STATE OF ILLINOIS ADLAI E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION NOBLE J. PUFFER, Director
DD7ISION OF THE STATE WATER SURVEY A. M. BUSWELL, Chief URBANA
BULLETIN NO. 39
GROUNDWATER IN THE PEORIA REGION
PART 1—GEOLOGY
LELAND HORBERG, STATE GEOLOGICAL SURVEY
PART 2—HYDROLOGY
MAX SUTER, STATE WATER SURVEY
PART 3—CHEMISTRY
T. E. LARSON, STATE WATER SURVEY
A Cooperative Research Project Conducted by The State Water Survey and The State Geological Survey
PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS
URBANA, ILLINOIS 1950 This report is also a publication of THE STATE GEOLOGICAL SURVEY as its BULLETIN NO. 75. STATE OF ILLINOIS ADLAI E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION NOBLE J. PUFFER, Director
DIVISION OF THE STATE WATER SURVEY A. M. BUSWELL, Chief URBANA
BULLETIN NO. 39
GROUNDWATER IN THE PEORIA REGION
PART 1—GEOLOGY
LELAND HORBERG, STATE GEOLOGICAL SURVEY
PART 2—HYDROLOGY
MAX SUTER, STATE WATER SURVEY
PART 3—CHEMISTRY
T. E. LARSON, STATE WATER SURVEY
A Cooperative Research Project Conducted by The State Water Survey and The State Geological Survey
PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS
URBANA, ILLINOIS 1950 ORGANIZATION
STATE OF ILLINOIS HON. ADLAI E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION HON. NOBLE J. PUFFER, Director
BOARD OF NATURAL RESOURCES AND CONSERVATION HON. NOBLE J. PUFFER, Chairman W. H. NEWHOUSE, PH.D., Geology ROGER ADAMS, PH.D., D.SC, Chemistry LOUIS R. HOWSON, C.E., Engineering A. E. EMERSON, PH.D., Biology LEWIS H. TIFFANY, PH.D., Forestry GEORGE D. STODDARD, PH.D., LITT.D., LL.D., L.H.D. President of the University of Illinois
WATER SURVEY DIVISION
A. M. BUSWELL, PH.D., Chief SCIENTIFIC AND TECHNICAL STAFF OF THE STATE WATER SURVEY DIVISION 60 Noyes Laboratory Box 232, Urbana
A. M. BUSWELL, PH.D., Chief
ENGINEERING CHEMISTRY
HERBERT E. HUDSON, JR., B.S., Engineer and Head T. E. LARSON, PH.D., Chemist and Head WINFRED D. GERBER, B.S., C.E., Engineer Emeritus Boiler Water Control Ground Water Hydrology RUSSELL W. LANE, M.S., Chemist HARMON F. SMITH, B.S., Associate Engineer FRANCIS X. BUSHMAN, B.S., Assistant Engineer Corrosion Research GEORGE E. NEHER, B.S., Engineering Assistant ROBERT M. KING, B.S., Assistant Chemist Surface Water Hydrology Analytical Chemistry WYNDHAM J. ROBERTS, M.S., Associate Engineer JACK BRUIN, B.S., Engineering Assistant WILMA L. PRINTY, B.S., Assistant Chemist ARTHUR H. BODENSCHATZ, B.S., Assistant Chemist Reservoir Sedimentation JOHN B. STALL, B.S., Assistant Engineer CHEMICAL RESEARCH Meteorology Bacteriology (In Cooperation with Chemistry Depart• GLENN E. STOUT, B.S., Supervisory and Assistant Scientist ment, University of Illinois) FLOYD A. HUFF, B.S., Assistant Professional Scientist HENRY F. MUELLER, B.S., Special Research Assistant GERALD W. FARNSWORTH, B.S., Engineering Assistant ARTHUR T. YAHIRO, B.S., Special Research Assistant KENNETH A. FAULK, Radar Operator JAMES A. WEST, Radar Operator Supersonics (In Cooperation with Food Technology Department, University of Illinois) Municipal Ground Water Survey LILLIAN RUSSELL, M.S., Special Research Assistant Ross HANSON, B.S., Associate Engineer JULIUS L. GEILS, B.S., Associate Engineer Organic Contaminant Detection in Water (In Co• operation with U.S. Public Health Service) ENGINEERING RESEARCH WALTER F. CLAUSSEN, PH.D., Research Assistant Professor MAX SUTER, PH.D., Engineer and Head ROBERT L. BOHON, M.S., Special Research Assistant CARL C. CHAMBERLAIN, Assistant Engineer DAYLE CLARK, Special Research Assistant VIRGINIA WISEGARVER, B.S., Engineering Assistant RUTH EVANS, M.S., Special Research Assistant JEAN D. FORTNEY, B.S., Special Research Assistant Peoria Region and Laboratory MARY A. SCHERI, M.S., Special Research Assistant ADOLPH R. KNODEL, B.S., Field Engineer Nitrification Studies (In Cooperation with U.S. ORVILLE W. VOGEL, B.S., Assistant Chemist ROBERT D. MAHAN, M.S., Assistant Engineer Public Health Service) M. IRENE VAN METER, M.S., Research Instructor Chicago-Foliet Region JOHN GERKE, M.S., Special Research Assistant TETSUO SHIOTA, M.S., Special Research Assistant JOHN B. MILLIS, Field Engineer JACOB S. RANDALL, B.S., Field Engineer HAROLD E. BEMENT, Engineering Assistant Consultant: East St. Louis Region Radar, WILLIAM G. ALBRIGHT, M.S., University of EUGENE G. JONES, B.S., Field Engineer Illinois FOREWORD
This publication is the outgrowth of investigations of the groundwater re- sources of the Peoria area by the State Water Survey and the State Geological Sur- vey. Considerable study has been given the water supplies at Peoria for many years, but detailed studies were begun in 1940 when some industries noticed a loss in yield of their wells. This report presents the findings from these studies to Janu- ary 1, 1946. Studies are continuing, and it is hoped that, with the help of the hydraulic laboratory under construction at Peoria, these will lead to further clarification of problems of the Peoria area. The geological and geophysical studies have been made by the State Geological Survey, and the hydrologic and chemical studies have been made by the State Water Survey. Both organizations are grateful for the keen interest and excellent Cooperation and assistance of the well owners, drillers, public officials, and many others of the Peoria region who have facilitated this work. A number of important facts about the groundwater resources of Peoria from a geologic, hydrologic, and chemical viewpoint are presented in the following pages. These include an improved geologic picture; a demonstration of the com- plexity of interrelations of natural recharge, inflow into the pumping area, and influence of floods; and new chemical data on the variations in composition of ground and surface waters. Overpumpage is shown to be the cause of the local water shortage and the water-level recession. Local interest is focused on possible remedial measures to supply sufficient water for the public and industrial needs at Peoria. The economic and legal aspects of any such measures will be of great importance, but as is demonstrated by the accompanying studies, the water resources available to Peoria as a Community are vast, and several alternate Solutions are available for consideration: 1. Use of river water. 2. Injection of river water to recharge overpumped groundwater aquifers. 3. Development of the extensive gravels of the buried Valleys outside the present overpumped area. It is hoped that this report will contribute materially to a better understanding of the nature of the water problems of the Peoria area and to their Solution. A study of this type develops new concepts that will be broadly applicable to many Illinois groundwater problems and therefore may be of value in many other areas.
A. M. BUSWELL Chief, State Water Survey
M. M. LEICHTON Chief, State Geological Survey January 12, 1950 CONTENTS
PART 1—GEOLOGY PAGE Chapter 1—Introduction...... 13 Location 13 Topography 13 Purpose of report 14 Previous investigations 14 Extent of subsurface data 15 Acknowledgments 15 Chapter 2—Types of Aquifers 16 Classification 16 Occurrence of groundwater 16 Chapter 3—Bedrock Formations and Their Groundwater Conditions 17 Regional relations 17 Mineral content of groundwaters 17 Pre-St. Peter formations 18 St. Peter and younger Ordovician formations 20 St. Peter sandstone 20 Galena-Platteville dolomite 20 Maquoketa shale 23 Silurian System 23 Devonian System 23 Devonian-Mississippian Systems 23 Kinderhook-New Albany shale 23 Keokuk-Burlington formations 24 Pennsylvanian System 24 Tertiary (?) System 24 Bedrock structure and groundwater movement 24 Chapter 4—Bedrock Topography and Its Relation to Glacial Aquifers 26 Description 26 Ancient Mississippi Valley 26 Wyoming bedrock Valley 27 Kickapoo Creek bedrock Valley 27 Pekin-Sankoty bedrock channel 27 Narrows of present Valley 27 Glacial aquifers in the buried Valleys 27 Chapter 5—Glacial Deposits and Groundwater Conditions 29 Classification of deposits - 29 Areal relations 29 Illinoian till piain 31 Wisconsin drift 31 Illinois Valley deposits 31 Subsurface relations 33 Sankoty sand 34 Kansan (?) stage 36 Illinoian stage 37 Sangamon deposits and the pre-Wisconsin surface 39 Wisconsin stage 39 Chapter 6—Further Development of Groundwater Supplies...... 41 Peoria metropolitan area 41 Present supplies 41 Areas favorable for development 41 Area I 45 Area II 45 Area III 45 Area IV 45 Area V 45 PAGE Region outside the Peoria metropolitan area 45 Appendix—List of Deep Wells 47 Summary of Pleistocene History 49
PART 2—HYDROLOGY
Chapter 7—Introduction 53 Area 53 History 53 Acknowiedgments 55 The problem 56 Summary of findings...... 56 Chapter 8—Peoria Area and Sources of Water Supply 58 Scope 58 Water sources 58 Drift wells 58 Rock wells 58 Streams 61 Chapter 9—Groundwater Investigations 62 Existing wells 62 Location and construction of wells 62 Observations of water levels 62 Groundwater level data 68 Hydrographs 68 Groundwater contour maps 68 Available storage 78 Overpumpage .. . 82 Amount of normal recharge 82 Measurements of pumpage 83 Uses of groundwater 83 Search for old records 83 Other data. 83 Precipitation 83 Test drilling. 83 Velocity determinations 84 Chapter 10—Surface Water Investigations 85 Illinois River 85 Flow and turbidity 85 Channel velocity 85 Other data 87 Illinois River tributaries 87 Chapter 11—Groundwater Replenishment Investigations 89 Natural infiltration studies 89 Rainfall on ground surface 89 Illinois River 89 Dredging in channel 89 Construction of Peoria lock and dam 89 Construction of Harvard Street bridge piers 92 Illinois River at flood stage 95 Artificial infiltration studies 95 Chapter 12—Interpretation of Hydrologic Observations 97 Sankoty field...... 97 North field...... 98 Central field...... 99 East Peoria portion 99 Peoria Industrial portion 101 Central field as a whole 102 Flood effects 102 Pekin field...... 104 PAGE Chapter 13—Remedial Measures 106 Reduction of pumpage and wastage 106 Development of new well fields...... 106 Area I...... 107 Area II...... 107 Area III 107 Area IV 107 Area V...... 107 Areas outside Peoria metropolitan district 107 Substitution of surface water 108 Replenishment of groundwater 108 Natural methods 108 Artificial methods 108 General land flooding...... 108 Infiltration pits 109 Recharge wells 109 Groundwater storage space 109 PART 3—CHEMISTRY
Chaper 14—General 113 Analytical methods 113 Glacial deposits 113 Chapter 15—Geologie Correlation 115 Chemical character 115 Glacial deposits 115 Illinois River 115 Bedrock 115 Temperature 116 Chapter 16—Hydrologie Interpretation 120 Method of approach 120 Interpretation of data 120 Pekin field...... 120 East Peoria field...... 123 Sankoty field...... 124 Peoria Industrial field...... 126 Discussion 128
ILLUSTRATIONS
PLATE 1. Bedrock surface in the Peoria region In pocket 2. Areal geology of the Peoria region In pocket 3. Cross-section of glacial deposits in the Peoria region In pocket 4. Locations of Observation wells In pocket FIGURE PAGE 1. Index map showing location of the Peoria region and the boundary of the "Coal Meas ures" strata 13 2. Generalized geologic column of bedrock formations above the Lower Ordovician 19 3. Structure map of top of the Devonian limestone in the Peoria region 21 4. Graphic logs of some deep wells in the Peoria region 22 5. Generalized geologic column of the glacial deposits in the Peoria region 30 6. Groundwater conditions in the Peoria region 32 7. Contour map of the Sangamon surface in the Peoria region 38 8. Areas near Peoria in which groundwater conditions are favorable 42 9. Bedrock surface near Peoria 43 10. Graphic logs of shallow wells in northwest Peoria and vicinity 44 11. Areas covered by electrical earth-resistivity surveys in the Peoria region 46 12. Peoria-Pekin area 54 13. Well fields in Peoria-Pekin area 59 FIGURE PAGE 14. Deep rock wells in area 60 15. River stage, well hydrographs and pumpage in Sankoty field...... 63 16. River stage and well hydrographs, North field...... 64 17. River stage and well hydrographs, East Peoria field...... 65 18. River stage and well hydrographs, Pekin field...... 66 19. River stage and well hydrographs, Peoria Industrial field...... 66 20. Available long-time data of water levels in Illinois River and wells at Peoria-Pekin.... 67 21. Groundwater surface contours, 1933 69 22. Groundwater surface contours, August 1941 70 23. Groundwater surface contours, flood peak, February 1942 71 24. Groundwater surface contours, September 1942 72 25. Groundwater surface contours, May 1, 1943 73 26. Groundwater surface contours, June 1, 1943 74 27. Groundwater surface contours, July 15, 1943 75 28. Groundwater surface contours, September 1943 76 29. Groundwater surface contours, September 1945 77 30. Thickness of saturated strata, 1933 79 31. Thickness of saturated strata, May 1943 80 32. Lowering of water surface, 1933 to May 1943 81 33. Rainfall, river levels, and groundwater levels, 1936-1945 84 34. Duration of Illinois River turbidities 85 35. Duration of Illinois River flows...... 86 36. Channel velocity in Illinois River before and after closure of the Peoria dam 87 37. Range of Illinois River temperatures 87 38. Infiltration capacities of Peoria area soils 90 39. Pumpage and water levels, Peoria Dam Construction, 1936-1937 91 40. Water level profiles and materials encountered, Peoria VVater Works Company pump- ing test 92 41. Well hydrographs and well locations, Peoria Water Works Company pumping test. . . 94 42. Location of infiltration pit and Observation wells 95 43. Pumpage and hydrographs of levels in Observation wells during infiltration tests 96 44. Selected well hydrographs and river levels, 1943 flood...... 100 45. Relative character of Illinois River and Farm Creek water 116 46. Recorded temperatures of Illinois River water and of Peoria, East Peoria, and Pekin well waters 119 47. Character patterns of waters from industrial wells south of Pekin 121 48. Character of Illinois River water 122 49. Calculated percentage of Illinois River water entering Corn Products Company wells.. 123 50. Character patterns from wells in East Peoria 124 51. Character patterns from wells in Sankoty field...... 125 52. Sampling data from Sankoty field...... 126 53. Character patterns of waters from Peoria Industrial field...... 127 TABLES
TABLE PAGE 1. Population of the City of Peoria 54 2. Well fields and field pumpage 58 3. Users and pumpage of Illinois River water 61 4. Change in volume of saturated material, 1933-1943 78 5. Uses of groundwater 83 6. Effect of changing conditions on channel velocity 86 7. Pumpage and water levels, Peoria dam construction, May 1936-May 1937 91 8. Changes in groundwater storage in Central field during and after 1943 Illinois River flood 104 9. Wells that penetrate bedrock 117 10. Percentage of river water from Corn Products Refining Company wells 123 PART 1
GEO LOGY
BY
LELAND HORBERG Associate Geologist
STATE GEOLOGICAL SURVEY CHAPTER 1 INTRODUCTION
LOCATION HE PEORIA region, in north-central TIllinois, includes all of Peoria County and adjoining portions of Stark, Marshall, Woodford, Tazewell, and Fulton counties (fig. 1). The area is 40 miles long and 37 miles vvide and embraces about 1700 square miles. Peoria, East Peoria, and Pekin are the cities forming the metropolitan area of the region. The principal villages serving rural communities are Henry, Lacon, Chilli- cothe, Wyoming, Toulon, Princeville, Elm- wood, Metamora, Eureka, Washington, Morton, and Mackinaw (pl. 1). Most of the region is covered by United States Geological Survey topographic maps, which are issued as the following quad- rangles: Bradford, Dunlap, Glasford, Ke- wanee, Lacon, Mackinaw, and Peoria.
TOPOGRAPHY Illinois River crosses the Peoria region diagonally from northeast to southwest and divides the area into two extensive upland plains. The river Valley is from 1½ to 8 miles wide and ranges in elevation from 435 to 550 feet above sea-level, which is 100 to 300 feet below the adjoining uplands. Nearly all of the upland east of the river is underlain by Wisconsin glacial drift, FIG. 1.—Index map showing location of the Peoria region and the boundary of the "Coal which forms an undulating drift-plain Measures" strata. crossed by broad morainic ridges. The stage of dissection is in early youth, and rock and relatively thin Illinoian drift over many of the smaller streams in their upper much of this area, the underlying bedrock reaches are flowing essentially on the sur- topography is reflected in the present land face of the drift-plain. The upland west surface, and bedrock is commonly exposed of the river has more diversified topography along the larger Valleys. Upland eleva- and includes Wisconsin morainic ridges on tions range from 600 to 850 feet above sea- the northeast and an older Illinoian drift- level east of the river and from 600 to 900 plain on the west and south (pl. 2). The feet west of the river, the highest altitudes Wisconsin moraines are continuations of occurring along the crests of the larger those on the eastern upland and have sim- moraines. ilar youthful topography with somewhat Most of the region is drained by Illinois stronger ridging. The Illinoian drift-plain River and its principal tributaries, Sandy is deeply eroded into numerous complex Creek, Crow Creek, Farm Creek, Kicka- Valley Systems and has restricted areas of poo Creek, and Mackinaw River. Only flat upland prairies. Because of high bed- the northwest corner of the area lies in a [13] 14 GROUNDWATER IN THE PEORIA REGION separate drainage basin that is drained by Subsequent publications include general Spoon River and its tributaries, Walnut studies of the mineral resources of the State Creek and Indian Creek (pl. 2). in which references are made to local de posits, and other reports, listed below, which PURPOSE OF REPORT contain more detailed descriptions of parts The report summarizes the geologic con- of the region. ditions Controlling the occurrence of ground- Artesian wells in Peoria and vicinity, by J. A. Udden: Illinois Geol. Survey Bull. 8, yearbook for water in the Peoria region and attempts to 1907, pp. 313-334, 1908. evaluate these conditions and indicate areas Geography of the middle Illinois Valley, by favorable for the development of additional Harlan H. Barrows: Illinois Geol. Survey Bull. 15, 128 pp., 1910. groundwater supplies. Geology and mineral resources of the Peoria, The area covered by the report extends Illinois quadrangle, by J. A. Udden: U.S. Geol. beyond the immediate environs of Peoria in Survey Bull. 506, 103 pp., 1912. The only detailed geologic report on the area. order that the regional extent of the glacial A notable type Pleistocene section—the Farm aquifers and buried or partly filled bedrock Creek exposure near Peoria, Illinois, by M. M. Valleys may be portrayed and their relations Leighton: Jour. Geol., vol. 34, pp. 167-74, 1926; also Illinois Geol. Survey Rept. of Inv. 11, pp. 3-9, to local water-bearing deposits considered. 1926; The Peorian loess and the Classification of the Although the study is based primarily on glacial drift sheets of the Mississippi Valley, by subsurface data, it takes into account the M. M. Leighton: Jour. Geol., vol. 39, pp. 45-53, 1931. These papers are important in classifying areal geology of the glacial deposits and bed the stratigraphy of the glacial deposits. rock formations and the data obtained from Water resources in Peoria-Pekin district: Illi several electrical earth-resistivity surveys. nois Water Survey Bull. 33, 114 pp., 1940. This report provides detailed description of many of the The areal geology is shown on an outline important wells and includes numerous water map (pl. 2) rather than on topographic analyses. sheets, because part of the area was mapped In addition to the above publications the geologically before the topographic maps following unpublished studies were avail became available. able to the writer and made it possible to No special attempt is made to analyze compile a detailed areal geology map of the hydrological and production data or surface region. supplies, since these aspects of the problem General geology and mineral resources of the have been under continuous investigation by Illinois deep waterway from Chicago to Peoria, by the Illinois State Water Survey for a num- H. B. Willman: Illinois Geol. Survey unpublished manuscript, 276 pp., 1931. ber of years.1 Glacial geology of the lower Illinois River Valley, by T. B. Root: Unpublished doctorate PREVIOUS INVESTIGATIONS thesis, Univ. of Chicago, 313 pp., 1936. The earliest publications dealing with Maps of glacial deposits showing sand and gravel resources, prepared under direction of George E. the geology of the Peoria region are those Ekblaw; maps of Peoria, Stark, and Tazewell of the original Geological Survey of Illinois, counties, by H. A. Sellin; maps of Marshall and Woodford counties by V. H. Jones: Illinois Geol. directed by A. H. Worthen, as follows: Survey unpublished maps, 1930. Fulton County, by A. H. Worthen: Geol. Sur Geologic map of the Glasford quadrangle, by vey of Illinois, Vol. IV, pp. 90-110, 1870. A. C. Bevan: Illinois Geol. Survey unpublished Marshall County, by James Shaw: Geol. Sur map, 1929. vey of Illinois, Vol. V, pp. 202-16, 1873. Bedrock surface and structure maps of the Glas Peoria County, by A. H. Worthen: Geol. Sur ford quadrangle, by H. R. Wanless: Illinois Geol. vey of Illinois, Vol. V, pp. 235-52, 1873. Survey unpublished maps, 1945. Stark County, bv H. A. Green: Geol. Survey of The results of electrical earth-resistivity Illinois, Vol. IV, pp. 325-33, 1870. Tazewell County, by H. M. Bannister: Geol. surveys summarized in the report (fig. 5) vey of Illinois, Vol. IV. pp. 176-89, 1870. were drawn from the following unpublished Woodford County, by H. A. Green: Geol. Sur- studies on file at the Illinois State Geologi vey of Illinois, Vol. IV, pp. 334-42, 1870. cal Survey:
1 Water resources in Peoria-Pekin District: Illinois State A preliminary earth-resistivity survey at Spar Water Survey Bull. 33, 114 pp., 1940; numerous unpublished land, by J. P. Gries, 1936. reports. GEOLOGY 15
Electrical earth-resistivity survey at Metamora, the glacial deposits (pl. 3) are based on by E. A. Atherton, 1938. Results of an electrical earth-resistivity survey about 900 logs of wells and borings, of at Eureka, by M. B. Buhle, 1939. which about 110 are records based on studies Results of an electrical earth-resistivity survey of sample cuttings. Information on the at the Sankoty well field, Peoria, by L. E. Workman and M. B. Buhle, 1940. deep-lying bedrock formations underlying Results of an electrical earth-resistivity survey the Pennsylvanian System (figs. 3 and 4) is at Brimfield, by M. B. Buhle, 1940. provided by 38 well records, of which 26 are Electrical earth-resistivity survey at Peoria and vicinity, by K. O. Emery, 1941. Includes Tenmile drillers' records and 12 are records based Creek, Sankoty, Kickapoo Creek, and part of East on sample studies. Peoria areas (fig. 8). Results of an electrical earth-resistivity survey ACKNOWLEDGMENTS southwest of Metamora, by M. B. Buhle, 1942. An electrical earth-resistivity survey in the The writer is indebted to several geol- vicinity of Elmwood, by M. B. Buhle, 1943. ogists and geophysicists for basic field data Electrical earth-resistivity survey at Camp Grove, by M. B. Buhle, 1944. without which the present study could not An electrical earth-resistivity survey for Wyo have been completed, to the engineers of the ming, by M. B. Buhle, 1944. State Water Survey for groundwater pro- Electrical earth-resistivity survey for East Peoria, by M. B. Buhle, 1945. duction figures, and to George E. Ekblaw, L. E. Workman, H. B. Willman, C. A. EXTENT OF SUBSURFACE DATA Bays, and M. M. Leighton of the Survey Interpretation of bedrock-surface features staff for criticism and aid in the prepara- (pl. 1) and the subsurface stratigraphy of tion of the manuscript and illustrations. CHAPTER 2 TYPES OF AQUIFERS
CLASSIFICATION slight depth down to thousands of feet deep, Aquifers in the Peoria region can be are filled with groundwater. classed on the basis of groundwater occur- The upper surface of this saturated zone rence and their geologic relations as follows: is termed the water-table, and its position is usually the depth at which water is en- A. Unconfined (water-table) aquifers. 1. Recent alluvium—largely shallow dug countered in borings and excavations. This wells or well points. is normally only a few feet below the sur 2. Surface deposits of sand and gravel— face in the Peoria region. The water-table shallow wells of various types. 3. Glacial till—commonly shallow dug surface roughly conforms to surface topog- wells. raphy, rising under the uplands and inter- B. Confined (artesian) aquifers. secting the ground surface along permanent 1. Sand and gravel deposits buried below streams, Springs, and swamps. Its position impervious glacial till or clays—drilled wells; water-levels are usually below fluctuates from season to season and year to the water-table. year. Owing to this intermittent draining 2. Shallow bedrock aquifers—usually drill ed wells; water-levels are usually below and recharge, the groundwater is in con- the water-table. stant motion, the movement under natural 3. Deep bedrock aquifers—drilled wells; conditions being more vigorous at the water- many of these wells flow or formerly flowed and had water-levels which rose table than at greater depths. above the water-table. In the upper part of the Saturation zone Of these types, the surface sand and the groundwater is unconfined and moves gravel deposits (A2) occurring mainly along freely under control of gravity down the the Illinois River Valley and the sand and slope of the water-table. Thus the shallow gravel deposits underlying glacial till on the wells, whose water-levels indicate the Posi uplands (B1) are most extensive. Because tion of the water-table, are termed water- of their proximity along the Valley, the table wells. In deeper wells the water is present large supplies near Peoria are ob- often confined between impervious layers of tained almost entirely from the former type clay in the glacial drift or shales in the bed (A2). The second type (Bl), however, is rock formations and is under artesian pres significant because widespread buried de sure. It is hydraulically independent of posits connect directly with the deposits in the water above, and water-levels in these the valley and contain undeveloped reserves. wells may be either above or below the These deposits underlie an extensive area up water-table. In a broad sense all wells of the valley from Peoria, and it is through this type are artesian wells. them that the local aquifers are recharged by Essentially all the wells in the Peoria lateral flow. region derive their water from rain and The deep bedrock aquifers (B3), al- melted snow which entered the ground and though capable of producing large quanti- filtered slowly downward into the zone ties of water, are limited as to use because of Saturation. In the case of unconfined of the high mineral content of their waters. aquifers, water-levels are subject to seasonal The remaining types (A1, A3, and B2) are fluctuations in precipitation. In confined unimportant as potential sources of large aquifers, however, the water is obtained supplies, but in some areas they are the only from areas more remote from the wells and sources available and are developed for small is unaffected by recent variations in precip private supplies. itation. Confined waters in the glacial drift in some cases may have traveled as much as OCCURRENCE OF GROUNDWATER 100 miles, and waters in the deep bedrock All openings in the surficial glacial aquifers could have come from much greater deposits and underlying bedrock, from a distances. [16] CHAPTER 3
