Ground-water Resources Of DuPage County, Illinois

GROUND-WATER RESOURCES OF DUPAGE COUNTY, ILLINOISARTHUR J. ZEIZEL, WILLIAM C. WALTON,ROBERT T. SASMAN, and THOMAS A. PRICKETTABSTRACTA rapidly increasing development of ground-water resources in DuPage County, Illinois,has resulted from the municipal and industrial growth in the Chicago metropolitan region.Evaluation of the ground-water resources of DuPage County provides a basis for theirdevelopment and management.Ground-water supplies are withdrawn from four principal geohydrologic units: 1) glacialdrift aquifers, 2) Silurian dolomite aquifer, 3) Cambrian-Ordovician aquifer, and 4) theMt. Simon aquifer. The glacial drift and Silurian dolomite aquifers receive recharge chieflyfrom precipitation that falls within the county limits. Relatively impermeable shales of theMaquoketa Formation separate these aquifers from the deeper Cambrian-Ordovician aquifer.Eecharge to the Cambrian-Ordovician aquifer occurs in the areas of Kane, McHenry, Kendall,Boone, and DeKalb Counties where the Maquoketa Formation is appreciably dolomitic, rela tively thin, or absent. The water moves southeastward from these recharge areas through theaquifer toward a deep cone of depression centered near Summit in Cook County.The total potential yield of the glacial drift and Silurian dolomite aquifers is calculatedto be 41 million gallons per day ( m g d ) ; the calculated potential yield of the Silurian dolomiteaquifer (38 mgd) is limited by recharge. Full development of the underlying Silurian dolomiteaquifer is assumed in estimating the potential yield of the glacial drift aquifers (3 mgd),and the yield of the glacial drift aquifers is considered as supplemental to the yield of theSilurian dolomite aquifer. Practical sustained yields of the deeper Cambrian-Ordovicianand Mt. Simon aquifers are calculated to be 4.3 mgd and 2.1 mgd respectively.Water levels in wells in the Cambrian-Ordovician aquifer in some areas have declinedas much as 635 feet since 1864, and the average decline over the county during the 96-yearperiod (1864 to 1960) was about 480 feet. Total withdrawals from the Cambrian-Ordovicianand Mt. Simon aquifers in 1960 (8.8 mgd) exceeded the calculated total practical sustainedyield of these aquifers (6.4 m g d ) .The Silurian dolomite aquifer is the most heavily developed source of ground water inDuPage County and yielded 68 percent of the 29.3 mgd pumped from all aquifers in 1960.The calculated practical sustained yield of this aquifer (35 mgd) exceeded total withdrawalsin 1960 and nonpumping water levels were not critical in any pumping center in the county.Extrapolation of pumpage graphs shows that the practical sustained yields of some pumpingcenters will be exceeded within 2 to 5 years and the practical sustained yields of all pumping .centers will be exceeded by 1985. Extrapolation of the pumpage growth curve for the countyshows that total ground-water withdrawals from wells will exceed the potential yield of theSilurian dolomite aquifer by about 1977.INTRODUCTIONof water levels in the deeper Cambrian-Ordovician aqui fer. The maps, data, and interpretations presentedprovide a basis for water-resource planning and a guideto the development and conservation of ground waterin the county.Detailed study in DuPage County was begun in 1957as part of a research program of the State GeologicalSurvey on geologic factors controlling ground water inthe Silurian dolomite aquifer in northeastern Illinois.The need for an evaluation of the ground-water resourcesof DuPage County was recognized in 1959 and coopera tive investigation by the State Geological Survey andthe State Water Survey was initiated. The State WaterSurvey collected data on water levels, pumpage, mineralPURPOSE AND SCOPEThis report presents a quantitative evaluation of theground-water resources of DuPage County, Illinois, andwas prepared cooperatively by the Illinois State Geo logical Survey and the Illinois State Water Survey.The geohydrologic characteristics of the ground-waterreservoir beneath the county are given along with ananalysis of past, present, and probable future develop ment of the ground-water resources. Special attentionis given to the Silurian dolomite aquifer and the associ ated glacial drift aquifers because of their potential assources of ground water. The importance of these aqui fers is emphasized by the rapidly increasing demandsfor water supply and the widespread continuing decline[7]

