO TOP OF THE DAKOTA AQUIFER, IN FEET BELOW LAND SURFAC E

900-- LINE OF EQUAL DEPTH TO TOP OF THE DAKOTA AQUIFER 11970) . RUGBY DASHED APPROXIMATELY LOCATED . INTERVAL 100 FEET (30.5m ) PLEASAN T AK E

•203 0

204 0 i960

• 198 0

50' 99°00' 98°i- 1810 \ l 98°40' ;''-Th 48°0 0

o A L~y00 TOK10 j WARtCK~ 11/,II — J R .67W. R.66W. R .65W. R .64W . R .63W. R.62W . 10 10 MILE S ' ' ji i'i I l, ~ I 10 O 10 KILOMETRE S FIGURE 6.-Depth to the top of the Dakota aquifer . siltstone interbedded with shale and claystone, which are too fine grained t o be of importance as an aquifer . Recharge to the Fox Hills aquifer is mainly in the central part of the stud y area,and is by direct infiltration of precipitation and water from streams an d lakes and by seepage through overlying glacial deposits . Ground-water movement through the Fox Hills aquifer generally is from the topographicall y high recharge areas toward the lower plains and valleys. Hydrographs of water-level fluctuations in observation wells indicate that maximum ground- water storage generally occurs during June and July (figs . 7 and 8). These hydrographs show a continuous increase in ground-water storage for th e period of record. They also show that the Fox Hills aquifer responds rapidly to seasonal and annual precipitation . Results of chemical analyses of water from 16 wells developed in the Fox Hills indicate that the water is a mixed sodium bicarbonate-sulfate type . The analyses showed a range in dissolved-solids concentration of 380 to 1,41 0 mg/l. The water is relatively soft, and the main constituents in order of mag- nitude are bicarbonate, sodium, sulfate, and chloride . A low calcium-magnesium ratio suggests that clay minerals or organic materials capable of base exchange are present in the Fox Hills aquifer an d are responsible for the soft water found in most parts of the aquifer . Water from the Fox Hills aquifer is distinguishable from that in glacial-drift aquifers by its softness and high sodium content . The water is satisfactory for mos t domestic and livestock uses, but caution may be advisable for people on a sodium-restricted diet (North Dakota State Dept. of Health, 1962) . The sodium hazard for irrigation use is high except in shallow recharge areas . Laboratory analyses of drill cuttings from the aquifer indicate porosities o f 43 to 45 percent and hydraulic conductivities of 7 to 16 ft/d (2 to 5 m/d) . Based on these and field data, wells developed in the aquifer should yield 4 to 100 gal/min (0.3 to 6 Us), with the larger yields occurring in areas o f greatest hydraulic conductivity and sandstone thickness .

Ground Water in the Glacial Deposit s

The principal glacial-drift aquifers in the two-county area occur in buried - valley, buried-outwash, and surficial-outwash deposits . Minor aquifers occu r in lacustrine, ice-contact, and till and associated sand and gravel deposits . For convenience of discussion and identification in this report and for futur e reference, the principal aquifers are named, commonly after nearby promi- nent geographic features such as lakes or cities . The approximate extent an d availability of water from these aquifers are shown on plate 2 (in pocket). The estimated potential yields to properly constructed wells in these aquifers range from 50 to 1,500 gal/min (3 .2 to 95 Us). These well yields are based on saturated thickness, estimated hydraulic conductivities, aquifer-test data, an d hydrologic boundaries . Where sufficient test-drilling and hydrologic data are available, an estimate of ground-water availability from storage is given for each aquifer . The estimates are given in acre-feet and are products of areal extent, saturate d thickness, and specific yield (about 0 .15). The storage estimates are provide d

2 1 1 1 1 1 1 1 1 1 1 1 I I I I I l I l l I l l 1 l l l l i l l

I.0

4 w U W w Cr U u) V) !Y

O 156-73-1200 0 z J 3 0J W m 5 w w w

J W JW K Cr W w a 3 3

2 . 0

7 A

I 1 N 8 1 1 1 1 1 1 1 1 1 1 I I I I I I I I I I I l l l l l i l l l l z R1, 6 - CO aF - 4 00 a - U= 2 I rI144 )- w - 0 0 r a ©0' J1 I ID JI I 0 J d J m 1968 1969 197 0 U J R 7 a FIGURE 7.-- Water-level fluctuations in a shallow well tapping the Fo x Hills aquifer, and precipitation at Rugby . 19

61 I 11111111111 1111111111 1 11111111111 8. 6 DASHED LINE INDICATES 154-71-2ODDD NO RECORD -18.7

-182w w

18.9 0 z J 3 157-74-22DAA 1 .6 9 co

IU- /' , F z

2 .0

7 z 1 0 0rn 8 ~w Q U 6 4 U LL? 2 a 0 0 S D J fr00 0 1967 1968 1969 197 0 FIGURE 8.- Water-level fluctuations in deep wells tapping the Fox Hills aquifer, and precipitation at Rugby.

for comparison purposes only and are based on static conditions . They do no t take into account recharge, natural discharge by evapotranspiration or springs , or ground-water movement between adjacent aquifers . The quantitative evaluation of these factors is beyond the scope of the present reconnaissance - type study. Buried-Valley Aquifers

There are four major aquifers in the buried valleys of Benson and Pierc e Counties. They are identified on plate 2 as the New Rockford aquifer, Spirit - wood aquifer system near Warwick and near Minnewaukan, and Kilgor e aquifer. All extend beyond the study area, but are herein discussed as they exist in Benson and Pierce Counties . 20 New Rockford aquifer

The New Rockford aquifer, in southwestern Benson County and southern Pierce County, extends westward into McHenry County and southeastward into Wells County (pl. 2). Trapp (1968, p . 41) applied the name New Rock- ford for the city in Eddy County . The aquifer was traced through Wells County to southwestern Benson County by Buturla (1970, pl . 2). The New Rockford aquifer was penetrated by 28 test holes in Benson and Pierce Counties. It is about 21 miles (34 km) long, generally 2 to 4 miles ( 3 to 6 km) wide, and underlies approximately 80 mil (207 km2) of the stud y area. The aquifer occupies a buried valley (fig . 4 and pl. 1) incised into the Fox Hills and Pierre Formations and is widest near Selz where drainage fro m glacial Lake Souris entered the valley . The top of the aquifer generally is about 150 feet (46 m) below land surface and the bottom extends to a depth of 383 feet (116 m) in places . The aquifer has an average thickness of 147 feet (45 m) . A large block of till partly obstructs the upper part of the aquifer between 2 and 5 miles (3 and 8 km ) west of North Dakota State Highway 3 in southern Pierce County (pl . 2). This obstruction consists of gravelly till, which is probably older in origi n than the surlicial Martin end moraine (pl . 3, sec. A-A' , in pocket) at thi s location. Particle-size analyses 2 of 36 samples indicate a westward gradation o f aquifer materials from medium and coarse sand (fig . 9) to a very fine and medium gravel (fig . 10). The gradation suggests that the source area for the aquifer material was west of Pierce County . The sand and gravel generally occur as separate, although somewhat interfingered, deposits (pl. 3, sec. B-B'). The materials are well sorted and have a mean porosity of 33 per - cent. Thin lenses of silty clay are interfingered throughout the aquifer. In order to determine the hydraulic properties of the New Rockfor d aquifer, an aquifer test was made in July and August 1969 by the Nort h Dakota State Water Commission and the U .S. Geological Survey using well 151-72-25BCB4 . The well had 250 feet (76 m) of 16-inch (0 .41-m) casing an d 45 feet (13.7 m) of 10-inch (0.25-m) nominal 50-slot screen exposed to the aquifer 250-295 feet (76-90 m) below land surface. The well pump consiste d of a four-stage 12-inch (0 .30-m) bowl assembly with 140 feet (42 .7 m) of 8- inch (0.20-m) pump column and was powered by a propane engine . Observa- tion wells were installed at 20 sites . These wells were located at distance s ranging from 270 feet (82 m) to about 6 miles (10 km) from the pumped well. The well was pumped at a constant rate of 1,420 gal/min (90 1/s) fo r

2 Samples from the major glacial-drift aquifers in Benson and Pierce Counties wer e analyzed for particle-size distribution (Randich, 1971, table 5) . Particle-size distribution curves were then prepared to graphically determine the mean particle size , uniformity coefficient (Cu), and sorting coefficient (Co) . Hydraulic conductivity and porosity of the samples were estimated from the particle-size analyses using the relationships described by Johnson (1963, p . 26-29). This correlation is reasonably close to results obtained from aquifer test sites . Transmissivity is calculated as the product of the average hydraulic conductivity and the saturated thickness of the aquifer .

21 100 0

90 0

LOCATION(S) I51-72-258CC I- 20 x C7 SAMPLE DEPTH (S) 220-341ft. w 3 0 PARTICLE SIZE RANGE OF 4 SAMPLE S MEAN SIZE CURVE 40 MEAN Cu 7.9 a: MEAN SD 2.2 w MEAN POROSITY 32 PERCEN T 50 't CALCULATED TRANSMISSIVITY(T) r re z a 43,000 ft . squared per da y - 0 w 40 60

1- P - z z w 30 70 w 0 0 a: w 20 80 w w 0,

90 1 0

0 N 0 0 0 0 0 0 0 ° 0 0 ru °o 0 0 00 0 0 0 0 0 0 0 0 to 0 0 O O O O O O 0 0 O O O 0 0

PARTICLE - S I Z E D I A M E T E R, I N M I L L I M E T R E S t- w SAND SIZES GRAVEL SIZES w SILT SIZE S Urn CLAY SIZES V.FIM E FINE MEDIU M COARS E V .COARS E M E FIN E MEDIU M COARS E COARS E IC w 0.004-0.0626 M M 0 16.0. 32.0 32 .0 .64. 0 a° 0a626-0.12] 1.0-2.0 2.0.4 .0 6 .0-16. . FIGURE 9 .-Particle-size distribution curves for samples from the eastern part of the New Rockford aquifer

100 1 1 0

90 10

LOCATION(S) .151-74-20AAA 2-- 20 x SAMPLE DEPTH(S) 250-300ft . 0

W 3 0 PARTICLE SIZE RANGE OF 3 SAMPLES MEAN SIZE CURVE MEAN Cu 12 .7 MEAN Su 2.0 m 50 MEAN POROSITY 28 PERCENT CALCULATED TRANSMISSIVITY(T) = z 38,000 ft . squared per da y - w 40

10 9 0

0 n a Ul m 0 0 O Cl) N • O 0 CD O O O O O 0 0 O O O N DI m 0 0 O O O O 0O 0 0 0• 0 0 O 0 O PARTICLE - S I Z E D I A M E T E R, I N MILLIMETRE S f' w SAND SIZES GRAVEL SIZE S SILT SIZE S U0) CLAY SIZE S FIN [ til t ODIUM COARS E .V.COARSE V. fIM [ FINE MEDIU M COARSE V.COARS E .