BEDRÜCK FORMATIONS AND THEIR GROUNDWATER CONDITIONS
REGIONAL RELATIONS Pre-Cambrian (?) Fond du Lac (?) sandstone The region is situated in the north- Pre-Cambrian western part of the Illinois coal basin (fig. Granite and other crystalline rocks 1), so that Pennsylvanian strata making up the "Coal Measures" occur directly MINERAL CONTENT OF below the glacial drift. A stratigraphic GROUNDWATERS section of about 200 feet of these strata is The Peoria region lies near the northern exposed at the surface along streams which margin of a large area encompassing most have been superimposed from the glacial of the coal basin (fig. 1) in which the deposits onto bedrock uplands. The under- groundwaters of the bedrock formations lying beds in the lower part of the Coal are highly mineralized and of limited Utility. Measures and the older bedrock forma- There appears to be an increase in mineral tions, however, are known only from sub- content toward the center of the basin, and surface data and from geologic relations this is indicated, in going from north to established outside the area. south, by the increasing mineral content of The stratigraphic succession from young- certain aquifers in the Peoria region. It est to oldest, and the Classification of the seems clear that the Silurian, Galena- formations in the Peoria region are as Platteville, and St. Peter waters at Toulon follows: and elsewhere in the northwestern part of Paleozoic era the region are less mineralized than the same Pennsylvanian System aquifers in the vicinity of Peoria. McLeansboro group Carbondale group Variations in the mineral content of the Tradewater group principal bedrock aquifers have been noted2 Mississippian System Iowa series in the vicinity of Peoria and may apply to Osage group the entire region. There appears to be a Keokuk-Burlington formations Mississippian-Devonian Systems decrease with depth in both the total mineral Kinderhook-New Albany shale content and sodium chloride content, so Devonian System that the shallower Keokuk-Burlington Cedar Valley limestone Wapsipinicon limestone waters are more highly mineralized than Silurian System the Silurian waters, which in turn are more Niagaran series Alexandrian series highly mineralized than those of the Galena- Ordovician System Platteville and St. Peter aquifers. The Cincinnatian series hydrogen sulphide content, however, ap Maquoketa shale Mohawkian series pears to increase with depth and is higher Galena dolomite in Galena-Platteville and St. Peter waters Platteville dolomite Chazyan series than in waters of the overlying aquifers. St. Peter sandstone The source of mineral matter in Solution Prairie du Chien series Shakopee dolomite presents numerous problems. Originally New Richmond sandstone much of it probably had its source in con- Oneota dolomite nate marine waters which were contained in Cambrian System St. Croixan series the bedrock formations at the time of their Trempealeau dolomite deposition. Since then changes in composi- Franconia dolomite Galesville sandstone 2 Udden, J. A., Geology and mineral resources of the Eau Claire formation Peoria quadrangle: U. S. Geol. Survey Bull. 506, pp. 91-93, Mt. Simon sandstone 1912: Illinois State Water Survey Bull. 33, pp. 16, 28-29, 31, 40, 60, 76, 97-98, 104 and 114, 1940. [17] 18 GROUNDWATER IN THE PEORIA REGION tion may have occurred by dilution with New Richmond sandstone—72 fresh waters entering the formation from feet thick Sandstone, white, medium and the surface or by gravitative settling of coarse-grained, incoherent, more mineralized waters toward the center some dolomite as above 72 1857 of the basin. Additions in mineral content Oneota dolomite—253 feet thick Dolomite, light gray, fine to are probably less important, but they could medium - grained, slightly have been derived from waters entering the sandy, and glauconitic 220 2077 aquifer from associated beds in which soluble Dolomite, light brown to gray, fine to medium-grained, with minerals, particularly sulphides, are present. white to light gray oolitic Sulphides are of common occurrence in the chert 33 2210 Cedar Valley limestone, Kinderhook-New Cambrian System—567+ feet thick Trempealeau dolomite—248 feet Albany shale, and in the coals and black thick shales of the Pennsylvanian System. Re- Dolomite, sandy, white, fine- peated changes in mineral content have grained, slightly glauconitic.. 36 2246 doubtless occurred with changing land Dolomite, white and pink, very fine-grained, slightly glauco altitude ever since deposition of the forma- nitic 175 2421 tions. The unconformities in the geologic Dolomite,gray to brownish-gray, section, which evidence former periods of slightly glauconitic and argil laceous, some pyrite and mica 37 2458 exposure and erosion, are especially signifi- Franconia dolomite—180 feet thick cant since they represent times when fresh Dolomite, sandy, brown and waters could have entered the formations. gray, mottled, fine-grained, slightly glauconitic and pyrit- ic, some brown shale 118 2576 PRE-ST. PETER FORMATIONS Dolomite, white to light gray with pink spots, fine-grained, Description.—Because the St. Peter sand- slightly porous 7 2583 stone is the oldest formation penetrated by Dolomite, sandy, gray to brown, mottled, fine-grained, slightly borings in the region, the characters of glauconitic, and argillaceous. 55 2638 deeper-lying rocks are inferred from records Galesville sandstone—139 feet thick of wells in adjoining areas. A sample study Sandstone, dolomitic, white to light brown, fine to coarse- of a well located seven miles west of the grained, few specks of glau- area in northern Fulton County provides conite 14 2652 much of this inf ormation and is given below: Sandstone, white, coarse to fine- grained, incoherent 23 2675 J. S. Young Co.—Midland Electric Coal Co., 1933, Sandstone, dolomitic, light gray with few brown spots, fine to NE. ¼, SE. ¼, NE. ¼, sec. 2, T. 8 N., R. 3 E. coarse-grained, incoherent... 15 2690 Sample study by Margaret Blair, 1933. Sandstone, white to light gray, Elevation—698 feet Thick- fine to coarse, incoherent, ness Depth some dolomite 56 2746 Feet Feet Sandstone, white, medium to Ordovician System coarse, incoherent 29 2775 St. Peter sandstone—268 feet thick Galesville sandstone or Eau Claire Sandstone, white, fine to coarse- formation grained, incoherent 268 1625 Dolomite, sandy, brown, mot Shakopee dolomite—160 feet thick tled, fine-grained 2 2777 Dolomite, red and light gray, No records of nearby borings are available fine-grained, with oolitic chert and interbedded shale, red, for the formation underlying the Gales silty 78 1703 ville sandstone, and the summary which Sandstone, gray and yellow, do- follows is based largely on subsurface lomitic, fine to coarse-grained, 3 incoherent, and porous 15 1718 studies in north-central Illinois : Dolomite, gray to red, fine to very fine-grained, argillaceous, 3 Willman, H. B., and Payne, J. N., Geology and mineral resources of the Marseilles, Ottawa, and Streator quad- slightly sandy 67 1785 rangles: Illinois Geol. Survey Bull. 66, pp. 53-55, 1942. GEOLOGY 19
FIG. 2.—Generalized geologic column of bedrock formations above the Lower Ordovician. 20 GROUNDWATER IN THE PEORIA REGION
Thickness in formity. The sandstone is white, medium- feet Min. Max. grained, friable, and contains abundant Cambrian System rounded and frosted quartz grains. Thin Eau Claire . formation—350-500 argillaceous beds in the upper part of the feet Dolomite, Sandy, gray to green- sandstone may be referable to the Glen ish-gray, finely crystalline, wood formation of northern Illinois. argillaceous 4 30 Sandstone, dolomitic, pink, buff Groundwater conditions. — Important and red, argillaceous, very quantities of water are probably obtainable glauconitic 225 250 from the sandstone throughout the area, Mt. Simon sandstone Sandstone, gray, yellow and but the water is highly mineralized. It is buff, very fine to coarse- probable that flowing wells from the St. grained, fossiliferous, sooty Peter could be obtained along the Illinois pyrite incrustations 100 170 Valley, as water in the deep well at the Pre-Cambrian (?) Fond du Lac (?) sandstone Illinois Asylum for the Incurable Insane Sandstone, pink, yellow and pur- (fig. 3, well 22) rose to an elevation of ple, with variegated shale and 4 conglomerate, lower portion about 600 feet above sea-level, which is arkosic 1600 2100 above the valley floor. Village supplies Granite and other crystalline rocks from wells ending in the St. Peter sand Groundwater conditions. — Important stone have been developed at Touion, quantities of water would probably be ob- Wyoming, Princeville, Elmwood, and Glas tainable from the Galesville sandstone, an ford. important aquifer throughout northern Illinois, and from crevice Systems in the GALENA-PLATTEVILLE DOLOMITE overlying dolomites. In the Midland Description. — The Galena-Platteville Electric Coal Company well (partial log dolomite which overlies the St. Peter sand given above), favorable reservoir conditions stone is composed of buff, crystalline, partly appear to exist in the Galesville sandstone vesicular dolomite above, and darker finer- and in crevices in the upper part of the grained dolomite with some cherty beds and Trempealeau and lower part of the Oneota occasional shale partings in the lower part. dolomites. The waters in these formations, Groundwater conditions.—The water ap- as in overlying beds, are probably highly pears to have a mineral content similar to mineralized and unsatisfactory except for that from the St. Peter,5 and in many places very limited uses. The water from the the two formations may be connected hy- Midland Electric Coal Company well is drologically. Because most of the water used for washing coal. occurs along fractures ("crevices") and bedding planes which have been enlarged ST. PETER AND YOUNGER by Solution, the quantity of water obtain ORDOVICIAN FORMATIONS able varies from place to place depending upon the size and abundance of the Solu ST. PETER SANDSTONE tion openings. The Logan Field Swimming Description.—St. Peter sandstone is Pool well (well 19) is reported to have penetrated in eight of the deep wells in the ended in a crevice, and Galena crevices area (figs. 2, 3, and 4, wells 3, 5, 7, 22, 25, were reported in the deep well at Wyoming. 28, 29, and 31) at elevations varying from Flowing wells have been drilled along the 593 feet below sea-level in the north to 1016 Illinois Valley where ground-surface eleva feet below sea-level in the south. None of tions are 535 feet or less (fig. 3, wells 9, 10 ?, the wells go through the entire formation, and 19). Probably most of the water is to but records in adjoining areas indicate that be obtained in the upper portion of the dolo the total thickness varies from about 150 mite. to 250 feet, and that the variations in thick 4 Udden, J. A., Geology and mineral resources of the ness are due to an important basal uncon- Peoria quadrangle: U. S. Geol. Survey Bull. 506, p. 90, 1912. 5 Udden, J. A., op. cit., p. 93. GEOLOGY 21
FIG. 3.—Structure map of the top of the Devonian limestone in the Peoria region. 22 GROUNDWATER IN THE PEORIA REGION
FIG. 4.—Graphic logs of some deep wells in the Peoria region. GEOLOGY 23
MAQUOKETA SHALE Silurian is the new well at Toulon which Description. — The Maquoketa shale ends in the underlying Maquoketa shale overlying the Galena-Platteville dolomite (Appendix, well 5). consists of upper and lower shales and a middle dolomite member, all of which vary DEVONIAN SYSTEM considerably in thickness. The shales are Description. — The Devonian rocks, green to gray and brown, dolomitic, especial- which overlie the Silurian System uncon ly in the lower member, and in places con- formably, include argillaceous limestones tain pyritic and phosphatic nodules; the and dolomites belonging to the Cedar Val dolomite beds are gray to brown, often ley and Wapsipinicon formations. The mottled, argillaceous, and vesicular. Thick- Cedar Valley beds are more argillaceous nesses of the formation vary from 150 to than the sublithographic limestone of the 235 feet, the Variation being due to the re- Wapsipinicon. Pyrite and chert are present lief on the unconformity at the top and in both formations. The system varies in possibly to some regional thinning to the thickness from 25 to 85 feet. south. Groundwater conditions.—The shaly Groundwater conditions. — Small a- character of the Devonian beds suggests mounts of groundwater may be present in that they are not important aquifers. They the dolomite beds, but the formation as a are probably connected hydrologically with whole is impermeable and does not merit the underlying Niagaran by a system of consideration as a source of supply. It forms Solution openings, and contain water of an impervious layer separating the Galena- similar composition. The abundant pyrite Platteville and Silurian aquifers. present in some places could cause increases in the hydrogen sulphide content of the SILURIAN SYSTEM water, but this has not been noted in the Description.—The Silurian dolomites Peoria region. There are no wells which overlie the Maquoketa shale unconformably are known to end in the Devonian beds. and are composed largely of white to gray, crystalline, vesicular dolomite. The Alexan- DEVONIAN—MISSISSIPPIAN drian strata forming the lower 50 feet or SYSTEMS so contain more chert than the overlying Niagaran and include basal beds which are KINDERHOOK-NEW ALBANY SHALE silty and sandy. There is a regional thin Description.—The Kinderhook-New Al ning of the system from 480 feet in the bany shale overlies the Devonian limestones northeast part of the region to 151 feet in without apparent unconformity. The shale the southwest part (fig. 4, wells 1 and 29), is green to brown, pyritic, partly dolomitic, which is one of the outstanding stratigraphic and contains abundant fossil plant spores, features of the area. Local variations in called Sporangites. Thin sandstone and thickness are due to the basal unconformity. dolomite beds are present in the upper half Groundwater conditions.—As in the of the formation. Except for places in the Galena-Platteville dolomite, abundant northern part of the area where pre- water would be obtainable from crevices Pennsylvanian erosion has cut down into and other Solution openings. the Kinderhook (figs. 3 and 4, wells 1, 4, Flowing wells have been obtained from and 5), the formation varies in thickness the Niagaran near Peoria where the ground- from 205 to 255 and in most places is about surface elevation is 550 feet or less (flg. 3, 225 feet thick. wells 11, 12, 13, 14?, 15, 16, 32?, and Groundwater conditions.—The shale 33?), and an increase in flow with decrease forms a thick impermeable layer which 6 in elevation has been established. The only separates the Niagaran and Keokuk-Bur- village well producing largely from the lington aquifers and is not to be considered as a possible source of groundwater. 6 Udden, J. A., op. cit., p. 94. 24 GROUNDWATER IN THE PEORIA REGION
KEOKUK-BURLINGTON FORMATIONS 10. Shale with ironstone concretions 9. Marine limestone Description. — The Keokuk-Burlington 8. Black sheety shale formations overlie the Kinderhook-New 7. Impure, lenticular limestone Albany shale without apparent uncon- 6. Shale formity. They form a massive unit of 5. Coal cherty, white to brown dolomite, which is 4. Underclay fine to medium-grained, fossiliferous, and 3. "Fresh-water" limestone partly glauconitic, interbedded with chert 1. Sandy shale and limestone. The formations are absent 1. Sandstone in the northern part of the area, where Within the 14 or 15 cyclothems recog the beds have been removed by pre-Penn- nized in the Peoria region, shale is the sylvanian erosion (figs. 3 and 4, wells 1 and dominant type of rock, followed by sand 5), and reach a maximum thickness of 212 stone and limestone. Sandstones are most feet in the southeast corner of the region important in the lower one-fourth of the (fig. 3, well 38). The average thickness sequence. in the vicinity of Peoria is about 150 feet. The thickness of the Pennsylvanian varies Groundwater conditions.—Groundwater from about 150 to 525 feet, the variations occurs in Solution openings along joints and being due primarily to relief on the bed- bedding planes and in fractured cherty beds, rock surface underlying the glacial deposits. especially in the upper part of the forma- Groundwater conditions.—No important tion. The aquifer is the uppermost which aquifers capable of producing large supplies has yielded flowing water, and at least four are present in the system. Small supplies of the flowing wells terminate within the for private use have been obtained in the formation (figs. 3 and 4, wells 17, 18, 20, western part of the area from limestone, and 21). Hydrostatic pressures seem to be sandstone, and occasionally coal beds at rel- considerably lower than in the other artesian atively shallow depths. The water from aquifers, the head being estimated at about these wells probably varies a great deal in 530 feet above sea-level in 1912.7 Because quality depending upon local stratigraphic of its high mineral content, the water relations, but it is known to have a high would be unsatisfactory for most purposes. mineral content in many places. TERTIARY (?) SYSTEM PENNSYLVANIAN SYSTEM A gravel deposit composed largely of yellow chert occurs below the Illinoian drift Description.—The Pennsylvanian beds at one point on the bedrock upland south overlap the older rocks and rest upon west of Peoria.10 Its composition is unlike progressively older strata from southeast to the glacial deposits in the region and is simi northwest, so that in places in the northern lar to "Lafayette-type" gravels which occur part of the region they lie directly on Kin at many places on the bedrock uplands to derhook shale. Included within the system the south and west. There are no wells in are an orderly repetition of more or less the region which are known to penetrate similar beds of: coal, black fissile shale, the deposit. limestone, shale and siltstone, sandstone, shale, and fire clay. This sequence, first BEDROCK STRUCTURE AND recognized by J. A. Udden8 in the Peoria GROUNDWATER MOVEMENT region and attributed to cycles of Sedimenta tion, has formed the basis for recent studies The area is situated structurally on the of the Pennsylvanian system. The follow- northwest flank of the Illinois basin, and ing ten units are now recognized in each 9 Weller, J. M., Cyclical Sedimentation of the Pennsyl vanian and its significance: Jour. Geol., vol. 38, pp. 97- cyclical repetition of beds or cyclothem 135, 1930: Wanless, H. R., Pennsylvanian cycles in western 9 Illinois: Illinois Geol. Survey Bull. 60, pp. 179-193, where fully developed. 1931; Weller, J. M., Henbest, L. G., and Dunbar, C. O., Stratigraphy of the Fusuline-bearing beds of Illinois: Illinois 7 Geol. Survey Bull. 67, pp. 9-34. 1942. Udden, J. A., op. cit., p. 94. 10 8 Op. cit., pp. 47-50. Udden, J. A., op. cit., p. 50. GEOLOGY 25 the pre-Pennsylvanian formations dip south- tions in areas where they are exposed at the southeastward at uniform rates of about 15 surface or under porous glacial deposits in feet per mile. The Pennsylvanian beds northern Illinois and southern Wisconsin. overlap progressively older strata in a north- The water in the Keokuk-Burlington aqui- west direction but have the same regional fer, however, would have to enter the for- mation in western Illinois and Iowa and structure with slightly less dip. These move into the area from the west. It is features are shown by structure contours possible that the Position of this aquifer on on top of the Devonian limestone, figure 3, the up-dip margin of the formation and and in the geologic cross-sections, figure 4. away from the line of most direct ground Groundwater in the bedrock formations water movement may account in part for moves down-dip so that the direction of the high mineral content of its water. Part movement in the Peoria region is from of the mineral matter may also be due to northwest to southeast. Water in the pre- waters moving downward into the aquifer Mississippian aquifers enters the forma from overlying Pennsylvanian beds. CHAPTER 4
BEDRÜCK TOPOGRAPHY AND ITS RELATION TO GLACIAL AQUIFERS
The bedrock surface on which the glacial south below the drift to the east of the pres deposits rest has its own uplands and Valleys ent valley. which in general do not accord with the The ancient Valley is both wider and present topography. In places in the Peoria deeper than the present valley. It has an region large buried bedrock Valleys under- average width of about 8 miles compared lie the present uplands and have no surface with about 3 miles for the present valley expression; in other places they have been and is entrenched 300 to 350 feet below ad- partly re-excavated and are followed by joining bedrock uplands. In the northern present streams. The presence of Kansan half of the area, the west bluff of the present and probably older deposits in the lower valley corresponds closely with the west part of the Valley fills near Peoria and to ern margin of the bedrock valley, but the the south indicates that most of the bed eastern bluff is composed entirely of glacial rock topography was carved in preglacial drift fill and lies 2 to 6 miles west of the time. buried eastern slope of the bedrock valley (pl. 1). DESCRIPTION The buried section of the ancient valley below Chillicothe is not expressed in the The outstanding feature of the bedrock present surface topography and is known surface is the ancient valley of the Mis only from subsurface data. The possible sissippi River which crosses the eastern part existence of such a valley, however, is in- of the region (pl. 1). Bedrock uplands dis- dicated physiographically by the narrow bed sected by tributary Valleys are present on rock channel of the present river between both sides of the ancient valley. The up- north Peoria and Pekin (pl. 1), which is land to the west covers over half the area incongruous with the broad valley above. and rises to elevations between 700 and 750 This relation suggests that the broad upper feet above sea-level; the upland to the east valley was eroded in the glacial fill of an is much less extensive and about 100 feet older bedrock valley and that the narrows lower. The bedrock surface ranges in ele- resulted from superposition across a spur vation from 750 feet above sea-level in the of the bedrock upland. It was on this west-central part of the region to below 300 general basis that Leverett11 suggested the feet above sea-level along the ancient Mis possible existence of a buried valley east sissippi Valley, giving a total maximum re- of Peoria long before the location of the lief of more than 450 feet. ancient Mississippi Valley was established from well records. The position of the bed ANCIENT MISSISSIPPI VALLEY rock valley is indicated by records of numer- The bedrock valley formerly occupied by ous wells which penetrate abnormally thick the ancient Mississippi leaves the present drift and show that bedrock elevations along Mississippi River above Rock Island in the old channel are below 400 feet as com western Illinois and continues eastward pared with 550 to 650 feet on adjoining under the drift to enter the Illinois Valley uplands. The presence of two deep Chan near the big bend at Hennepin. Continuing nels surrounding a bedrock island south of south, the Valley enters the northeast corner Washington is indicated by bedrock eleva of the Peoria region and follows Illinois tions of 430 to 490 feet near the center of River to a point south of Chillicothe where 11 Leverett, Frank, The Illinois glacial lobe: U. S. Geol. it leaves the present valley and continues Survey Mon. 38. p. 500, 1899. [26] GEOLOGY 27 the lowland. With additional data this Emery13 in 1941. Since then additional Interpretation may be changed, although wells which support Emery's Interpretation bedrock elevations of less than 400 feet are have been drilled along the channel. shown by well records on all but the north The Valley is 2 to 3 miles wide and is en- side of the island. trenched 275 feet into a spur of the bed rock upland west of the buried ancient WYOMING BEDROCK VALLEY Mississippi Valley. The lowest bedrock The presence of buried Wyoming Valley elevation is 323 feet above sea-level, as re joining the upper Spoon River drainage vealed by a well in the south end of the basin with the ancient Mississippi Valley to buried section of the Valley. the east is revealed by low bedrock eleva Because of the presence of pre-Kansan tions in southwestern Marshall and southern Sankoty sand within the Valley, it is believed Stark counties (pl. 1). It is believed that to be preglacial in age. Although alterna preglacial Spoon River above the narrows tive interpretations are possible, the bed northwest of Elmwood followed a reversed rock elevations slightly more than 400 feet course northeast to a point south of Wyo along present Illinois Valley, north of ming where, joined by preglacial Walnut Peoria, suggest that the Pekin-Sankoty Creek, it continued eastward to join the channel may represent a southward con- ancient Mississippi. The bedrock valley is tinuation of Wyoming Valley. In this case two to three miles wide and lies 100 to the narrow upland separating the Valley 250 feet below surrounding bedrock up- from the ancient Mississippi Valley to the lands. east was largely removed by later erosion during Sangamon and possibly late Wis KICKAPOO CREEK BEDROCK VALLEY consin and recent time. The partly buried bedrock Valley of Kickapoo Creek coincides with the west NARROWS OF PRESENT VALLEY branch and lower course of the present The youngest and shallowest section of stream and enters Pekin-Sankoty channel the present valley between Peoria and East northwest of Peoria. In preglacial times Peoria was cut by the superimposed Illinois the Valley appears to have been occupied by River after the deposition of the Illinoian a stream which flowed eastward from south glacial drift. It forms a narrow bedrock western Knox County across present Spoon trench separating two Segments of the River and entered the present Kickapoo isolated upland east of the Pekin-Sankoty Valley through a buried valley south of channel (pl. 1 and fig. 8). Rock benches Elmwood. Another bedrock valley about are present on both sides of the Valley, and five miles to the north appears to be con the channel below the 400-foot contour is nected to Kickapoo Valley by a headwater less than one-half mile wide. The lowest spillway of interglacial and recent origin. reported bedrock is 363 feet above sea-level, which is about 40 feet higher than the Pekin- PEKIN-SANKOTY BEDROCK CHANNEL Sankoty channel to the west. To the north This channel is represented by a buried the valley widens and merges with the bedrock valley which leaves the ancient buried ancient Mississippi Valley. Mississippi Valley above Peoria, extends southward under the upland northwest of GLACIAL AQUIFERS IN THE the city to the mouth of Kickapoo Creek, BURIED VALLEYS and continues southward along the present Illinois Valley past Pekin (pl. 1). The Glacial sand and gravel deposits supply buried northern section of the Valley, shown most of the groundwater used in the region, on Udden's bedrock surface map12 as a and their distribution is determined largely broad tributary of the present Valley, was by the Position of large bedrock Valleys. first indicated as a through-channel by 13 Emery, K. O., Electrical earth-resistivity survey at Peoria and vicinity: Illinois Geol. Survey unpublished re- 12 Op. cit., pl. V, p. 92, 1912. port, fig. 2, 1941. 28 GROUNDWATER IN THE PEORIA REGION