8DUPAGECOUNTYGROUND-WATERquality of water, and well tests. Well logs, drillingsamples, geophysical logs, and other geologic informa tion were provided by the State Geological Survey.PREVIOUS REPORTSGeneral information on the ground-water resourcesof DuPage County is included in reports on: The Ar tesian Waters in Northeastern Illinois (Anderson, 1919),The Groundwater Possibilities in Northeastern Illinois(Bergstrom et al., 1955), and Preliminary Report onGround-Water Resources of the Chicago Region, Illinois(Suter et al., 1959). Other published and unpublishedreports which contain information on the water re sources and the geology of the county are listed in theSelected References at the end of this report.W E L L NUMBERING SYSTEMThe well numbering system used in this report isbased on the location of the well and on the system ofrectangular surveys of the U. S. Government for identi fication.The well number has five parts: county abbreviation,township, range, section, and coordinates (number andletter) that give location within the section. Sectionsare divided into one-eighth mile squares with eachsquare containing 10 acres. A normal section of onesquare mile contains eight rows of eighth-mile squares:an odd-size section has more or fewer rows. Squares arenumbered from east to west and lettered from southto north starting at the southeast corner as illustrated:DuPage CountyT39N, R9E,sec. 30The well number of the well shown is DUP 39N9E30.6f. When more than one well is in a 10-acre squarethey are identified by arabic numbers after the lowercase letter in the well number.ACKNOWLEDGMENTSThe basic geologic and hydrologic data upon whichthis report depends were provided through the coopera tion of many county, municipal, and industrial officials,RESOURCESengineers, water-well contractors, and well owners. Spe cial thanks are due Orville L. Meyer, former ChiefEngineer of the DuPage County Health Department,for the many valuable logs of water wells made avail able during the investigation.The U. S. Geological Survey supplied logs, hydrographs of wells, and pumping test data from ArgonneNational Laboratory and arranged for the loan of thedeep-well current meter used in the geophysical investi gation. The Illinois Division of Waterways installedand furnished data from stream gages.The geological and geophysical studies incorporatedin this report were conducted by the State GeologicalSurvey. Discussion of the units below the MaquoketaFormation has been modified for DuPage County fromCooperative Ground-Water Report 1 (Suter et al., 1959).The hydrologic and water chemistry studies were madeby the State Water Survey.Arthur J. Zeizel, of the State Geological Survey, wasresponsible for the processing and analysis of the geo logic and geophysical data and assisted in geohydrologicinterpretations. The authors of the State Water Surveyparticipated in the following manner: William C. Wal ton supervised computation and analysis of the hydrologic and chemical data and assisted in geohydrologicinterpretations; Robert T. Sasman collected, processed,and analyzed water level and pumpage data; Thomas A.Prickett processed and aided in the analysis of basichydrologic data, made most of the hydrologic computa tions, and assisted in geohydrologic interpretations.Many present and former members of both agencieshave assisted in the preparation of the report and inthe collection and processing of data. Among these areGeorge B. Maxe'y, James E. Hackett, Robert E. Berg strom, Grover H. Emrich, Francis Wobber, Lowell A.Reed, and Richard Cannon of the staff of the GeologicalSurvey and Harmon F. Smith, Jacob S. Randall, Rich ard J. Schicht, George E. Reitz, William H. Baker,Sandor Csallany, Robert R. Russell, and W J Woodof the Engineering staff of the State Water Survey.The chemical analyses of water from wells were madeby the Chemistry Section of the Water Survey. Sectionson climate and statistical analysis of geologic controlswere prepared, in large part, by Stanley A. Changnonand James C. Neill, respectively, both of the WaterSurvey.GEOGRAPHYLOCATION AND GENERAL F EATURESDuPage County is in the northeastern part of Illinois(fig. 1). It is about 18 miles square, has an area of 331square miles, and includes all of townships 38 to 40north, ranges 9 to 11 east, and part of township 37north, range 11 east (figs. 2 and 3). It is bounded onthe north and east by Cook County, which contains thecity of Chicago, on the south by Will County, and onthe west by Kane County. Quadrangle topographicmaps, published by the U. S. Geological Survey, coverthe area (pl. 1, in pocket).In 1950 about 60 percent of the land in DuPage