FIGURE 10.-Particle-size distribution curves for samples from the western part of the New Rockford aquifer . 7,200 minutes (5 days) . The water was discharged into an existing pothole near the site . The water level in the pothole rose about 1 foot (0 .3 m) during the test. Drawdown and recovery measurements were made on all wells . No other wells in the area were known to be pumping from the aquifer during the test. Drawdown of the potentiometric surface as a result of the pumping i s shown in figure 11 . Wells in the shallow unconfined aquifer were not in- fluenced — either because there is no direct hydraulic connection or th e period of pumping was not long enough . Figure 12 shows long-term water- level trends and the effects of this test in well 151-72-36AAA1, 6,000 fee t (1,800 m) from the pumping well . The aquifer-test data were analyzed according to methods devised b y Theis (1935, p . 519-524) and Cooper and Jacob (1946). The analyses show a transmissivity range of 40,000 to 56,000 ft 2/d (3,700 to 5,300 m 2/d) and a storage coefficient of about 0 .0007. The analysis of the data from observatio n well 151-72-25BBC (fig . 13), which is 600 feet (180 m) from the pumpe d well, shows confined aquifer conditions, and influences of impermeable boundary effects by departures from the type curve. A straight-line solution, using the drawdown obtained in six observation wells after 5 days of pumpin g (fig. 14), generally represents the mean transmissivity of the aquifer in the test area. The specific capacity of the pumped well after 5 days of pumping was 7 9 (gal/min)/ft [16 (Us)/m] of drawdown . This indicates that the aquifer at thi s site may yield as much as 1,500 gal/min (95 Us) with about 20 feet (6 m) of drawdown after 5 days of pumping . Analysis of the test results indicates , however, that due to boundary conditions in the test area, varying lithologies , and slow recharge, sustained yields to wells would generally be restricted t o the 750 to 1,000 gal/min (48 to 63 Us) range. Recharge to the New Rockford aquifer in Benson and Pierce Counties is by percolation of water through shallow overlying aquifers and by underflow from adjacent and underlying bedrock deposits (p . 1). These shallow aquifers, which contain unconfined water, are recharged by precipitation (fig. 15) and have water levels 10 to 50 feet (3 to 15 m) higher than the New Rockfor d aquifer. They are potentially large sources of recharge to the New Rockford aquifer. In the western part of the area, where the New Rockford aquifer underlies the Martin end moraine (pls . 2 and 3), substantial recharge als o occurs from prairie potholes . Clear Lake appears to by hydraulically connected to the aquifer . Water levels, in the New Rockford aquifer show only small annual fluctuations, indicating that recharge is nearly balanced by natural discharge (figs . 12 and 16) . A long-term increase of ground water in storage shown in figure 16 is the result of above-average precipitation . Water levels in the western part of the aquifer (fig . 16) are generally 40 to 50 feet (12 to 15 m) higher than in the eastern part (fig. 12). Ground-water movement through the aquifer system is generally east to southeast . The difference in head is due to recharge occuring in the western part of the aquifer and the mass of til l partially blocking the buried valley in T. 151 N ., R. 73 W. A ground-water 24

R.73 W. R.72 W . R.71 W .

6 6

\' J Po.oF~P

OF 2 Fo 600E cF T.151 N . 2.5 2. 6 ®l\

I.7 ___ C ,U 1 4,<, SELZ Eh, 2 .5 `M11 5. 0 36 31 36 31 P

99°5 0 0 1/ 2 2 3MILE S I I I 1/2 2 KILOMETRE S

EXPLANATION s o PUMPED WELL • OBSERVATION WEL L

-6— LINE OF EQUAL DRAWDOWN —snows DECLINE o f WATER LEVEL AFTER PUMPING 1420 g°I/min (901/s ) FOR 7200 MINUTES (1969) . INTERVAL 1.0 FOOT (0.30m)

FIGURE 11.-Locations of wells in the New Rockford aquifer, and drawdown caused by aquifer test near Selz.

7 3

w 7 4 U N < 72 Ir 22 .0 2 w Q 1969 J 073 z ---- a w 0 74 w m 1- 75 w w w Z 7 6 J W wW w 77 23 .5 a 3 w a 7 8 7 1

21.8 7 2 1970 22. 0

73 mint NmIIIIMWINIIMIIII 22 .2

5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 _ 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 2 5 JANUARY FEBRUARY MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER FIGURE 12 .-Water-level trends in the New Rockford aquifer .

r 2/t, IN METRES SQUARED PER DAY 103 1 4 105 106 10 7 1 I I 10 I 1 1 1 1 1 1 I I I I I I III I I 1 1 1 1 1 1 I I I 1I I III I I I I I I I

-1 . 0

-0 .5

15 .3 0 W(u) T 15 .3x1420x1 s 0 .4 0 _ 54,000'1 2/da y

4Tu 4x54,000xO .01 S- -70x10 4 r 2/t 3 .1x10 6 MATCH POIN T ' W(u)=I . O u=0 .0 1 -0.1 0

-0 .05

0.1 II I 104 1 0 5 106 10~ 108 1 0 9 r 2/t, IN FEET SQUARED PER DAY FIGURE 13.- Type-curve calculation of transmissivity (T) and storage coefficient (S), well 151-72-25BBC, Ne w Rockford aquifer test (1969) .

DISTANCE (r) FROM PUMPED WELL, IN METRES 102

5 I I I I I I I I 1 1 1 1 1 1 1 I 151-72 .36AAAI r 6000FEET -1 .6

-1 .8 6

0 7

-2 .2

T 70 .60 - 70 .6 x I420 56,000 ft?/day 5s/DIog 10r 1.8 S r 2.25T(t/r 2)0 =2 .25x56,000[5/( 9x106 )2 1.9x10 5

-2 .4

8 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 02 10 3 10 4 DISTANCE (r) FROM PUMPED WELL, IN FEET FIGURE 14.- Straight-line solution of transmissivity (T) and storage co - efficient (S), New Rockford aquifer test (1969).

divide, where recharge is occurring, appears to be located near the Pierce - McHenry County border . Water levels in these areas indicate that ground - water movement is southeast in Pierce County and northwest in McHenr y County. About one-half million acre-feet (0.6 km3) of water is available from storage within the Benson and Pierce Counties segment of the New Rockford aquifer. Water from the New Rockford aquifer is generally a sodium bicarbonat e 28

19 l I I l I l l l l l l l l l l l I I I I I I I I I I I I I I I I I I DASHED LINE INDICATES NO RECOR D 151-71-21000 6. 0

2 0

21 6. 4

6 .6 w U cc m 23 N 12 z J 0 151-72-16DDD 2 3 .8 w m I 1 3 w w LL z

4. 2 > 14 24 W

3 I51-73-30A A D 7. 5

25 – –

26 — 8 . 0

2 7

8.5 2 8 z z 10 Om F w 8 a~ 6 - ? - 4 w 2 aa 0 011111 DJ I DJ I D J 1967 1968 1969 1970 FIGURE 15 .-- Monthly water-level fluctuations in shallow aquifers overlyin g the New 'Rockford aquifer, and precipitation at Balta. 29

29 IIIII IIII I DASHED LIN E 8.9 INDICATE S 196 7 9 .0 151-74-27BBC NO RECORD 9 . 1 30 w U 2 9 w 8. 9 a 196 8 U) -9.0 Z -9.1 Z 3 0 3 0 J J 3 2 8 w 0 -8.6 co w w G ! 1 I- -a 8 Luw 29— 1969

-9.0 w Jw m w I- 3

-8. 4

28 1970 -8. 6

29 I I I I I I I I I I IIII I IIIII I I I I I IIIII 11111 IIIII IIIII IIIII IIIII IIII I -8. 8 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 _ 5 15 25 5 15 25 5 15 25 5 15 25 JANUARY FEBRUARY MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER CCTOBER NOVEMBER DECEMBER FIGURE 16 .-Water-level fluctuations in the New Rockford aquifer showing long-term increase in storage . type, but locally it is a mixed sodium bicarbonate-sulfate type . The dissolved - solids concentration of 18 water samples ranged from 450 to 1,250 mg/l , and averaged less than 700 mg/1 . Most of the samples were in the C3 (high salinity) classification for irrigation (fig . 5). The sodium-hazard classificatio n ranged from Si (low sodium) to S2 (medium sodium) . The highest concentrations of sodium and sulfate were found along the flanks and near the base of the aquifer where recharge from the underlying bedrock may be significant. Analyses of samples taken during the 5-day aquifer test at 151-72-25BCB 4 showed that calcium increased 22 percent, bicarbonate 5 percent, and di - solved solids about 4 percent . The increase in calcium and bicarbonate suggests vertical leakage from overlying materials. The New Rockford aquifer is potentially the most productive aquifer i n Pierce County. Little water was withdrawn from wells in the aquifer in 1971 , while the recharge-discharge relationship was in a state of near equilibrium . Yields to properly constructed wells range from 250 to 500 gal/min (16 t o 32 Us) in most parts of the aquifer and from 500 to 1,500 gal/min (32 to 9 5 Us) in the central part (pl . 2). Spiritwood aquifer system The aquifer system was first named by Huxel (1961, p . 179-181) in Stuts- man County. It was traced northward through Barnes County by Kelly (1964 , p. 161-165) . In Eddy County, Trapp (1968, p . 68-69) identified a buried- valley aquifer that he believed to be part of the Spiritwood aquifer system . Downey (1973, p. 27) traced an aquifer, which is part of the Spiritwoo d system, from Eddy County through the southwestern corner of Nelso n County to the Benson County line. There are two segments of the Spiritwood aquifer system in Benso n County. These segments are separated geographically and have some differin g hydraulic and chemical characteristics . Thus, the buried-valley aquifers in southeastern and eastern Benson County are herein considered as two parts , the Spiritwood aquifer system near Warwick and the Spiritwood aquife r system near Minnewaukan . Spiritwood aquifer system near Warwick . – This segment of the Spirit- wood aquifer system occurs in a buried valley that underlies about 12 mi l (31 km2) of southeastern Benson County . It underlies part of the Warwick aquifer (pl. 2;) and extends north beneath an east-trending end moraine an d Devils Lake. Results from drilling nine test holes indicate that the top of the aquife r lies from 79 to 180 feet (24 to 55 m) below land surface . The Spiritwood aquifer has an average thickness of about 94 feet (29 m) in this area. Large thicknesses of lake-deposited clay and silty clay interfingered with sand over- lie the aquifer, indicating a period of glacial stagnation during which a lake occupied the overlying area (pl. 3, sec. C-C" ). Particle-size analyses were made on 19 samples of aquifer material take n from the test holes . Particle-size graphs for these samples indicate a range i n aquifer materials from medium and very coarse sand in the upper parts to very fine and medium gravel in the lower parts . Distribution curves for fou r 31 samples from test hole 151-62-27AAA2 are shown in figure 17 . The porosity ranges from 25 to 45 percent and averages about 34 percent . The calculate d transmissivity averages about 22,400 ft2/d (2,080 m2/d) and the hydraulic conductivity for selected intervals ranges from 29 to 402 ft/d (9 to 123 m/d) . Recharge to the aquifer is primarily from overlying glacial-drift deposit s and underflow from connecting tributary buried valleys . Some recharge is from adjacent bedrock formations . Water levels in the aquifer are generally 14 to 20 feet (4 to 6 m) below land surface, except in the northern part of T. 151 N., where the aquifer underlies an end moraine . Here the water levels range from 40 to 61 fee t (12 to 19 m) below land surface. Hydrographs indicate a delayed response t o precipitation (fig . 18) due to low permeability of overlying deposits . The gradual rise of water levels during the period of record indicates an increas e in storage, which can be attributed to seepage from East Devils Lake . East Devils Lake was dry in 1968 . Overflow from Devils Lake and high runoff during 1969 partly filled East Devils Lake, and lake levels continued to rise during the period 1969-74 . About 125,000 acre-feet (0 .15 km3) of water is available from storage within the Benson County segment of the Spiritwood aquifer system nea r Warwick. The water in the Spiritwood aquifer system near Warwick is generally a calcium bicarbonate type in the central part of the aquifer and a sodium bicarbonate type near the flanks . The sulfate concentration decreases along the axis of the aquifer from north to south . The water is generally high in calcium and magnesium and is very hard . Dissolved solids in six sample s ranged from 319 to 1,000 mg/l and averaged 464 mg/l. All the samples were in the irrigation classification C2, medium-salinity hazard, and S1, low-sodiu m hazard (fig. 5) . Based on present data (1970), potential yields to wells (pl . 2) should range from 250 to 1,500 gal/min (16 to 95 Us) . Spiritwood aquifer system near Minnewaukan . – This segment of the Spiritwood aquifer system extends from near Leeds in northwestern Benso n County, southeast to near the city of Minnewaukan, and eastward beneat h Devils Lake (pl. 2) . The aquifer materials were deposited in an ice-margina l channel during an early age of glaciation in the area . The aquifer was previ- ously called the Grahams Island aquifer (Paulson and Akin, 1964, p . 38) when part of it was first identified east of Minnewaukan . The Spiritwood aquifer system near Minnewaukan underlies about 60 mil (155 km2); it was penetrated by 48 test holes in Benson County . The top o f the aquifer is generally less than 100 feet (30 m) below the land surface , and the overlying materials are mostly till and lacustrine deposits . The saturated thickness of the aquifer ranges from 7 to 159 feet (2 to 48 m) and averages 50 feet (15 m). Particle-size analyses were determined for 21 samples of aquifer material s taken from test holes . Particle-size distribution graphs for these sample s show that the most productive aquifer materials generally range from mediu m sand to medium gravel. However, these materials are randomly interbedde d throughout the aquifer (p1. 3, sec. D-D' ) . Figures 19 and 20 illustrate 32

too l I I I 1 to

90 1 0

LOCATION (S) .151-62-27AAA 2 20 x 0 SAMPLE DEP TN (S) 140-290fI. w 30 3 PARTICLE SIZE RANGE O F 4 SAMPLE S 6 0 MEAN SIZE CURVE • MEAN Cu 6.9 MEAN So 2.1 w 5 0 MEAN POROSITY 34 PERCENT CALCULATED TRANSMISSIV I TY(T ) z 22,400 M. squared per da y - w 40

• w 2 0 a

9 0 10

10 0 N n7 V N to CO O O ' N O O 0 0 O 0 0 0 N 0 • N N 0 0 O 0 O O O 0 O M 10 O O O O 6 O O O O O O O O 0

PARTICLE - S I Z E D I A M E T E R, I N MILLIMETRES z SAND SIZE S GRAVEL SIZE S W N SILT SIZES CLAY SIZES FINE FINE M EOIUM COARSE .F.COARS E V .FIRE ME0. M COARS E N .COARS E N L <0.004 MM o.ow-0.on26 MM .25 Lazo 2.0-4.0 R.O46 .0 10.0. 9). 0 52.0.64. 0 a 0 0O62S0.129 O.125-0 FIGURE 17 .-Particle-size distribution curves for samples from the Spiritwood aquifer system near Warwick .