This relation applies not only in the Peoria it appears that sags above partially buried region, but is indicated by subsurface data Valleys were sites of deposition of younger throughout the State and by numerous outwash. groundwater studies in other areas. Aside from the ice-drainage conditions, The fundamental reason for the prev- there are two additional reasons which alence of sand and gravel aquifers along favor the occurrence of groundwater aqui bedrock Valleys is found in the conditions fers along bedrock Valleys: under which glacial outwash was deposited. 1. There is a Statistical advantage of During the glacial invasions of the Pleisto- encountering sand and gravel where the cene epoch, large volumes of water from the glacial drift is thickest and this is over melting ice were concentrated along the buried Valleys. larger Valleys and, being overloaded with 2. Initial concentrations of outwash with- debris, they deposited valley-trains of sand in the Valleys are more likely to be preserved and gravel which extended for many miles from later glacial erosion than deposits on downstream from the glacier fronts. Drain bedrock uplands which could be swept away age conditions in other areas were disrupted readily and destroyed. and streams, formerly eroding, began to aggrade their Valleys with sand, silt, and As compared with most areas in the gravel. In some places the Valley deposits State, the Peoria region is favorably situated were later overriden by the ice and buried with respect to bedrock valley aquifers. The by glacial till; in others the Valleys were bedrock Valley of the ancient Mississippi left open. Both cases are illustrated by the is one of the largest in the State and con- ancient Mississippi Valley in the Peoria tains thick deposits of sand and gravel. region. During later stages of glaciation Additional deposits occur along the Pekin- younger valley-trains were superimposed Sankoty channel, the present valley of on the older fill in Valleys which remained Illinois River close to the metropolitan cen open or had been re-excavated during the ter, and in rural areas along Kickapoo Creek intervening interglacial stages. In places and Wyoming bedrock Valleys. CHAPTER 5
GLACIAL DEPOSITS AND GROUNDWATER CONDITIONS
CLASSIFICATION OF DEPOSITS derived from the Labradorean center with The glacial deposits or "drift" overlie the possible exception of the Kansan. The the bedrock formations unconformably, fill stratigraphic succession and the Classification in and bury the irregularities on the bed of the glacial deposits in the Peoria region rock surface, and constitute the main fea- is as follows: tures of the present land surface. They are Cenozoic era composed dominantly of unstratified boul- Quaternary period Pleistocene epoch dery clays called glacial till, but include Wisconsin glacial stage stratified outwash deposits of sand, silt, and Mankato substage gravel. Wind-blown deposits of silt, de- Lake Chicago outlet river deposits Cary substage rived in the main from outwash in the Val Valley-train deposits leys, form the loess deposits which overlie Tazewell substage and interlie the till sheets. In its surface Valley-train deposits Normal drift expression the drift is characterized by a Metamora drift number of distinctive land forms, the out- Bloomington drift standing being (1) moraines, which are Leroy drift Shelbyville drift broad, arcuate ridges of till formed by Iowan substage accumulation of debris at the edge of a Iowan loess Sangamon interglacial stage glacier when the ice front was more or less 14 Late Sangamon loess stationary, (2) ground moraines, which Early Sangamon soil form the wider Stretches of rolling plains Illinoian glacial stage between the moraines, (3) outwash plains, Glacial drift Yarmouth (?) interglacial stage which are flat plains of sand and gravel Silt built up along the margin of the ice sheet Kansan (?) glacial stage and front the moraines, and (4) valley- Glacial till Pre-Kansan (?) trains, which are outwash deposits confined Sankoty sand within Valleys draining away from the glacier. AREAL RELATIONS During the Pleistocene or glacial epoch The surface distribution of the various Continental ice-sheets formed in Canada glacial deposits in the region (shown in around three great centers: the Labradorean plate 2) form three physiographic areas: center in eastern Canada, the Keewatin Cen (1) the Illinoian till-plain in the western ter west of Hudson Bay, and the Cordil- part of the region, (2) the Wisconsin leran center in western Canada. From the moraines covering most of the remaining two eastern centers the ice advanced south- area, and (3) the Wisconsin valley-train ward into central United States and ulti- terraces and recent deposits along Illinois mately most of the Mississippi drainage Valley and its tributaries. Except for small basin was glaciated. Four independent exposures along deep Valleys the pre- stages of glaciation separated by intergla- Illinoian deposits are concealed below cial stages are now generally recognized. These are, from oldest to youngest, the 14 Subsequent to the writing of this report there has been a revision in the Classification of the deposits referred to Nebraskan, Kansan, Illinoian, and Wis herein as late Sangamon loess. It has been proposed by M. M. Leighton that these deposits be given a place name, consin. In the Peoria region the glacial namely "Farmdale loess," from exposure at the Farm Creek section near Farmdale, Tazewell County, Illinois. He re- deposits include Kansan (?), Illinoian, and gards the Farmdale loess as pro-Wisconsin (pre-Iowan) Wisconsin drift (fig. 5), all of which were rather than late Sangamon age: personal communication, 1946. [29] FIG. 5.—Generalized geologic coluran of the glacial deposits in the Peoria region. (See footnote 14, page 29.) GEOLOGY 31 Most of the moraines are bordered by younger drift and are best known from only narrow fringes of outwash and, except subsurface studies. for the extensive outwash plain south of Wyoming in southeastern Stark County, no ILLINOIAN TILL PLAIN large outwash plains were formed. Instead, Description.—The Illinoian till plain most of the thick outwash deposits were val- forms a relatively flat upland surface which ley-trains, and are now reduced to terrace has been maturely to submaturely dissected remnants along the larger Valleys. A high- by streams. Formerly the drift sheet level remnant of the Bloomington outwash covered the entire region, but it is concealed plain forms the upland, 590 to 600 feet below Wisconsin drift in the eastern part above sea-level, in the northwest part of of the area (pls. 2 and 3). The average Peoria (secs. 5, 6, 7, and 8, T. 8 N., R. 8 thickness of the drift sheet resting on the E.). bedrock uplands is about 35 feet, although Groundwater conditions.—The ground along buried bedrock Valleys it may reach water conditions in the area are extremely thicknesses up to 200 feet. variable and will be discussed in greater de Groundwater conditions.—Except for tail in connection with subsurface relations. restricted areas above bedrock Valleys, In contrast to the Illinoian drift area, groundwater conditions are unfavorable, small private supplies are available through- out the area, and all but a few isolated wells and most supplies are from shallow dug obtain water from glacial aquifers (fig. 6). wells in the drift or to the top of rock and This is due to the greater average thickness from bedrock wells penetrating sandstone of the Wisconsin drift, which is roughly 125 or limestone in the upper part of the feet, to its deposition at or near the margin Pennsylvanian (fig. 6). Municipal supplies of the glacier, and to the fact that older within the area at Toulon, Wyoming, underlying deposits are in most places more Princeville, Elmwood, and Glasford are than 100 feet thick and include water-bear- secured from deep bedrock wells. ing sands and gravel. WISCONSIN DRIFT The deeper aquifers in the Wisconsin Description.—The Wisconsin drift sheet drift generally occur at depths of less than forms an extensive upland plain traversed 100 feet, although in some areas depths up by morainic ridges which have a general to 200 feet are reached. Most of the water- north-south to northwest-southeast trend bearing deposits are discontinuous and lentic- (pl. 2). The moraines were formed during ular and are unfavorable for obtaining the Tazewell glacial substage and, in the important supplies. They appear to be order of recession, include the Shelbyville, thickest and most continuous near the outer Leroy, Bloomington, Metamora, and Nor margins of the moraines. The lower aqui mal, of which the Bloomington is the most fers are confined or partially confined by prominent. The moraines are often drain- overlying deposits of relatively imperme age divides and influence the Position of able till. streams. In most places the outer fronts rise more abruptly from the general upland An extensive, shallow unconfined aquifer level than the back slopes which descend is coextensive with the outwash plain in gradually or by a series of steps. The southeastern Stark County where domestic ground-moraine tracts between moraines supplies are obtained from wells 25 to 40 are flat to gently rolling and have less local feet deep. relief than the moraines. There has been considerable erosion of the moraines and ILLINOIS VALLEY DEPOSITS ground-moraines along Illinois River, but Description.—Wisconsin valley-train ter- over much of the area the drainage is poor races are the most conspicuous feature along and the degree of erosion is much less than the Illinois Valley and, as shown on plate on the Illinoian till plain. 2, cover the major part of the Valley floor 32 GROVNDWATER IN THE PEORIA REGION
FIG. 6.—Groundwater conditions in the Peoria region. GEOLOGY 33 in the wider portions of the Valley. In trib- part to the widespread occurrence of the utary Valleys terrace remnants are present sands and gravels of the Wisconsin valley- along Mackinaw River, Kickapoo Creek train and in part to the presence below much and Sandy Creek, and to a lesser extent of the valley of the important deeper along Crow Creek and Farm Creek. The Sankoty aquifer which will be described glacial outwash deposits underlying the more fully later. Most private supplies terraces and flood plains are composed al- along the valley, part of the municipal most entirely of stratified sand and gravel supplies at Henry, Lacon, and Chillicothe, and are exposed at many places. and industrial supplies along the narrows Three main terraces, about 520, 480, and between Peoria and East Peoria are secured 460 feet above sea-level, are present along from unconfined or partially confined the main Valley. A large part of the city aquifers in the Wisconsin outwash. Out of Peoria below the "bluff" is built on the wash deposits along Mackinaw Valley pro- 520-foot terrace. It is believed that the vide part of the village supply at Mackinaw 520- and 480-foot terraces represent erosion and were formerly utilized at Eureka. levels cut by the Kankakee torrent during the Cary substage in a thick deposit of out In general the most favorable areas for wash which at one time almost filled the developing these aquifers are on the terraces Valley. The lower 460-foot terrace is un- themselves. The terrace margins and the derlain by deposits of different composition areas shown as alluvium in plate 2 should be from the upper terraces and is believed to avoided if possible. be a depositional feature formed by the Lake Chicago outlet river during the late SUBSURFACE RELATIONS Cary and Mankato substages.16 A generalized geologic column of the In addition to the terraces, recent de glacial deposits in the Peoria region, as re- posits of flood-plain alluvium, alluvial-fan vealed from a study of outcrops and well material, and dune sand occur along the cuttings, is shown in figure 5. Valley. Except for the dune sands, which occur chiefly on the terraces on the east side Variations in the stratigraphic succession of the Illinois River, these Sediments occur and the relations of the deposits to the bed- at flood-plain levels, are less well sorted, rock surface and present topography are and contain larger amounts of silt and clay. shown in the graphic cross-sections, plate Alluvial fans are prominently developed at 3. It is evident that the Peoria region had the mouths of Farm Creek, Tenmile Creek, a complex Pleistocene history of successive and on the east side of the river opposite glacial and interglacial stages, causing the Chillicothe. The growth of the alluvial disruption of the old drainage of preglacial fans shifted the Position of the river channel times, new Systems of drainage for each in westward and is responsible for the river's terglacial stage, and repeated Alling and re- constrictions and expansions. At Peoria excavation along the general course of the the fan of Farm Creek gave rise to Lake ancient Mississippi Valley. This resulted Peoria.16 in a complex of deposits which vary both vertically and horizontally. There was Groundwater conditions.—Geologie con- order, however, in the chronology of these ditions are favorable throughout almost all events and they are summarized in the the valley (fig. 6), and small to large Appendix. supplies of groundwater probably would be obtainable in most places. This is due in It is apparent from a study of the cross- sections that some alternative interpreta- 15 Willman, H. B., and Ekblaw, George E., personal tions are possible and, because of the complex communication; Willman, H. B., and Payne, J. N., Geology and mineral resources of the Ottawa, Marseilles and Streator relations, certain conclusions are considered quadrangles: Illinois Geol. Survey Bull. 66, pp. 167-75, 222-25, 1942; Ekblaw, George E., and Athy, L. F., Glacial to be tentative. The same general succes Kankakee torrent in northeastern Illinois: Bull. Geol. Soc. Amer., vol. 36. pp. 417-28, 1925. sion, however, has been encountered so often 18 Barrows, H. H., Geography of the middle Illinois Val in borings in the region and in adjoining ley: Illinois Geol. Survey Bull. 15, pp. 8-11, 1910. 34 GROUNDWATER IN THE PEORIA REGION areas, that the following broad relations are composed of crystalline rocks, quartzite, appear to be well substantiated: dolomite, and chert in about that order of 1. There is a widespread and thick de- abundance, indicating derivation from a pre- posit of sand, called the Sankoty sand, which Cambrian terrain. The crystalline rocks rests on bedrock and originally filled the include fragments of granite, rhyolite, dio- ancient Mississippi bedrock valley up to rite, basalt, gneiss, and greenstone. The elevations of more than 500 feet above sea- deposit is commonly oxidized and in places level. the upper portion has been leached. 2. The sand is overlain by Illinoian and The thickness of the sand varies greatly probably Kansan drift (pl. 3, cross-section because of the irregular bedrock surface C-C'). on which it was deposited and the uncon- 3. A broad valley was eroded in Illinoian formity at the top. Along Illinois Valley drift sheet and down into the Sankoty sand the thickness varies from about 50 to 150 during the Sangamon interval as shown by feet, and under the uplands, over buried Val• leys, it may reach a possible maximum of subsurface relations in the northern half almost 300 feet, although the average thick• of the region (pl. 3, cross-section A-A', ness would be closer to 100 feet. B-B' and C-C'). 4. The valley was largely buried by Wis• The composition of the deposit and over- consin drift of the Tazewell substage but lying deposits is shown in the following re- re-excavated so that outwash deposits of cord based on the study of samples from a the later Cary and Mankato substages now well at the Sankoty water field: occur at low elevations within the present M. Ebert and Co.—Peoria Water Works Co., NW. valley. ¼, SE. ¼, NW. ¼, sec. 15, T. 9 N., R. 8 E., Peoria Co. SANKOTY SAND Sample set No. 6521 studied by K. O. Emery and Leland Horberg Description.—The Sankoty sand is named Elevation—495 feet from the Sankoty water field north of Thick- ness Depth Peoria, in which area numerous wells pene- Feet Fect trate the deposit and provide most of the Recent alluvium water for the city supply. Soil and silt with organic material. 10 10 Silt, Sandy, pebbly, buff, contains The sand differs from most glacial sands angular pebbles 60 70 and has a number of distinctive charac- Pleistocene series teristics which are readily recognized in Wisconsin outwash (?) sample cuttings. In its most typical aspect Sand and gravel, buff 15 85 the sand is composed of 70 to 90 percent Sankoty sand quartz grains of which 25 percent or more Sand, pebbly, clean, contains are pink, rounded, and polished. The pink numerous pink polished grains 20 105 color appears to be due largely to inclusions Sand, as above, and gravel 20 125 Sand, pink 12 137 of hematite. Many grains are pitted and Pennsylvanian System frosted as well as polished. Polishing is Siltstone not restricted to rounded grains. The tex- The distribution of the sand in the ture is usually medium-grained but varies Peoria region, as in adjoining areas, is from silty fine sand to coarse gravelly sand. determined by the bedrock topography, and Beds of gravel, silt, and, in places, thin clays occurrences are limited to the ancient Mis• are associated with the sand. In many places sissippi Valley and the Pekin-Sankoty Chan• the sand has ferruginous coatings on the nel. Outside the area the sand has been grains and ferruginous cement, giving a recognized in cuttings from wells along the yellow or reddish color. Abundant humus valley south as far as southern Tazewell is present in some sections and in places ex- tends through the entire thickness of the County and north to the big bend at Henne• deposit. Exclusive of quartz, the grains pin and thence west as far as Prophetstown in southern Whiteside County. A some- what different deposit containing more GEOLOGY 35 dolomite particles, but occupying a similar ly from the Sankoty sand, are secured at stratigraphic position, has been recognized Chillicothe, Peoria, Pekin, and Washington along the buried bedrock Valley of ancient and probably also at Henry, Lacon, Mor Rock River which joins the Mississippi ton, and Mackinaw. There is additional Valley in central Bureau County. It ap- production from industrial wells in South pears from the evidence now available that west Peoria and Pekin and from numerous the sand constitutes a widespread and prob- domestic wells throughout the region. Large ably continuous fill along the deep bedrock undeveloped groundwater reserves are pres Valleys of the ancient Mississippi drainage ent along the ancient Mississippi Valley, and significant additional supplies may be obtain- system and may even extend northward into able along the Pekin-Sankoty channel. Wisconsin and Minnesota. The most favorable locations for future The origin and age of the deposit is un- development are determined by the thick- certain and involves several unsolved Prob ness of the deposit and by variations in its lems. As indicated by the well record at permeability. The areas of maximum Washington (pl. 3, cross-section C-C, well thickness are outlined approximately by 6) and by several sample-study records in contours along the deeper parts of the bed adjoining areas, the sand underlies Kansan rock Valleys (fig. 6), but variations in drift and is thus early Pleistocene or pre- permeability have no ascertainable system- glacial in age. The uniform composition, atic distribution. It is desirable, therefore, oxidation, and humus content of the de even in areas where geologic conditions ap- posit indicate nonglacial derivation and a pear favorable, that the selection of specific source in the Paleozoic sandstones and locations be preceded by electrical earth- crystalline rocks of Wisconsin and Minne resistivity surveys and test drilling. The sota. Nevertheless, the causes for the primary problem is one of determining the change from valley erosion to aggradation localities in which the sand has highest are most logically ascribed to changes in permeabilities. drainage conditions accompanying glacia- tion. It is suggested, therefore, as a work- Under the uplands the aquifer is confined ing hypothesis that alluviation of the ancient below relatively impervious till and is in- Mississippi Valley to an elevation of possibly dependent hydrostatically from overlying 560 feet was initiated by the onset of aquifers. Because the sand occurs along the Nebraskan glacial conditions and continued ancient Mississippi Valley at relatively low into Aftonian time. A relatively high base- elevations about 500 feet above sea-level, level seems to be recorded until the Sanga- the hydrostatic levels are low. Along the mon interglacial erosion, as the available valley, where the sand is overlain by Wis elevations of the top of the sand where it consin outwash and recent alluvium, the underlies Illinoian drift are above 500 feet aquifer is largely unconfined and water- along both the ancient Mississippi and levels coincide closely with the river level. Pekin-Sankoty Channels. The possible al ternative that a very narrow pre-Illinoian The regional extent of the sand along the valley was excavated to a lower level along ancient Mississippi Valley and its tributaries the present Valley between Peoria and East above Peoria is of great significance from Peoria cannot be disproved. The slope of the Standpoint of the large recharge area the Sangamon piain (flg. 7), however, that is provided. This condition might favors the interpretation that this section have been anticipated, as the high produc- of the valley was established on the Illinoian tivity of the Sankoty aquifer near Peoria drift and is therefore younger. could hardly be explained on the basis of a local deposit. It is believed that the im- Groundwater conditions.—The Sankoty portant recharge areas are to be found along sand is the most extensive glacial aquifer in the present valley north to the big bend the region and one of the largest in the at Hennepin, in the Green River lowland State. Municipal supplies, which are large- in Bureau, Henry, and Whiteside counties, 36 GROUNDWATER IN THE PEORIA REGION and possibly along the upper Mississippi Same, gravelly 5 265 Gravel up to 3/8", largely oxi Valley. At most places in these areas the dized quartzite grains, some sand is overlain directly by permeable de- crystallines, highly polished, posits of outwash and alluvium. Minor re with sand as above 15 280 Sand, coarse, as above, some charge probably takes place through the gravel 5 285 drift sheets on the uplands by way of Wis Sand, coarse to very coarse, as consin and Illinoian sands and gravels and above, some gravel 5 290 by seepage along the top of the bedrock or Gravel, up to 3/8", as above. . . 2 292 even through bedrock formations. Sand, medium, as above 3 295 Gravel, up to ¾", as above... 3 298 Sand, medium to coarse, as KANSAN (?) STAGE above 2 300 Sand, medium as above, nu Description.—Drift, probably of Kansan merous pink grains 5 305 age, has been recognized in only two sets Sand, medium to coarse, as of sample cuttings (pl. 3, A-A', well 1, and above, numerous pink grains 5 310 C-C', well 6). The record of one of these Gravel, granular up to 3/8", as above 5 315 wells, drilled at Washington in northern Gravel, granular up to ¼" and Tazewell County, is given below: coarse sand, as above 5 320 No sample 5 325 Chris Ebert—Washington City No. 3, NW. ¼, Coarse sand, some gravel, as sec. 24, T. 26 N., R. 3 W., Tazewell Co. above 9 334 Sample Set 12110 studied by Leland Horberg Sand, medium to coarse, some Elevation—760 feet gravel, as above 6 340 Same, many grains with hema- Thick- ness Depth tite coatings 5 345 Feet Feet Sand, as above, medium to Pleistocene series coarse 5 350 Wisconsin stage Sand, as above, coarse to me Tazewell loess dium, hematite coatings. ... 5 355 Soil, dark brown 3 3 Same, largely coarse 10 365 Silt, slightly calcareous, oxi- Sand, as above, coarse to very dized, yellow 7 10 coarse, gravelly 5 370 Same, calcareous 5 15 PENNSYLVANIAN SYSTEM Tazewell substage Siltstone, calcareous, micaceous, Till, calcareous, maroon-gray 68 83 light greenish-gray 5 375 Gravel, granular up to ½", The correlation of this record with sub- varied lithology 5 88 divisions of the Pleistocene is based in part Same, ¼ to ¾"...... 5. ' 7" 93' 7" on subsurface relations indicated by sample- Illinoian (?) stage Till, calcareous, grayish-brown 31' 5" 125 study records in adjoining areas to the east Same, silty 5 130 and south where numerous wells penetrate Same 20 150 Kansan drift at a similar stratigraphic Posi Same, gravelly 14 163 tion and at comparable and consistent ele- Gravel, up to ¾", varied lith ology 10 163 vations. It is also to be noted that the Yarmouth (?) stage correlation of the top of the Illinoian drift, Silt, sandy, calcareous, green- which is uncertain from the cuttings, is con gray, oxidized 7 180 sistent with numerous elevations of the Silt, sandy, calcareous, brown- ish-gray 5 185 Sangamon in areas nearby (fig. 7). Kansan (?) stage The Yarmouth (?) silt overlying the Till, calcareous, brownish-gray 15 200 Kansan ( ?) till in this record is correlated Gravel, granular, up to ½".. . 