Planning a Domestic Groundwater Supply System

ISWS-73-CIR116 Circular 116 STATE OF ILLINOlS DEPARTMENT OF REGISTRATION AND EDUCATION

by JAMES P. GIBB

ILLINOIS STATE WATER SURVEY URBANA 1973 CONTENTS PAGE Introduction ...... 1 Planning summary ...... 1 Water requirements ...... 2 Gathering data ...... 3 Occurrence and movement of groundwater ...... 3 Availability of groundwater ...... 5 Types of wells and pumps ...... 7 Wells ...... 7 Pumps ...... 7 Water quality ...... 9 References ...... 11 Appendix A – Information requests ...... 12 Appendix B – Public health offices ...... 13 Printed by authority of the State of Illinois – Ch. 127, IRS, Par. 58.29 (12-73-3000) (Second Printing 5-78-3000) PLANNING A DOMESTIC GROUNDWATER SUPPLY SYSTEM

by James P. Gibb

Introduction Groundwater is used as the source for almost all individual farm and domestic water supply systems in Illinois. Approximately 88 percent of the state’s public water supplies also use groundwater as a source of supply. Altogether, groundwater supplies serve about 3,700,000 persons in the state, or approximately 34 percent of the total population. A public water supply system usually is and recommended methods for a prospective developed with the assistance of city and owner of a domestic well to determine his consulting engineers, the State Geological water requirements and to gather meaningful Survey, the State Water Survey, and the En- information for planning his supply are pre- vironmental Protection Agency. Individuals sented. wishing to develop a private groundwater Also included are brief discussions on the supply can seldom afford the advice of a occurrence, movement, availability, and consulting engineer, but should take advan- quality of groundwater in Illinois, and the tage of the free services available to them commonly used types of wells and pumps. from the Illinois Department of Public More detailed discussions on well develop- Health, the State Geological Survey, and ment, pump installation, and water quality our organization. and treatment of domestic and farm water Nearly 700 requests for information con- supply systems are presented in Water Survey cerning groundwater conditions in specific Circulars 117 and 118 (see References). locations of Illinois are answered yearly by This study is part of a continuing program the Illinois State Water Survey. Approx- of water-resource investigations being con- imately 40 percent of these requests are ducted by the Illinois State Water Survey from individuals seeking advice on locating, under the general direction of Dr. William C. developing, or treating home or farm ground- Ackermann, Chief, and John B. Stall, Head water supplies. of the Hydrology Section. The report was Many of these requests are answered with prepared under the direct guidance of letter-type reports prepared jointly by the William H. Walker. State Water Survey and State Geological Sur- vey from available geohydrologic data in their basic record files. In many cases, the use of Planning Summary this information on groundwater and geologic The successful development of a farm or conditions at a specific site has saved con- domestic water supply system depends most siderable time, effort, and money in well con- heavily on the available resources at the struction. However, several thousand wells location of interest. As would be expected, are constructed each year without the use in areas where water is plentiful and easily of such information. obtained, little difficulty is encountered and This circular presents basic information the importance of preplanning is minimized. needed to plan and develop a domestic However, in areas where water is scarce or groundwater supply. A logical step-by-step difficult to obtain, careful planning becomes planning summary is outlined. Accepted more important and should be undertaken