13 IIIIIIIIIII IIIIIIIIIII I I I I I I I I I I I IIIIIIIIII I DASHED LINE INDICATES 4. 0 151-62-34DDD NO RECORD

. 2

4 .4

4. 6 152-63-10DAC

4. 6

5.0

— DJ DJ D J 1967 1968 1969 1970 FIGURE 18 .— Water-level fluctuations in the Spiritwood aquifer system near Warwick, and precipitation at Warwick .

the generally poor sorting and wide range of particle sizes, respectively, in the aquifer materials . An aquifer test was conducted using a 4-inch (100-mm) partially pene- trating well (154-67-11DDD1). The well was pumped at a rate of 30 gal/min

3 4

100 I I I I I I I I I I l I I I I I I Izz 9 i l I I ► ~ I 0 1 0 LOCATION(S) 80 . 152-65-7000 S 20 x O SAMPLE DEPTH(S) 62-140ft. C7 w 70 w PARTICLE SIZE RANGE OF • . . 30 3 4 SAMPLES 60 MEAN SIZE CURV E MEAN Cu 6.9 MEAN Su 2 .3 m 50 MEAN POROSITY 26 PERCENT W z CALCULATED TRANSMISSIVITY(T) . Cll _ 15 .000 ft. squared per day 40 1- z I- 30 z q w o rc 0 w 2 0 q w 0. 0.

10 0

0 m U) ID m o N q 0 0 q 0 0 00 0 O0 O 0 0 0 0 cm N e w q 0 O O O O O O 0 O O O O O O O PARTICLE-SIZE D I A M E T E R, I N MILLIMETRE S ~ II SAND SIZES GRAVEL SIZE S 0 o) CLAY SIZE S SILT SIZES e 0.004-0.0.5 UM Eri FINE MMU M CO668E .V.CO68S E V.iIM E ilx f M EOIU M COARSE V.CON NNE w .0.00,1MM ~06YS-O.I ]S 0.116.0.16 0.16.0.3 ).o.a0 aaa.o 8.0 .)6.0 )e.a3a o 33 .0.66.0 'FIGURE 19.- Particle-size distribution curves for samples from the upper sediments of the Spiritwood aquife r system near Minnewaukan .

lo o 0

90 0

LOCATION(S) 152-66-21AA D

SAMPLE DEPTH(S) 100-209ft.

PARTICLE SIZE RANGE OF 7 SAMPLE S MEAN SIZECURVE MEAN Cu 5 MEAN So 2 .2 t 0 MEAN POROSITY 31 PERCENT w 5 CALCULATED TRANSMISSIVITY(T) = Z 54,000 ft . squared per da y -LL 40

z 3 0 o • w 20 a-

1 0 9 0

0 10 0 1n a Ia co o 0 0 0 In 0 0 0 Q In N O 0 0 O O 0 0 0 O 0 0 0 Q O N 0 m iO m O O O O o o o 0 0 O O O O O O O

P A R T I C L E S I Z E D I A M E T E R I N MILLIMETRE S Zyj N SAND SIZES GRAVEL SIZES Ow 1n CLAY SIZES SILT SIZES .FINE FINE MEDIUM O ARSF . V .TINE MEDIUM COARS E oA6s E W LL 60.004 MM 0.004.0.002! NM 0 0026-0V .120 0.125. 0.25 1 . 0 - 2 . 0 2.0- CO 4 IRE 8.0100 10 .0.32.0 32.0. 64 .0 FIGURE 20.- Particle-size distribution curves for samples from the lower sediments of the Spiritwood aquife r system near Minnewaukan . (1.9 Us) for 6,00 minutes. One observation well 100 feet (30 m) north of th e pumped well was used to monitor effects of pumping. Results show that th e transmissivity of the aquifer at this site is about 4,000 ft 2/d (370 m2/d) and the specific capacity of the well is 14 (gal/min)/ft [2 .9 (1/s)/m] of drawdown . Recharge to the aquifer is from overlying glacial-drift deposits and adjacent bedrock formations . Figure 21 shows hydrographs of wells develope d in the aquifer in an area of shallow water levels with rapid recharge fro m precipitation. Figure 22 shows a hydrograph of well 154-67-11DDD1, whic h is in an area where recharge is relatively slow and where there has been a slow but gradual increase of water in storage . Water levels in the aquifer are deeper than 100 feet (30 m) near Brinsmade, owing, in part, to very littl e recharge through thick overlying till due to draining of most prairie potholes in this area that formerly were sources of recharge . About 290,000 acre-feet (0 .36 km3) of water is available from storage in the Spiritwood aquifer system near Minnewaukan . The calculated hydraulic conductivity iFor selected intervals ranges from 13 to 938 ft/d (4 to 286 mid) . The calculated transmissivity for the aquifer is highly variable, but average s about 20,000 ft 2/d (1,900 m2/d). Water in the Spiritwood aquifer system near Minnewaukan is generall y a mixed sodium sulfate-bicarbonate type, but it is also high in calcium an d chloride content . However, the quality varies considerably from place to place and with depth . The section of the aquifer extending from Brinsmade to Minnewaukan contained water with about 2,000 mg/1 dissolved solids . This water is high in iron, boron, and sodium content . In other parts of th e aquifer, the water quality was considerably better, with the dissolved solid s generally being less than 1,200 mg/1. The classification for irrigation us e ranged from C2 to C4, medium to . very high salinity hazard, and Si to S4 , low to very high sodium hazard (fig . 5). There are several small-yield domestic and livestock wells in this part of the aquifer, but properly constructed high-capacity wells may yield as muc h as 500 to 1,500 gal/min (32 to 95 Us) in places . Persons planning to drill wells in the aquifer should consider areal differences in chemical quality o f the water in addition to differences in availability .

Kilgore aquifer

The Kilgore aquifer is located in a buried valley underlying the Kilgor e and Girard Lake areas in southwest-central Pierce County (pl. 2) . The aquife r materials were deposited by water discharging from glacial Lake Souris . The aquifer underlies about 25 mil (65 km2) and was penetrated by 15 test holes . The thickness ranges from 0 to 241 feet (73 m) and averages about 60 feet (18 m) . Geologic sections of the aquifer deposits are shown in sectio n E-E'on plate 3. Recharge to the Kilgore aquifer is from direct infiltration and from wate r accumulated in surface depressions overlying the aquifer . Water levels are generally 10 feet (3 m) or less below land surface. Water in the aquifer is unconfined and hydraulically connected with Kilgore and Girard Lakes . 37

1 4 II IIIIIIIIIII IIIII(IIIII II1 111I I DASHED LINE INDICATES 153-66-18DDD NO RECORD

4. 5 — 1 5 —

1 6 f —

5. 0

0 J

1 53-66-21AAB

—I .0

-1 . 5

10 0

0 0 DJ DJ DJ I D 1967 1968 1969 1970 FIGURE 21 .- Water-level fluctuations in the Spiritwood aquifer system near Minnewaukan, and precipitation at Maddock . 38

17 11111 11111 1111 1 IIII I 5 .2 DASHED LINE INDICATES 154-67-I I DD D NO RECORD 1967 5. 2 18

-5 .0

_t 2

1968 -5. 4

5. 0

5 . 2 1969

5 .4

-4.6

-4. 8 6

-5. 0 1970

1 7 5. 2

5 .4 18 I I I I I IIIII I I I I I 11111 IIIII IIIII IIIII IIIII 11111 IIIII IIIII IIII I 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 2 5 JANUARY FEBRUARY MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER FIGURE 22.- Water-level fluctuations in the Spiritwood aquifer system near Minnewaukan showing a gradua l increase in storage . About 150,000 acre-feet (0 .18 km3) of water is available from storage i n the Kilgore aquifer. The water is generally a sodium bicarbonate type ; dissolved solids of five samples ranged from 348 to 1,210 mg/l . The best quality water is a calcium bicarbonate type that is found near areas of rapid recharge. The classification for irrigation use ranged from C2 to C3, medium- to high-salinity hazard , and Si to S2, low- to medium-sodium hazard (fig . 5) . Based on present data, potential yields to properly constructed well s may be from 50 to 500 gal/min (3.2 to 32 Us) . The largest yields can be obtained along the central axis of the aquifer (pl. 2).

Buried-Outwash Aquifers Two small aquifers associated with buried-outwash deposits in Benso n County are shown on plate 2 as the Maddock and Leeds aquifers . The two aquifers consist of localized deposits of sand and gravel buried beneath till .

Maddock aquifer The Maddock aquifer, which underlies about 8 mil (21 km2) in south- central Benson County near the city of Maddock (pl . 2), was penetrated b y three test holes . The aquifer directly overlies the Pierre Formation, and is overlain by till (pl. 3, sec. F-F') . It ranges from 0 to 83 feet (25 m) in thickness and averages about 70 feet (21 m). Generally the upper part of the aquifer is sand and the lower part is fine to medium gravel . Calculations, using data from particle-size graphs, show that hydraulic conductivity of the aquifer ranges from 115 to 261 ft/d (35 to 80 m/d) and that porosity is abou t 30 percent. Water-level fluctuations in the Maddock aquifer (151-69-15AAA) and in overlying glacial-drift deposits (151-69-10DAA) are shown in figure 23 ; they indicate a gradual increase of water in storage . Water in the Maddock aquife r generally is under confined conditions, whereas in the overlying drift th e water is unconfined . The water table in the overlying drift and water level s in the Maddock aquifer respond quickly to spring snowmelt and precipitation (fig. 23). Ground water in the eastern part of the Maddock aquifer i s believed to be semiconfined because a stream has cut through most of the confining bed. Water levels in the aquifer range from about 10 to 30 fee t (3 to 9 m) below land surface . Water movement through the Maddock aquife r is generally south toward the Sheyenne River . Recharge to the aquifer is derived from percolation of precipitation through the overlying glacial deposits and by inflow from adjacent deposits . About 55,000 acre-feet (0 .07 km3) of water is available from storage i n the Maddock aquifer. Water in the Maddock aquifer ranges from a mixed calcium bicarbonate - sulfate type in areas of recharge to a sodium bicarbonate-sulfate type in areas of discharge . Dissolved-solids concentration ranged from 598 to 1,51 0 mg/1. The classification for irrigation use was C3, high-salinity hazard, an d Si to S3, low- to high-sodium hazard (fig . 5). Potential yields to wells in the Maddock aquifer range from 10 to 25 0 gal/min (0.6 to 16 1/s; pl. 2). 40

10 11111111111 Illlllllitl 11111111111 1111111111 1 DASHED LINE INDICATES 151-69-IODAA NO RECORD

/--'‘ — — I i I 3.5 i 1

i ,J

4.0

-8.6 151-69-15AAA

8 .8 29 --a-\ , 9. 0

z — co -to 200 Qw H 2 100 U _J

0 a J_ I DJ DJ DJ D 1967 1968 1969 1970 FIGURE 23 .-- Water-level fluctuations in the Maddock aquifer (151-69- 15AAA) and in overlying glacial-drift deposits (151-69-10DAA) , and precipitation at Maddock .