CLIMATEFig. 1. Location of DuPage County.County was in farms; however, expansion in suburbandevelopment from the city of Chicago has resulted inrapid municipal and industrial growth. The principalcommunities are along the east-west lines of the Chicagoand Northwestern and the Chicago, Burlington, andQuincy Railroads. Wheaton, with a population of about24,000, is the county seat. Argonne National Laboratoryencompasses about five square miles in the southeasternpart of the county.All the communities in DuPage County obtain theirwater supplies from ground water. Water required bythe industries for processing and cooling and water forrural and residential use is also obtained from wells.T O P O G R A P H Y A N D DRAINAGEDuPage County lies in the Great Lake and TillPlains sections of the Central Lowland Province, a gla ciated lowland that extends from the AppalachianPlateau on the east to the Great Plains of Kansas,Nebraska, and the Dakotas on the west. All of thecounty is in the Wheaton morainal country subdivisionof the Great Lake section except the southwestern part,which is in the Bloomington ridged plain subdivisionof the Till Plains section (Leighton et al., 1948, p. 18).The county is characterized by low, broad, glacialmoraines with numerous swamps and undrained areas.The numerous undrained areas in the moderately dis sected upland are characteristic of young, poorly-inte grated drainage systems in glaciated regions. Bedrockis exposed and affects surface features only locally.The west and east branches of the DuPage River andSalt Creek flow generally south. The Des Plaines Riveris the southeastern county boundary and flows south 9west. The valleys of the two branches of the DuPageRiver and Salt Creek originated during depositionof glacial materials and have not been significantlymodified since. In a few places the rivers transect highmorainal ridges; for example, the West Branch of theDuPage River west of Winfield. The southern reachesof the Bast Branch of the DuPage River in DuPageCounty are above a bedrock valley that has been par tially filled.The Des Plaines River flows in a valley formed bydissection of a bedrock divide by an earlier river. Thefloor and the lower slopes of the valley walls are cutin bedrock. This valley was an outlet channel Of glacialLake Chicago and later carried discharge from otherglacially ponded waters in the Superior, Huron, Brie,and Michigan basins (Bretz, 1955, p. 33). The naturaldrainage of the Des Plaines River has been altered byman by construction of the Illinois and Michigan Canaland the Chicago Sanitary and Ship Canal.In most places, relief in the upland is less than 50feet. Relief is greater along major valleys borderedby morainal deposits and often reaches a maximum ofabout 90 feet. The upland surface rises graduallytoward the northwest and attains an elevation of about830 feet near the northwest corner of the county. Thelowest elevation is 585 feet in the Des Plaines RiverValley, thereby giving a maximum relief of about 245feet.CLIMATEPrecipitation, evapotranspiration, and temperatureare the climatic factors directly related to the avail ability, storage, movement, and withdrawal of groundwater. Temperature influences evapotranspiration andinfiltration and also affects the rate and distribution ofground-water withdrawal.The climate of DuPage County is a humid continentaltype with cold, moderately dry winters and warm tohot, wet summers. Some minor effects on the climateare produced by Lake Michigan, but these are generallyminimal, especially in regard to the temperature. Thelake does affect the weather conditions sufficiently toproduce approximately 1 to 1.5 inches of the averageannual precipitation of 34.2 inches that occurs in thecounty.Sixty percent of the average annual precipitationoccurs during the warmer half-year, April-September.About 40 percent of the average annual precipitationcomes from thunderstorms and about 10 percent isderived from snowfall. Normally June is the wettestmonth and February the driest month. The averageannual and monthly precipitation values for DuPageCounty are shown in table 1. Observations of waterlevels in DuPage County indicate that, in general, recharge from precipitation to the ground-water reservoir

10DUPAGE COUNTY GROUND-WATER RESOURCESFig. 2. Principal geographic features of DuPage County.