1 before any development attempts are made. satisfy peak demand periods occurring each Suggested steps in planning are as follows: day. A minimum amount of water to fight small fires also may be desirable but 1) Determine your water requirements generally is not considered a necessity for 2) Obtain all available information on the small farm and domestic systems. water resources in your area — a) Ask for written reports on the Studies conducted on water consumption availability of groundwater in your in Illinois by the Farmers Home Adminis- area from the State Water Survey and tration and the Water Survey indicate that State Geological Survey 35 gallons per day per person is a reasonable (see appendix A) daily water consumption value to assume b) Make an inventory of wells near for most farm and domestic water supplies. your property (obtain depth, yield, However, for planning purposes it is sug- and water quality information) gested that 50 gallons per day per person c) Talk with several well drillers who be used. Additional daily water needs for are experienced in the type of well watering livestock also can be estimated construction required from the data in table 1. 3) Compare the economics of possible alternatives Table 1. Daily Water Requirements 4) After the well construction is scheduled, Per producing milk cow 35 gallons (includes allowance for dairy barn contact the State Department of Public and milk-house sanitation) Health to see if an inspector can visit Per beef cow 15 gallons the well site during construction Per horse or mule 15 gallons Per 100 chickens 10 gallons In many instances a clear-cut solution to Per hog 5 gallons obtaining a desired water supply may not be Per sheep 3 gallons obvious. In cases of this type, a great deal of responsibility is shifted to the driller you Peak water demand periods for farm and employ. It is therefore most important that domestic uses seldom occur at the same time. you employ a competent driller experienced Required flow rates for various modern in the type of work that will be required. agricultural and home conveniences, such as To better acquaint yourself with the prob- milking machines, dishwashers, washing ma- lems you and your driller face in developing chines, and water softeners, normally do not a farm or domestic water supply system, exceed 5 or 10 gallons per minute (gpm). please ask for Circulars 117 and 118. These It is therefore seldom necessary to equip a publications give more details on wells and farm or domestic well with a pump larger drilling methods, pumps and pumping sys- than 10 gpm. tems, and water quality and treatment for When a farm or domestic water supply small water supplies. They also provide system is being planned, it is most important guides for estimating the various costs to think in terms of daily water needs in- involved. stead of the more common concept of well yields (gpm). As previously suggested, 50 gallons per day per person is a reasonable Water Requirements value to use, and for a family of 4, this A properly designed water system should suggests that 200 gallons per day would be provide adequate water to meet daily needs desirable. throughout the year and also should be If 25 head of beef cattle are to be watered, capable of delivering water fast enough to another 375 gallons (15 gal/head X 25 head)

2 or a total of 575 gallons per day would be water conditions in your area. Questions required. should be asked concerning the types of If a 10-gpm well is used to produce this wells they drill, the methods used in con- quantity of water, it would need to be pumped struction, and the prices they charge. The for only about 58 minutes each day. The selection of a competent well driller equip- same 575 gallons per day could be obtained ped and experienced for the particular type from a 1-gpm well (assuming there is adequate of well you require is probably the most storage to satisfy peak demand periods) if it critical portion of the planning phase of were pumped for about 9 hours and 35 min- your water supply. utes. This is a relatively short time compared Finally, if a well is to be constructed, the with the 12- or 24-hour pumping periods that State Department of Public Health should are normal for municipal and industrial wells. be contacted. If the Department has ad- vance notice of the time and place of the well construction, they will, if possible, Gathering Data make an inspection trip to the well site to After the water requirements for a pro- insure that the well is constructed according posed farm or domestic water supply are to the Well Code. Advice on submitting known, a comprehensive search for informa- water samples for bacterial analyses can tion on the available groundwater resources also be obtained from the Health Depart- in the area of interest should be undertaken. ment (see appendix B for addresses of As a first step, it is suggested that the State Regional Health Department offices). Water Survey or State Geological Survey be contacted to obtain information from their files (see appendix A for address and in- Occurrence and Movement structions). of Groundwater The letter-type reports that the Surveys Groundwater in Illinois begins as precip- provide indicate the potential for developing itation that seeps downward into the ground the desired supply in the area of interest, the through the soils. Figure 1 shows the gen- types and depths of wells that are used, the eralized cycle of water movement from the type of well probably most suited, and the atmosphere as precipitation to the surface anticipated yield and chemical quality of and then away from the area either through water normally obtained in the area. These the ground or as surface runoff into flowing reports are prepared free of charge. streams and again into the atmosphere by In addition to these reports, it would be evaporation and transpiration of plants. advisable to obtain information, on wells in Water enters and filters slowly down your area (within 1 or 11/2 miles of the prop- through the ground until it reaches a level erty in question) from the owners or from where all available space between soil par- well contractors who constructed the wells. ticles is completely water filled. Water This is needed because records of all the contained in this zone of saturation is wells in your area may not be on file at the groundwater, and its upper surface is the two Surveys. The additional facts on local water table. wells will permit a more detailed interpreta- The water table throughout Illinois nor- tion of the information contained in the mally lies some 5 to 10 feet below ground written reports. level in the lowland areas along streams and It is also desirable to talk to several well rivers and perhaps as much as 25 to 50 feet drillers who are familiar with the ground- below ground level in the upland areas. The