Leeds aquifer The Leeds aquifer is located in north-central Benson County 3 miles (5 km) west of the city of Leeds (pl. 2). The aquifer is underlain and overlain by separate till deposits (pl. 3, sec. G-G'). It underlies about 7 mil (18 km2) and was penetrated by 13 test holes. The aquifer thickness ranges from 3 to 51 feet (1 to 16 m) and averages 23 feet (7 m). Aquifer materials, as shown by figure 24, are mostly coarse sand to medium gravel. Based on particle-size analyses, the mean porosity is about 34 percent, and the estimated transmissivity is about 400 ft 2/d (37 m2/d). Aquifer test results show that transmissivity of the Leeds aquifer range s from 300 to 600 ft2/d (28 to 56 m2/d). While pumping 100 gal/min (6 1/s ) 41

u s 0

90 1 (

LOCATION (S) 356-69-I5DDD AND n 8 0 156 69-34A88 2 1 SAMPLE DEPTH(S) 130-149, 80-13011 . . W 70 E. 3 PARTICLE SIZE RANGE OF • . MI 4 SAMPLES 60 MEAN SIZE CURV E ® ArA q~ MEAN Cu 7.8 MEAN Sp 2.4 n 50 MEAN POROSITY_ 34 PERCEN T / 1 W A 5 1 CALCULATED TRANSMISSIVITY(T)per day f 400 ft . squared d per day LL n 40 . 6 1

30 7 1 20 "AEI 8,

10 9 1

0 1 ( 0 0 o w o o 0 O O o 0 O O O O 0 0 0 0° m co 0 0 0 0 0 0 0 0 0 0 0 0 0 "' ° -. co 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PARTICLE-SIZE DIAMETER, I N MILLIMETRE S SAND SIZES GRAVEL SIZE S CLAY SIZES SILT SIZE S .004 MM 0. V .FINE N E MEDIU M COARSE .V.COARSE IN E FIN E MEDIU M COARS E V.COARS E <0 004.0.0626 MM 306]6. 0.125 0 .12S-0.2S 0 .26.0.6 1.0.2.0 2.0.4. 6 4 .6.6. 0 6.0.16 .0 16.0.52.0 32.0.64 .0 FIGURE 24 .-Particle-size distribution curves for samples from the Leeds aquifer.

for 100 hours, the water level in well 156-69-15DDD declined about 12 fee t (4 m) and did not return to levels measured before the test for 6 months . The slow recovery is attributed to dewatering of the aquifer during the test , and the presence of confining beds in the vicinity of the test site that restricted recharge. The high clay content mixed with the sand and gravel i s the major factor limiting potential well yields in the Leeds aquifer .

Recharge . to the Leeds aquifer is from overlying glacial-drift deposits and from intermittent streams that flow across the northern part of the aquifer . Water-level fluctuations responding to seasonal precipitation in two parts o f the aquifer are shown in figures 25 and 26 . Seasonal water-level fluctuations in the southwestern part of the aquifer are shown in figure 25. Annual change s in storage in the central part of the aquifer are indicated in figure 26 ; a substantial increase shown in 1970 is due to above-normal precipitation . Water levels generally range from 10 to 15 feet (3 to 5 m) below land surface. About 17,500 acre-feet (0.02 km3) of water is available from storage i n the Leeds aquifer. The water in the Leeds aquifer is a mixed sodium sulfate-bicarbonat e type. Dissolved solids in 12 samples ranged from 1,340 to 2,670 me and averaged 1,710 mg/l . The water is generally very hard and is high in boro n concentration . The classification for irrigation was C4, high-salinity hazard, and S2 to S3, medium- to high-sodium hazard (fig . 5). In 1971, three wells that produced less than 10 gal/min (0 .6 Us) for domestic and livestock use were developed in the aquifer . The potential yield to wells (pl. 2) is probably less than 75 gal/min (4.7 Us).

2 111111 11111111111 I I I I I I I I I I I 11111111 1 DASHED LINE INDICATES NO RECORD 155-69-4AAA 3.8

ct 8-) 4.02ct

z N O z 4.2> w J 8 c W w 4.4 3 m

5 z 10 -Ow ' 8 ~Z 6 a– 4 wz 2 a 0 DIIIII DJ DJ D J a 1967 1968 1969 197 0 FIGURE 25 .-- Water-level fluctuations in the southwestern part of the Leeds aquifer, and precipitation at Leeds . 43

14 111111111 V I I 1 1111111111 1 II 1 DASHED LIN E 4. 3 INDICATES NO RECORD DEPTH 200 FEE T 4. 5 15 1 4

1969

4. 2 1 4

1970 4. 4

15 11 I I I 11111 11111 V III 11 III V III 11 III 11111 11111 11111 11111 I 5 1525 5 15255 1525 5 15255 1525 5 15255 1525 5 15255 15255 1525 5 15255 152 5 J F M A M J J A S 0 N D FIGURE 26.- Water-level fluctuations in the central part of the Leeds aquifer.

Surficial-Outwash Aquifers Surficial glacial-outwash deposits comprise significant aquifers in fou r areas in Benson and Pierce Counties . The glacial outwash was transported b y melt water from the glaciers and for the most part, was deposited beyond the end moraines associated with the glaciers . Aquifers formed in the de - posits are the Warwick, Esmond, Pleasant Lake, and Tokio . These aquifers generally contain the best quality ground water available in the two-count y area. Warwick aquifer The Warwick aquifer underlies about 30 mil (78 km2) of eastern Benson County (pl . 2). Paulson and Akin (1964, p . 30) described the Warwick out - wash deposits as extending from the North Viking moraine in Benson an d Ramsey Counties, south to the Sheyenne River valley in Eddy and Nelso n Counties. 44 Based on 40 test holes, the aquifer thickness ranges from 20 to 200 fee t (6 to 61 m) and averages about 74 feet (23 m) . Geologic section H-H'(pl . 3) shows the different lithologic units near Warwick . Northeast of Warwick the aquifer overlies a part of the Spiritwood aquifer system, as shown on section C-C" (pl . 3). Particle-size distribution curves (fig. 27) indicate that the aquifer material s are rather uniform . The mean porosity is 42 percent and the estimated hydraulic conductivity ranges from 21 to 214 ft/d (6 to 65 m/d) . The results of 10 aquifer tests in the Warwick aquifer are summarize d in table 2 . Two of the tests were made as part of this investigation at site s 151-63-25ADB1 and 151-62-19ADD1 . Water-level drawdown and recovery in the Warwick aquifer resulting fro m pumping 242 gal/min (15 Us) from well 151-63-25ADB1 for 4,500 minutes (3.13 days) are shown in figure 28 . The test data indicate the aquifer has a transmissivity of 10,700 ft 2/d (990 m2/d). The aquifer at well 151-62-19ADD1 consists primarily of gravel . The transmissivity here is almost twice as large as at well 151-63-25ADB1 wher e the aquifer consists of a sand and gravel mixture . Recharge to the Warwick aquifer is derived mainly from direct infiltration of precipitation . Ground-water movement through the aquifer is sout h toward the Sheyenne River. Water-level fluctuations in several parts of the aquifer are shown i n figures 29-31. Long-term water-level trends in an observation well about 70 0 feet (213 m) east of the eastern-most well in the city of Devils Lake (Ramse y County) well field are shown in figure 29 . The decrease of water in storage during the period 1960-70 is due mainly to increased withdrawals of wate r from the aquifer. Well 151-62-19ADD1 (fig. 30) records water-level fluctuations in a relatively unused part of the aquifer . Water levels vary less than 1 foot (0.3 m) during the year owing to little water use in this part of th e aquifer and the high specific yield of the deposits. The relationships of water-table fluctuations and corresponding stage changes in Shinbone Lake (p1 . 2) are shown in figure 31. The lake, which is hydraulically connected to the aquifer, receives little direct runoff because o f the high permeability of the surrounding surface deposits . During most of the year, water discharges from the aquifer into the lake . The Warwick aquifer in Benson County contains about 300,000 acre-fee t (0.37 km3) of ground water available from storage. The water in the Warwick aquifer is primarily a calcium bicarbonate type . Dissolved-solids concentrations ranged from 222 to 1,010 mg/l, and average d less than 300 mg/1. In most areas near bedrock highs (pl . 1), the water was a sodium bicarbonate type and dissolved solids were at least 1,000 mg/1 . All samples were in the irrigation classification C2, medium-salinity hazard, an d S1, low-sodium hazard (fig . 5). Water in Shinbone Lake was a sodium bicarbonate type with dissolved solids ranging from 1,570 to 1,930 mg/1 . Re- sidual sodium carbonate exceeded the recommended limit (U .S. Salinity

10 u

9 1 C

LOCATION (S) 151-63-25ABC I 25AD84, 35000, 350CC, 35000 2( SAMPLE DEPTH(S) 6-7 20-25, 15-25, 35-45, 15-25 ft . 3 1 PARTICLE SIZE RANGE OF 5 SAMPLES MEAN SIZE CURVE 41 MEAN Cu 2 . 1 MEAN So 1. 5 MEAN POROSITY 42 PERCENT 5 1 w 5 CALCULATED TRANSMISSIVITY(T) = z 10,000 ft. squared per day w 4 6 1

2 8

1 1 0 m a In ID co o 0 0 N m o u) 0 0 0 O o o o O O O O O O O N of N tif .r N O m 10 N 0 O 0 0 0 0 0 0 O o 0'r 0 b H N O m O O O 0 0 0 0 0 o ri 0 O o O

P A R T I C L E - S I Z E D I A M E T E R I N MILLIMETRES SAND SIZES GRAVEL SIZES CLAY SIZE SILT SIZE S S V.FINE FIN E MEDIUM COARSE V .CO .S E V.FIN E FINE MEDIUM ARS E V.COERS E A 0.004 MR 0 .00x .0.062! M M J06 6-0.12! 0 .1360 .2 6 1.0-2.0 S.0 .113.0 10.0.92.0 32 .0,4. 0 FIGURE 27.-Particle-size distribution curves for samples from the Warwick aquifer.

TABLE 2 . — Summary of data obtained from pumping tests in the Warwick aquifer .

Numbe r Well of Date Well diam- Screened Duration Static Draw- Specific obser- Trans - of dept h ete r interva l Discharge of test water leve l dow n capacit y vatio n missivit y Test locations test (ft) (in) (ft) (gal/min) (days) (ft below lsd) (ft) [(gal/mint/ftl wells (ft'/d )

151-62-19ADD1 5- 1-68 38 4 33-38 90 0.63 17 .5 2 .5 36 1 20,600 t o 5- 2-68 151-63-20C D D 11' 8- 2-51 135 12 120-133 148 1 18 .23 2 8,700 t o 8- 3-5 1 151-63-20CDD11 12 8-15-52 135 12 120-133 200 30 21 .00 28 .0 7 4 6,300 and to 151-63-20CDD12 9-16-52 155 12 127-147 300 30 22 .04 14 .0 21 — — 151-63-20CDD12' 4-22-52 155 12 127-147 150 .17 19 .42 4 .3 35 3 7,800 151-63-20CDD12' 4-29-52 155 12 127-147 320 1 19 .36 10 .2 31 7 7,000 t o 4-30-5 2 151-63-25ADB1 8- 8-68 40 17 20-40 242 3 .13 7 .68 15 .9 15 4 10,700 to 8-11-6 8 151-63-29ABB' 11-15-61 167 12 550 1 21 .4 13 .6 40 1 11,90 0 to 11-16-6 1 151-63-29ABC1' 8- 9-61 112 12 65 .5-70 650 1 16 .6 6 .5 99 2 10,50 0 to and 8-10-61 74-11 2 151-63-29ABC2' 5-14-62 89 12 — 500 1 17 .7 14 .4 35 to 5-15-6 2 151-63-29ACB' 9-12-61 110 12 78-85 1,200 1 14 .6 13 .6 88 2 10,900 to and 9-13-61 96-110

°Results from Paulson and Akin, 1964, p . 34 . 'Two wells discharging .