17' 6" 217' 6" Till, calcareous, partly oxi on the basis of its oxidized character, its dized, dark brownish-gray. 12' 6" 230 Position below unoxidized till, and its Till, calcareous, brownish-gray 20 250 Pre-Kansan (?) Sankoty sand" similarity to silt associated with Yarmouth Sand, coarse, some granular soil in other areas. It is considered alluvium gravel, numerous, rounded rather than loess because of its sandy charac polished grains, many pink grains, largely quartz, many ter. The Kansan (?) till, as in other areas, oxidized grains, about 75% is darker than the overlying Illinoian and quartz 10 260 Wisconsin tills. So far as is known, the a No Striae noted on pebbles. GEOLOGY 37 gravel penetrated in the well may be a small Loesslike silt, leached, grayish-yellow local deposit. to brown with carbon specks, un- stratified 5-6 In addition to the subsurface occurrences Same, slightly calcareous 2 of old drift noted above, probable old drift Illinoian glacial stage was described by J. A. Udden17 from ex- Gumbotil, leached, oxidized, chocolate brown to red, tenacious, siliceous posures west of Illinois River along La- pebbles 4 marsh Creek in the NE. ¼ of sec. 10 and Till, calcareous, grayish, limestone near the NE. corner of sec. 3, T. 7 N., R. 7 pebbles 41 E., Peoria County. The drift is described Naturally in well cuttings many of the as including boulder clay, silt, sand, and details shown by the above section cannot sandy gravel. be recognized, but in most sample sets the Groundwater conditions.—Some ground- essential relations are clear. Because of the water may be obtainable locally from sand mixing of materials in drilling and the 5- and gravel in the Kansan (?) drift, but foot interval at which most samples are the deposit as a whole is not continuous taken, the thinner units cannot always be enough to warrant consideration as an im- identified. This is particularly true of the portant aquifer. Iowan loess and the late Sangamon loess. However, the maroon-tinted Wisconsin till, ILLINOIAN STAGE the dark-colored Sangamon soil, the leached Description.—Illinoian drift is encoun- and oxidized Illinoian gumbotil, and the tered in most wells which go through the underlying unaltered gray Illinoian till can Wisconsin drift and is recognized in numer- usually be distinguished in sample cuttings. ous well records. The character of the In drillers' records the Sangamon soil is drift and its relation to overlying deposits commonly recognized and logged as "old are also revealed in surface exposures. A soil," "peat," "black muck," or "dark clay," measured section of the deposits at the well- and the underlying weathered till as "yellow known Farm Creek locality east of Peoria hardpan," "yellow clay," or "green clay." is summarized below: In places where unaltered Wisconsin till Farm Creek exposure alone the S. line SE. ¼, sec. rests on eroded unaltered Illinoian till, the 30, T. 26 N., R. 3 W., Tazeweil County18 two tills cannot be distinguished in drillers' Elevation—678 feet Thick- logs, and it is often impossible to do so from ness sample cuttings of a given well, but nearby Feet wells may furnish the clue. Pleistocene series Wisconsin glacial stage The Illinoian till, in contrast to the over• Soil, light gray, loessial 1-1½ lying Wisconsin till, is more compact, but Loess, leached, brown 3½ appears to contain more sand and silt, has Loess, calcareous, yellow 0-2½ Tazeweil substage a darker gray color, and is without the Bloomington gravel, discontinuous, maroon tint found in the younger till. brown 0-4 Thicknesses of the till-sheet vary from 0 to Shelbyville till Till, calcareous, oxidized, yellow. . . 2-6 150 feet, the average thickness east of the Till, calcareous, gray with maroon river being about 100 feet (pl. 3). tint, lenses of gravel 26-30 Sand and gravel, ranging in thickness Iowan substage Iowan loess, calcareous, bluish-green from a few inches to as much as 50 feet, on fresh surface, fossiliferous, peaty occur as beds and lenses in the till and and woody 6 commonly are encountered near the middle Sangamon interglacial stage Soil, leached, dark with flakes of car• or at the base of the drift-sheet. A rather bon, wood fragments, loessial in tex- continuous deposit appears to be present ture 1-1½ over a wide area in eastern Tazeweil Coun• ty. The deposits vary in composition from 17 Op. cit., pp. 52-53. 18 Leighton, M. M., A notable type Pleistocene section— silt and silty sand to clean gravel. They the Farm Creek exposure near Peoria. Illinois: Jour. Geol., vol. 34, pp. 167-174, 1926; Illinois Geol. Survey Rept. Inv. differ from the Sankoty sand in having a 11, pp. 3-9, 1926; The Peorian loess and the Classification of the glacial drift sheets of the Mississippi Valley: Jour. Geol., vol. 39, pp. 45-53, 1931. 38 GROUNDWATER IN THE PEORIA REGION
FIG. 7.—Contour map of the Sangamon surface in the Peoria region. GEOLOGY 39
greater variety of types of rocks and miner- drift-sheet and into the underlying Sankoty als with lower percentages of quartz grains. sand. This interpretation is based on Groundwater conditions.—The Illinoian sample-study records in which the maroon- aquifers are the sources of supply for tinted Wisconsin till rests on thin Illinoian numerous domestic wells in the eastern drift or directly on Sankoty sand at abnor- part of the area, and in places important mally low elevations. The trend of the quantities of water may be obtainable from valley in Sangamon time corresponds rather them. More data are needed from test closely with the present valley (fig. 7), and drilling and resistivity surveys before favor- it seems likely that present drainage was able localities can be definitely indicated. established along a sag on the Wisconsin It is probable that the so-called "middle drift-sheet above the older valley. sand" in the vicinity of Washington is From the evidence available it thus ap of Illinoian age, as distinguished from pears that the preglacial bedrock valley of an "upper sand" at the base of the Wiscon the Mississippi was partially re-excavated sin and a "lower sand" which is the at least twice and probably three times dur- Sankoty. The only municipal supply de- ing the Pleistocene: (1) by the ancient Mis rived from an Illinoian aquifer is possibly sissippi during the Sankoty-Illinoian in- that at Washburn in northern Woodford terval, (2) by the ancient Mississippi dur County. ing the Sangamon interglacial stage, and (3) by the Illinois River in post-Wisconsin SANGAMON DEPOSITS AND THE time. PRE-WISCONSIN SURFACE WISCONSIN STAGE Sangamon deposits consisting largely of soil and loess are preserved below the Wis Description.—As noted previously, the consin drift throughout most of the south- Wisconsin till is characterized by its ma- eastern part of the region and provide an roon-gray color and a less sandy texture important datum in subsurface studies. than the underlying Illinoian till. A differ- The surface of the Sangamon piain in this ence in coherence is also indicated by drillers area and the large pre-Wisconsin valley who commonly log the Wisconsin till as eroded below it farther north are shown by "clay" and the older tills as "hardpan" or a generalized contour map in figure 7. As "hard clay." Thicknesses of the drift-sheet shown by this map, the piain slopes re- depend largely on the surface topography gularly southwestward from an elevation and reach a maximum of more than 250 feet of about 680 feet above sea-level in north- under the highest moraines. The average eastern Tazewell County to elevations thickness is about 125 feet. slightly less than 600 feet near the Illinois Lenses and local beds of sand and gravel River. The piain crosses the ancient Mis of variable thickness occur irregularly within sissippi bedrock valley without interruption the drift and a rather persistent deposit and lowest elevations are along the present appears to be present at its base (pl. 3). river. These relations indicate that essen- The larger deposits within the drift prob tially the present course of Illinois River ably mark boundaries between morainic was established on the Illinoian drift-sheet. members and are most common along the The ancient Mississippi Valley of Sanga outer edges of the individual moraines. mon time, which is revealed by subsurface The deposits contain a variety of rocks and data in the northern half of the region, minerals which were derived largely from appears to have been eroded to a level of sedimentary rocks, although igneous and about 470 feet or 130 to 200 feet below the metamorphic fragments are numerous. They adjoining till-plain (pl. 3, A-A', B-B', and vary in texture from silty sand to coarse C-C'). In the vicinity of Chillicothe the gravel. valley was probably over 10 miles wide and Groundwater conditions.—A large Pro in places was eroded through the Illinoian portion of the domestic supplies in the 40 GROUNDWATER IN THE PEORIA REGION northern and eastern parts of the region are ber are shallow water-table wells in the secured from Wisconsin aquifers, and the upper part of the drift. It is improbable municipal supply at Metamora is from the that large supplies would be obtainable ex- basal sand and gravel. Most of the wells cept in local areas. are less than 100 feet in depth and a num- CHAPTER 6
FURTHER DEVELOPMENT OF GROUND- WATER SUPPLIES
The geologic relations described in pre- PEORIA METROPOLITAN ceding chapters have a direct bearing on the AREA further development of groundwater sup- plies in the region, and from them the PRESENT SUPPLIES following major conclusions are reached: The principal areas of present municipal 1. The deep bedrock aquifers are capable and industrial supplies extend southward of producing important quantities of water along the west side of the Illinois River but are of very limited use because of the from the Sankoty field on the north to south- high mineral content of their waters. west Peoria (fig. 8). In these areas wells 2. The most important aquifer in the were developed early in the history of the region is the Sankoty sand, which forms a city and their locations were determined by thick fill in the ancient Mississippi bedrock geographic factors rather than a knowledge valley and its tributaries; it is a regional of the geologic conditions. It was a fortu- aquifer with a large recharge area in north- nate circumstance that the Sankoty and ern Illinois and for a large part of the Wisconsin valley-train aquifers were avail- region is untested and undeveloped as a able to contribute to industrial growth. As source of groundwater. indicated by figure 8, the principal aquifer 3. The Wisconsin valley-train deposits in the Sankoty field and possibly in the along the present Illinois Valley are next southwestern tip of the industrial area is in importance and in many places occur as the Sankoty sand (see page 35). In the channel fills within the Sankoty sand body intervening area of higher bedrock between and are recharged through it. the central industrial area and East Peoria, Sankoty sand has not been recognized, and 4. In local areas important supplies may Wisconsin outwash deposits appear to be be obtainable from sand and gravel deposits the main source of supply. It is noteworthy, at the base of the Wisconsin drift or within however, that the outwash deposits are in the Illinoian drift. contact with Sankoty sand on the north and The various geologic conditions deter- east and probably are recharged through it. mining the occurrence of groundwater in On the basis of the areas shown in figure the region are shown by maps in figures 6 8 and production figures of the State Water and 8. These maps indicate that favorable Survey,20 it is estimated that the average conditions for small to large supplies exist daily pumpage from the two principal aqui throughout most of the eastern half of the fers for the year 1945 was as follows: region and that large supplies may be obtain able from Sankoty sand along the ancient Sankoty sand and Wisconsin outwash Mississippi bedrock valley, the Pekin- Sankoty field area 21.1% Sankoty bedrock channel, and from Wis Southwest industrial area 40.2% consin outwash deposits along the present Wisconsin outwash Industrial area 38.7% Illinois Valley. It is to be emphasized, however, that the maps show general con AREAS FAVORABLE FOR DEVELOPMENT ditions, and that plans for development of large supplies at specific locations should Areas recommended for possible testing be preceded by evaluation of the records and development on the basis of geologic of nearby wells and possibly by electrical conditions and electrical earth-resistivity earth-resistivity surveys and test drilling. 20 Personal communication. [41] 42 GROUNDWATER IN THE PEORIA REGION
FIG. 8.—Areas near Peoria in which groundwater conditions are favorable. GEOLOGY 43
FIG. 9.—Bedruck surface near Peoria. FIG. 10.—Graphic logs of shallow wells in northwest Peoria and vicinity. GEOLOGY 45 surveys are indicated by numerals in figure extension northward seems feasible. Favor 8. The numerals are used for reference able areas are indicated by the earth-re- only and do not necessarily indicate the sistivity survey (fig. 8), and it is probable relative importance of the areas. that similar conditions exist to the north Area I.—This area lies along the Illinois and west. Valley south from the vicinity of Kickapoo Area IV.—This area is situated east of Creek and represents a part of the exhumed Illinois River and extends north from the section of the Pekin-Sankoty channel. The vicinity of Tenmile Creek. Sankoty sand deposits in the area have a maximum thick- overlain by Wisconsin outwash and alluvi ness of about 140 feet and include alluvium um is present along the valley and extends and Wisconsin outwash overlying variable under the till sheets forming the bluffs to thicknesses of Sankoty sand. The outwash the east (pl. 3, C-C). Near the river the gravels appear to be thickest to the north, Sankoty sand may have been removed during where favorable conditions were indicated erosion of ,the present valley. The favor by the resistivity survey (fig. 8), and to able geologic conditions indicated by the thin southward into sections having greater resistivity survey appear to continue north thicknesses of overlying clay and silt. The and east for many miles. The area is un- Sankoty sand varies in composition from developed and additional subsurface data fine sand to gravel. An unusually coarse are needed to establish the most desirable gravel facies was penetrated in test wells locations. of the Commercial Solvents Corporation in Area V.—The area is situated east of the sec. 19, T. 8 N., R. 8 E. Further develop- river and extends north from Farm Creek. ments should be preceded by test drilling in Along Farm Creek Valley the Sankoty sand the area of high resistivities and along the is overlain by alluvium and Wisconsin out deep part of the bedrock channel (fig. 9). wash and possibly in places by thin Illinoian Area II.—The area includes the buried till. On the upland it is overlain by Wis section of the Pekin-Sankoty channel west consin, Illinoian, and possibly older drift and north of the main part of the city (pl. 3, D-D'). The available data indi in which Sankoty sand is overlain by thick cate that the sand may reach a possible glacial drift. The sand reaches a maximum maximum thickness of about 130 feet, but thickness of about 150 feet and seems to be very little is known about its composition. composed largely of sand with minor Favorable conditions along Farm Creek are amounts of silt and gravel (fig. 10). As indicated by resistivity surveys (fig. 8). most of the area remains to be tested, it Under the adjoining uplands resistivity constitutes an important potential source of values appear to be masked by thick till de supply. The most favorable conditions posits and the favorable area north of Farm probably exist along the deep part of the Creek is extended beyond that of the re bedrock channel and in the Kickapoo Creek sistivity finding on the basis of subsurface re-entrant. data. Area III.—The area represents an ex- REGION OUTSIDE THE PEORIA tension of the Sankoty field aquifer north- ward along the Illinois Valley and north- METROPOLITAN AREA westward under the bluffs. Along the The Sankoty sand within the ancient valley, Sankoty sand rests on bedrock and Mississippi and Pekin-Sankoty bedrock Val is overlain by Wisconsin outwash or till and leys combined with the outwash deposits alluvium (pl. 3, wells 3 and 4, C-C'). The along the present Illinois Valley underlie deposit thickens away from the river and an extensive area of large groundwater re- reaches its maximum thickness under the serves. Additional supplies may also be bluffs where it is overlain by thick Wiscon obtainable from deposits along Wyoming sin drift. The productivity of the aquifer and Kickapoo Creek bedrock Valleys and at Sankoty field is well known from numer- from buried glacial sands in the eastern ous wells and with proper spacing a further part of the region (fig. 6). In a number 46 GROUNDWATER IN THE PEORIA REGION
FIG. 11.—Areas covered by electrical earth-resistivity surveys in the Peoria region. of places resistivity surveys have indicated area, however, additional data would be favorable localities in these and other areas, needed to substantiate the conclusions based as shown in figure 11. Over most of the on regional relations. GEOLOGY 47
APPENDIX
LIST OF DEEP WELLS
1. W. H. Gray Co.—Henry City, 1886. Near sec. 2, T. 8 N., R. 8 E., Peoria County. NE. corner, NW. 1/4, SE. 1/4, sec. 16. T. 13 Elevation—450±. Flowing well, originally N., R. 10 E., Marshall County. Elevation— an oil test. Total depth variously reported 491. Ends in Galena dolomite at a depth as 1100 to 1200 (Galena dolomite) and 1600 of 1335 feet. Sample set 195 studied by J. to 1700 (St. Peter sandstone). Incomplete A. Udden and H. X. Bay. record. 2. M. Ebert Co.—Sarah Ditering, 1941. Near 11. Central Park well (now Illinois Power and NW. corner, sec. 10, T. 12 N., R. 7 E., Light Co.), 1875. 700 feet W. and 700 feet Stark County. Elevation—675±. Ends in S. of NE. corner, sec. 3, T. 8 N., R. 8 E., Burlington limestone at depth of 360 feet. Peoria County. Elevation—475 feet. Flow Driller's record. ing well now capped. Ends in Niagaran dolomite at depth of 915 feet. Driller's 3. Mr. Dean—Wyoming City, 1902. Near NE. record. corner, NW. 1/4, NW. 1/4, sec. 1, T. 12 N., R. 6 E., Stark County. Elevation—710±. 12. Glen Oak Park well. 900 feet E. and 200 Ends in St. Peter sandstone at depth of 1557 feet S. of center, sec. 34, T. 9 N., R. 8 E., feet. Incomplete record. Peoria County. Elevation—534. Formerly flowed. Ends in Niagaran dolomite at depth 4. Toulon City No. 1, 1911. 1230 feet N. and of 1040. Samples examined by J. A. Udden. 1300 feet E. of SW. corner, sec. 19, T. 13 N., R. 6 E., Stark County. Elevation—738. 13. Gray-Milaeger Well Co.—Glen Oak Park Ends in St. Peter sandstone at depth of 1449 Swimming Pool, 1923. 200 feet S. and 500 feet. Incomplete record. feet E. of NW. corner, NE. 1/4, sec. 3, T. 8 N., R. 8 E., Peoria County. Elevation— 5. Varner Well Drilling Co.—Toulon City No. 515. Flowing well. Ends in Niagaran dolo 2, 1942. 20 feet from No. 1 well. Eleva mite at depth of 1023 feet. Driller's record. tion—738. Ends in Maquoketa shale at depth of 780 feet. Sample set 8441 studied by M. 14. Dean Sulphur Water Well, Spring Street, P. Meyer Supplements driller's record. Peoria. NW. 1/4, sec. 3, T. 8 N., R. 8 E., Peoria County. Elevation—495. Ends in 6. Sewell Well Co.—Princeville City No. 1, Niagaran dolomite or Devonian limestone 1914. Near SE. corner, sec. 13, T. 11 N., R. at depth of 875 feet. Probably flowed. Old 6 E., Peoria County. Elevation—745. Ends record compiled by A. L. Campbell. in St. Peter sandstone at depth of 1560. Sample study by T. E. Savage. 15. Sulphur Water House Bathing Co., 1885. 950 feet S. and 1030 feet W. of NE. corner, 7. Thorpe Well Co.—Princeville City No. 2, sec. 9, T. 8 N., R. 8 E., Peoria County. 1938. 420 feet N. and 260 feet W. of SE. Elevation—485. Flowing well. Ends in corner, sec. 13, T. 11 N., R. 6 E., Peoria Niagaran dolomite at depth of 878 feet. County. Elevation—745. Ends in Galena Driller's record. dolomite at depth of 1342 feet. Sample set 3001 studied by M. B. Buhle. 16. Voris or Bailey's well, 1860. 650 feet N. and 1000 feet E. of the SW. corner, NW. 1/4, 8. John Deitrick and Co.—Banta No. 1. Oil sec. 33, T. 26 N., R. 4 W., Tazewell County. test, SW. 1/4, NW. 1/4, SW. 1/4, sec. 26, Elevation—455. First flowing well in Peoria T. 28 N., R. 2 W., Woodford County. Eleva region, now capped. Ends in Niagaran tion—740. Ends in Niagaran dolomite at dolomite at a depth of 734 feet. Driller's depth of 893 feet. Driller's record and a record. few sample cuttings studied by L. E. Work- man. 17. Colean Factory. NW. 1/4, NE. 1/4, sec. 32, T. 26 N., R. 4 W., Tazewell County. Eleva 9. Peoria Mineral Co.—Hart Lee, drilled about tion—453. Flowing or capped. Ends in 1900. 1500 feet E. and 750 feet S. of the Keokuk-Burlington dolomite at depth of 320 NW. corner, sec. 23, T. 26 N., R. 4 W., feet. Incomplete record. Tazewell County. Elevation—475. Flow- ing well. Ends in Galena dolomite at depth 18. Carter brickyard well. NE. 1/4, NW. 1/4, of 1497 feet. Driller's record. NE. 1/4, sec. 6, T. 25 N., R. 4 W., Tazewell County. Elevation—465. Flowing or capped. 10. Grant Street Well (now La Tourneau Co.), Ends in Keokuk-Burlington dolomite at drilled sometime between 1868 and 1888. depth of about 370 feet. Incomplete driller's 500 feet E. and 2180 feet S. of NW. corner, record. 48 GROUNDWATER IN THE PEORIA REGION
19. Gray-Milaeger Co.—Logan Field Swimming corner, SW. 1/4, sec. 27, T. 8 N., R. 5 E., Pool, 1922. 500 feet S. and 1400 feet E. of Peoria County. Elevation—640. Ends in St. center, sec. 18, T. 8 N., R. 8 E., Peoria Peter sandstone at depth of 1560 feet. County. Elevation—535. Flowing well. Sample set 3926 studied by F. E. Tippie. Ends in crevice in Galena-Platteville dolo- 30. Hanna City Oil and Gas Co.—Sonnemaker mite at depth of 1297 feet. Driller's record. No. 1, 1926. 600 N. and 1600 feet E. of SW. 20. C. W. Hicks—Acme Harvester Co. Near corner, sec. 28, T. 7 N., R. 6 E., Peoria center, E. 1/2, sec. 25, T. 8 N., R. 7 E., County. Elevation—510. Ends in Blooming- Peoria County. Elevation—460. Flowing or ton chert at depth of 315 feet. Sample set capped. Ends in Keokuk-Burlington dolo- 640 studied by L. E. Workman. mite at depth of 266 feet. Driller's record. 31. C. P. Brant and Co.—Glasford City, 1917. 21. Evans Co., 1933-34. 400 feet W. of center, NW. 1/4, NW. 1/4, SW. 1/4, sec. 22, T. 7 sec. 36, T. 8 N., R. 7 E., Peoria County. N., R. 6 E., Peoria County. Elevation— Elevation—460±. Flowing or capped. Ends 614. Ends in St. Peter sandstone at depth in Keokuk-Burlington dolomite at depth of of 1685 feet. Driller's record. 489 feet. Driller's record. 32. Pekin City Mineral Springs Park No. 1. 22. J. P. Miller and Co.—Illinois Asylum for 1250 feet S. and 1250 feet W. of NE. corner, Incurable Insane, 1903. 500 feet N. of SE. sec. 2, T. 24 N., R. 5 W., Tazewell County. corner, sec. 26, T. 8 N., R. 7 E., Peoria Elevation—525. Flowing or formerly flowed. County. Elevation—605±. Water came to Ends in Devonian or upper Silurian strata within 13 feet of surface. Ends in St. Peter at depth of 990 feet. Record from memory, sandstone at depth of 1864 feet. Driller's Thomas Cooper. record. 23. M. Ebert and Son—Pleasant Valley School, 33. Chris Ebert Co.—Pekin Mineral Springs 1936. Near center of N. 1/2, SW. 1/4, sec. Park No. 2, 1916. Close by No. 1 well. 1, T. 8 N., R. 7 E., Peoria County. Eleva Elevation—525. Originally flowed. Ends tion—550. Probably ends near top of in Devonian or upper Silurian at depth of Keokuk-Burlington dolomite at depth of 365 1000 feet. Driller's record. feet. Driller's record. 34. Turner-Hudnut Co.—W. B. Aydelott Salt 24. A. M. Myers—Phillips No. 1 oil test, 1923. Well, before 1916. 700 feet W. and 500 NW. corner, NE. 1/4, NE. 1/4, sec. 2, T. 8 feet N. of SE. corner, sec. 20, T. 24 N., R. N., R. 7 E., Peoria County. Elevation— 4 W., Tazewell County. Elevation—685. 500±. Flowing water in Niagaran dolo Ends in Keokuk-Burlington dolomite at mite. Ends in Maquoketa shale at depth depth of 757. Driller's record. of 1160 feet. Driller's record. 35. O'Brian well, 1876. One-third mile W. of 25. C. P. Brant and Co.—Peoria County Home, NE. corner, sec. 14. T. 25 N., R. 4 W., Taze 1918. SW. 1/4, NE. 1/4, sec. 9, T. 8 N, R. well County. Elevation—738. Probably 7 E., Peoria County. Elevation—690. Ends ends in Maquoketa shale at depth of 1442 in St. Peter sandstone at depth of 1755 feet. feet. Incomplete driller's record. Driller's record. 36. Morton Oil and Gas Co.—William Strunk 26. Blue Bell Oil Co.—Kyle No. 1 oil test, 1939. No. 1 oil test, 1939. Near center, sec. 18, T. 444 feet S. and 376 feet E. of NW. corner, 25 N., R. 3 W., Tazewell County. Eleva SW. 1/4, NW. 1/4, sec. 17, T. 8 N., R. 6 E., tion—727. Ends in Maquoketa shale at Peoria County. Elevation—700. Ended in depth of 1385 feet. Sample set 3353 studied Niagaran dolomite at depth of 1010 feet. by J. N. Payne. Sample set 3829 studied by I. T. Schwade. 37. R. Bartelmay Co.—Mathis No. 2 oil test, 27. Kickapoo Development Co.—Super No. 1 oil 1941-43. 534 feet N. and 491 feet E. of SW. test, 1928. Sec. 10, T. 9 N., R. 5 E., Peoria corner, NW. ¼, SW. ¼, sec. 24, T. 25 N., County. Ends in Burlington chert at depth R. 3 W., Tazewell County. Elevation— of 430 feet. Sample set 729 studied by L. 785. Ended in Galena dolomite at depth of E. Workman. 1798 feet as of 1944. Sample set 8243 studied 28. Elmwood City, 1896. 2000 feet N. and 450 by Dorothy Speziale. feet E. of SW. corner, sec. 8, T. 9 N. R. 5 E., Peoria County. Elevation—620. Ends 38. H. V. House Co.—W. H. Greening No. 1 oil in St. Peter sandstone at depth of 1498 feet. test, 1939. NW. 1/4, NW. 1/4, SE. 1/4, sec. Incomplete record. 28, T. 24 N., R. 2 W., Tazewell County. Elevation—675. Ends in Niagaran dolo 29. Algona Oil Co.—Charles Cramer No. 1 oil mite at depth of 1230 feet. Sample set 3744 test, 1939. 330 N. and 330 feet W. of SE. Studied by F. E. Tippie. GEOLOGY 49
SUMMARY OF PLEISTOCENE HISTORY
AGE SUB-AGE GEOLOGICAL EVENTS
Recent Deposition of flood-plain alluvium, alluvial fans, and dune sand; erosion of minor Valleys.
Mankato and late Cary Lake Chicago Outlet River eroded down and deposited lower terrace 460 feet above sea-level.
Cary Kankakee torrent eroded 480- and 520-foot terraces on the higher of which the greater part of Peoria is built.
Wisconsin Marseilles moraine Farm Ridge moraine Cropsey moraine Glacial Lake Illinois Normal moraine Metamora moraine Tazewell Bloomington moraine 600-foot outwash terrace fronting moraine at Peoria Leroy moraine Glacial Lake Kickapoo Shelbyville moraine
Iowan Loess deposition
Sangamon d. Weathering and soil and peat formation. c. Deposition of Late Sangamon loess. b. Weathering and soil formation; Valley erosion. a. Ancient Mississippi occupies present course of Illinois River between Peoria and E. Peoria.
Illinoian Deposition of Illinoian drift.
Yarmouth Weathering and soil formation; Valley erosion.
Kansan Deposition of Kansan drift.
Aftonian ? Erosion of Valleys in Sankoty sand and bedrock.
Nebraskan ? Sankoty sand deposition.