WELL LOCATIONSFig. 3. Location of selected wells and test borings.11

12DUPAGE COUNTY GROUND-WATER RESOURCESTable 1. Monthly and Annual Climatic Data(based on 1936-1960 gustSeptemberOctoberNovemberDecemberAnnualAverMean age pretempera- cipitaturetion( eatestprecipitationamount(in)year5.55 19603.22 19577.23 19489.42 19466.97 194510.65 19398.00 19576.38 193710.27 193610.87. 19543.56 19454.32 , 193645.58 42i95019561946195319401952193919431956rate of population growth shows a marked increasewhen contrasted to the 5,112 persons per year rate ofincrease during the previous 10 years (fig. 32.2is greatest in the spring, that is, after the ground thawsand before vigorous plant growth begins.On the average, 120 days per year have measurableprecipitation. Daily precipitation equaling or exceeding0.25 inch can be expected on 40 days per year on theaverage. The average monthly and annual snowfallvalues for the county are shown in table 1. In Decem ber and January, the months of greatest average snowfall, approximately 45 percent of the average monthlyprecipitation is derived from snowfall.The length of the growing season also influencesrecharge because plants intercept most of the watersoaking into the soil zone during this period. The grow ing season for the Chicago region ranges from 160 to 170days. Dates of beginning and end of the growingseason (the period between killing frosts) most com monly occur in late April or early May and in October,respectively.As shown in table 1 there is a wide variation in meantemperature throughout the year. July on the averageis the warmest month and January normally is thecoldest month. There are no significant variations inthe mean monthly and annual temperatures within thecounty. On the average, 90 days per year have dailymean temperatures below freezing. Temperatures equalto or greater than 90 degrees occur 25 days per yearon the average. During the period of frequent andpersistent daily temperatures below freezing, little orno recharge to the ground-water reservoir occurs be cause the ground is frozen and relatively impermeable.POPULATIONFigures released by the U. S. Bureau of the Censusshow that during the interval 1950 to 1960 the popula tion of DuPage County increased from 154,599 to313,459. These figures represent a gain of 102.8 percentand a rate of increase of 15,886 persons per year. ThisFig. 4. Growth of population in DuPage County.As would be expected because of the proximity ofDuPage County to the city of Chicago, urban popula tion during 1950 to 1960 increased considerably overrural population (127.9 versus 22.7 percent), and today85.5 percent of the total population of the county isin urban areas.Demand for water supplies and pumpage rates closelyfollow these trends (compare figs. 4 and 27), and thedistribution of the population in the county influencesground-water use. Thus, urban development results inareas of concentrated pumpage. The population of thetownships in DuPage County is given in table 2.ECONOMYThe quantity and quality of the ground-water sup plies of DuPage County have been, up to the present,adequate to meet the demands of what was formerlylargely an agricultural economy.Favorable soil, topography, annual rainfall, temper ature range, and length of growing season have resultedin the production of a wide variety of crops. Crops

BEDROCK STRATIGRAPHYTable 2. Population of DuPage County by rs 3,480154,599313,459Township1960grown are chiefly feed crops for the dairy and livestockfarms. The metropolitan area of Chicago creates thedemand for dairy products, fresh vegetables, flowers,plants, and eggs.A shift in the economy from agriculture to manufacturing has been taking place as the suburban areasgrow. This shift is evident by comparison of the statistics available from the U. S. Census of Manufacturers(1954, 1958) and the U. S. Census of Agriculture (1950,1959).The number of farms and the percentage of the landin farms have decreased rapidly since 1950. The 776farms in 1959 represent a decrease of 54 percent. Inthis nine-year period, the percentage of land in farmshas decreased 12.3 percent to 48.3 percent. Eliminationand incorporation of the smaller, marginal farms isshown by the increase in the average size of farms(131.0 acres in 1959 versus 90.0 in 1950). Dairy farms13predominate in DuPage County and in 1950 they madeup about 18 percent of the farms. Livestock and cashgrain farms ranked second and third. Farm water supplies are obtained from ground water. Only five acreswere irrigated in 1959 in contrast to 63 acres in 1950.The number of business establishments increase

72 Elevation of piezometric surface of Cambrian-Ordovician aquifer, . October 1960 75 73 Decline of artesian pressure in Cambrian-Ordovician aquifer, 1864-1960 76 74 Water levels in deep sandstone wells at Villa Park, Elmhurst, and Bensenville, 1945-1960 76 75 Hardness of water from the Silurian dolomite aquifer 79