0 .0 0 .0

-0. 2

-0. 4

-0. 6 151-63-25ADB I PUMPING WELL DRAWDOW N TIME DRAWDOW N 10 13 .25 FEET 100 14 .1 7 1000 15 .3 4 3000 15 .7 3 4500 15 .97 I 26 I 0 1000 2000 3000 4000 5000 6000 7000 8000 900 0 MINUTES SINCE PUMPING BEGAN FIGURE 28.- Water-level drawdown and recovery in the Warwick aquifer caused by pumping well 151-63- 25ADB1 for 3.13 days (1969).

1 1 1 I I I I I I I I I I I I I I I I I - I I I I - 11 1 I I I I I I I I I I 1 1 1 - 1 1 1 I I I I I I 1 1 1 -

` D DEVILS LAKE WELL FIEL 5. 0 STARTED WITHDRAWA L

.\...s....vj ...\.is. 5 .5 DEPTH 67 FEET

6. 0

6. 5

200 0 2

a =

10 0 a z

1~! W P 1967 1968 1969 0 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1970

FIGURE 29 .- Long-term water-level trends in the Warwick aquifer near the city of Devils Lake (Ramsey County)

well field, and precipitation at Warwick .

1 7 IIII I IIIII 1111/1111 1 5 .2 DASHED LIN E INDICATE S 196 7 5. 3 NO RECORD 151-62-19ADDI 5.4 18 5 .5 w o 1-0 1 7 5. 2 w 1968 5 .3 7 N 5 .4 c 18 5 .5 w z J 3 3 16 O O w J m W 5.0 to

I- Ww 1 7 1969

>18 - - W J J 93 X 1 6 Si 3 u 3 3 5 .0

1 7 '~_ _ 5 .2 1970 __ - 5 .4 18 IIIII IIIII 11111 I I I I I IIIII °II -I _I I IIIII 11111 lIIII_III11 IIIII 1111 1 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 5 15 25 JANUARY FEBRUARY MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER

FIGURE 30.- Water-level fluctuations in a relatively unused part of the Warwick aquifer showing seasona l change in storage.

3 IIIII111111 IIIIIIIIIII IIIIIIIIIII IIIIIfIIII I DASHED LINE INDICATE S -I .0 151-63-26BCC NO RECORD

4 —

5 1.5

w O Ui

0 z a 2.0 -' 3 0 J w m

In w 1.0 151-63-26CBB w

/~ 1.2 j > J 1 .4 w 1-

151-63-35000 2 .0

7 — 2. 2

2.4 8

V1 r ~ I '\ 2.6

9 ow 1463 w m z m a w w a LL o 146 2 O m w a OF- F w w Jw W a -1 1461

z_ z 5 O m )O z-w 0 g 1- o a z 0 0 DJ DJ DJ D Wz CT- =I 111111 0 J 1967 1968 1969 197 0 w FIGURE 31 .•- Water-level fluctuations in the Warwick aquifer, stage changes in Shinbone Lake, and precipitation at Warwick . 51 Laboratory Staff, 1954, p . 81) of 2.5 meq/l for irrigation only in the surface - water lakes in the area . Generally the aquifer contains some of the bes t quality ground water available in North Dakota . The dissolved-solids concentration is less than in many surface waters . The Warwick aquifer supplies about 0.84 Mgal/d (3,200 m 3/d) from four wells, via a 20-mile (32-km) pipeline, for the city of Devils Lake . This is only a small part of the potential water-yielding capability of the aquifer . Potential yields ranging from 50 to 500 gal/min (3.2 to 32 Us) are obtainabl e from most parts of the aquifer (pl . 2), and yields of about 1,500 gal/min (95 Us) are obtainable in some parts of the aquifer.

Esmond aquifer

The Esmond aquifer, which is located in southwestern Benson Count y near Esmond (pl . 2), consists of sand and gravel deposits along the southern side of the Heimdal and Martin end moraines (fig. 4). Part of the materials may have been deposited by outflow from glacial Lake Souris through the Long Lake kettle chain (pl . 2). The aquifer, which underlies about 20 mil (52 km2), was penetrated by 25 test holes . The thickness ranges from 10 to 75 feet (3 to 23 m) an d averages 28 feet (9 m) . Figures 32 and 33, which show particle-size distri- butions for samples collected in the southern and northern parts of the aquifer, respectively, indicate that the aquifer material is mostly sand . The porosity is about 38 percent and the estimated hydraulic conductivity range s from 5 to 220 ft/d (2 to 67 m/d) and averages 72 ft/d (22 m/d) . An aquifer test was conducted using well 153-71-17DDD1 . The well was pumped at 102 gal/min (6 .4 Us) for about 23 hours. Two observation well s 50 and 100 feet (15 and 30 m) from' the pumped well were monitored . The results of the test indicate an average transmissivity of 15,000 ft2/d (1,400 m2/d) at this site . Recharge to the Esmond aquifer is from direct infiltration of precipitatio n and from seepage of intermittent streamflow . Also, some underflow move s into the aquifer from the Fox Hills Formation in the northwestern part o f the area. Springs discharge water from the aquifer along the east bank o f Trappers Coulee and the north bank of the Sheyenne River . Seasonal responses of ground-water levels to precipitation with an overall increase i n storage due to above-average precipitation during the period of record (1967 - 70) are shown in figure 34 . About 70,000 acre-feet (0 .08 km3) of ground water is available from storage in the Esmond aquifer. Water in the Esmond aquifer is mainly a calcium bicarbonate type . Locally, in the northwestern part of the aquifer, the water is a sodium bicarbonate type — probably as a result of recharge from the Fox Hills Forma- tion. Dissolved solids in five water samples ranged from 348 to 524 mg/ l and averaged 444 mg/l. The classification for irrigation (fig . 5) was C2 to C3, medium- to high-salinity hazard, and Si to S2, low- to medium-sodiu m 52

10 0 0

90 1 0 LOCATION(S) . 152-71-9DD D 20 x SAMPLE DEPTH(S) I-50 ft. O

PARTICLE SIZE RANGE OF 30 3 6 SAMPLES >- 40 00 MEAN Cu 6.1 MEAN Sa 2.0 w rc 0 MEAN POROSITY 38 PERCENT w 5 CALCULATED TRANSMISSIVITY(T) 50 125 . D: z 14,000 tt . squared per da y u-_ 4 0 O 60 O

z 1-- 3 0 w 70 wz o 0 • T w 2 0 80 w 0 a-

10 9 0

0 m v In ID co o N.i N U, O O 0 0 000 00 0 0 O O N m 0 0 0 0 0 o 0 0 0 0 0 0 0 0 0 PARTICLE-SIZE D I A M E T E R, I N MILLIMETRE S w SAND SIZES GRAVEL SIZE S w CLAY SIZE SILT SIZE S O Ny S V.FIN E FIN E MEDIU M COARSE VCOARS E V .FIN E FIM E MEDIU M COARSE Y .COARS E K w <0 .006 MM 0 .004-0 .0626 M M 3.0626.0.126 0 .125-0 .26 0.26 .0 .5 1 .0.2.0 16 .0.910 0 92.0-64 .0 a 0 FIGURE 32 .-Particle-size distribution curves for samples from the southern part of the Esmond aquifer .

100 0

90 1 0

LOCATION(S) . 153-71-2000 C 20 i SAMPLE DEPTH(S) 0-80 ft. 0 w 30 3 PARTICLE SIZE RANGE OF 3 SAMPLES I'.' • 0-

MEAN SIZE CURV E 40 0 0 MEAN C0 6 . 0 YI w M EAN POROSITY 35 T PERCEN 50 n CALCULATED TRANSMISSIVITY(T) = 4 000 fl. squared per day LL 0 4 0 60 r z z 3 0 70 w 0 0 IZ K w 2 0 80 . D . C. 10 I! I 90 0 m v in 1D co 0 0 0 O la O O m a In N 'N+ °o 0 N 0 0° °0 °o 0° 0 0 0 0 0 0 ° a IO 10 0 0 o 0 0 o 0 0 0 o 0 0 0° 0 0

PARTICLE-SIZE D I A M E T E R, I N MILLIMETRE S '' w w SAND SIZES GRAVEL SIZES N CLAY SIZE SILT SIZES v S V .FINE FINE MEDIUM COARS E , .COARS E V .FINE FIN MEDIUM COARS E .COARS E ~ LNL <0.004 MM 0.004. 0 .0625 MM .0.8E 1 .0 6.0 16.0 16.0-32 .0 ;re 0

FIGURE 33.-Particle-size distribution curves for samples from the northern part of the Esmond aquifer .

2 4 l

152-71-IOC CC DASHED LINE INDICATE S NO RECORD 7. 4

7. 6 2 5

l52-71-27CB B

3 .2

3. 4

-3.6

S DJ DJ DJ D 1967 1968 1969 1970 FIGURE 34.- Water-level fluctuations in the Esmond aquifer, and precipitation at Balta.

5 5 hazard. The residual sodium carbonate exceeded 2 .5 meq/l in the area of sodium bicarbonate type water. Several wells tap the Esmond aquifer for domestic and livestock supplies . These wells generally yield less than 10 gal/min (0 .6 1/s). Potential yields to wells fully developed in the aquifer may range from 50 to 250 gal/min (3 .2 to 16 1/s).

Pleasant Lake aquife r

The Pleasant Lake aquifer is located in northeast-central Pierce County , east of Rugby (pl . 2) and west of a large end-moraine complex . The aquife r underlies about 25 mil (65 km2) and was penetrated by 26 test holes . The aquifer thickness ranges from 4 to 98 feet (1 to 30 m) and averages abou t 42 feet (13 m) . The major part of the aquifer is sand, but lenses of grave l are common in the basal part in some areas . Geologic section ,J-J' (pl. 3) shows the irregular distribution of materials that form the aquifer . Particle-size distribution curves for materials in the eastern part of th e aquifer are shown in figure 35 . The materials are well sorted, and porosity is about 45 percent . The hydraulic conductivity from nine intervals range s from 16 to 308 ft/d (5 to 94 m/d) and averages 104 ft/d (32 m/d). An aquifer test was conducted on well 157-72-36ADD during a municipa l water-supply study for the city of Rugby in 1965 (Froelich, 1965, p . 32-36). Test results indicate that the transmissivity of the Pleasant Lake aquifer at this site is about 9,500 ft2/d (880 m2/d) and that the water in the aquife r is under leaky confined conditions . Another test made as part of the presen t study was conducted on well 156-71-4BBA in the eastern part where th e aquifer is generally under unconfined conditions . The well was pumped a t 21 gal/min (1 .3 1/s) for 23 hours . The average transmissivity was 4,800 ft2/d (450 m2/d) at this site . Recharge to the Pleasant Lake aquifer is derived mostly from direct in - filtration of precipitation and infiltration of water accumulated in potholes . Also, in some areas recharge is from upward movement of water from the Fox Hills Formation . Springs discharge large quantities of ground water from the aquifer into Northern Broken Bone Lake . Water-level records from well 157-71-32DAA (fig. 36), which taps the central part of the Pleasant Lake aquifer, show an increase in ground-wate r storage for the period of record (1967-70) responding to increases in precipitation. The water level in well 157-72-36ADD3 (fig. 37), located near the city of Rugby well field, declined about 22 feet (7 m) from 1966 throug h 1970 due to pumping . The hydraulic gradient in the eastern part of the aquifer is about 10 ft/mi (2 m/km) westward, generally conformable with the land surface. There is about 150,000 acre-feet (0.18 km3) of ground water available from storage in the Pleasant Lake aquifer. The water in the Pleasant Lake aquifer is a mixed calcium-magnesiu m bicarbonate-sulfate type. Water in the underlying Fox Hills Formation is a sodium bicarbonate type, and, in places, upward migration of water from th e Fox Hills has increased the sodium content in water in the Pleasant Lak e 56

10 0 0

9 0 0

LOCATION(S) . 156-71-4BBA F - 20 x SAMPLE DEPTH(S) 0-60ff . 0 w 3 0 PARTICLE SIZE RANGE O F 4 SAMPLE S MEAN SIZE CURV E m m 6 0 40 MEAN Cu 2 . 1 2 MEAN So 1. 3 w MEAN POROSITY 45 PERCEN T 50 m CALCULATED TRANSMISSIVITY(T) = 3400 11. squared per day a - 0 L, 4 0 60

z z 30 1 70 • 0 w0 a: a: w 2 0 80 w C. 0.