Preglacial Erosion of ancient Mississippi bedrock Valley and its tributary bedrock Valleys. PART 2
HYDROLOGY
BY
MAX SUTER Head, Engineering Research Sub-division
STATE WATER SURVEY ABBREVIATIONS
MSL Mean Sea Level Elevation, 1929 adjustment ft foot or feet gpm gallons per minute mgd million gallons per day cfs cubic feet per second hr hour (hours) ppm parts per million
DATUM PLANES
ELEVATION OF ZERO OF GAGE OF WEATHER BUREAU Peoria: Memphis datum 435.50 ft. Mean sea-level 1914 adjustment 428.50 ft. Mean sea-level 1929 adjustment 428.39 ft. Peoria city datum 22.28 ft. Pekin: To August 31, 1930 (1929 adjustment) 431.14 ft. Since September 1, 1930 (1929 adjustment) 433.07 ft. CHAPTER 7
INTRODUCTION
AREA As the Situation became known, several N INTENSIVE investigation of water practices for the conservation of ground Aresources in the Peoria-Pekin area was water were voluntarily adopted by some started in 1940. Part 2 contains the review of the industrial users. These are (a) the and summary of the work done and con- use of cooling towers and recirculating clusions reached by January 1, 1946. The Systems, and (b) the use of Illinois River investigation is continuing and supplemen- water by a few of the larger industries, tary reports will be prepared as the study especially during the winter season when progresses. low water temperatures are ideal for cool ing and condensing purposes. Despite these The area studied is located in central practices the groundwater Situation became Illinois on the Illinois River and is about progressively worse as withdrawal continued 160 miles below Chicago and 200 miles to exceed the natural replenishment. above St. Louis as measured along the water route. The Peoria-Pekin area is a highly Other methods must be devised to obtain industrialized district requiring an enormous a better balance between replenishment and volume of water. The industrial areas are use of groundwater. The current outlook surrounded by the fertile agricultural prairie is uninviting, even for maintaining the lands of the com belt. present groundwater supply in the industrial In 1940 the population of the 32 square- area on a dependable basis. It is of im- mile area was about 180,000 of which mediate importance to provide for the in- 105,087 resided in the city of Peoria and creasing demand for water that results from 19,407 in the city of Pekin, located nine normal growth of the municipalities and miles downstream from Peoria. The total industries in the area. New industries re population in 1946 was estimated to be quiring much groundwater may hesitate be- about ten percent greater than it was in fore they move into the area. 1940. The public water supply of Peoria is obtained largely from wells located north of HISTORY the city, but private and industrial supplies The Peoria-Pekin area has long enjoyed are located throughout the city and ad- an enviable reputation for its abundant jacent area. The public demand in the supply of potable water obtained by vertical area was estimated (in 1945) to be 20 mil- wells from shallow sand and gravel deposits lion gallons per day and private and in that serve as groundwater reservoirs. The dustrial demand about 65 million gallons uniform low temperatures and satisfactory per day, making the total estimated ground mineral quality of the water have been at- water withdrawal for the Peoria-Pekin area tractive to many industries. With the con- about 85 million gallons per day. tinued development and exploitation of this In earlier years river water was used by natural resource, a shortage became ap- distilling plants for cooling purposes in parent in certain limited areas and the Situa the winter, and during the summer season tion became sufficiently critical in the latter the plants were shut down when the water part of 1940 to Warrant a detailed study temperature was too high. After 1933 of the problem. The State Water Survey some of these plants began to operate con- was requested to assist in solving this tinuously and used groundwater almost ex- problem which is of vital importance to the clusively. Large quantities of groundwater future welfare of the City of Peoria and are used also by the meat-packing industries, neighboring communities and to the State machinery manufacturing plants, and other of Illinois. manufacturers. In the last few years mäny [53] 54 GROUNDWATER IN THE PEORIA REGION
FIG. 12.—Peoria-Pekin area. wells have been put into Operation by stores, TABLE 1.—POPULATION OF THE CITY OF PEORIA theatres, and restaurants for air condition- ing. These growing demands for ground- Year Population Increase water have a direct influence on the ground- percent water resources of the area. 1860 14,045 This increased demand for groundwater 1870 22,849 62.7 28.1 has resulted in a lowering of water levels 1880 29,259 1890 41,024 40.2 in wells, and available records show that 1900 56,100 36.7 during the past 15 years groundwater levels 19.3 1910 66,950 13.7 have receded from 1½ to 2½ feet per year 1920 76,121 37.9 throughout the area. The groundwater sur- 1930 104,969 0.11 1940 105,087 face in the Peoria industrial areas is from 20 to 25 feet below the water surface of the Illinois River. In many places very little The population of the City of Peoria thickness of the water-bearing deposits re- according to the U. S. Census is shown in mains saturated with water, and in some table 1. It is apparent that water con- places where the deposits are shallowest sumption in the area has been governed some wells are dry as far as pumping capac- more by industrial activity than by popula ity is concerned. In other places wells can tion growth because the greatest recession be used only intermittently or at greatly in groundwater levels occurred during the reduced yields. last decade although the increase in popula- HYDROLOGY 55 tion was only 0.11 percent. Areal popula- D. Evaluation of possible remedial meas- tion trends are closely parallel to that of ures. Peoria. 12. Reduction of pumpage from wells Some of the basic hydrologic data of the by the use of recirculation. Peoria-Pekin area were published in 1940 13. Evaluation of other groundwater by the State Water Survey in Bulletin No. sources. 33, a compilation of all available physical 14. Replacement of some demands on and chemical data on wells of record in the groundwater by the use of surface area at that time. Those data are not re- water. produced in this report. With the Organiza 15. Improvements to existing wells. tion of available facts completed, a research program was formulated for the investiga- 16. Groundwater replenishment by ar- tion and study of all available water re- tificial infiltration. 1 sources in the area. The remainder of Part 2 is a summary An outline of the water resources in- of the work accomplished, the fundamental vestigation, conducted where needed in Co discoveries made, and the conclusions operation with other agencies, is as follows: reached as of January 1, 1946, on the hydrology of the region. An extensive dis- A. Location of sources of water. cussion of facts learned and conclusions 1. Location of all wells in the terri reached is postponed until the continuing tory and collection of pertinent data investigation has uncovered more facts, in- on each. cluding the practicability of proposed re 2. Study of the geological and topo- medial measures now being studied on an graphical conditions. experimental scale. 3. Study of the sources of water in the glacial deposits. ACKNOWLEDGMENTS 4. Study of surface water resources. The State Water Survey acknowledges the most generous Cooperation and assistance B. Estimate of amounts and quality from from everyone called upon during the course different sources. of the program. This wide Cooperation has 5. Study of variations in groundwater been one of the most pleasant factors in the levels. work and thus has been the major contri- 6. Study of velocity of the ground bution to its success. water flow. The study was begun at the Suggestion of 7. Study of influence of increased the National Resources Planning Board. gradients on the inflow to the main Unremitting support of the project was pumping areas. given by the Peoria Association of Com 8. Study of variations in the chemical merce, which placed all its facilities and composition of groundwater from Services at the disposal of the State Water different wells. Survey, and arranged frequent meetings in 9. Study of chemical composition of which the progress of the investigation was surface water. made known to the interested industries, thus inspiring their Cooperation. C. Determinations of present and future consumption. Valuable assistance was received from federal, State, and local governmental 10. Determination of the actual with- agencies including the U. S. Corps of En- drawal. gineers, the U. S. Geological Survey, the 11. Analysis of the amounts allocated Soil Conservation Service, the U. S. to different uses. Weather Bureau, the Illinois Geological Survey, the University of Illinois Agricul- 1 Suter, Max, A Pilot Study of Groundwater Resources in Peoria County, Illinois. Trans. Amer. Geo-physical Union, tural Experiment Station, the State Depart- pp. 493-500, 1943. 56 GROUNDWATER IN THE PEORIA REGION ment of Public Health, the City of Peoria, existence of over-exploitation had to be the Peoria Park Board, and the Sanitary established and possible remedial measures, District of Chicago. if necessary, investigated. It was recog- The Peoria Water Works Company fur- nized also that any necessary remedial meas nished much local information and made ures must be capable of satisfying future bacteriological analyses of the Illinois River estimated requirements as well as alleviating water. any existing deficiencies. Most of the local well drillers furnished The earliest observations pointed to a information on wells, well logs, and other simple explanation, but as data were accu- pertinent data. mulated it became apparent that no single All the industries and private well owners simple explanation would suffice for the area. cooperated generously in permitting access Emphasis, therefore, was placed more and to their properties for the purpose of lo- more on obtaining more extensive and re- cating wells and observing water levels; liable data, a problem that, in itself, had many of them provided assistance in the many difficulties. Few active wells were making of observations on well levels and equipped for Observation of water levels; pumpage, and in supplying the data. The still fewer abandoned wells were available industries also raised funds for special in- for study, and very few wells were equipped vestigations and for the design of remedial with meters for measuring pumpage. Al- measures. though well owners were willing to co- The correlations and interpretations pre- operate, wartime difficulties and restrictions sented herein are based primarily on the hindered the introduction of new methods facts provided by the cooperative efforts of Observation. In many cases the best acknowledged above. study possible was far from the most de- sirable plan. The work was started in November 1940, by Max Suter of the Urbana office of the SUMMARY OF FINDINGS State Water Survey. In June 1941, an office was opened in the Alliance Life Build For years before the start of the investi- ing in Peoria and W. Herget was resident gation reported in this bulletin, the State engineer there until May 1942. Since that Water Survey had been collecting data on time A. R. Knodel has been resident engi wells, their location, construction, logs, neer, with Max Suter remaining in charge. pump capacities, and chemical analyses of J. J. Doland and J. J. Woltmann acted the water; but practically no data on pump as advisors in many phases of the study. age and water levels. With the start of the C. C. Chamberlain and Miss Virginia present investigation older data were re- Wisegarver assisted in preparing the data checked, water levels were collected con- for study and correlation. The author is tinuously and expressed on sea-level datum, indebted to Harrison E. Romine, Associate actual quantity of pumpage was closely estimated, and periodic analyses of river Engineer, Engineering Sub-Division, for and well waters were made. In a short his careful technical review and editing. time some interesting tendencies were in- THE PROBLEM dicated which have been confirmed and Briefly, the problem was: to determine amplified by the accumulation of new data the existing Status of groundwater resources; and the recovery of older records. to determine what was happening and had Some of the conclusions reached thus far happened to this natural resource and why; are: and to develop any necessary remedial meas (1) A general recession of the water ures. Thus it was necessary to search out level over a period of years was established the sources of groundwater and to deter as a fact in the Peoria well fields. This mine the existing and potential availability recession is due to overpumpage, but it of water at each well field in the general has been characterized by continually rising area being studied. The existence or non- and falling water levels with a general HYDROLOGY 57 downward trend rather than a uniform (8) The wells in the area are in several lowering of water levels. Other sub-areas well fields which for practical purposes are have been developed as fully as present hydrologically independent; that is, there Operations will permit, and still other sub- is no immediate interference from wells in areas have undeveloped resources. one field with wells in the other fields, al (2) The studies indicate that the over- though factors common to all, such as rain pumpage in the Peoria industrial area over fall and river stages, may influence all fields a period of'a few years has averaged about at the same time. 6 million gallons per day. (9) The danger of dewatering a well or This amount is calculated from the re- well field is less (a) where the wells are duction of the amount held in storage over deeper, because the bedrock surface eleva a period of years and is based on a constant tum is low; (b) where the saturated thick- pumpage rate. Any increase in this pump- ness of the coarse materials increases below age will increase the overpumpage. the groundwater level; and (c) where the (3) High precipitation periods and high general inflow can come freely from more river stages each cause a rise in the water than one direction. levels in the wells. As these two factors generally occur at the same time, it is (10) The main natural recharge of the difficult to evaluate their effects individual- groundwater is from precipitation over the ly. Interpretations are further complicated Peoria area and contiguous areas. It reaches by the effect of pumpage. the well fields through the more or less (4) At normal river stages there is continuous gravel and sand beds, but the apparently no significant recharge of relative contribution of each source of re groundwater from the Illinois River above charge has not yet been determined. This Peoria lock and dam, although the ground natural recharge, however, is insufficient to water level near the river is always below satisfy present groundwater demands. the river stage. Recharge apparently does (11) There are undeveloped water re occur at normal river stages in the Pekin sources outside the Peoria Industrial area area. where new industries could be established, There is some infiltration from the river or the areas could be developed to supply during floods, but the hydrologic evidence does not permit determining the amount of additional water to Peoria. This is pri- this infiltration. marily an economic problem and is beyond (5) The rise in groundwater levels the scope of this report. during wet periods signifies some actual (12) Remedial measures for Peoria are increase in water storage, but the quantity required in order to halt recession of the cannot be calculated accurately, and the groundwater table. Measures to be con- source of this increase of stored water has sidered are reduction of present pumpage; not yet been clearly determined. replenishment of aquifers by artificial re (6) At periods of constant navigation charge; greater use of river water, and pool level, the recession in the Peoria in development of new groundwater fields; dustrial wells near the river has averaged better spacing, arrangement, development, from 5 to 6 feet per year, whereas during and care of wells. These methods can be the years 1943 through 1945, with above- carried on singly or simultaneously. normal rainfall and high floods annually, the recession amounted to about 1 foot per (13) Artificial recharge water is avail- year. As of January 1, 1946, levels were at able from the Illinois River and local trib- an all-time low in most of the wells. utaries. To completely relieve the ground (7) The groundwater conditions at water shortage by artificial recharge, it may Peoria are very complex and are difficult be necessary to construct recharge facilities to interpret. at several places. CHAPTER 8
PEORIA AREA AND SOURCES OF WATER SUPPLY
SCOPE A Classification of these wells by well field and usage is given in table 2. The This report covers the same general area estimated pumpage from the major wells as State Water Survey Bulletin No. 33. It during 1945 is shown, but the pumpage embraces the communities of Peoria from domestic wells was relatively insignif- Heights, City of Peoria, and Bartonville icant. in Peoria County; and East Peoria, Creve Coeur, and Pekin in Tazewell County. TABLE 2.—WELL FIELDS AND FIELD PUMPAGES The area under intensive study, containing about 32 square miles, is shown in figure Number of Wells 12. Hydrologically, the area contains six Estimated general subdivisions: Well field pumpage Total Idle Major mgd. Illinois River and tributary streams from active which surface water supplies are obtained. Sankoty. . . 32 11 13 10.2 Sankoty, North, Central, and Pekin well North 25 14 10 5.7 fields, from which groundwater supplies are Central.... 215 45 155 48.2 Pekin 22 obtained. 89 57 20.2 Total. . . 361 91 235 84.3 Bedrock formations which are known to contain water. The term "well field" designates an area ROCK WELLS within which a continuous interference can be traced from well to well. The well fields Information was available on 23 bedrock are separated by geological features or non- wells varying in depth from 320 feet to pumped areas, and interference between the 1864 feet, of which 9 wells are in active well fields is therefore not observed in service (fig. 14). Eighteen wells were routine pumping practice, although it is completed in various formations above a possible that the complete cessation of pump depth of 1300 feet; three wells were com ing in certain fields would in time influence pleted at depths of 1400 to 1500 feet in adjoining fields. the Galena-Platteville dolomite; and two wells drilled to 1755 and 1864 feet pene- WATER SOURCES trate the St. Peter sandstone. The bedrock aquifers contain water un- The water sources described below are der artesian pressure, but the pressures vary classified under drift wells, deep rock wells, from aquifer to aquifer with indications that and streams. the deepest aquifers have the highest pres Drift wells are wells completed in sand sure. A few of the rock wells are flowing, and gravel deposits above the top of the bed but pressures have been dropping with time rock. The drift wells are grouped by well and in many wells the hydrostatic level is fields. Rock wells are classified in a sepa below ground level. Some wells tap several rate group. water-bearing strata and deliver water of DRIFT WELLS varying mineral quality depending on draw- The Water Survey has accumulated data down and length of pumping period. Min on 361 drift wells located in the well fields eral quality is discussed in the section on outlined on figure 13. chemistry, but it can be noted here that HYDROLOGY 59
FIG. 13.—Well fields in Peoria-Pekin area. 60 GROUNDWATER IN THE PEORIA REGION
FIG. 14.—Deep rock wells in Peoria-Pekin area. HYDROLOGY 61
TABLE 3.—USERS AND PUMPAGE OF ILLINOIS RIVER WATER
Industry Average pumpage mgd.
Bemis Bro. Bag. Co Nominal Hiram Walker & Sons, Inc 20.0 summer—8.0 winter Central Illinois Light Co. (Eas.t Peoria Plant) 115.0 Keystone Steel & Wire Co 70.0 American Distilling Co 3.0 Commonwealth Edison Co 500.0 Com Products Refining Co 12.0 as a general rule the waters from bedrock navigable channel in the river and an aver wells are highly mineralized and corrosive, age of about 1500 cfs. of treated sewage with temperatures ranging from 60° to from Chicago. In former years untreated 78° F. Such waters are generally not de- sewage from Chicago and downstream cities sirable for municipal or industrial use. was discharged into the Illinois River, Pumpage from these wells was negligible, giving the river a reputation of being as the average daily consumption was about heavily polluted. This reputation is not 0.3 million gallons. upheld by chemical and biological studies. The studies show that the water can be STREAMS used, as it is of a quality that is amenable The Illinois River, which flows through to treatment. Nevertheless, because of the Peoria-Pekin area, is the natural and public opinion the water has not been used main source of surface water. The low for municipal or domestic needs, but about river flow is about 5000 cfs. (3250 mgd.) 700 mgd. are used by industries for cooling and could therefore furnish ample water and condensing purposes. Table 3 is a for all existing needs. tabulation of users and pumpage of Illinois River water. The flow includes the normal runoff from the watershed plus water diverted Other potential sources of surface water from the Great Lakes-St. Lawrence River are Farm Creek, Kickapoo Creek, Tenmile watershed. The diversion at Chicago in Creek, and the Mackinaw River. These cludes an average of about 1500 cfs. for streams have not been utilized as water sewage dilution and maintenance of a supply sources. CHAPTER 9
GROUNDWATER INVESTIGATIONS
Any comprehensive water resources in- than the State Water Survey. The princi- vestigation must include the collection of pal function of the Survey was to direct every fact and every possible bit of Informa and coordinate activities, to act as a Clearing tion which may be pertinent. Oftentimes it house for information, and to analyze and is impossible to obtain precise physical meas- interpret the information collected. urements, and there are usually isolated areas where no data can be obtained. Many EXISTING WELLS potential avenues explored are found to be blind alleys. LOCATION AND CONSTRUCTION Usually in a groundwater study, access OF WELLS to tbe saturated materials can be gained only from artificial openings, such as wells, Most of the available data on location test borings, and excavations. These are and construction of existing wells had been not always located at the most Strategic published, or was on file at the start of this places. Where such openings do occur it investigation, so it was necessary mainly to is usually impossible to secure all the de- collect data only on new construction. sirable information, and other factors usual OBSERVATIONS OF WATER LEVELS ly hinder the collection and preservation of continuous records. It was known from Water-level data were obtained from 112 previous experience that the bedrock forma- drift wells in the area including a con tions would not be a satisfactory source of tinuous record of levels in 23 idle wells. groundwater, so this section concerns only In selecting wells for water-level meas sand and gravel water sources. urements, the primary objective was to The basic data for the hydrologic ground cover the area completely with a network water study were obtained from wells, and of Observation wells, closely spaced in areas the observations included: of heavy pumpage. An ideal distribution a. Location and construction of wells. of Observation wells was naturally im b. Measurements of water levels (in- possible because of absence of wells at de- cluding reduction to common datum sirable locations. In some wells mechani- plane). cal defects or well operating conditions c. Determinations of pumpage. made observations impractical. d. Chemical composition of water. During the period of the investigation Secondary data which were considered many changes occurred: well operating schedules were changed; wells were aban- pertinent to the investigation were: doned or restored to Service; and new wells a. River stages, discharges, temperatures, were drilled. The distribution of Observa and water qualities. tion wells is shown on plate 4. b. Climatological information (rainfall, air temperature, etc.). Water-level measurements in some wells were made periodically with steel tape or Other special observations were made with pressure gage on air line. Where con when conditions were favorable or when ditions permitted, continuous water-level possible value of information thus gained recording instruments were installed. The justified the necessary expenditures. most useful and reliable data were obtained Most of the observations were made, un- from recording instruments because inter- der cooperative agreements where necessary, vals between periodic measurements had to by agencies both public and private, other be selected with great care to assure a true [62] FIG. 15.—River stage, well hydrographs, and pumpage in Sankoty field. FIG. 16.—River stage and well hydrographs, North field. FIG. 17.—River stage and well hydrographs, East Peoria field. 66 GROUNDWATER IN THE PEORIA REGION
FIG. 18.—River stage and well hydrographs, Pekin field.
FIG. 19.—River stage and well hydrographs, Peoria Industrial field. HYDROLOGY 67
FIG. 20.—Available long-time data of water levels in Illinois River and wells at Peoria-Pekin. 68 GROUNDWATER IN THE PEORIA REGION picture of changing conditions. At times, GROUNDWATER CONTOUR MAPS the desired control of interval between meas- As detailed data on groundwater levels urements could not be achieved. Also, the became available, generalized contour maps error in periodic measurements by generally showing the upper limits of the saturated untrained personnel was greater than auto- water-bearing material were constructed. matic instrument error. In the few areas where semi-artesian condi The measurements were only of "non- tions exist, the contours represent the hydro- pumping" water levels, which are the ob- static pressure of the confined water. Such served levels in wells from which water is conditions exist under the river bed and in not being pumped. The term "static" about 5 percent of the remainder of the water level is commonly used but, in areas area. Water-level contours of various of heavy pumpage, water levels are in nearly periods from 1933 to 1945 are shown in constant movement because of changes in figures 21-29. nearby pumpage, in barometric pressure, in After a few maps were constructed and climatic (rainfall) conditions, and in river the general pattern recognized, it was then stages in certain areas. The observed water possible to construct, from the meager data levels were definitely not static, and it was available, a generalized map showing con the change in water levels that was im- ditions in 1933. It was about this time that portant. the present heavy pumpage started. Much can be learned from study of the GROUNDWATER LEVEL DATA groundwater contour maps. First, the direction of groundwater movement at any HYDROGRAPHS point can be determined. Direction of the horizontal component of flow is at a right To gain an idea of the changes in water angle to any contour line towards a contour levels with time, all water-level data were of lower value. Second, if some knowledge plotted, using convenient scales, as eleva- of areal geology is possessed, other geologic tion in feet above mean sea-level versus facts may be inferred. Third, by comparing time. Figures 15-19 are examples of this a water-level contour map with a bedrock type of plotting and include the most useful surface contour map of the same area, the water-level data (hydrographs) collected. depth of water at any point can be deter Figure 20 is a general summary of long- mined. This is a very significant factor in time areal changes and contains all the determining possible yield of a well con historical water-level data available. structed at that point. Also, the volume of saturated water-bearing material can be From previous investigations it was estimated, or accurately calculated if the known that many factors can affect water original data permit construction of precise levels in wells. Some of these factors are: maps. Fourth, comparison of any two infiltration from rainfall, streams, or maps shows changes in conditions over the flooded land; elastic compressibility; exist- area during the intervening period. The ing and previous pumpage; lateral move volume of material dewatered or re- ment of groundwater from adjacent areas; saturated can be calculated. Then if the and variations in atmospheric pressure. Be specific yield of the water-bearing material cause these factors are often active simul- is known, the gain or loss in storage can be taneously, it is difficult to determine the computed. The quantity of water yielded relative effects of the various factors, but by gravity drainage from saturated water- the effects of single factors must be evaluated bearing material is termed the specific yield before a logical explanation of areal hydrol- and is expressed as a percentage of the total ogy can be offered. volume of the material. HYDROLOGY 69
FIG. 21.—Groundwater surface contours, 1933. 70 GROUNDWATER IN THE PEORIA REGION
FIG. 22.—Groundwater surface contours, August 1941. HYDROLOGY 71
FIG. 23.—Groundwater surface contours, flood peak, February 1942. 72 GROUNDWATER IN THE PEORIA REGION
FIG. 24.—Groundwater surface contours, September 1942. HYDROLOGY 73
FIG. 25.—Groundwater surface contours, May 1, 1943. 74 GROUNDWATER IN THE PEORIA REGION
FIG. 26.—Groundwater surface contours, June 1, 1943. HYDROLOGY 75
FIG. 27.—Groundwater surface contours, July 1, 1943. 76 GROUNDWATER IN THE PEORIA REGION
FIG. 28.—Groundwater surface contours, September 1943. HYDROLOGY 77
FIG. 29.—Groundwater surface contours, September 1945. 78 GROUNDWATER IN THE PEORIA REGION
TABLE 4.—CHANCE IN VOLUME OF SATURATED MATERIAL, 1933-1943
Volume of saturated material, 1933-1943 *Average Well field loss in 1933 May 1943 Difference storage (sq. mi. ft.) (sq. mi. ft.) (sq. mi. ft.) mgd. Sankoty 651.0 505.5 145.5 0.62 North 193.7 175.3 18.4 0.08 Central 2,216.8 1,568.4 648.4 2.78 Pekin 327.7 305.9 21.8 0.07 Total 3,389.2 2,555.1 834.1 3.55
* Assuming specific yield is 7.S percent.