3 Figure 1. Generalized cycle of water movement position of the water table changes by season contain abundant water in their minute pores in response to variations in precipitation. between grains, but the flow of water through In Illinois, practically all recharge (refilling) these small pore openings is restricted to such of groundwater reservoirs occurs between the an extent that it cannot freely enter a well. first of November and the end of April, Layers of these relatively impermeable mater- during periods when evaporation and tran- ials (clay, silt, shale) may occur above or spiration losses are minimal, soil moisture between aquifers and greatly control the move- needs have been satisfied, and the ground is ment of groundwater. unfrozen. Seasonal changes in water table Under normal conditions, the upper glacial levels should be expected to range from 5 to materials are regularly recharged by precip- 15 feet during years of normal rainfall. itation occurring in the immediate vicinity. In glacial drift deposits or unconsolidated The water continues to move freely down- materials, water fills the voids between the ward under the influence of gravity and sand, gravel, clay, and silt particles that pressure to the lower drift deposits and in make up the deposits. In bedrock forma- some areas into the underlying bedrock tions, water may be contained either in the formations. However, when layers of almost spaces between partially cemented grains of impermeable materials such as clay or shale sandstone or in the fractures or solution are present, the downward movement of cracks of limestone or dolomite. water is practically stopped. A saturated formation of sand, gravel, Aquifers lying below such confining beds sandstone, limestone, or dolomite that is obtain their water from some distant capable of yielding water to wells in usable recharge area where the confining beds are quantities is called an aquifer. Other earth missing or where the aquifer is exposed or materials such as clay, silt, and shale may outcrops at the land surface (figure 1).

4 Water entering permeable formations in an gravel capable of yielding adequate water outcrop or recharge area also may become for farm and domestic use (1 to 10 gpm) confined downslope beneath impermeable ma- usually are present in most parts of Illinois. terials. In cases of this type, pressure is ex- In some areas these may be difficult to locate erted on the groundwater in the confined or may require special well construction to aquifer by the weight of water above it. be utilized. In general, a 3-foot thick section When a well penetrates such an aquifer of sand and gravel should be capable of downslope from the recharge area, pressure yielding an adequate farm or domestic supply forces the water to rise in the well above the to a small-diameter (4-inch) drilled well. Sand top of the aquifer. The water in this instance or gravel deposits thinner than this usually is confined (or artesian) water, the well is an are best developed by large-diameter (36-inch) artesian well, and the upper surface of the augered wells. water in the well is called the piezometric Major sand and gravel aquifers capable of pressure surface of the aquifer. When the yielding municipal and industrial supplies piezometric surface of the aquifer is above (100 to more than 1000 gpm) are located land surface, wells tapping the aquifer are in three general areas of the state. High called flowing artesian wells (see figure 1). yielding deposits are found along the Mis- Subsurface flow of groundwater is very sissippi, Illinois, Ohio, and Wabash Rivers. slow in comparison with that of overland Permeable fill materials of sand and gravel water flow. Under normal hydraulic gradi- also are found in ancient buried valleys, ents, groundwater may travel horizontally such as the Troy, Rock, Mahomet, and only a few feet a day through sand and Cache Valleys, and in the present day valleys gravel or creviced limestone and dolomite, of the Kaskaskia, Little Wabash, and Embarras and only a few feet per year through sand- Rivers. Other high yielding sand and gravel stone and other finer-grain deposits such as aquifers deposited by glacial actions are clay and shale. scattered throughout large areas of north- For example, in one of the most perme- eastern and central Illinois. able water-bearing sand and gravel formations Figure 2 roughly outlines the yield in the state at Peoria, groundwater movement potential of sand and gravel deposits through was determined to be about 1800 feet in 5 Illinois. This generalized map may not in- months, or 12 feet per day, to a heavily clude many small and yet undefined areas pumped industrial well. On the other hand, of high yielding sands and gravels. As men- in a silty clay formation underlying a farm tioned earlier, more detailed definition of in Washington County, groundwater move- specific sites can be obtained from the State ment was determined to be less than 200 Water Survey and State Geological Survey. feet in 20 years, or 10 feet per year. In most of central Illinois, farm and domestic water supplies are obtained from sand and gravel aquifers. The underlying Availability of Groundwater bedrock formations in these areas usually Groundwater for farm and domestic use are not tapped unless a satisfactory supply throughout Illinois is obtained either from cannot be developed in the unconsolidated sand and gravel deposits found in the uncon- materials. This is primarily because water solidated materials above bedrock or from from the bedrock aquifers in this part of sandstone or limestone units in the bedrock the state is too highly mineralized for do- formations. mestic uses. Thin discontinuous deposits of sand and In northern and western Illinois where the