10 90

0 00 co o 0 0 0 co a N In m d o N N 0 O O o• 0 0 0 0 0 O 0 q 0 m 0 0 0 0 0 0 0 0 0 0 q 0 0 0 0

PARTICLE-SIZE D I A M E T E R, I N MILLIMETRE S z w SAND SIZES GRAVEL SIZE S w N SILT SIZES 0 N CLAY SIZE S E FIN E MEDIUM COARS E .V .COARS 2 V .FIN E FIM E MEDIU M 06RSE V .COAMS E 0.000 0.0616 M M V.FIN C1y 00.004 MM 30626-0.126 0 .125.0.26 1.0.2.0 6.0.36.0 0.0-31 .0 33.0.60 .0 i O FIGURE 35 .-Particle-size distribution curves for samples from the Pleasant Lake aquifer . to IIIIIIIIII I 1111111111 1 IIIIIIIIII I

157-71-32DAA DASHED LINE INDICATE S N NO RECORD .

w 4.5 3

5.0

17 O w 8 a~ 6 a Z 4 z 2 aw 0 N D J DJ DJ D 1967 1968 1969 1970 FIGURE 36.- Water-level fluctuations in the central part of the Pleasan t Lake aquifer showing an increase in ground-water storage , and precipitation at Rugby. aquifer. Dissolved solids in six water samples ranged from 225 to 452 mg/1 and averaged 310 mg/l. Residual sodium carbonate did not exceed 2.5 meq/l in any of the samples and was less than 1 in most . The classification for irrigation was C2, which is a medium-salinity hazard, and S1, which is a low-sodium hazard (fig . 5). Several wells withdraw water from the aquifer for domestic and livestoc k purposes . These generally yield less than 10 gal/min (0 .6 Us). The city of Rugby has two municipal wells yielding an average of 153 gal/min (10 Us ) 58 5 3 iris iiii j

157-72-36ADD 3

1 7

59 1 8

6 1 cr 0 a 63 Ja 3 0 J W m 1-- 65 w w z w 6 7 > WJ wW

7 1

2 2

7 3

75 2 3

75,000 U_ >- Do O o 50,000 z a tri o 1a Luw 25,000 w

0 11111 0 ` 1 11111111m1111111111m1n11111111111110 1966 1967 1968 1969 1970 FIGURE 37.- Water-level fluctuations in the Pleasant Lake aquifer affected by pumpage for the city of Rugby . 59 from the aquifer . It is doubtful if this yield can be maintained in futur e years due to declining water levels (fig . 37). Potential sustained yields to properly developed wells in the aquifer (pl . 2) probably range from 50 to 150 gal/min (3.2 to 16 1/s).

Tokio aquifer

The Tokio aquifer is located in southeastern Benson County west o f Tokio (pl. 2). The aquifer consists of a collapsed outwash deposit . along the southern side of the North Viking end moraine . The Tokio aquifer, which underlies about 30 mil (78 km2), was penetrate d by 15 test holes . It consists of sand and gravel with locally abundant till an d clay. The aquifer thickness ranges from 10 to 89 feet (3 to 27 m) and average s about 32 feet (10 m). The hydraulic conductivity for seven intervals range s from 58 to 308 ft/d (18 to 94 m/d) and averages 151 ft/d (46 m/d). The porosity averages about 35 percent. Recharge to the Tokio aquifer is derived from infiltration of precipitatio n through the surface materials, and southward movement of ground wate r from North Viking end moraine . Big Coulee (pl. 2) is the major drain of ground water from the aquifer . Figure 38 compares discharge of Big Coulee near Fort Totten with fluctuations in ground-water levels and precipitation . These indicate the prompt responses of water levels in the aquifer as relate d to precipitation and streamflow . During most of the year, streamflow in Bi g Coulee is sustained by ground water discharged from the Tokio aquifer. The bed of the coulee is about 50 feet (15 m) below the surface of the outwash. The high hydraulic conductivity of the outwash deposits and steep gradient of the water table account for the rapid ground-water discharge from the aquifer. Water levels range from about 2 feet (0.6 m) below land surface nea r Big Coulee to 45 feet (14 m) in other parts of the aquifer . About 110,000 acre-feet (0.13 km3) of water is available from storage in the Tokio aquifer. Water in the Tokio aquifer is a calcium bicarbonate type . Dissolved solids in four samples averaged 330 mg/1. The irrigation classification was C2, medium-salinity hazard, and S 1, low-sodium hazard . Several wells yielding less than 10 gal/min (0.6 Us) have been developed in the aquifer for domestic and livestock supplies . Yields to properly constructed wells probably would be less than 100 gal/min (6 1/s; p1.2). The most desirable locations for maximum yields are along Big Coulee and near pot - holes .

Minor Glacial-Drift Aquifers

Numerous relatively small and localized glacial deposits that yield les s than 50 gal/min (3.2 Vs) to wells for domestic and livestock purposes occu r throughout the two-county area . These deposits are classified according to glacial origin as (1) Lake Souris deposits, (2) ice-contact deposits, and (3) till and associated sand and gravel deposits . 60

02 0 0 0 NW W a wI- 1 5 w w U m D U z _1 0 w

S U !n O z 5 w 2 J S 0 0 2 0 1 5 4.6 DASHED LINE INDICATE S 151-65-228DC I NO RECOR D 4.8 16 - w 5 .0 t

— 0Z 5 .2 Q

0 w 5.4 m (n

1-w 2 151-65-2CCD z w i > W 0 .6 J / K W Q 3 / 0 .9

` 1 / l 1 i

1. 2 4

0 In - z

a 1„" DJ DJ D J 1967 1968 1969 1970 FIGURE 38 .-- Water-level fluctuations in the Tokio aquifer, discharge o f Big Coulee, and precipitation at Warwick. 6 1 Lake Souris deposit s

Lake Souris glacial deposits cover parts of 12 townships in western Pierc e County (fig. 4). The deposits, which were penetrated by 35 test holes, are generally less than 100 feet (30 m) thick . Figure 39 shows particle-siz e distribution curves for core samples collected near Round Lake, northwestern Pierce County. The median particle size is very fine sand, the average porosity is 32 percent, and the transmissivity is estimated to be 160 ft2/d (15 m2/d). The hydraulic conductivity for eight samples of Lake Souris deposits range s from 2 to 160 ft/d (1 to 49 m/d) and averages about 42 ft/d (13 mid) . Recharge to the Lake Souris deposits is from infiltration and percolatio n of precipitation through surficial materials, and lateral movement from topo- graphically higher deposits of end moraine that lie to the east . Figure 40 shows that a general increase in ground-water storage has occurred from 1967 through about June 1970. The large water-level fluctuations are indicative o f rapid responses to spring thaws, seasonal precipitation, low specific yield s for the deposits, and high evapotranspiration discharges . About 0.7 million acre feet (0 .9 km3) of ground water is available from storage in the Lake Souris deposits . Water in the Lake Souris deposits ranged from a mixed calcium-sodiu m bicarbonate type in south-central Pierce County to a mixed sodium-calcium sulfate type in the northern part of the county. Generally the sodium-calcium sulfate type water occurs where the lake deposits are relatively thin . All the ground water sampled from the lake deposits was very hard . Therefore, in some areas wells have been drilled through the lake deposits and develope d in the underlying Fox Hills Formation in order to obtain relatively soft wate r for domestic purposes .

Ice-contact deposits

Ice-contact deposits occur in Pierce County and locally in Benson Count y along the northern sides of end moraines, as shown in figure 4 . These deposits occupy hills and ridges (some rather sinuous) that are conspicuously highe r than the surrounding terrain and consist of poorly sorted sand, gravel, an d silt. One such feature, locally named Devils Heart Butte, forms a prominen t hill near Tokio in Benson County. Recharge from precipitation moves through the deposits rapidly, as show n by small water-level fluctuations (fig. 41), and above-average precipitation (as occurred in 1969-70) is needed to increase the amount of water in storage . Because these deposits generally are located on topographic highs (hills) an d are readily discharged, only the lower one-half or less (generally less than 20 feet) of the material remains saturated for any length of time — thu s restricting potential yields to wells . The water in the ice-contact deposits is highly variable in quality an d ranges from a calcium bicarbonate to sodium sulfate type. Dissolved solids for 16 samples ranged from 220 to 1,060 mg/1 and averaged 548 mg/1. Re- sidual sodium carbonate exceeded 2 .5 meq/l in about half of the samples . 62

Im o 0

9 0 to

LOCATION(S) . 158-74-35BB B I- 80 20 I • (3 SAMPLE DEPTH(S) I-53ft . w - 7 0 30 PARTICLE SIZE RANGE OF 3 SAMPLES I_"•~~~I >- 6 0 MEAN SIZE CURV E 40 MEAN Cu 14. 5 D: MEAN So 1 . 6 w a: 5 0 MEAN POROSITY 47 PERCENT 50 w CALCULATED TRANSMISSIVITY(T) = Z 161 tt . squared per day - 4 0 r 3 0 )Ai 70 w 0 ac • 2 80 w D

9 0 10

0 m O In ID m o 0 0 0 0 0 • • . dD O O o 0 0 0 O O 0 q O 0 O O O CJ O O O O O q O O

PARTICLE-SIZE D I A M E T E R, I N MILLIMETRE S z w SAND SIZE S GRAVEL SIZE S w t•' SILT SIZES o CLAY SIZE S V.FIN E FIN E MEDIUM COANSE .V .COANS E FIN E FIN E MEDIU M COANE E V12.COAE.0- 5 S E <0 .004 MM 0.064.0.0633 M M 30625. 0.125 .126-0.x6 Lo-x. o ao-4 .o 4.0.0.0 0.0-I6.o 10.63x .0 9x.0.64.0 w w 0 a 0 FIGURE 39.-Particle-size distribution curves for samples from Lake Souris glacial deposits .

III IIII 11111 11111111111 IIIIIIIIII I 154-73-19ADA DASHED LINE -1 .0 NDICATES NO RECORD

i- - –L 5 I

6 -

-2. 0

2. 5

154-74-17000

- ~ / I 1.0

1 I I - r -

1 1 1 1. 4 r ~ 1 5 ~\ I

r 1, `\ 6 . 8

7 2.2

z 00 z-w F- 00 I ' I~+1

- U J SI DJ DJ DJ D a- 1967 1968 1969 970 a FIGURE 40.- Water-level fluctuations in Lake Souris glacial deposit s and precipitation at Balta. 64

30 7 1 1 1 1 1 1 1 1 1 1 1111111111 1 1111111111 1 DASHED LINE INDICATE S NO RECORD 154-69-15BBA r 3 1

z—

1968 1969 1970 FIGURE 41 .- Water-level fluctuations in ice-contact deposits, and precipitation at Leeds.

65 In 1971, there were several small-yield domestic and livestock well s developed in the ice-contact deposits. Potential yields to wells probabl y would be about 50 gal/min (3 .2 Us) .