Available storage.—The available storage porosity, and specific yield are not identical. of each well field was computed by con- When a material is drained by gravity, a structing differential, water surface—top of certain volume of water is always retained bedrock, contour maps with fixed areal by capillary and molecular forces. Labora boundaries. The differential maps were tory tests of aquifer samples from the Peoria constructed from the water level contour area indicated a specific yield of 20 to 28 maps and a bedrock surface contour map, percent. The entire thickness of saturated similar to plate 1, in Part 1, and show the material undoubtedly has an average specific depth of water above the bedrock surface yield that is much less because the upper throughout the area for the date selected. strata that are dewatered and resaturated The limit of influence of pumpage in each generally are composed of smaller particles, well field was a natural boundary to use less uniformly sorted than the screened in computation of the volume of saturated aquifer sections. In much of the area there material, but these limits were somewhat is more than one aquifer and the separating indefinite and changed with time. The relatively watertight strata tend to reduce boundaries actually used were an arbitrary the average possible yield. The average line located about one-half to one mile out- specific yield of the aquifer is not yet known. side the known limits of influence, except In Chapter 12, under certain assumptions, where bedrock outcrops formed a natural the upper limit of average specific yield is boundary. calculated to be about 7.5 percent. Using an average specific yield of 7.5 percent, the Water-surface—bedrock differential con- average daily loss in storage for the 10-year tours for 1933 and May 1943, prior to period is shown in the last column of table flood, are shown in figures 30 and 31. 4. An assumed specific yield of 15 percent Water—surface—water—surface differential would double the values shown. contours for 1933 and May 1943 are shown on figure 32. This figure shows the ap- The approximate loss in storage for the proximate actual lowering of the water sur ten-year period (12,900 million gallons) is face. about one-third of one year's pumpage. From the water-surface—bedrock differ 31,000 million gallons. The volume of ential contour maps the volume of saturated water in storage in 1933 was about 53,000 material was calculated in square-mile feet. million gallons (7.5 percent specific yield) The values for 1933 and May 1943 are or about 1.7 years supply at average pump given in table 4. age rates, if all of it could have been re- Laboratory tests of saturated materials covered. It is then obvious that the water collected during drilling Operations indi- pumped cannot have come entirely from cated the percentage of void Spaces varies storage. Otherwise the field would have from 28 to 33 percent. Void space, or been pumped dry long ago. HYDROLOGY 79
FIG. 30.—Thickness of saturated strata, 1933. 80 GROUNDWATER IN THE PEORIA REGION
FIG. 31.—Thickness of saturated strata, May 1943. HYDROLOGY 81
FIG. 32.—Lowering of water surface, 1933 to May 1943. 82 GROUNDWATER IN THE PEORIA REGION
Overpumpage.—Overpumpage is defined loss for a ten-year period was 2.8 mgd. in as the amount of pumpage exceeding the the Central field, if the overpumpage were natural recharge or perennial yield of a calculated on a three-year basis, 1939 water-yielding deposit. Overpumpage can through 1941, it would give a value of be determined if average annual recharge about 6.0 mgd. and average annual withdrawal are known. It should be noted that these calculations Net loss in storage is not a direct, or an are based on two primary assumptions. exact, measure of overpumpage. One, that water-table conditions exist, there- The decline of water levels or loss of by permitting use of water-level contour storage in a developed well field also creates maps to calculate changes in volume of a steeper hydraulic gradient (slope of water saturated material, and two, that pumpage surface) causing more water to flow into the was uniform during the period. On the well field from its sources of recharge. basis of available evidence, the first assump- Therefore, until other factors are con- tion is fairly valid. There are no exact sidered, it cannot be said that a loss in data to support the second assumption. storage is a direct measure of overpumpage Pumpage by the Peoria Water Works although it is evident that such a decline Company steadily increased from an aver in water level cannot continue indefinitely. age of 7.3 mgd. in 1935 to an average of Theoretically, on a level bedrock surface, 11.1 mgd. in 1941 and 14.3 mgd. in 1945, this process could continue until at the exact or the pumpage was doubled in ten years. center of pumpage there would be no Some of this increase was due to a replacing saturated material. Practically, conditions of industrial pumpage by the city supply. become critical long before that. The bed Through these years, variations in industrial rock surface is uneven, so that wells located water requirements occurred but were rel- on bedrock ridges would be dry while nearby atively small, seldom more than ±20 bedrock-valley wells were still usable. Also percent. Therefore pumpage was not uni a certain depth of water over bedrock is form and it is possible that overpumpage necessary to provide the necessary "draw- did not exist throughout the selected ten- down" in a pumped well. Drawdown is year period, but was concentrated in shorter defined as the lowering of water level with- periods. Since the last assumption appears in a pumped well, necessary to create a to be most logical, an arbitrary value of hydraulic gradient that will cause water to 6.0 mgd. average loss in storage will be used move through an aquifer into the well. In for tentative calculations until a more ac- addition to drawdown needs, a certain curate value can be obtained. amount of screen submergence is necessary to provide inflow area to the well. Amount of normal recharge.—The differ- ence between the average pumpage (84 In May 1943 the depth of water over mgd.) and the average loss in storage (6.0 bedrock in a large part of the Central field mgd.) gives the approximate average normal was less than 20 feet, and the water levels recharge (78 mgd.) to the developed well of that date are taken as the minimum de- fields, but it does not give any clue as to sirable. Water levels continued to decline the source of recharge. For the Central somewhat after that date, even with exces- field the average normal recharge would be sive rainfall, so it is evident that overpump 42 mgd. (48 mgd. pumpage minus 6 mgd. age exists. loss in storage), but the calculated loss in On examination of long-time hydrographs storage in the other fields is less than the (fig. 20) it is seen that the period of normal error in the data. Viewed from a greatest decline in water levels, which coin- cided with a period of deficient rainfall, different angle, if normal recharge is known was 1939 through 1941. From 1936 and pumpage is known, then the difference through 1938 and from 1942 through 1945 is overpumpage or unexploited water, de- minimum water levels were about the same pending on the relative values of recharge from year to year. So while the average and pumpage. Thus if the average annual HYDROLOGY 83 recharge can be determined, the safe yield of TABLE 5.—USES OF GROUND WATER the area is known. Million Percent Measurements of pumpage.—Reliable Type of usage gallons of measurements of pumpage were very diffi- per day total cult to obtain because only a f ew flow meters Municipal 19.0 22.5 were installed at well pumps. Where Air conditioning 2.8 3.3 10.0 11.9 meters were not installed, pumpage was Steel plants Food industries 9.5 11.3 usually estimated from nominal pump capac- Distilleries 12.0 14.2 ity and average daily operating time, but 14.0 16.6 Non-beverage distilleries 17.0 20.2 in many places even this information was Other pumpage unavailable. In such cases the pumpage Total 84.3 100.0 was estimated from whatever data were available. It was hoped, and believed, that cern about the possibility of a diminishing the total average pumpage was a good ap- water supply. However, a few isolated re proximation because of compensating errors. cords were obtained which indicated the However, it was generally not possible to general trend of changing conditions. determine normal variations in pumpage. The pumpage from the Sankoty field was OTHER DATA mainly for the municipalities of Peoria and To correctly interpret past and current Peoria Heights, all of which was metered. changes in groundwater conditions, certain The largest part of pumpage in the North other data were necessary. These data, like field is by the Peoria Water Works Com the basic hydrological data, were obtained pany, and the balance of the pumpage is by from many sources. a few industries. Except for four indus- Precipitation.—The natural source of tries, all pumpage in the North field is replenishment of groundwater resources is metered. precipitation which may have fallen recently In the Central field, with the exception or long ago, nearby or far away. The of East Peoria, there was no municipal available rainfall data collected by various pumpage prior to 1946. Only a very small agencies were obtained for comparison with part of the industrial pumpage and none water-level, pumpage, and river-stage in of the pumpage for air conditioning plants formation. Most of the data were assembled was metered. Nevertheless, the uniformity and analyzed by J. L. Page, Department of Operation during the war period allowed of Geography, University of Illinois. A a fair estimate of the industrial pumpage. graph showing rainfall, Illinois River levels, The estimates of water consumption by air and selected well hydrographs is presented conditioning plants are, however, unreliable. in figure 33. In the Pekin field only a small amount Test drilling.—To Supplement the net- of the pumpage is for municipal uses, and work of Observation wells it became de- that is metered. The requirements for air sirable to construct test wells in locations conditioning are small and indefinite, and where no facilities for water-level measure only a small part of the large industrial ments were available, or where additional pumpage is metered, but the rest could be information was needed. All wells were estimated with a fair reliability. constructed by local drilling contractors Uses of groundwater.—The uses of after competitive bidding. groundwater in the area for 1945 are shown To Supplement the water-level Observa in table 5. tion network, 6-inch wells were drilled at Search for old records.—An effort was Bradley, Madison, and Lincoln Parks in made to collect old operating and water- Peoria; at the East Peoria Sewage Treat- level data, but the effort was generally un- ment Plant; and at the Sword property in successful as the usual practice had been to East Peoria. For groundwater velocity record no data as long as there was no con- measurements, two additional 4-inch wells 84 GROUNDWATER IN THE PEORIA REGION
FIG. 33.—Rainfall, river levels, and groundwater levels, 1936-1945. were drilled at Madison Park, Lincoln from the 4-inch wells drilled previously and Park, the Sewage Treatment Plant and used for velocity measurements. Sword property. Three 8-inch wells were Velocity determinations.—For ground also drilled at the Hiram Walker & Sons, water velocity measurements, three test Incorporated plant for obtaining data dur- wells were drilled at the corners of 50-foot ing an artificial recharge experiment. equilateral triangles. Water levels were Drilling the Bradley Park well in Octo- measured very carefully to determine direc- ber 1941 disclosed the presence of the buried tion of movement. Then common salt was valley lying west of Peoria which had been added to the upstream well and length of suspected from the groundwater contour time required for the salt to appear in the map of August 1941. That was before the downstream wells permitted calculation of resistivity survey made in 1942 by K. O. velocity. Appearance of salt in the down Emery, State Geological Survey. Because stream well was determined by increase in of the great depth to bedrock, the plans for conductivity of water. making velocity measurements at this loca- The results were not entirely satisfactory tion1 were abandoned. The discovery of as the salt appeared in the other wells slowly the buried Valley was checked by a test hole and in irregularly rising amounts. The drilled at the Christian Buehler Memorial data collected indicated that the average Home in September 1943 with pipe salvaged groundwater velocity was about 50 feet per day at the locations where measurements 1 See p. 27 of Part 1, Geology. Udden has bedrork at ±350 feet. were made. The hydraulic gradient ob- Bradley well at 346.6 feet. Christian Buehler Home well at 353.1 feet. served was about 2 feet per mile. CHAPTER 10
SURFACE WATER INVESTIGATIONS
ILLINOIS RIVER revealed that the turbidity was generally low, as might be expected, because low With the recognition that the Illinois velocities in the lake-like basins between River and areal tributaries might be a major Hennepin and Peoria would be favorable source of groundwater replenishment, an for Sedimentation. The turbidity was be evaluation of the factors affecting river-bed low 50 ppm, more than half the time, but permeability was made. storms of course caused periods of high At the time when exploitation of ground turbidity. The yearly maximum varied water resources was greatly increasing, two from 270 to 800 ppm. A Statistical analysis possible significant and mutually dependent of the data is shown in figure 34. events occurred in the history of the Illinois River. Simultaneously with reduction in diversion of water from Lake Michigan into the Illinois River, the river was subjected to strict artificial control of low water stages at Peoria by the construction and Operation of the Peoria lock and dam. The Illinois River in the Peoria-Pekin area consists of three distinct reaches separated by a natural structure and an artificial structure. The Farm Creek alluvial fan is a natural dam (see Part 1 on Geology) creating Lake Peoria which extends up the valley beyond Chillicothe. Below this natural dam (or below Franklin Street bridge) the river is confined to a rel- atively narrow channel for several miles, but this reach is subdivided by the Peoria FIG. 34.—Duration of Illinois River turbidities. dam. The river has a slope of 21.4 ft. (1.1 inches per mile) from 70 miles above to A study to determine relationship between 160 miles below Peoria. Most of the fall turbidity and velocity was made, but it was is concentrated (19.5 feet) at two naviga- found that no Statistical relationship existed. tion dams, which leaves an average slope of It was found that turbidity was high im- 0.05 inch per mile for the actual river mediately after the beginning of an increase course. Pool stage above the Peoria dam in river flow (higher stream velocity) but is 440 feet MSL. and below the dam is 430 that turbidity decreased rapidly and was feet MSL. These conditions make the relatively low at flood crests. This is at- stream an aggrading river, with low flow tributed to the flashy discharge characteris- velocities incapable of moving any sediment tics of local tributaries. except very fine particles. CHANNEL VELOCITY FLOW AND TURBIDITY By order of the U. S. Supreme Court, The Sanitary District of Chicago col- effective January 1, 1939, the diversion of lected daily turbidity samples at the old water from Lake Michigan into the Illinois upper bridge (now removed), and analysis Waterway was reduced from 5000 cfs. to of the data for the years 1935 through 1945 an average of 1500 cfs. To maintain a [85] 86 GROUNDWATER IN THE PEORIA REGION navigable Channel in the waterway, the Peoria lock and dam was constructed and placed in Operation concurrent with the re- duction in diversion. The stream-flow data, 1925 through 1945, of the Illinois River at Peoria col- lected by the U. S. Geological Survey were used to determine the effects of diversion and stage-control on channel velocity, and hence, the possible effect on channel Sedimentation. Preliminary calculations indicated that de- creased diversion and stage-control would have very little or no effect on the stream velocity in Lake Peoria. Therefore, the investigation was confined to the channel between Franklin Street bridge and the Peoria dam. The stream-flow data revealed that from 1925 through 1938 the discharge was never less than 5000 cfs., from 1926 through 1929 was never less than 10,000 cfs. and that the discharge from 1925 through 1938 was less than 10,000 cfs. about 15 percent of the FIG. 35.—Duration of Illinois River flows. time. From 1939 through 1945 discharge was less than 5000 cfs. about 20 percent of Using values for the cross-section near Cedar Street bridge (mile 161.51) the the time and was less than 10,000 cfs. about minimum stream-velocity during the 1925- 60 percent of the time. Maximum dis 38 period was 2.2 feet per second, and mini charge at pool stage is 16,000 cfs. Diver mum velocity during the 1939-45 period sion and stage-control had no effect on peak with reduced diversion and stage control discharges, in fact, the maximum discharges was 0.5 feet per second. Reduced diversion measured were in 1944 and 1945. The alone would decrease velocity (using 1925- relative duration of flows is shown in figure 38 data) to 1.9 feet per second, and stage 35. Using representative cross-sections of control alone would reduce velocity to 1.3 the channel near the Peoria & Pekin Union feet per second, but the two factors operating R. R. bridge, Cedar Street bridge, and simultaneously have had a great effect on Illinois Terminal R. R. bridge, the stream channel velocity at low flows. velocity under varying conditions was cal- Some river bed sampling was done in culated (see table 6 and fig. 36). 1923 and 1941 by the State Natural His-
TABLE 6.—EFFECT OF CHANGING CONDITIONS ON CHANNEL VELOCITY
Velocities ft./sec. Duration days cfs or less Before closure of dam After closure of dam
1925-38 1939-45 160.71 161.51 162.15 160.71 161.51 162.15
5,000 0 67.7 1.42 2.00 1.53 0.50 0.75 0.65 10,000 52.5 202.4 1.55 2.25 1.78 1.03 1.53 1.25 15,000 195.0 259.4 1.65 2.42 2.00 1.52 2.25 1.85 16,000 216.0 275.0 1.68 2.48 2.06 1.68 2.48 2.06 20,000 254.0 297.7 1.76 2.60 2.20 25,000 306.3 321.7 1.85 2.75 2.43 HYDROLOGY 87
FIG. 36.—Channel velocity in Illinois River before and after closure of Peoria dam. tory Survey and the State Water Survey bottom. During the artificial infiltration and comparison of the few samplings re- test in August and September of 1941, the vealed that there were more silt deposits pump intake screen clogged with weeds and in 1941 than in 1923. However, no quanti Shells every time a loaded barge tow passed. tative data on areal extent and thickness However, empty barge tows caused little of deposits were collected. Prior to 1939 clogging. the channel was dredged regularly so that the river bottom had a high ratio of ex- OTHER DATA posed sand and gravel. After 1939, velocity Data on water temperatures, chemical conditions were more favorable for Sedimen quality, biological stability, and bacterio- tation, but increase in and change of type logical conditions of the Illinois River were of navigation apparently have tended to dis- also collected and studied. The relative turb the Sedimentation. The change from occurrence of daily temperatures is shown slow-moving low-horsepower stern wheel in figure 37 and data on chemical quality tow boats to much faster propeller-driven are given in Part 3 on Chemistry. The tow boats moving deeper draft barges has other studies are being continued for use in caused increased turbulence near the river the proposed artificial recharge investiga- tion. They are of little significance in the groundwater study, except that the water quality is within the Standards set for raw waters usable in treatment plants for pot- able public water supplies.
ILLINOIS RIVER TRIBUTARIES
The local tributaries, Kickapoo, Farm, and Tenmile creeks, were studied to deter- mine possible contribution to the areal groundwater resources. The U. S. Geolog- ical Survey has been gaging the flow of Kickapoo Creek since October 1941 and of Farm Creek since May 1943. All these streams have great variations in flow from flash floods during rainstorms to long periods FIG. 37.—Range of Illinois River temperatures. of very low flow. 88 GROUNDWATER IN THE PEORIA REGION
Farm Creek has little visible flow at Creek fan indicates that the deposits are times, but has considerable water in its irregularly sorted (see Part 1) and that Channel alluvial deposits from which a great wells constructed in the southern areas of part of the East Peoria water is obtained the outwash deposits are of small capacity. from shallow (25-foot) wells. No major Similar results were obtained in the Kicka water supplies have been developed in the poo Creek fan. However, groundwater re shallow channel deposits of Kickapoo and charge can and probably does occur through Tenmile creeks. the fans, but the quantity cannot be deter- During flood discharges all the streams mined from available hydrologic data. carry considerable debris which has been The Mackinaw River probably contrib- deposited in alluvial fans in the Illinois utes to the Pekin well field, but is con- River Valley. Test drilling in the Farm sidered to have no effect on the Peoria fields. CHAPTER 11
GROUNDWATER REPLENISHMENT INVESTIGATIONS
As the complexity of the study was recog- ILLINOIS RIVER nized, other special observations or studies A few opportunities were presented to were made in an effort to discover new f acts observe the possible effect of disturbance of or to interpret existing conditions. One river bed on groundwater conditions. These of the problems concerned the source of opportunities were dredging in the river groundwater—whether it was the Illinois channel and construction of Peoria lock and River, storage in the sands and gravels, or dam and the Harvard Street bridge piers. rainfall on the well fields and contiguous Dredging in Illinois River Channel.—A areas. In an attempt to ascertain the permit was granted R. G. LeTourneau, source, or sources, of the groundwater, the Incorporated, in January 1945, by the following investigations were made. Illinois Division of Waterways, for the removal of about 500,000 cubic yards of NATURAL INFILTRATION material from the river channel (Lake Peoria) just upstream from Grant Street in STUDIES Peoria. The material was used for hydrau lic land fill adjacent to the Company plant. RAINFALL ON GROUND SURFACE The conditions of the permit were that In Cooperation with the Soil Physics (1) dredging Operations would cease im- Division of the Illinois Agricultural Ex mediately at any particular place if gravel periment Station a field investigation of the were encountered, (2) bacteriological infiltration of water into the various soil samples were to be collected from the two types of the Peoria area was made in 1942. LeTourneau wells and the Bemis Brother The study was made by R. S. Stauffer, Bag Company well before and during Assistant Professor of Soil Physics.1 dredging Operations. From the data obtained during the field When Operations ceased in January 1946 tests and the University of Illinois Agricul a total of 770,000 cubic yards of material tural Experiment Station soil maps, figure had been removed from approximately mid- 38 was constructed to show infiltration channel. Gravel was encountered fre- rates of the different soils in the area north- quently and Operations were immediately west of Peoria. It should be noted that shifted. No contamination was detected in the maximum possible rate of infiltration the well samples. of the surface soils is shown but no informa- Construetion of Peoria lock and dam.— tion is made known about subsoil percola- During construetion of Peoria lock and tion, quantity of water that might be lost dam (near Creve Coeur) a large quantity by evaporation and transpiration, or what the actual average rate of infiltration into of water was pumped from the cofferdam the groundwater stream might be. Geo excavation. Pumpage was continuous from logic conditions are favorable for water May 26, 1936, to September 11, 1937, and movement towards Peoria, but as yet the the data collected on pumpage, river stages hydraulic gradient, necessary to cause move and cofferdam water levels by the Corps of ment, has been only partially determined. Engineers are shown in figure 39. Table 7, showing total pumpage, average daily 1 Stauffer, R. S., Infiltration of Soils in the Peoria area: Illinois State Water Survey Rept. Inv. 5, 1949. pumpage, and average drawdown relative [89] FIG. 38.—Infiltration capacities of Peoria area soils. HYDROLOGY 91
FIG. 39.—Pumpage and water levels, Peoria dam construction, 1936-1937.
TABLE 7.—PUMPAGE AND WATER LEVELS, PEORIA DAM
Average Average Average elevation Year and month Total drawdown pumpage pumpage inside relative to mill. gal. mgd. cofferdam river stage MSL 1936 May 285 14.2 435.0 6.0 June 593 19.7 416.0 21.3 July 922 29.7 410.5 25.3 1061 34.1 410.2 25.5 September 1001 33.4 408.2 29.8 October 977 31.5 407.7 31.4 November 850 28.3 407.0 32.2 December 673 21.7 409.4 28.4 1937 January 621 20.0 413.0 30.0 682 24.4 411.0 31.4 March 716 23.1 410.4 31.6 April 688 22.2 409.4 33.8 May 780 25.2 411.0 33.4 Total 9819 Av. 26.1* Av. 410.4 Av. 29.5*
* Excl. May 1936.
to river stage by months, was prepared from gallons on September 7, 1936. Nearly the data available. Data on cofferdam water 12,000 million gallons were pumped from levels were not available after May 31, the excavation during the 15-month con 1937. struction period at an average rate of 24.4 The minimum water level inside the mgd., which is equivalent to approximately cofferdam was 406.0 feet MSL. on Novem one-half of the daily pumpage from wells ber 30, 1936; greatest drawdown below in the Central field. The relative percent- river stage was 37 feet on May 10, 1937; ages of groundwater and river water leakage and maximum pumpage was 41.7 million pumped from the excavation has not been 92 GROUNDWATER IN THE PEORIA REGION
FIG. 40.—Water level profiles and materials encountered, Peoria Water Works Company pumping test. determined, but the average elevation of Survey, and a series of Observation wells water levels in the cofferdam (410.4 feet) was constructed between the dam site and was below any groundwater levels in the the southern end of the Peoria industrial Peoria-Pekin area. Water levels in near- area. Water level observations revealed by wells were at elevation 430± feet at that the radius of influence of cofferdam the beginning of construction and dropped pumpage was about one mile, but the center to 423± feet during construction. There- of pumpage of the Central field was about fore, it appears most probable that a con- three miles from the dam. siderable quantity of groundwater was Construction of Harvard Street bridge pumped from the excavation. piers.—Prior to preparing specifications for During the construction period of the the Harvard Street bridge piers some con- lock and dam there was a large increase in cern was expressed about the effect of pier pumpage from the Central field. In construction on the public water supply, August 1936 a water level recession in wells since some of the piers would be within 1000 in the Central field was observed and was feet of the Peoria Water Works Company thought to be the result of pumping at the main well. Therefore, a cooperative study cofferdam. The Corps of Engineers re- was made by the State Division of High quested assistance from the U. S. Geological ways, the State Department of Public HYDROLOGY 93
Health, the State Geological Survey, the level in the adjacent Observation well, Attorney General of the State, the City of whichever was higher. Groundwater levels Peoria, the Peoria Water Works Company, in the Observation wells varied from 420.0 and the State Water Survey: (1) to deter- to 428.0 feet MSL. and pool stage was at mine possible hydrologic or sanitary effects 440 feet. The groundwater was under of pier construction on the public water artesian pressure below the river bed and supply, (2) if deleterious effects were produced boils in the bottom of the coffer possible, to formulate construction plans to dam excavations. Daily bacteriological avoid these effects. tests were made of the water from the main A series of Observation wells, spaced 200 well and no contamination was detected. feet apart, was constructed on a line from During the construction of three of the the Water Company main well to the pro- bridge piers, it was possible to obtain un- posed bridge location, and water level meas- disturbed samples of the materials forming urements were made in these wells from the river bottom. The first layer of 1 to August 22 through 29, 1938, while pump- 2 inches thickness was a very fluid, slimy silt ing in the main well at rates of production containing about 80 percent water. The from 2.5 to 4.0 mgd. These observations next layer of about six inches was a yellow revealed a definite hydraulic gradient from to brownish silt, hard enough that foot the proposed bridge site to the main well, tracks impressed about ½ inch deep. This the slope varying from 1.5 feet per 1000 silt contained 30 percent water and could feet at no pumpage to 10.0 feet per 1000 feet be molded. The third layer was a blue at a 4.0 mgd. rate of production. When clay-like silt, hardening rapidly with depth, pumping at a rate of 4.0 mgd. the water and at a depth of 18 inches it contained only level was lowered 12.0 feet at the well 12½ percent water and was too dry to be and 4.2 feet at the bridge location. Also, molded. The latter type of silt continued groundwater level in the Observation well to the bottom of the deposition. at the bridge location varied from 10 to Samples of these clays were obtained by 14 feet below river stage. Peoria lock and pushing 1½-in. copper tubing, with sharp dam was not in use during the test and edges, into the clay and digging out the there was no regulation of flow at Peoria. tubes. The ends of the tubing were closed The well locations, well hydrographs, and with rubber stoppers. Permeability tests other data are shown in figures 40 and 41. were made on three of the samples in the With this knowledge, the pier construc copper tubing as taken in the field. The tion plans were modified to prevent any permeability of the 6-inch long samples of possible contamination of the groundwater. the silt (12½ percent moisture content) The procedure followed was to construct an against 10 feet head was 0.6, 0.75, and 1.0 Observation well at the upstream end of ml. in 12 hours. This would give a flow each (piers 7, 8, 9, and 10) pier cofferdam of about 0.5 mgd. over an area of 5 square and during excavation to keep the water miles at a gradient 2:1 (20 ft. loss of head inside the cofferdam pumped to the bottom through 10 ft. strata) an insignificant of the excavation or to elevation of water amount. (See equation below.)