5 Figure 2. Generalized yield potential of sand and gravel deposits

6 uppermost bedrock units occur close to the ately below the casing and opposite the ground surface (less than 100 feet) and are water-bearing deposit to hold back the sand known to produce sufficient quantities of particles, yet permit free entry of water into good quality water, bedrock wells are used the well. If the well is finished in a water- for farm and domestic water supplies. In the bearing sandstone or limestone formation, remainder of Illinois only limited farm or do- the overlying unconsolidated materials are mestic water supplies are obtainable from very cased out to prevent caving, and an open thin sandstone and limestone formations. bore hole is constructed into or through the Figure 3 roughly outlines the yield potential aquifer. of the shallow (less than 600 feet) bedrock Bored wells, 36 inches in diameter, are formations throughout Illinois. As with the used in areas underlain by thin stringers of sand and gravel deposits, this generalized map low yielding materials not capable of pro- may not include small areas of higher yields, ducing water at rates high enough to satisfy and more detailed information on specific small-diameter wells. These wells provide sites may be obtained from the State Water storage of water to satisfy peak demand Survey and Geological Survey. periods and allow for continual seepage to refill the well during times of nonpumping. The modern day large-diameter wells are Types of Wells and Pumps cased with sections of precast concrete pipe placed one upon the other. A layer of Wells gravel, usually 3 to 4 inches, is placed around Wells can be classified into types according the casing from about 10 feet below land to the method used in constructing the well surface to the bottom of the well. or hole in the ground. The two most com- Both drilled and bored wells should be mon types of wells used for farm and domes- sealed at the top to prevent the entrance of tic water supply in Illinois are drilled and surface water and thus minimize the occur- bored wells. The type of well most suited for rence of bacterial pollution. This normally a given location depends on the available is accomplished by installing a pitless adapter aquifers in the area, the anticipated water unit or by placing cement grout around the requirements, and the economic capabilities upper 10 feet of the well casing. of the farmer or home owner. The construction and finishing techniques Drilled wells, 4 inches in diameter, are most for each type of well are discussed in detail commonly used to tap water-bearing sand and in Circular 117. The state rules and regula- gravel and bedrock formations in much of tions setting specific requirements for well Illinois. These wells are used in parts of the construction materials and methods are given state where the aquifers are capable of replen- in the Illinois Water Well Construction Code ishing water to a well almost as quickly as it published by the Bureau of Environmental is pumped. Providing the aquifer capability Health, Illinois Department of Public Health. is adequate, a 4-inch well normally will accom- modate a domestic size pump of any type and provide for adequate domestic well yields. Pumps Drilled sand and gravel wells usually are Nearly all farm and domestic wells in cased with steel pipe from land surface to the Illinois are equipped with electrically driven top of the water-bearing sand to prevent caving pumps of four types. These are submersible, of the overlying materials. A length of com- jet, centrifugal, and piston type pumps. Ap- mercially made well screen is placed immedi- proximately 90 percent of all new pumps