Till and associated sand and gravel deposit s

Sand and gravel lenses interspersed in till form aquifers of local importance. These aquifers generally are limited to small areas and are isolate d from one another by confining layers of till . The areal extent and location of these aquifers are virtually impossible to predict using existing data ; however , the sand and gravel lenses seem to be more common in end moraines (fig . 4) than in other forms of till deposits . All test holes drilled in end moraine s penetrated one or more lenses of sand or gravel capable of producing small yields to wells. Ground water found in these deposits ranges from a mixed calcium sulfate- bicarbonate to a mixed sodium bicarbonate-sulfate type . The chemical qualit y of the water is highly variable, but the concentration of dissolved solid s generally increases with depth . Dissolved solids for seven samples ranged from about 400 to 1,700 mg/l and averaged 840 mg/1 . The water generally is very hard . Almost half of all domestic and farm wells in the area are developed i n till and associated sand and gravel deposits. The wells commonly range from about 10 to 200 feet (3 to 61 m) in depth, and are either hand dug, bored, or drilled. Yields from these wells range from 1 to about 12 gal/min (0 . 1 to 0 .8 1/s). Sustained yields are dependent upon the size, hydraulic conductivity, storage coefficient, and recharge of the deposits . In some places the water in some of these aquifers is under adequate pressure to flow a t land surface.

UTILIZATION OF GROUND-WATER RESOURCE S

Most of the water supplies in Benson and Pierce Counties are derive d from ground-water sources . There are no large manufacturing industries o r irrigation projects in the area (1970) . However, the potential exists for development of large supplies in many areas .

Farm Supplies

Most of the domestic and livestock wells in Benson and Pierce Countie s are drilled or dug less than 100 feet (30 m) deep; they commonly do no t penetrate below the first water-yielding zone . Yields of such wells generally range from 2 to 20 gal/min (0.1 to 6 .1 Us). These supplies are obtained fro m glacial-drift and shallow bedrock aquifers .

66 Estimates of the amount of ground water pumped daily for domestic an d livestock use are : Individual Population requirements or Pumpage Use (gaud) number (gal/d)

Domestic' 100 Benson County 2 6,416 600,000 Pierce County 2 3,434 300,000 Livestoc k Cattle 15 Benson County 340,000 600,000 Pierce County 327,000 400,000 Hogs 5 Benson County 3 1,800 9,000 Pierce County 3 1,600 8,000 Sheep 1. 5 Benson County 3 7,400 11,000 Pierce County 3 3,600 5,400 Poultry . 1 Benson County 325,000 2,500 Pierce County 334,000 3,400 Total 1,939,300

' Does not include communities having municipal supplies . 2 U .S. Bureau of the Census, 1971 . 3 North Dakota State University, 1968.

Public Supplies

Devils Lake, Fort Totten, Leeds, Maddock, Minnewaukan, and Rugb y obtain their municipal supplies from ground-water sources. Total pumpage in 1970 by the six municipalities was estimated to be about 1 .2 Mgal/d (4,500 m3/d). Residents of other communities are dependent upon privately owned wells. Devils Lake (Ramsey County) obtains its water supply from four wells i n the Warwick aquifer . Pumpage by these wells averaged about 0 .84 MgalJd (3,200 m3/d) in 1970 . The water is transported via pipeline 20 miles (32 km) to Devils Lake . Ground water from this source is low in dissolved solids , and of a calcium bicarbonate type . Additional large-yield wells may be in - stalled in this aquifer for expansion of present supplies . Fort Totten obtains its water supply from a well developed in a gravelly till and fractured shale near the contact between the drift and the Pierre Formation. Fort Totten used about 40,000 gal/d (150 m 3/d) in 1970. The aquifer is recharged readily from local precipitation . If proper well spacing is maintained, these materials should yield sufficient quantities of water fo r about twice the present population of Fort Totten . 67 Leeds is using highly mineralized water from wells in the Dakota aquife r for sanitary and fire-protection purposes . The wells pumped about 25,00 0 gal/d (95 m3/d) in 1970 . Residents haul their drinking water from a shallo w well on the west side of the city . The well is developed in a small glacial san d and gravel deposit in an intermittent-stream valley. The deposit is an isolated deposit associated with till and is not part of or connected to any majo r aquifer in the area . The Leeds aquifer, located about 3 miles (5 km) west o f the city, may be capable of yielding up to 50 gal/min (3 .2 Us) to wells . Maddock obtains water from a minor glacial-drift aquifer 2 miles (3 km ) west of the city . Daily use by the city in 1970 was about 100,000 gallons (380 m3). The Maddock aquifer, located about 3 miles (5 km) southeast of the cit y could be used if an additional supply is needed . Minnewaukan pumped about 22,000 gaud (80 m 3/d) in 1970 from two shallow wells, which are located near the center of the city, developed in a minor glacial-drift aquifer underlying the city . The Spiritwood aquifer, located about 3 miles (5 km) east of the city, is capable of yielding about 1,500 gall min (95 Us) to wells if additional water is needed . Rugby pumped about 220,000 gaud (830 m3/d) in 1970 from two wells in the Pleasant Lake aquifer and transported the water 5 miles (8 km) via pipe - line to city reservoirs . The aquifer contains a sufficient quantity of groun d water to sustain additional development of wells about 4 miles (6 km) eas t of the present well field .

SUMMARY AND CONCLUSION S

Ground water is obtainable in Benson and Pierce Counties from aquifer s in the preglacial rocks of Cretaceous age and from aquifers in the glacial drift of Pleistocene age . The aquifers in the preglacial rocks are more widely distributed, but the aquifers in the drift will provide higher yields and bette r quality water. Aquifers in the preglacial rocks occur in the Dakota Group and the Pierr e and Fox Hills Formations. The Dakota aquifer consists of sandstone and lie s from about 1,400 to 2,200 feet (430 to 610 m) below land surface in Benso n and Pierce Counties. Wells tapping the aquifer will generally flow at lan d surface altitudes between 1,500 and 1,600 feet (460 and 490 m) . The water contains about 4,000 mg/l dissolved solids and is a sodium sulfate to a mixe d sodium sulfate-chloride type . Because of its depth, mineralization, and the general availability of water from shallower aquifers, the Dakota aquifer has not been extensively used. The Pierre aquifer consists of shale, which is highly fractured in man y localities . Small quantities of soft sodium bicarbonate, sodium sulfate, o r sodium chloride water are available from fracture zones and are sufficient for most domestic and stock purposes . The Fox Hills aquifer consists of semiconsolidated sandstone in the uppe r part. The lower part is mostly siltstone interbedded with shale and claystone . Wells developed in the aquifer will yield 4 to 100 gal/min (0 .3 to 6 Us) of soft, high-sodium water . The water is satisfactory for most domestic and livestock uses .

68 The principal glacial-drift aquifers are composed of sand and gravel ; they occur in buried-valley, buried-outwash, and surficial-outwash deposits . The New Rockford aquifer, Spiritwood aquifer system, and Kilgore aquifer ar e buried-valley aquifers and are the largest potential sources of water in Benso n and Pierce Counties. Wells developed in these aquifers are capable of yielding 50 to 1,500 gal/min (3.2 to 95 Us) of sodium bicarbonate to calcium bicarbonate type water. Sulfate concentrations may be high in some localities. Buried-outwash deposits are relatively small in areal extent when com- pared with other glacial deposits . The Maddock and Leeds aquifers occur in buried-outwash deposits in Benson and Pierce Counties . Wells in these aquifers have potential yields of 10 to 250 gal/min (0.6 to 16 Us). The water generally is a mixed calcium-sodium bicarbonate-sulfate or a mixed sodiu m sulfate-bicarbonate type . The Warwick, Esmond, Pleasant Lake, and Tokio aquifers occur in surficial-outwash deposits . The Warwick aquifer is the most extensive and i s capable of yielding about 1,500 gal/min (95 Us). The Esmond, Pleasant Lake , and Tokio aquifers are generally thin and yield less than 250 gal/min (16 Us) to wells. The surficial-outwash aquifers yield the best water in the report area . The major glacial-drift aquifers underlie nearly 300 mil (780 km2) in Ben- son and Pierce Counties and contain about 1 .8 million acre-feet (2.2 km3) of water in available storage . Hydrologic data for the major glacial-drift aquifers are presented in the summary table . Minor glacial-drift aquifers occur in ice-contact, lacustrine, and till an d associated sand and gravel deposits . These deposits contain numerous localized aquifers that yield adequate water supplies for domestic and livestoc k use . Wells in these deposits rarely yield as much as 50 gal/min (3.2 Us ) and generally yield less than 10 gaUmin (0.6 Us). The water is highly variable in quality but generally is very hard . Practically all water used in Benson and Pierce Counties is from ground- water sources . About 2 Mgal/d (7,600 m3/d) was pumped for domestic and livestock uses in 1970 . Devils Lake, Fort Totten, Leeds, Maddock, Minne- waukan, and Rugby have municipal water systems . The amount pumped by the six communities was estimated to be about 1 .2 Mgal/d (4,500 m 3/d) in 1970 . Therefore, the total pumpage of ground water in the two-county area i n 1970 was about 3.2 Mgal/d (12,100 m3/d).

69 Summary of data for major glacial-drift aquifers

Estimate d Averag e water avail- Aquifer saturated able from Potential yield extent thickness storage to well s Aquifers (mil) (ft) (acre-feet) General type of water General irrigation class (gaUmin )

New Rockford 80 147 500,000 Sodium bicarbonate C3-S1 to C3-S2 250 to 1,500 Spiritwood system 12 94 125,000 Calcium bicarbonate C2-S1 250 to 1,500 near Warwick Spiritwood system 60 42 290,000 Sodium sulfate- C2-S1 to C4-S4 50 to 1,500 near Minnewaukan bicarbonate Kilgore 25 60 150,000 Sodium bicarbonate C2-S1 to C3-S2 50 to 250 Maddock 8 70 55,000 Calcium or sodium C3-S1 to C3-S3 50 to 250 bicarbonate-sulfate Leeds 7 23 17,500 Sodium sulfate- C4-S2 to C4-S3 10 to 75 bicarbonate Warwick 30 74 300,000 Calcium bicarbonate C2-S1 50 to 1,500 Esmond 20 28 70,000 Calcium bicarbonate C2-S1 to C3-S2 50 to 250 Pleasant Lake 25 42 150,000 Calcium-magnesium C2-S1 50 to 150 bicarbonate-sulfate Tokio 30 32 110,000 Calcium bicarbonate C2-S1 10 to 250 SELECTED REFERENCE S