Over 5 square miles at 20:1 slope
At slope 2:1 this would be 94 GROUNDWATER IN THE PEORIA REGION
FIG. 41.—Well hydrographs and well locations, Peoria Water Works Company Pumping fest. HYDROLOGY 95
Dredging of the river bed by the Le- of areal groundwater conditions before, Tourneau Company and pier construction during, and after the floods of 1943, 1944, for the Harvard Street bridge revealed and 1945 was made. More frequent water that silt deposits at these locations ranged level measurements in some wells were ob- from 5 to 25 feet in thickness. tained. A discussion of the observations ILLINOIS RIVER AT FLOOD STAGE is included in Chapter 6. It was generally known that floods in the Illinois River were accompanied by ARTIFICIAL INFILTRATION marked rises in groundwater levels. This STUDIES phenomenon has led many to believe that major recharge of the water-bearing de• To obtain some idea of the feasibility of posits occurs during floods. restoring groundwater by land flooding, a relatively large scale experiment was made. In an effort to provide a logical explana- Hiram Walker and Sons, Incorporated, tion for this phenomenon, a detailed study furnished land, equipment, chemicals, and labor for the tests. The relative locations of the test pit (abandoned gravel pit) and all Observation wells are shown in figure 42. Water was pumped from the Illinois River at an approximate rate of 2200 gpm. (average 3.2 mgd.), chlorinated, and dis- charged into the test pit having a surface area of about 0.1 acre. The pumping periods, behavior of water levels, and groundwater temperatures in selected Ob• servation wells are indicated in figure 43. Salt tests made to measure groundwater velocity indicated velocities ranging from 75 to 200 feet per day. Bacteriological contamination attributed to the infiltration test was detected in a nearby well owned by Armour and Co. The average rate of infiltration during the test periods was 37 million gallons per acre per day. Possibly the most significant phenomenon observed was the close similarity of well hydrographs in relation to recharge in the test pit with hydrographs of wells along the river bank during Illinois River flood FIG. 42.—Location of Infiltration pit and Obser• vation wells. periods. FIG. 43.—Pumpage and hydrographs of levels in Observation wells during infiltration tests. CHAPTER 12
INTERPRETATION OF HYDROLOGIC OBSERVATIONS
The factors governing groundwater main Station (in the North field). Be- development, conservation (beneficial use) ginning in January of 1943 there occurred and replenishment are very complex. In a period of heavy rainfall culminating in making the necessary simplifications and the flood of May 1943 in which Peoria generalizations required for a general un- Water Works Company pumpage was re derstanding or mathematical treatment of duced from about 10 to 4 mgd. but the the involved phenomena, there are many maximum change in river stage was 17 opportunities to ignore or minimize the feet as compared to a 30-foot rise in ground influence of pertinent data and thus be led water levels. From June 1943 to February astray in logical reasoning. It is with this 1944 was a period of deficient rainfall and knowledge in mind that, in the following, with pumpage averaging about 8.9 mgd., the more stress is given to the relationships groundwater level at the center of pumpage between the interacting forces than to the dropped to 405 feet MSL. as compared to presentation of explanations. Where ex- river pool stage of 440 feet. It is un- planations are given they are admittedly fortunate that no water-level data are incomplete and serve only as an aid to available prior to 1941, since there is no planning until more facts and studies permit other means of determining the effect, if the formulation of better explanations. any, of closing Peoria lock and dam. Examination of the water-level contour SANKOTY FIELD maps (figs. 21-29) and the water-water differential contour map (fig. 32) reveals The Sankoty well field is isolated from the existence of local recharge, but not the the effects of other well fields by bedrock source. The wet period in September and outcrops and distance. October of 1941 would indicate the possi- In figure 15 are shown Illinois River bility of considerable direct Infiltration ex- stages, non-pumping water levels in Peoria cept that a thick layer of Wisconsin drift Water Works Company well No. 7 (con- overlying the Sankoty sand (see Part 1 on structed in 1911) located near the center Geology) might preclude rapid direct in- of the Sankoty field, and the monthly pump- filtration. Not shown but pertinent to the age by the Peoria Water Works Company, possibility of recharge from the upland area from 1941 through 1945. It is seen that is the hydrograph of the Municipal Sani- water level in well No. 7 was always below tarium well. For a brief period after the river stage but that changes in groundwater flood crest of 1943, water level in this well levels were much greater than changes in was above river stage although water levels river stages. Comparing river stages, water in wells nearer the river were below river levels and rainfall (flg. 33) for Septem stage. This indicates that substantial re ber and October of 1941 it is seen that there charge was occurring from the upland areas. was excessive rainfall in the area, and that On the east side of the river, Wisconsin while the maximum rise in river stage was glacial outwash sands and gravels of the 5 feet, groundwater levels rose 25 feet. At Illinois River Valley fill are in contact with the same time pumpage was reduced to an the Sankoty sands and also the alluvial out average of about 2.5 mgd. (including no wash fan of Tenmile Creek located south- pumpage for certain periods), as the field east of the field. Thus there is the possi was used only when necessary to Supplement bility that considerable recharge occurs from pumpage from the Peoria Water Works these directions. [97] 98 GROUNDWATER IN THE PEORIA REGION
The present channel of the Illinois River through 1945. This field shows the same is also eroded in the Sankoty sand1 and general relationship between river stage, direct infiltration from the river is a possi- groundwater levels, and rainfall that was bility, but this portion of the channel (Lake observed in the Pekin and Sankoty fields. Peoria) is extensively silted. Using the During periods of receding river level after permeability data obtained during construc- major floods there is a noticeable time lag tion of the Harvard Street bridge piers in groundwater level recession in wells pro- (Chapter 11) and using generous estimates gressively farther from the Peoria Water for thickness of silt and hydraulic gradient, Works. This effect is attributed to pump the maximum recharge from the approxi- age by the Peoria Water Works Company mately five square miles of river bed in a as it accounts for about 90 percent of the favorable position at pool stage to recharge field pumpage. It is also noted that ground the Sankoty field could be about 1.0 mgd., or water levels at the Allaire-Woodward about 10 percent of the pumpage. Company are occasionally above river stage Other possible sources of recharge are for a brief period after passage of river from Dunlap buried Valley to the west and crest stage. At the LeTourneau plant, the buried Mississippi channel to the north. water levels were sometimes above river The groundwater divide in the Pekin- stage, and after the flood of 1944 which Sankoty channel connecting Sankoty and was accompanied by heavy local rainfall, groundwater levels were above river stage Central fields precludes recharge' from that from mid-1944 through 1945. This would direction, and the bedrock hill just south of indicate local direct recharge from the bluff Sankoty is an effective barrier. There is area west of the field because the bedrock as yet no hydrologic data available to per- hill is presumably impervious and thus a mit estimation of relative contribution from barrier to lateral groundwater movement. each of the various possible sources. However, during most of 1945, ground The lowest noted depth of water over water levels remained 3 to 5 feet above river bedrock in the field was about 40 feet (Feb- stage, and this may have been due, in part, ruary-March 1945) when field pumpage to the hydraulic fill being placed in the was about 13.0 mgd. This plus the be- area (Chapter 11). This may also be an havior of water level indicates that although indication of direct surface recharge. the field is not seriously overpumped, it has been fully developed. However, individual The difference in groundwater level and wells have pumping levels below top of river stage at the Peoria Water Works screens during low-water periods, which Station is favorable to infiltration from the generally shortens well life and causes river, but less than one Square mile of river operating difficulties. bed is within the possible cone of influence and, using permeability data as before, the NORTH FIELD river recharge would be about 0.2 mgd. or about 4 percent of the pumpage. The be- The North well field is limited in extent havior of water levels in the Observation and development by both topographic and wells during the pumping test of 1938 (figs. subsurface geologic features, being located 39 and 40) possibly indicates that consider- on a narrow terrace between the Illinois able recharge was occurring from the river. River and the bluff. The field is limited on The water-level profile was normal except the northwest and southeast by buried bed for Observation well No. 5. The shoreline rock hills. at the time was between Observation wells Figure 16 shows Illinois River stages and No. 4 and No. 5 and the abrupt rise in hydrographs of wells at the Peoria Water hydraulic gradient between the two wells Works main Station, Bemis Brother Bag indicates that recharge was occurring near Company, Allaire-Woodward Company and well No. 5. Details of construction of the R. G. LeTourneau and Company from 1941 Observation wells are not available and it 1 See Plate 3. is possible that the change in gradient is HYDROLOGY 99 the result of leakage around the casing, but Shallow wells in Farm Creek Valley seem the behavior of water levels at the different unaffected by deeper wells in the Illinois pumping rates indicates greater infiltration valley. than could occur around a single string of In the valley of the Farm Creek and the pipe. top part of the alluvial fan of the Farm The other possible sources of recharge Creek in the Illinois River valley are shal are lateral flow from the ancient Mississippi low sand deposits (25 to 30 feet deep) fur- channel and from the alluvial outwash fan nishing considerable water. The East of Tenmile Creek which is directly opposite Peoria municipal supply and a few air con- the Peoria Water Works. No hydrologic ditioning wells are in this aquifer. Wells data are available that will permit estima- in this aquifer seem to be unaffected by the tion of relative quantity of recharge from pumpage in the nearby but deeper wells of each of the various possible sources. the Caterpillar Company, but show rapid Pumpage was commenced in the North changes with rainfall and flash-floods of field by the Peoria Water Works in 1892, Farm Creek, from which they are in all and in 1909 it was reported that ground- probability directly recharged. This might water levels varied with river stage and that explain the low visible flow at times in Farm in a dry year the estimated available yield Creek and the development of these shallow of the main well was 5.0 mgd. and of all deposits to the maximum safe yield in dry auxiliary and reserve wells about 3.4 mgd. periods. Estimated average pumpage increased from The larger industrial supplies have been 4.5 mgd. in 1904 to 6.08 mgd. in 1908 and developed in outwash deposits of Farm to 8.0 mgd. in 1910 at which time develop- Creek which perhaps are mingled with ment of Sankoty field was started. Illinois valley-train deposits (see Part 1 on By comparison of the above data with the Geology). The slope of the bedrock hill average pumpage data available from 1941 on which the North well field is located through 1945 it is apparent that the total extends beneath the Illinois River to the average pumpage from the field had been East Peoria field, and consequently wells reduced, and that although the 1945 devel- drilled near the river encounter bedrock at opment was probably somewhere near the shallower depths than wells drilled nearer safe annual yield of the field, there was no the east bluffs. overpumpage, and with due regard to well Conditions in the southern part of the spacing, very limited additional supplies East Peoria portion are typical of confined could be developed. During low ground- groundwater. This was observed clearly water periods there is only 15 to 20 feet while drilling the test wells at the East of water above the bottom of the wells to Peoria sewage treatment plant. On the provide for necessary drawdown and screen other hand no such confined water condi submergence. tions were found in the northern part at the Sword property although much fine silt was found. CENTRAL FIELD Illinois River stages and hydrographs of For discussion purposes the Central well water levels in wells owned by Caterpillar field is divided into the East Peoria portion Tractor Company and the East Peoria and the Peoria industrial portion. sewage treatment plant are shown in figure 15. The period of Observation is too short EAST PEORIA PORTION (1942 through 1945) to develop any signif- The East Peoria portion has some pecu- icant trends. It appears that groundwater liarities which distinguish it from the re- levels are primarily controlled by rate of mainder of the Central field. The hydro- pumping (minor changes excluded) at the logic data indicate two partially independent Caterpillar plant and that this effect masks aquifers in this portion of the Central field. any but the major changes caused by varia- FIG. 44.—Selected well hydrographs and river levels, 1943 flood. HYDROLOGY 101 tions in rainfall or river stages. Approxi- PEORIA INDUSTRIAL PORTION mately 80 percent of the field pumpage The Peoria Industrial field includes all (6.0 out of 7.6 mgd.) is withdrawn by the the area west of the Illinois River and Caterpillar Company. During flood periods north of Kickapoo Creek not included in there is a definite lag of groundwater level the well fields previously described. Wells peaks behind river crest stage and the lag are located throughout the area but the is greater at the Caterpillar plant, which major pumpage is concentrated in a narrow is farther from Illinois River, than at the belt along the Illinois River between Frank East Peoria Sewage Works. This is more lin Street bridge and Kickapoo Creek. clearly shown in figure 44, which gives the hydrographs during the flood of 1943. At It was shown in Chapter 9 that recharge peak river stages, the East Peoria Sewage to the Central field must occur from some Works well flowed, thereby preventing source or sources, since if the water had determination of maximum groundwater come only from storage the field would have levels. This behavior is analogous to sand been pumped dry long ago. Study of the boils which commonly occur behind levees available data reveals that the possible during flood periods in many areas and is major recharge sources are direct surface attributed to artesian conditions. infiltration, infiltration and percolation from present and buried Kickapoo Valleys, The general shape of groundwater con- and infiltration and percolation from the tours in the East Peoria field (figs. 21-29) Illinois River. It also appears that most of indicates general movement of water from the recharge occurs during river flood the Farm Creek alluvial fan to the Peoria periods which generally coincide with industrial district. However, Caterpillar periods of heavy local rainfall, thus even Company pumpage distorts the contour when fair data are available it is difficult to lines to a certain extent. Figure 26, show- determine relative effects. ing groundwater contours on June 1, 1943, In figure 33 are shown the long-time clearly shows a restricted cone of influence (1936-1945) hydrographs of wells at in the East Peoria industrial area which Hiram Walker and Sons, Incorporated, and indicates recharge from all directions, Farm the Peoria Sanitary District, together with Creek to the east and the Illinois River to river stage and rainfall data. Both these the north, west, and south. There is also plants are located near the river and near probably direct surface infiltration from the center of heaviest pumpage. A study rainfall. In 1944, a connection was acci- of this and of some earlier water-level data dentally broken on a fuel oil storage tank shown in figure 20 (1933-1945) indicates at the Caterpillar plant and the oil which a continual fluctuation in groundwater escaped reached a nearby pumped well in levels which have a close relationship with a very short time. Although the physical river stages, but which are not as closely properties of oil and water affecting rate of related to areal rainfall variations as are movement are different, the incident does the fluctuations in Sankoty field. It was indicate that direct surface infiltration oc- observed in the Sankoty field that the heavy curs. rainfall in late 1941 together with a major reduction in withdrawal, and relatively The present pumped area appears to be minor changes in river stage, caused a 25- developed to maximum potential yield, and foot rise in water levels. In the North test drilling in the southern area of the fan field the comparable rise was 20 feet, but in indicates less favorable materials. As good the Hiram Walker wells in the Central or better water-bearing material may be field the rise was less than 5 feet. Thus it located in the up-stream area of Farm Creek appears that there was less rapid recharge to fan, but the effect of additional develop- the Peoria Industrial field than to the ment on yield of existing wells cannot be Sankoty and North fields although the total predicted. quantity was probably greater. It is also 102 GROUNDWATER IN THE PEORIA REGION observed that although levels subsequently effect of floods before and after closing the fell, none of the levels dropped to the Peoria lock and dam but little information previous 1941 low, prior to the flood of is available for the earlier period and it is February 1942. the latter period with which we are most concerned. It is also observed on figure 33 that the longest period of uninterrupted recession in In figure 44 are shown hydrographs of groundwater levels was from early 1939 certain wells from April 10 to October 1, until late 1941 during which time the river 1943, a period which includes the flood of stage was controlled, there was a rainfall April 25 to July 1, with crest on May 23. deficiency, and there were no floods. It is The average of Armour and Hiram Walker also observed that floods in 1942, 1943, and well data is plotted as one curve. These 1944 caused large changes in water levels, plants and the Century Distilling Company but little benefit to groundwater levels was are located on the river. During rising observed as compared to the effects of lesser river stages there was a very short time floods in 1936, 1937, and 1938. As the lag in rise of groundwater levels, but during pumpage did not change greatly in the falling river stages there was a very pro- period 1943 to 1945, this does not seem to nounced time lag in recession of ground be a major factor. It may be pertinent to water levels. Three months after the river note that these wells are adjacent to that stage had returned to pool level, ground portion of the Illinois River below Lake water levels in these wells were about 5 Peoria and above Peoria lock and dam. feet higher than on April 10, although no Rate of infiltration during low river stages change occurred in rate of pumping. This may have been influenced by lowered diver- is in definite contrast to groundwater level sion and river stage control resulting in low behavior in the East Peoria field where stream velocities with consequent greater pre-flood levels recurred promptly. tendency to bed silting. The Lincoln Park well is located about 3000 feet from the river and the Armour- CENTRAL FIELD AS A WHOLE Hiram Walker wells. Water levels con- tinued to decline slowly in this well from Despite the somewhat independent be- April 10 to May 20 and then started a slow havior, particularly during floods, of water rise to a maximum level which was reached levels in the East Peoria and the Peoria about July 1, by which time the river had Industrial well fields, the fields are hydro- returned to pool stage. logically interconnected. This was demon- At the time of the peak at Lincoln Park, strated by variations in water levels in cer- water levels in the Hiram Walker and tain recorder wells which could be traced Armour wells had returned from higher to known causes. Shutdowns at the Cater values to the same elevation as that in the pillar and Hiram Walker plants, which Lincoln Park well. . did not occur simultaneously, were reflected Water level in the well declined slowly in the East Peoria sewage plant recorder from July 1 to October 1. On April 10, well. Likewise, water levels in recorder and from September 1 to October 1, the wells at Pabst Brewing Corporation and level was 7 feet above water levels in the Gipps Brewing Company were affected by Armour-Hiram Walker wells. This is be- variations in pumpage at the Caterpillar lieved to be the normal condition of the plant and by Hiram Walker's pumpage. hydraulic gradient (slope of water surface) Water levels in the Sword well were in between the Lincoln Park well and fluenced by Caterpillar pumpage, but not Armour-Hiram Walker wells and is attrib- by any other pumpage. uted to the effect of heavier pumpage in Flood Effects.—The effect of all floods the vicinity of the latter wells. Therefore, on groundwater levels appears to have been if the hydraulic gradient between the wells similar, so a study of one flood appears to be on April 10 and on September 1 is a sufficient. There may be some difference in "normal" or "stable" condition, then the HYDROLOGY 103
rise in areal water levels between April 10 The pumpage during this period in 1943 and September 1 represents an actual in- was fairly constant and did not vary more crease in the volume that is saturated with than ±5 percent. water. During the "stable" periods, ground- In Chapter 9, the average net change in water movement would be from the Lincoln volume of saturated material was computed Park well to the industrial area (towards for the ten-year period 1933 through 1943. the river). However, from May 20 to By the same methods, the apparent changes June 22 water levels in the Armour-Hiram in storage during rising and falling river Walker wells were above the water level in stages during the flood of 1943 was com the Park well and groundwater movement puted. The periods selected were May 1 during the period was away from the river. to June 1, June 1 to July 15, and July 15 This plus the shape of groundwater con- to September 1. The river crested May 23, tours (fig. 26) does not, however, clearly but water levels in wells reached maximum identify the source of the water. elevations from four days to four weeks The same phenomena are observed later, depending on location of wells and farther up the river opposite the lower end distance from the river. During the period of Lake Peoria. In figure 19 is shown the from June 1 to July 15, conditions were hydrograph of wells at Peoria County Jail, very unstable as the water levels in some Palace Theatre, and the Peoria Apron and wells were rising and in others levels were Towel Supply located approximately 1400, receding as the field was adjusting itself to 2200, and 3000 feet from the Illinois River, changing rates of infiltration and relatively respectively. There is a distinct time lag constant pumpage. Although this adjust- between rise in river stage and rise in ment appears to be entirely without reason groundwater level, and the time lag in- when one studies individual well hydro- creases with increased distance from the graphs, it is actually very orderly when one river. In each case the well farthest from studies the water-level contour maps (figs. the river reaches its peak when water in the 25-28). After July 15, water levels in the wells closer to the river declines to the field began a normal adjustment to pumping elevation of that peak. conditions and well hydrographs were simi- The hydrograph of the Bradley Park well lar to those obtained in other areas during (fig. 20), located in the Pekin-Sankoty well field pumping tests. buried Channel and in the present valley of If, after assuming no outflow to the river Dry Run Creek, reveals that water levels or inflow from the uplands, the specific in this well have been 1 to 5 feet above pool yield is calculated for the period July 15 to stage for the period of Observation. Changes September 1, 1943, a value of 7.3 percent in river stage have little or no effect on water levels in this well. There is apparent- is obtained. If it is attempted to calculate ly some relationship between water levels comparative "balance sheets" for inflow, and areal rainfall, which indicates field re recharge, pumpage, and removal-from-stor- charge from the northwest. age for any flood period, a balance cannot The areal groundwater contours also re- be obtained, no matter what specific yield veal the same phenomena, but insufficient (in the range 0-30 percent) is assumed. quantitative hydrologic data are available This makes it appear that there is some in- to permit estimation of relative contribution terfering influence, possibly a compressi- of the various sources of recharge. Calcula- bility effect. In table 8 are shown material tions made from the groundwater contour balances for the periods between May 1 maps are not exact, since the contours are and September 1. of necessity somewhat generalized. How The data available are not adequate on ever, such calculations give a good idea of the following points, which require further 2 the magnitude of the observed changes. investigation:
2 Suter, Max, Apparent changes in water storage during 1. Extent of artesian influences in the floods at Peoria, Illinois: Trans, Amer. Geophysical Union, area. Vol. 28, pp. 425-437, June 1947. 104 GROUNDWATER IN THE PEOR1A REGION
TABLE 8.—CHANGES IN GROUNDWATER STORAGE IN CENTRAL FIELD DURING AND AFTER 1943 ILLINOIS RIVER FLOOD
Change in volume of Apparent Pumpage Net _ change in per change in Saturated *Water in storage day storage Period materials storage Million Million mgd. Sq. mi. ft. gals. mgd. gals. Average May 1-June 1 +233.5 +3650 + 122 +48 +170 June 1-July 15 - 65.5 -1024 - 23 +48 + 25 July 15-Sept. 1 -142.2 -2224 - 49 +48 - 1 May 1-Sept 1 + 25.8 + 402 + 3.3 +48.2 + 51.5
* 7.5% specific yield.
2. Exact quantity of recharge On figure 32 it is shown that the water- a. From upland areas. level recession in the Pekin field from 1933 b. From the river. to May 1943 was 10 feet at the center of 3. Influence of compressibility on water pumpage, although figure 20 reveals that the maximum Variation at the Pekin Water levels in wells in the industrial area. Works has been about 16 feet for the period 4. Presence of outflow to the river. of Observation and the net recession for the 10-year selected period was 5 feet. The PEKIN FIELD shape of the differential contours also in- dicates that the influence of pumping does The Pekin well field is at a distance from not extend much over a mile from any other pumped areas, and interferences which pumped well. In Chapter 9 it was shown would complicate an explanation of hydro- that the water extracted was not from logic conditions are localized in the indus storage, and that the water must be replen- trial district south of Pekin. As shown in ished from some source. The water-level the section on geology, the wells of the contour maps (example, fig. 29) indicate Pekin field penetrate the Sankoty sands that rather steep hydraulic gradients exist and gravels of preglacial Wyoming Valley both towards the river and to the bluffs as well as more recent alluvial deposits. but not very steep ones parallel to the river, On figure 18 is shown Illinois River stages and that the influence of pumpage is very at Pekin and non-pumping levels at the localized. This means that replenish- Pekin Water Works for the years 1939 ment must occur within the local area. through 1945; on figure 20 is shown Still the actual source or sources of re groundwater levels from 1933 through charge is not revealed but may be either 1945; and figure 33 gives rainfall de- from the Illinois River, the Mackinaw partures from the mean. The lowest River, or direct infiltration from the sur- groundwater levels occurred simultaneously face, or a combination of all three. In Part with a prolonged period, July 1939 to July 3 on Chemistry it is shown that all three 1941, of deficient rainfall. This also coin- sources do contribute to the local recharge. cided with a period when the Illinois River In the period from 1933 to 1943 there stage was never above 439 feet MSL. and was an unknown increase in pumpage which only infrequently was above 435 feet. The could account for part of the observed 10- normal river stage at Pekin prior to closing foot recession. An increased hydraulic Peoria lock and dam and reduction of gradient is the natural result of increased diversion from Lake Michigan was about pumpage; it provides the energy required 435 feet MSL. and after closure was about to move the water. Also during this period 431 feet. the normal river stage was lowered about HYDROLOGY 105
4 f eet, possibly lowering the natural hydrau- ly for best well yields. However, the avail- lic gradient to the pumped wells which had able evidence indicates (1) that the ground- to be compensated by an equal lowering of water resources of the area are not over- water level at the wells. Increased pump- developed, and (2) that additional water age and lower river stage appear to be is available to existing or potential users sufficient cause to account for the industrial without detrimental effects on present area water-level recession, so there appears developments providing that consideration to be no cause for immediate alarm over the be given to geologic conditions and that existing Situation. hydraulic principles be applied to well The present industries in the area may spacing. have both wells and plants spaced too close- CHAPTER 13
REMEDIAL MEASURES
In previous chapters, it is shown that the increase in the demand for water, and pres- Central well field and particularly its ent trends are towards higher per capita Peoria Industrial portion is the only well consumption, both for domestic purposes field in the Peoria-Pekin area where the and for industrial needs. It is therefore condition of the groundwater supply is difficult, if not impossible, to reduce water critical, although it is apparent that the consumption unless an actual shortage Sankoty and North well fields are devel- exists. However, by eliminating waste uses, oped to near maximum potential. There- the rate of increase in consumption can be fore, possible remedial measures are dis- held to a minimum. cussed primarily from the viewpoint of For many purposes, more recirculating alleviating conditions in the Peoria Indus Systems using either groundwater or surface trial field. water could be substituted for "single shot" There are many possible Solutions to the groundwater cooling. In many air con problem of recreating a dependable and ade- ditioning installations the only change in quate groundwater supply in the Peoria the groundwater pumped is a 2° F. tem- area. The methods discussed may be classi- perature rise between well and sewer. This fied as follows: is an inefficient use. In many plants, water 1. Reduction of pumpage and wastage. first used for cooling could then be used 2. Development of new well fields. for processing. Economic studies based 3. Substitution of surface water. both on short-term and long-term planning may give vastly different results. 4. Replenishment of groundwater. Another possible Solution, negative in ap- DEVELOPMENT OF NEW proach, would be to attempt nothing and let economic and geographic factors bring a WELL FIELDS readjustment in conditions with resultant Another possibility for relieving the exist- detrimental effects to all but a few. The ing and potential groundwater shortage in purpose of this study is to suggest possible the Peoria industrial area is the development Solutions that would be of benefit to all. of new well fields, conveying the water through pipelines to existing users. To re- REDUCTION OF PUMPAGE lieve the existing shortage of about 6.0 mgd., AND WASTAGE a single field with a safe annual yield equiv- alent to Sankoty field (about 10 mgd.) It was shown that the approximate over- would be required. To relieve the probable pumpage in the Central field was about future shortage in addition to the existing 6.0 mgd. The annual increase in water shortage would require the equivalent of consumption is estimated to average from two Sankoty-like developments. On the 1 to 3 mgd., most of which will be for in basis of geologic and hydrologic data, such dustrial use and air conditioning. Thus, potential well fields do exist. The actual low-temperature water during the warmer development, of course, will be determined months, obtainable from wells only, is re- by economic and other considerations as quired. The increased overpumpage may well as geologic and hydrologic factors. easily reach 20 mgd. in 10 years. This On figure 7, in Part 1, are shown the water must be provided by some means. areas contiguous to the Peoria industrial Normal growth of industries, population, area which from geologic data are favorable and Standard of living necessitates a steady for the development of groundwater. The [106] HYDROLOGY 107 same areas are discussed on the basis of miles to avoid interf erence with the Sankoty hydrologic data in addition to the geologic field. Drilling in the upland areas revealed data. that only the lower few feet of Sankoty sand Area I is within limits of influence of is saturated and that large capacity wells Peoria Industrial pumpage, so additional cannot be constructed. This limits devel development in this area will only increase opment to the Illinois River flood-plain the existing water shortage in the Peoria north of the south line of Township 10 Industrial area. The hydrologic data North. Ten to 12 miles of pipeline would (Chapter 12) indicated very little infiltra- be needed to convey the water to existing tion from the Illinois River at normal users as the carrying capacity of present stages upstream from Peoria lock and dam, lines was reported to be fully utilized. On and additional wells would intercept water the basis of hydrologic data, the area is now moving to the center of pumpage. favorable for development of additional supplies. Much exploratory and testing There are two other areas downstream work will be needed to determine the actual which may be capable of furnishing a safe quantity of water that might be developed. yield of several million gallons per day. The area over Pekin-Sankoty channel between Area IV includes the Tenmile Creek Peoria lock and dam and Pekin would re- alluvial fan and areas northward. There quire about five miles of pipeline including has been considerable test drilling and well a river crossing to make the water avail- testing in the southern end of this area, able at Peoria. The area in the bend of the which has revealed a large potential supply. river opposite Pekin has not been explored. The water has a high iron content which Its development would require about eight must be removed to make it satisfactory for miles of pipeline to Peoria and protection use. The area may be an intake area for of facilities against flood. recharge to the Sankoty and North fields. About nine miles of pipeline (including Area II is also within the limits of in a river crossing) would be required to make fluence of Peoria Industrial pumpage and the water available to existing users. additional development will increase the existing water shortage. Drilling in the Area V located north of Farm Creek is Pekin-Sankoty channel between Sankoty from general hydrologic principles not re- field and the Central field has been dis- garded as being favorable. Any develop appointing in that it has not been possible ment along the Illinois River bottoms to develop large capacity wells in the ma- would be within the range of influence of terials encountered. Total thickness of un- pumpage from the Central field. Where consolidated materials in the Kickapoo thick drift deposits (upland area) overlie Creek re-entrant is about 40 feet, thus def- water-bearing sands and gravels, the rate initely limiting the yield of any well, and of recharge is generally low. Although any development would intercept water now large quantities of water can often be moving to the center of pumpage. It is pumped from existing storage in such areas possible that constructing wells in the coarse for a few years, the safe annual yield is materials known to exist near the inter- much smaller than in a deposit of equal size section of Pekin-Sankoty buried channel and present Kickapoo Creek will permit which is recharged from close-by sources. operating economies, but this will not alle- The area does Warrant additional study, viate the existing shortage. particularly if a tentative decision is made to supply groundwater to Peoria from out- Area III is located in Pekin-Sankoty side areas. channel north of Sankoty field. The cone of recession of the Sankoty field extends Other Areas outside the Peoria metropoli- about one mile from the center of pumpage. tan district have not been thoroughly in- A similar development in similar materials vestigated but it is apparent that ground would require a minimum distance of two water supplies could be developed. 108 GROUNDWATER IN THE PEORIA REGION