7 Figure 3. Generalized yield potential of shallow bedrock formations

8 installed throughout Illinois are of the sub- of these are old installations, and only a mersible type. very small number of new piston pumps Submersible pumps provide a smooth even are now being installed in the state. Piston flow of water and are available in a wide pumps can pump water conataining very range of capacities and head ratings. They small amounts of sand, are particularly use- require no frost proofing or well house and ful in 2- or 3-inch diameter wells, and are have proven to be very dependable and quiet. easily adaptable to hand operation in case Among the known inconveniences of this of a power failure. However, they character- type of pump are that they are easily dam- istically create a pulsating discharge and are aged by sand, they must be pulled from the limited in their practical yield capabilities. well to be worked on, and they are limited More detailed information about pumps to 3-inch or larger wells. Only one manu- is given in Circular 117. facturer currently is making the 3-inch pump, A sketch of a typical domestic well in- several make 4-inch and larger pumps. stallation is shown in figure 4. This is a Jet pumps are estimated to be the second 4-inch diameter drilled well, 75 feet deep, most common type of pump used in new do- finished in sand and gravel. It is equipped mestic well installations in Illinois. For pum- with a 5-foot length of screen and a 5-gpm ping from depths less than about 15 feet, submersible pump. This well could yield shallow well jet pumps commonly are used, over 7000 gallons of water a day if pumped and for deeper pumping lifts deep well jets continuously. It can provide water for a are required. Jet pumps have relatively few family of 4 (200 gallons per day) in approx- moving parts, can be offset from the well, imately 40 minutes. and are easily accessible for repairs and maintenance. However, they are easily damaged by sand and may require higher horsepower Water Quality motors than other types of pumps to pump Desirable water for farm and domestic the same quantity of water, particularly at use should be free from bacteria and should deep pumping lifts. contain no objectionable or dangerous con- Centrifugal pumps are one of the simplest centrations of minerals or gases. Many wells types of pumps and are commonly used for in Illinois appear to be properly located and pumping water from depths less than 15 to constructed and should produce water con- 20 feet below the level of the pump. They taining little or no harmful bacteria. How- normally produce a smooth even flow of ever, it is still advisable to have periodic water and will pump water containing some bacterial analyses on well water that is being sand with minimum resulting damage. They used for drinking and cooking. also usually are reliable and have a good Water from all aquifers in Illinois com- service life. This type of pump is almost monly contain objectionable concentrations always offset from the well and is easily of iron and hardness. In the past, tolerance accessible for maintenance purposes. Problems of these minerals has been the common occasionally encountered in using centrifugal practice. Today, however, more and more pumps are the easy loss of prime and ex- private water supply systems are being equip- tremely low efficiencies unless operated very ped with home water treatment units to close to the manufacturer’s design head and remove these objectionable minerals. It is speed. likely that the general quality of water from Piston type pumps are one of the oldest all private water supply systems in Illinois types of pumps still in use in Illinois. Most could be improved by such equipment.

9 Figure 4. Sketch of typical domestic well installation

10 High concentrations of natural gases such Hydrogen sulfide, although not dangerous, as methane and hydrogen sulfide also are does create a very offensive ‘rotten egg’ odor. common in isolated areas of Illinois. This gas normally can be effectively removed Wells producing a water-methane gas mix- from water for domestic use by aeration or ture should always be properly vented at the by chlorination followed by an activated well and throughout the distribution system carbon filter. to minimize the explosion hazard of this gas. More detailed discussion of water quality In extreme cases, aeration of the water may be and types of water treatment for farm and necessary to safely dissipate this deadly gas. domestic uses is presented in Circular 118.

References Gibb, James P. 1970. Groundwater availability in Ford County. Illinois State Water Survey Circular 97. Gibb, James P. 1973. Wells and pumping systems for domestic water supplies. Illinois State Water Survey Circular 117. Gibb, James P. 1973. Water quality and treatment of domestic groundwater supplies. Illinois State Water Survey Circular 118. Gibson, Ulrie P., and Rexford D. Singer. 1969. Small wells manual. Department of State, Agency for International Development, Washington, D. C. Ground water and wells. 1966. Edward E. Johnson, Inc., St. Paul, Minnesota. Ivens, J. Loreena. 1969. Teaching water conservation. Office of Superintendent of Public Instruction, State of Illinois, Springfield. Private water systems. 1968. Midwest Plan Service, Iowa State University, Ames, Iowa. Sanderson, E. W. 1971. Groundwater availability in Piatt County. Illinois State Water Survey Circular 107.