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Survey Bull. 22. Brookhart, J. W., and Powell, J. E., 1961, Reconnaissance of geology an d ground water of selected areas in North Dakota : North Dakota State Water Comm . Ground-Water Studies no. 28, p. 58-68. Brown, Eugene, Skougstad, M . W., and Fishman, M . J., 1970, Method s for collection and analysis of water samples for dissolved minerals an d gases: U.S . Geol. Survey Tech . Water-Resource Inv., Bk. 5, Ch. Al, 160 p. Buturla, Frank, Jr ., 1968, Geology and ground water resources of Wells County; pt. II, Ground water basic data : North Dakota Geol. Survey Bull. 51 and North Dakota State Water Comm . County Ground Wate r Studies 12, 118 p. — 1970, Geology and ground water resources of Wells County ; pt. III, Ground water resources: North Dakota Geol. Survey Bull. 51 and North Dakota State Water Comm . County Ground Water Studies 12, 57 p . Carlson, C . G., and Freers, T. F., 1975, Geology of Benson and Pierc e Counties, North Dakota : North Dakota Geol. Survey Bull. 59, pt. I, and North Dakota State Water Comm . County Ground Water Studies 18, pt. I, 32 p. Cohen, Philip, 1963, Specific-yield and particle-size relations of Quaternar y alluvium, Humbolt River Valley, Nevada; U.S . Geol. Survey Water- Supply Paper 1669-M, 24 p. Colton, R. B., Lemke, R. W., and Lindvall, R. M., 1963, Preliminar y glacial map of North Dakota : U.S . Geol. Survey Misc . Geol. Inv. Map I-331. Cooper, H . H ., Jr., and Jacob, C . E ., 1946, A generalized graphical method for evaluating formation contacts and summarizing well-field history : Am. Geophys . Union Trans ., v. 27, no . 4, p. 526-534. Downey, J. S ., 1970, Ground-water resources of Nelson County, northeastern North Dakota: U.S. Geol. Survey Hydrol. Inv. Atlas 428, 1 p. 71 — 1971, Ground-water resources of Walsh County, northeastern, North Dakota: U.S . Geol. Survey Hydrol . Inv. Atlas 431, 1 p. 1971, Ground water basic data, Nelson and Walsh Counties, North Da- - kota: North Dakota Geol. Survey Bull . 57, pt. II, and North Dakota State Water Comm . County Ground-Water Studies 17, pt . II, 459 p. — 1973, Ground-water resources, Nelson and Walsh Counties, North Da- kota: North Dakota Geol . Survey Bull . 57, pt. III, and North Dakota State Water Comm . County Ground-Water Studies 17, pt . III, 67 p. Durfor, C. N., and Becker, Edith, 1964, Public water supplies of the 100 largest cities in the United States, 1962 : U.S. Geol. Survey Water-Suppl y Paper 1812, 364 p . Easker, D. G., 1949, The geology of the Tokio quadrangle : North Dakota Geol. Survey Bull. 24, 35 p. Fenneman, N. M ., 1946, Physical divisions of the United States : U .S. Geol. Survey map prepared in coop . with Physiog . Comm., U.S. Geol. Sur- vey, scale 1:7,000,000. (Repr. 1964). Froelich, L . L., 1965, Ground-water survey of the Rugby area, Pierc e County, North Dakota: North Dakota State Water Comm . Ground-Wate r Studies no. 62, 70 p. Hansen, D. E ., 1955, Subsurface correlation of the Cretaceous Greenhorn- Lakota interval in North Dakota : North Dakota Geol . Survey Bull . 29, 46 p. Hantush, M . S., 1964, Hydraulics of wells, in Chow, Ven Te (ed.), Advances in hydroscience, v . 1 : New York, Academic Press, Inc., p. 281-442. Hem, J . D ., 1970, Study and interpretation of the chemical characteristic s of natural water: U.S. Geol. Survey Water-Supply Paper 1473, 2d ed . , 363 p. Hubbert, M. K., 1940, The theory of ground-water motion : Jour. Geology, v. 48, no. 8, pt. 1, p. 785-944. Huxel, C . J., Jr., 1961, Artesian water in the Spiritwood buried-valley complex, North Dakota: U.S . Geol. Survey Prof. Paper 424-D, p. D179- D181. Jacob, C . E ., 1946a, Report of the subcommittee on permeability : Am . Geophys . Union Trans ., v. 27, no . 2, p. 245-256. — 1946b, Notes on the permeability coefficient and its units : Am. Geophys. Union Trans., v. 27, no. 2, p. 265-273. Johnson, A . I., 1963, Application of laboratory permeability data: U.S. Geol. Survey open-file report, 33 p . Kelly, T. E ., 1964, Geohydrology of the Spiritwood aquifer, southeaster n North Dakota: U.S . Geol. Survey Prof. Paper 501-D, p. D161-D165 . Lohman, S. W., 1972, Ground-water hydraulics: U.S . Geol. Survey Prof. Paper 708, 70 p . Lohman, S . W., and others, 1970, Definitions of selected ground-wate r terms, revisions and conceptual refinements : U.S. Geol. Survey Water- Supply Paper 1988, 21 p. Meinzer, O . E., 1923, Outline of ground-water hydrology with definitions : U .S. Geol. Survey Water-Supply Paper 494, 71 p .

72 1949, Occurrence, origin, and discharge of ground water, chap . 10b in - Meinzer, O . E., (ed.), Hydrology : New York, McGraw-Hill Book Co . , Inc., p. 385-443. Meinzer, O. E., and Wenzel, L . K., 1942, Movement of ground water and its relation to head, permeability, and storage, chap . 10b in Meinzer , O . E . (ed.), Hydrology, New York, McGraw-Hill Book Co ., Inc., p. 444-477. Mitten, H . T., and others, 1968, Chemical quality of surface waters in th e Devils Lake basin North Dakota, 1952-60 : U .S. Geol. Survey Prof. Paper 1859-B, 42 p. National Weather Service, 1931-71, Climatological data, North Dakota : Ann. S umm. 1930-70, v. 40-79, no . 13. North Dakota State Department of Health, 1962, The low sodium diet in cardiovascular and renal disease : Sodium content of municipal waters i n North Dakota: 11 p. — 1964, Chemical analyses of municipal waters in North Dakota : 25 p. North Dakota State University, 1968, North Dakota crop and livestock statistics, annual summary for 1967, revisions for 1966: Ag. Statistics no. 18, 76 p. Paulson, Q. F., and Akin, P . D., 1964, Ground-water resources of the Devils Lake area, Benson, Ramsey, and Eddy Counties, North Dakota : North Dakota State Water Comm . Ground Water Studies no . 56, 211 p. Randich, P. G., 1968, Ground-water levels in North Dakota, 1966 : North Dakota State Water Comm . Ground Water Studies no . 74, p. 83-86. — 1971, Ground-water basic data, Benson and Pierce Counties, Nort h Dakota: North Dakota Geol . Survey Bull. 59, pt. II, and North Dakota State Water Comm . County Ground-Water Studies 18, pt. II, 360 p. — 1972, Ground-water availability in Benson and Pierce Counties, north- central North Dakota : U.S. Geol. Survey Hydrol. Inv. Atlas 476, 1 p. Randich, P. G., and Bradley, Edward, 1962, Ground water resources in th e vicinity of Leeds, Benson County, North Dakota : North Dakota State Water Comm . Ground Water Studies no . 44, 27 p. Robinove, C . J., and others, 1958, Saline-water resources of North Dakota : U .S . Geol. Survey Water-Supply Paper 1428, 72 p . Simpson, H. :E ., 1929, Geology and ground water resources of North Dakota : U. S. Geol. Survey Water-Supply Paper 598, p. 71-76 and 187-189 . Stallman, R. W., 1963, Electric analog of three dimensional flow to well s and its application to unconfined aquifers: U.S. Geol. Survey Water- Supply Paper 1536-H, p . 205-242. Swenson, H. A., and Colby, B. R., 1955, Chemical quality of surface waters in the Devils Lake basin North Dakota: U .S. Geol. Survey Water-Suppl y Paper 1295, 82 p. Tetrick, P . R., 1949, Glacial geology of the Oberon quadrangle : North Dakota Geol . Survey Bull. 23, 35 p. Theis, C. V., 1935, The relation between the lowering of the piezometric surface and the rate and duration of discharge of a well using ground- water storage: Am . Geophys . Union Trans ., v. 16, p . 519-524.

73 1940, The source of water derived from wells: Civil Eng., v. 10, no. 5, - p. 277-280. Todd, D . K., 1960, Ground-water hydrology : New York, John Wiley and Sons, Inc., 336 p . Trapp, Henry, Jr., 1966, Geology and ground water resources of Eddy an d Foster Counties, North Dakota : pt. II, Ground water basic data : North Dakota Geol . Survey Bull . 44 and North Dakota State Water Comm. County Ground Water Studies 5, 243 p . - 1968, Geology and ground water resources of Eddy and Foster Counties , North Dakota; pt. III, Ground water resources : North Dakota Geol. Sur- vey Bull. 44 and North Dakota State Water Comm . County Ground Water Studies 5, 110 p. Upham, Warren, 1895, The glacial Lake Agassiz : U.S . Geol . Survey Mon. 25, 658 p. [1896] . U.S . Bureau of the Census, 1971, U .S . census of population : 1970. Number of inhabitants, North Dakota : Final Rept. PC(1)-A36, 26 p. U.S . Public Health Service, 1962, Drinking water standards : U.S. Public Health Service Pub. 956, 61 p. U.S . Salinity Laboratory Staff, 1954, Diagnosis and improvement of saline and alkaline soils : U.S. Dept. Agriculture Handb. 60, 160 p . Walton, W . C ., 1962, Selected analytical methods for well and aquife r evaluation : Illinois State Water Survey Bull . 49, 81 p. Wenzel, L. K ., 1942, Methods for determining permeability of water-bearin g materials, with special reference to discharging-well methods: U.S. Geol. Survey Water-Supply Paper 887, 192 p . Wilcox, L . V., 1955, Classification and use of irrigation waters : U .S. Dept. of Agriculture Circ. no. 969, 19 p.

74 GLOSSARY OF SELECTED TERMS

Aquifer — a formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantitie s of water to wells and springs . Area of influence — the area encompassed by the periphery of the "cone of depression" commonly caused by a discharging well . Bedrock — the consolidated rock underlying the glacial and alluvial deposits . Capture — water withdrawn artificially from an aquifer is derived from a decrease in storage in the aquifer, a reduction in the previous discharge from the aquifer, an increase in recharge, or a combination of thes e changes . (See Theis, 1940, p . 277.) The decrease in discharge plus the increase in recharge is termed capture . Cone of depression — the depression roughly conical in shape produced i n a water table or potentiometric surface by a discharging well . Drawdown — decline of the water level in a well or in nearby wells durin g pumping. Evapotranspiration — a term embracing that part of the precipitation re - turned to the air through direct evaporation from water or land surfaces and through transpiration by vegetation, no attempt being made to dis- tinguish between the two. Flowing well -- well having sufficient head to discharge water above the land surface. Gaging station — site where stream-discharge measurements are made an d records of stage are kept to calculate the flow. Ground water — water in the saturated zone . Ground-water divide — boundary of aquifer region contributing to well or spring discharge. Hydraulic conductivity — if a porous medium is isotropic and the fluid i s homogeneous, the hydraulic conductivity of the medium is the volume o f water at the existing kinematic viscosity that will move in unit tim e under a unit hydraulic gradient through a unit area measured at righ t angles to the direction of flow . Hydraulic gradient — the change in head per unit of distance in a give n direction. Hydrograph -- a graph showing stage, flow, water level, or other property o f water with respect to time . Inflow — movement of ground water into an area in response to a hydrauli c gradient. Irrigation — the controlled application of water to arable lands to suppl y water for crop demands not satisfied by rainfall . Kettle — a depression in drift, made by the wasting away of a detached mas s of glacier ice that had been either wholly or partly buried in the drift . Lacustrine — formed by or deposited in a lake environment . Losing stream — a stream that contributes water to the ground-water reser- voir. Observation well — a well in which water-level data are measured . 75 Percolation — the movement under hydrostatic pressure, of water throug h the interstices of a rock or soil . Perennial stream — a stream that flows continuously . Permeable rock — a rock that has a texture permitting water to move through it under ordinary pressure differentials . Porosity — the ratio of the total volume of openings to the total volume of a rock or soil. Generally expressed as a percentage or a decimal fraction. Potentiometric surface —an imaginary surface defined by the levels to which water will rise in tightly cased wells . Radius of influence — the distance from a discharging well to a point on the periphery of the cone of depression . Recharge — addition of water to the zone of saturation . Runoff — that part of the precipitation that appears in surface streams . Specific capacity — the rate of discharge of water from a well divided by the drawdown of water level within the well . Specific yield (dimensionless) — the ratio of (1) the volume of water which the rock or soil, after being saturated, will yield by gravity to (2) the volume of the rock or soil . Stage — the height of a water surface above an established datum plane . Stage is often used interchangeably with the term "gage height." Static water level — the level at which water will stand in a tightly case d well at a time when the water level is not affected by pumping from other wells in the aquifer . The static water level coincides with the potentio - metric surface at a given well . Storage, ground water — water stored in openings in the saturated zone . Storage coefficient — the volume of water an aquifer releases from or take s into storage per unit surface area of the aquifer per unit change in head. Till — serves both as a genetic and descriptive term, and indicates an un - sorted and unstratified mixture of material ranging from clay to boulder in size. Transmissivity — the rate at which water, at the prevailing field conditions, is transmitted through a unit width of the aquifer under a unit hydraulic gradient. Water table — that surface in an unconfined water body at which the pressur e is atmospheric. It is defined by the levels at which water stands in well s that penetrate the water body just far enough to hold standing water . Zone, saturated — in the saturated zone all voids, large and small, are ideally filled with water under pressure greater than atmospheric.