Any such area, however, has to be studied REPLENISHMENT OF not only for its possible water yield, but also GROUNDWATER for the economic evaluation of its use. This It became apparent during this investiga latter phase is outside of the sphere of tion that replenishment of groundwater studies of the State Water Survey. resources by artificial means seemed the Additional areas used for groundwater most practical method of completely solving supplies must furnish, economically, the the existing groundwater problems. Some present deficit of about 6 mgd., plus water experimental work was done and much more for industrial expansion, or these areas may will be needed to overcome operating be incorporated in a regional plan for de- difficulties. There is an adequate source of centralization of industry and for the loca- reasonably good quality water available— tion of new industries. The econom- the Illinois River. ical considerations of bringing additional groundwater to the Peoria Industrial area NATURAL METHODS may naturally be changed by the demand Increased recharge by natural means was for water and by relative changes in con- ruled out on the basis of relative high cost struction costs. and lack of control. The field infiltration studies indicated that the natural recharge SUBSTITUTION OF SURFACE in the upland areas could be increased by contour farming, but there is as yet no WATER proof that increased recharge in the upland Surface water from the Illinois River area would materially increase the ground water supply at Peoria. Dredging in the can be and is being used for certain purposes Illinois River channel was ruled out be- where bacteriological purity, chemical qual- cause a 15-year record of dredging in the ity, and temperature are of minor impor- channel between Franklin Street bridge and tance. Temperature of the water is im- Peoria dam did not indicate much benefit portant for cooling and condensing pur to groundwater resources, and even if poses, and some industries use surface water benefits did occur there could be no con only when its temperature is below that of trol over possible bacterial contamination the groundwater. Certain industries, by or temperature of water recharged. installing equipment to handle larger volumes of warm surface water as com- ARTIFICIAL METHODS pared to smaller volumes of colder ground Artificial infiltration can be accomplished water, have reduced the drain on existing by several methods including (1) flooding groundwater supplies. Others could do the of suitable but otherwise unprepared land, same. It would require a plant-by-plant (2) infiltration pits which are specially pre- investigation to determine the practicability pared and maintained to recharge untreated of this method, and there is also a practical water, and (3) recharge wells through limit to the reduction in groundwater with- which only clean pure water can be put into drawal that could be obtained. existing aquifers. For many uses, both temperature and General land flooding is practicable only quality are of major importance. This re- where a very particular set of geographic, quires treatment of the raw water and also geologic, and hydrologic conditions occur limits use to periods when cold water can simultaneously over a fairly large area con- be obtained from the river. tiguous to the groundwater reservoir. The rate of infiltration is generally about one It appears that intermittent use or year- mgd. per acre in such areas. Such areas around use with treatment is not a com- are apparent in the Peoria-Pekin area, but plete Solution to the problem, although such none appear to be close enough to the Peoria usage can ease the existing Situation. Industrial field to be of value to that area. HYDROLOGY 109
Infiltration pits also require a special set space is available to last through the dry of natural conditions, but the conditions are season and (2) that conditions are favor- not as rigid as for general land flooding. able for a high percentage recovery of the A smaller area is required, as the rate of infiltrated water. Calculations from ground infiltration is about 20 mgd. per acre, but water contour maps show that on an aver- excavation of overburden (if any) to the age 250 square mile feet of gravels are top of clean (water-transmitting) sand and available for storage below elevation 440 gravel is necessary, and periodic removal of feet. To store 10 mgd. for six months on silt accumulations during use is required. a basis of 10 percent specific yield would The only water treatment required is require 86 square mile feet. This much chlorination. storage is available below an elevation of 423 feet. Recharge wells require the same careful construction that is used in pumped wells, There is little danger that this stored and often the same well can be used for water will be lost, even by outflow below both purposes—as a return well in certain the dam. The lowest river elevation below seasons and as a pumped well at other the Peoria dam is 430 feet, due to the effect of the LaGrange dam 77 miles below the times. In order to avoid well failure it is Peoria dam. At this elevation the average necessary to remove all solid and organic storage space is 125 square mile feet, or material and to stabilize chemically the more than that needed for the Peoria re- water before putting it into the well. Ex- quirements. perience in other areas indicates that even with water treatment, it is necessary to In conclusion, it appears that both infil rehabilitate the return wells from time to tration pits and return wells are feasible in the Peoria area, but too little is known of time. operating costs and difficulties to favor one Groundwater Storage Space.—Artificial over the other. Much additional large scale infiltration aims to store cold surface water experimental work is required before the Underground. To be effective it requires best method is known and it may be that (1) that sufficient Underground storage both will have a place in the Peoria area. PART 3
CHEMISTRY
BY
T. E. LARSON Head, Chemistry Sub-division
STATE WATER SURVEY CHAPTER 14
GENERAL
While the geologic and hydrologic studies to bacterial changes in nitrogen Compounds were in progress, water samples were col- that can take place in the samples during lected at many points in the Peoria-Pekin the time between sampling and analysis. district. Study of the results of these Sulfates were determined by the gravimetric analyses was carried on in liaison with the procedure. Methods were in accordance other parts of the work. with procedures in the Ninth Edition of Since it was found, by correlation, that A.P.H.A. Standard Methods of Water the water from a particular source is of Analysis. generally constant character, it became possible to interpret the analytical data to GLACIAL DEPOSITS show the origin of the waters obtained in The immediate Peoria-Pekin area offered each well field. Changes in character that no fixed reference values for the quality of occurred at any particular well were ac- water to be expected from any particular companied by relative changes in hydrostatic glacial deposit, because extraction and re pressure in the immediate vicinity as a re- charge during the history of well water use sult of both extraction and recharge. It in the immediate area have altered the com- was therefore necessary to consider rainfall, position of the available water in the forma- river elevations, and such pumpage records tions and continue to do so. and water level data as were available. To establish a working basis for compari- The study concerned the water quality son, well water samples were obtained from of the Illinois River and the industrial and the geologic formations in the region sur municipal well fields of Peoria, and also those of Peoria Heights, East Peoria, and rounding the area under study. Pekin. All available records on farm and In Part 1 it has been shown that a broad Community wells in the surrounding area buried Valley connected with the Mississippi within roughly a 25-mile radius were also River existed at one time about 20 miles included. With few exceptions only drift east of Peoria. Bedrock elevations range wells above the bedrock were examined from 300 to 750 feet MSL (Mean Sea which range in depth from about 50 to 300 Level datum). Ground surface ranges feet. Water from the bedrock is not con- from 440 to 850 feet MSL. This buried sidered in this report because it is highly rock valley is now filled with a preglacial or mineralized and is not a major water supply early glacial sand deposit (called Sankoty factor in the area. sand) to an elevation of about 500 feet MSL. This sand is also found in places ANALYTICAL METHODS along and under the present Illinois River The determinations made on the samples and at the base of another buried valley included Volumetric procedures for chloride, north and west of Peoria. alkalinity, calcium, magnesium, and total The Sankoty sand is covered almost uni- hardness, a colorimetric procedure for iron, formly by the Illinoian glacial till. The and the conductivity procedure for total latter was extensively cut by streams and mineral content. Nitrates were determined does not constitute a major source of water. on some samples because this constituent For the most part the Sankoty and Illinoian was found to be present in an appreciable formations are overlain by the deposits from concentration. This determination is not the Wisconsin glacial period. These Wis considered of quantitative significance due consin moraines and till-sheets are extensive [113] 114 GROUNDWATER IN THE PEORIA REGION and cover almost the whole area. There found only in discontinuous and lenticular has been considerable erosion along the pres- deposits in the Wisconsin drift, but the out ent Illinois River, and outwash deposits are wash deposits below the lower terrace along found here and as narrow fringes bordering the Illinois River are generally well strati- the moraines. These deposits are thickest fied and are therefore favorable areas for in these areas. For the most part water is groundwater development. CHAPTER 15
GEOLOGIC CORRELATION
CHEMICAL CHARACTER was consistently distinctive for waters from any formation. GLACIAL DEPOSITS ILLINOIS RIVER Water from the Sankoty formation was found to be invariably characterized by a Another factor considered in this study low sulfate content and by the presence of is the quality of the Illinois River water. appreciable concentrations of ammonia and There is a dam across the narrow Channel iron. All 66 samples of water from this of the river south of the industrial district, formation showed these waters to have a which maintains a minimum level of 440 sulfate content less than 7 ppm. The iron feet MSL. in the river and in Lake Peoria. content was invariably greater than 1.0 The quality of the river water (minimum ppm. and the ammonia up to 10 ppm. flow 4000 second-feet) is influenced not by the pool level but by the total flow and by Waters from the Wisconsin drift and the the Proportion of the total flow which glacial outwash deposits are characterized originated as diversion from Lake Michigan by the presence of appreciable sulfate con and as sewage from Chicago. centrations (greater than 10 ppm.). A The mineral quality of the Illinois River further distinction was apparent in the water is characterized by its hardness-sulfate nitrate content. Waters from glacial out ratio. In general, the hardness (as CaCO ) wash deposits and from outwash Valleys cut 3 varies linearly with the sulfate (SO ") in any of the lower formations almost al- 4 concentration. The total hardness varies ways had a high percentage of nitrate. from 182 to 352 ppm. and the total mineral Samples from 21 wells penetrating glacial content from 196 to 443 ppm. The Chlo outwash were found to contain 12 to 425 rides vary from 7 to 30 ppm. The nitrate ppm. nitrate. The iron content of these content is less than 15 ppm. The sulfate- samples was frequently but not always low hardness characteristic of the Illinois River and the sulfate content ranged from 40 to water is distinctively different from that of 207 ppm. Some wells in the Wisconsin Farm Creek water (fig. 45) and from any formation near the areas where the bedrock of the groundwaters in the area (figs. 48, crops out yield water of 600-1000 ppm. 50, 51, 53). sulfate. Waters from all 19 samples from lentic- BEDROCK ular sand deposits in the Wisconsin drift Below the drift, water can be and is ob- areas contained 0 to 1 ppm. ammonia, 1 to tained from the Pennsylvanian sandstones, 15 ppm. nitrates, and 15 to 102 ppm. sul the Keokuk-Burlington limestone, the Silu- fate. The iron content varied from 0.2 to rian dolomite, the Galena-Platteville dolo- 6 ppm. mite, and the St. Peter sandstone. Analyses The hardness and alkalinity of the of these waters are tabulated in table 9 samples from each formation were far from according to depth. distinctive, ranging from 200 to 400 ppm. Water from the Pennsylvanian formation and 300 to 450 ppm., respectively, for just below the drift is typified by analyses Sankoty water. For the Wisconsin and of waters from two wells located just west outwash waters, the hardness ranged from of Peoria. These waters are characterized 300 to 600 ppm. and the alkalinity from by a high mineral content, chiefly chloride, 200 to 500 ppm. Neither the hardness- the absence of sulfate, and the relatively low alkalinity nor the calcium-magnesium ratio hardness. [115] 116 GROUNDWATER IN THE PEORIA REGION
62° to 70° F. The most correct value is estimated to be 70° F. Water from the St. Peter sandstone at the Asylum well has a total mineral content of about 1600 ppm., a chloride concentra tion of about 300 ppm. and a sulfate con centration of 650 ppm. The total hard ness is about 300 ppm. The temperature has been reported as 77° and 78° F. One peculiarity has been noted in the rock wells. The Grant Street well in 1934 yielded water of quality typical for Galena- Platteville water at a depth greater than 1400 feet. Analyses in 1941 through 1945 have shown this water to contain a higher chloride concentration approaching that which is typical for Silurian water. Actual- ly in 1934 the presence of some Silurian water in this well was evidenced by the re ported odor of hydrogen sulfide which still persists. The increase in chloride has been quite large and may be an indication of partial bridging in the well between the Silurian and Galena-Platteville formations. The Peoria Mineral Company well now on the R. G. LeTourneau private farm, located on the east side of the Illinois River just north of East Peoria, has shown a consistently increasing chloride concentra tion and the samples collected in 1933 and 1941 were reported to have an odor of hydrogen sulfide. These data indicate that FIG. 45.—Relative character of Illinois River and Farm Creek water. at these wells the artesian head of the Galena-Platteville formation has receded to a point where it is below the non-pumping Water from wells in the Keokuk-Burling- level of the Silurian formation. thereby per- ton formation (320-757 feet depth) has an mitting the entrance of some Silurian water. exceptionally high mineral content (8000 ppm.), greater than that of any of the other At the Peoria State Hospital well the water is largely typical of St. Peter sand formations, and is characterized by a chlo stone quality when pumped at 200 gpm. but ride concentration of about 4500 ppm. The includes a high proportion of Silurian water sulfate concentration is absent or very low. when pumped at 600 gpm. Water from wells finished in the Silurian formation (774-1040 feet depth) is also TEMPERATURE highly mineralized (3500 ppm.) and is characterized by the presence of sufficient The temperature data have been analyzed hydrogen sulfide to produce an obnoxious with the following factors in mind. odor. The chloride content of this water 1. The ground temperature at the sur- is about 1500 ppm. and the hardness is face varies seasonally with air temperature. generally about 175 ppm. The temperature This Variation becomes less and less with of this water has been variously reported as increased depth to approximately 50 feet TABLE 9.—WELLS THAT PENETRATE BEDROCK
* Hydrogen sulfide present. ** Collected during drilling. 118 GROUNDWATER IN THE PEORIA REGION where the temperature should be equal to 6. At any particular well, the tempera or somewhat less than the average annual ture of the water measured at the pump dis- temperature which at Peoria is about 52° charged is also affected by the discharge F. The depth of 50± feet is approximate pressure or the change in pressure as the and will depend on the composition of the water passes through the tap. It can also materials above. The Variation in the be affected by friction at tight bearings or temperature of the ground above 50 feet by recirculation within the well if there is will have a definite lag behind the seasonal a hole in the pump bowls or column pipe. Variation in air temperature due to the heat The temperature of water pumped by means capacity of the ground. of air lift will of course not be representa- tive. 2. Below 50± feet the temperature steadily increases with increased depth, and Comparison of recorded temperatures below sea-level in this vicinity the rate is shows that the normal groundwater tem above 1° F. per 67 feet. The ground perature is 54°-56° F. This has been temperatures at elevations between sea-level established at the Meadowbrook Dairy, the and 50 feet below the ground surface vary Peoria Municipal Sanitarium wells, and at accordingly where a sea-level temperature of Schwab's Dairy well. The recorded tem 58-59° F. is estimated. peratures at the Allaire-Woodward and 3. Flowing groundwater has a pro- Muirson Label Company wells are in- nounced effect on the temperature at any fluenced by passage through elevated tanks depth. Recharge water warms or cools the and long pipelines in the building. At ground to a temperature between that of the Pekin the temperatures are somewhat high recharge water and that of the ground. because the water passes through about 25 This effect decreases with increasing dis- feet of 1-inch pipe before it reaches the tance between the point of recharge and the sampling point. point of sampling because the heat capacity At the Peoria Heights wells the tempera of the ground eventually absorbs the differ- tures are somewhat lower, possibly due to the ence in temperature. Increasing geologic fact that the wells are located in a shaded time, or strictly speaking, increasing the area on the east side of the bluffs. total quantity of water increases the distance The waters from the Power House well of temperature influence from the point of of the St. Francis Hospital, from Peoria rech arge. Heights wells Nos. 4 and 5, the Peoria 4. Chemical reactions taking place in and Water Works well No. 7, and the Creve between the ground and the water affect Coeur wells rarely display any appreciable the temperature depending on whether heat deviation from the normal groundwater is evolved or absorbed. The Solution of temperature. gases is always attended by the evolution of Figure 46 shows the recorded tempera heat, and the Solution of solids may be at tures at the American Distilling Company tended by the evolution or the absorption well, the new East Peoria city wells, and of heat. The Solution of 1 ppm. CaSO4 at three of the Hiram Walker (plant No. evolves 0.02 calories per liter. This is not 1) wells. This figure also shows the re of quantitative significance in groundwater corded temperature of the Illinois River studies. and the mean monthly air temperatures. It 5. Bacterial activity may also have an will be noted that the East Peoria wells effect on temperature. The conversion of are about 25 feet in depth. At a depth as elements of one Compound into another great as this the air temperature could hard- often evolves an appreciable amount of heat. ly cause the groundwater temperatures to For example, 1 ppm. NH4+ when con- vary from 46°-63° F. The chemical data, verted to NO3— evolves 5.8 calories per however, indicate with certainty (fig. 51) liter. Naturally a large portion of this that a large percentage of the water from heat is used for energy by the bacteria. these wells is obtained indirectly from Farm CHEMISTRY 119
FIG. 46.—Recorded temperatures of Illinois River water and of Peoria, East Peoria, and Pekin well waters.
Creek. The temperature variations are tion. The effect of steam lines and the therefore attributed to local recharge. presence of buildings in this vicinity appears The Hiram Walker wells are about 50 to be great. feet in depth. The No. 2 well is dosest to No satisfactory explanation is offered for the river, No. 5 the farthest, and No. 3 al- the apparent increased uniformity of the most as far. The No. 2 well-water tempera temperature of the American Distilling ture varies seasonally with about a three Company well water from June 1943 to months lag behind the Variation in the December 1945. Illinois River temperature and about a four months lag behind the Variation in the mean The temperatures at the Hotel Pere monthly air temperature. It is interesting Marquette 76-foot well are higher than to note that seasonal Variation in the tem normal, probably due to its location in the perature of the No. 3 well water is not as steam district. The Caterpillar Tractor great and that the general temperature has Company 66-foot well No. 9 also yields decreased since 1940. Also the tempera water of high temperature, presumably due ture of the No. 5 well water (62° F.) is to its location on grounds occupied by build appreciably higher and has but little Varia ings heated from a central steam plant. CHAPTER 16
HYDROLOGIC INTERPRETATION
METHOD OF APPROACH and Sankoty water with a small quantity of Illinois River water. However, if this It became evident early in the investiga- were true, first, each pattern should be con- tion that each well or group of wells in a fined within a narrow band limited by the particular well field required a study sepa hypothetical mixtures of these two waters. rate and distinct from the others. Each was Actually the hardness variations overhang influenced by local geological conditions and the band on both sides, indicating the local pumpage. presence of a considerable proportion of The greatest variations in analyses of water from other sources. Second, several samples from individual wells were found tests have shown that the Saturation index to occur in the sulfate and hardness concen- of Sankoty water is positive, indicating trations and it was found that the relative Saturation with respect to calcium carbo- concentrations of these two constituents nate. Third, waters from the Sankoty for- served as excellent bases for interpretation. mation invariably contain more than 1 ppm. Variations were also noted in the tempera- iron. No indication of iron has been given ture and in the alkalinity of the water from in the analyses of the water from these wells. some wells. The alkalinity variations Sup Water from the American Distilling Com port the interpretation that there is some pany well shows only four samples con- infiltration of river water into the water- taining more than 0.1 ppm. iron out of 72 bearing gravel. Estimates of the sources samples. These considerations indicate that of the water at any well are based on the the Pekin field derives water from a major general character of the waters, as exempli- source other than the Sankoty and the Wis fied graphically by patterns showing the consin formations. hardness-sulfate relationships, rather than on the month-to-month variations. This The Illinois River is a possible third procedure is necessary due to the rapid source of water. Since this water has a changes that have been found to take place negative Saturation index, it could readily from day to day and even from hour to dissolve additional calcium and magnesium. hour. On the basis that all sodium and potas- sium salts and all salts of calcium and magnesium other than dolomite are very INTERPRETATION OF DATA soluble when compared to the solubility of dolomite, it was assumed that over a long PEKIN FIELD period of time practically all of the soluble This field is located on the east side of salts in the ground formation under and the Illinois River south of Peoria and down- near the river have been leached out, where- stream from the dam. It includes the as much of the relatively insoluble dolomite Pekin city wells and the industrial wells still remains. With this consideration in southwest of Pekin. Figure 47 shows the mind it was then postulated that if Illinois water quality patterns for several of these River water entered the ground, its chemi- wells and for the three possible sources. It cal character would be altered only by the is apparent that the quality from each well Solution of dolomite, thereby increasing the varies considerably. In view of the charac hardness and alkalinity by equal but not ter identifications discussed so far, two in- predictable amounts. terpretations could be made. Therefore, the pattern for the Common It may be reasoned that the patterns rep- wealth Edison Powerton Station well No. resent mixtures of Wisconsin drift water 9 is interpreted to represent mixtures of [120] CHEMISTRY 121
FIG. 47.—Character patterns of waters from Industrial wells south of Pekin.
Sankoty water (no sulfate) with Illinois analyses of samples of water from their River water and possibly some Wisconsin wells. At no time were analyses found to or outwash water. be identical in quality or character to The patterns for the Powerton Station Illinois River water, but with the aid of the wells No. 4 and No. 1, and the Corn Prod assumptions concerning the possible altera- ucts Company wells Nos. 1, 3, and 2 are tion of river water quality, an equation was interpreted to show these waters to be pre- developed to indicate the percentage of dominantly mixtures containing progres- water originally from the river in each sively greater proportions of Wisconsin or sample. outwash waters with water of Illinois River The character of Illinois River water was origin. Further consideration of the rela defined by the general relationship between tive location of these wells with respect to the hardness and sulfate content and the the Illinois River and to the Channels to the hardness and alkalinity (figs. 45, 48).
Powerton Station and of the relative pump- Hardness = 2.86 (SO4) - 20 age from these wells and other wells in the Hardness = 1.85 (Alk.) - 50 immediate district confirms and explains the Alkalinity = 1.55 (SO4) + 16 Interpretation of the analytical data. On passing through the ground toward In 1943, during and after a severe flood, the well this water would dissolve some the Corn Products Company made frequent dolomite and thereby increase in hardness 122 GROUNDWATER IN THE PEORIA REGION
FIG. 48.—Character of Illinois River water. and alkalinity by "Z" ppm. but the sulfate The groundwater is exemplified by a hard content would be unaltered. If the sulfate, ness of 610 ppm., an alkalinity of 325 ppm., alkalinity, and hardness of the transferred and a sulfate content of 600 ppm. and altered river water are called A, B, and 100 SO4* = x A + (100 - x) 600 C then, 100 Alk.* = x B + (100 - x) 325
A = SO4 100 Hd.* = x C + (100 - x) 610 B = Alk. + Z B = 36 + C - 1.31 A C = Hd. + Z and, B = 1.55 A + 16 + (C - (2.86 A - 20)) = For the purpose of illustration Table 10 36 + C - 1.31 A indicates the data used for the calculation If the groundwater quality is arbitrarily of the percentage of river water obtained exemplified by the analysis showing the from the Corn Products Refining Company greatest hardness and sulfate content then wells on June 10, 1943. the percentage (x) of river water in any The assumption of a definite point value sample can be calculated from the S04*, for groundwater and of a straight-line re- Alk.* and Hd.* of any particular sample. lationship for hardness-sulfate and hard- CHEMISTRY 123
FIG. 49.—Calculated percentage of Illinois River water entering Com Prod ucts Company wells.
TABLE 10.—PERCENTAGE OF RIVER WATER FROM return to character indicative of river water CORN PRODUCTS REFINING COMPANY WELLS origin. This set of interpretations is typical of the approach at the other well fields. Sulfate Alkalinity Hardness River Well water ppm. ppm. ppm. percent EAST PEORIA FIELD
1 213 281 465 87 In East Peoria, the city wells are located between Farm Creek and a small branch 2 551 336 585 6 tributary. It is evident from figure 50 that 3 348 292 525 60 a large percentage of the water obtained from these wells is indirectly from Farm Creek. The old wells appear to contain a ness-alkalinity for river water are actually greater concentration of water from Farm rough approximations and involve a maxi- Creek than the new wells. The tempera- mum possible error of about 50 percent, but ture of the water from these city wells of it was found that reasonable deviations from 25-foot depth varies seasonally from 46° these groundwater values and river charac- to 63° F. ter relationships did not alter the trend of At the Caterpillar Tractor Company the results shown in figure 49. considerable Variation in quality occurs from The data are interpreted to indicate that one well to another. Figure 50 shows the the heavy rain accompanying the flood general character of the water obtained period recharged the groundwater supply from well No. 9 over a period of five years and permitted a high percentage of ground and from each of the other wells on two water to be pumped from the wells for a specific dates. It appears that water ex- temporary period of about one month after ceptionally high in sulfates is obtained from the flood period. This was followed by a the Wisconsin drift at the bluffs to the south 124 GROUNDWATER IN THE PEORIA REGION
FIG. 50.—Character patterns from wells in East Peoria. as exemplified by the character of the water The Muirson Label Company well No. at the Caterpillar well No. 15. 3 (fig. 51) shows a considerable Variation in quality because of its proximity to all SANKOTY FIELD three of the recharge or inflow sources. In the Sankoty field located north of The pumpage from this well (0.1 MGD.) Peoria Heights about three miles north of and from the Minneapolis-Moline Com the main pumping Station of the Peoria pany well (0.001 MGD.) is low but the Water Works Company, the quantity of quality is greatly influenced by the pump water extracted for the city supplies is such age in the nearby heavy producing area. that approximately three months pumping would completely dewater the formation in Peoria Water Works well No. 7, which the immediate area of the wells in this field, is perhaps at the center of the greatest if there were no water entering from sur- amount of extraction (fig. 51), also appears rounding areas and no recharge. to be centered in the ranges of quality ob- CHEMISTRY 125
FIG. 51.—Character patterns from wells in Sankoty field. tained from the three sources. The quality with regard to the sulfate and hardness con- appears to be predominantly on the side centrations. Typical patterns for the waters of typical Sankoty water (zero sulfate) obtained in this field are compared with rather than on the side of Wisconsin drift possible recharge waters. or the Illinois River water. The tempera- The quality of these waters varies from ture is predominantly about 54° F. but that of typical original Sankoty formation occasionally varies to 53° and 58° F. water such as that found in Peoria Heights The quality of the water from each of well No. 4 and in the Peoria Municipal the wells varies considerably and at this Sanitarium well (located near the buried field no clear distinct interpretation could valley northwest of Peoria) to that of be made. However, here again the varia- Illinois River water, which contains an tions in quality for each particular well are appreciable sulfate concentration. In gen- limited to a specific or characteristic pattern eral, the hardness and the sulfate concen- 126 GROUNDWATER IN THE PEORIA REGION
FIG. 52.—Sampling data from Sankoty field. trations are not as great as those found in this field in June 1945. The data collected certain samples from Peoria Heights wells are shown in fig. 52. Unfortunately, the Nos. 1 and 2 at the bluffs on the south side Operation of the wells at this time did not of the heavy producing area. permit sufEcient sampling to establish any These latter wells by virtue of their definite conclusions other than that con proximity to the bluffs often appear to ob- siderable Variation in quality occurs from tain water having a considerable proportion day to day. of Wisconsin drift water of relatively high hardness and sulfate. PEORIA INDUSTRIAL FIELD It appears that water enters the heavy At the Hiram Walker plant (fig. 53) in producing area of the Sankoty field (Peoria the industrial field, the records of analyses Heights No. 5, Peoria Water Works Nos. as determined by Hiram Walker and Sons 7, 9, 10, 11, 12 and 13) from the Wisconsin are interpreted to show that much of the drift, from the underlying Sankoty sand water obtained from the No. 2 well, which and possibly from the Illinois River. is closest to the river, has come indirectly An attempt was made to obtain further from the river (solid pattern), and that information by daily sampling of wells in only after the high rainfall periods in 1942 CHEMISTRY 127
FIG. 53.—Character patterns of waters from Peoria Industrial field. and 1943 was an appreciable amount of these incidentally appear largely typical in groundwater (high sulfate) obtained (ex- character of waters from the glacial out- tended dotted pattern) at this well. wash from the northwest. In this well field the relative patterns of Third, the Sanitary District well, which water character from several wells are in- is closer to the river, yields water of lower terpreted to indicate the sources of water ob sulfates, indicating a large proportion of its tained from these wells. source to be from the river. First, the Hiram Walker well No. 2 appears to obtain much of its water from Fourth, spot samples at other wells show the river, whereas No. 7, further from the greater amounts of river water origin to be river, constantly yields water of a greater present at the location of the wells closer to sulfate content. the river. Of corresponding interest is the Second, the Schwab Dairy and the new fact that the wells showing a high river Dodge Street well waters are almost identi- water percentage are not the heavy produc- cal, and by virtue of a high nitrate content ing wells in this field. 128 GROUNDWATER IN THE PEORIA REGION
DISCUSSION ground at each field, but do indicate that it did to a variable extent, depending on the Some question has been raised concerning location of the well. the extent to which river water may enter Overall it is estimated that some 34 per the groundwater formations. This question cent of the estimated pumpage of the area is based on the fact that the river bottom exclusive of Sankoty field is of river origin. above the dam is covered with a silt deposit The 11 mgd. pumped in the Pekin field of an estimated average thickness of 10 below the dam derives some 73 percent of feet and a maximum recorded thickness of its water from the river. Of the 37 mgd. 25 feet. It is conceivable that this silt de pumped in the Peoria industrial and the posit (having only about 12 percent water East Peoria fields, only 14 percent is esti content) may act as a relatively impervious mated to be of river origin. Ten of the 14 barrier to the transfer of river water. The percent is estimated to be from Farm Creek. interpretations, however, do not indicate No estimate is made on the percentage at where or how river water entered the Sankoty field.