11 APPENDIX A – INFORMATION REQUESTS

Groundwater information requests should be accompanied by as much of the following data for each type of request as possible.

For a new supply c )Type of well (dug, bored, drilled, etc.). Information requests should be accompanied d) Depth of well (in feet below land surface). by the following data: e) Water levels (in feet below land surface) 1)The legal location of the proposed well site before and during pumping. Include the to the nearest quarter of a quarter section, pumping rate (in gallons per minute or township, range, and county (for example, gallons per hour). NE¼ of the NE¼, Section 10, T 16 N, f) Capacity, make, and type of pump (for R 6 W, Sangamon County). example, 3 gallons per minute, Red Jacket deep well jet). 2)Estimated daily water requirement (in g) Depth to bottom of pump intake. gallons) or explanation of planned use (for h) Driller’s log of well. example, domestic supply for 4 persons, i) Casing length and diameter. 10 bead of cattle, and 100 bead of swine). j) Screen length, diameter, and slot size. 3)Information on existing wells located in the vicinity of the property (depth, adequacy, For water quality information quality of water, etc.). or problems Information requests concerning the chemical For existing well problems quality of water should be accompanied Information requests should be accompanied by the following: by the following data: 1) Complete information on the well as 1)A complete explanation of the problem described above. including any recent changes in pumping 2)A one-quart water sample from the well. equipment, water use, etc. a )The sample should be collected at a 2)Complete information on the well(s) point in the system located on the well including: side of any pressure tank or water treat- a) Legal location of the well to the nearest ment equipment (filter, softener, etc.). quarter of a quarter section, township, b) Collect the sample after the well has range, and county. been pumped for about 10 or 15 b) Distances from potential sources of minutes to insure that the water sample pollution (septic tank, feedlots, comes directly from the water-bearing privies, sewer lines, etc.). formation and not from storage.

Information requests to the State Water Survey should be sent to: Illinois State Water Survey Water Resources Building P. O. Box 232 Urbana, Illinois 61801

12 APPENDIX B – PUBLIC HEALTH OFFICES

Regional Offices Addresses Counties Served Illinois Department of Public Health Carroll, De Kalb, Jo Daviess, Lee, Ogle, Stephenson, 4302 North Main Street Whiteside, Winnebago Rockford, lllinois 61103 Phone 815-877-8051 Illinois Department of Public Health Bureau, Fulton, Henderson, Henry, Knox, La Salle, 5415 North University Avenue Marshall, McDonough, Mercer, Peoria, Putnam, Peoria, Illinois 61614 Rock Island, Stark, Tazewell, Warren, Woodford Phone 309-691-2200 Illinois Department of Public Health Boone, Du Page, Grundy, Kane, Kankakee, Kendall, Box 910 Lake, McHenry, Will 48 West Galena Boulevard Aurora, Illinois 60507 Phone 312-892-4272 Illinois Department of Public Health Cook 1919 West Taylor Room 809 Chicago, Illinois 60612 Phone 312-341-7290 Illinois Department of Public Health Adams, Brown, Calhoun, Cass, Christian, Greene, 4500 South Sixth Hancock, Jersey, Logan, Macoupin, Mason, Menard, Springfield, Illinois 62706 Montgomery, Morgan, Pike, Sangamon, Schuyler, Scott Phone 217-786-6882 Illinois Department of Public Health Champaign, Clark, Coles, Cumberland, De Witt, 2125 South First Douglas, Edgar, Ford, Iroquois, Livingston, McLean, Champaign, Illinois 61820 Macon, Moultrie, Piatt, Shelby, Vermilion Phone 217-333-6914 Illinois Department of Public Health Bond, Clinton, Madison, Monroe, Randolph, St. Clair, 9500 Collinsville Road Washington Collinsville, Illinois 62234 Phone 618-345-5141 Illinois Department of Public Health Alexander, Clay, Crawford, Edwards, Effingham, 2209 West Main Street Fayette, Franklin, Gallatin, Hamilton, Hardin, Jackson, Marion, Illinois 62959 Jasper, Jefferson, Johnson, Lawrence, Marion, Massac, Phone 618-997-4371 Perry, Pope, Pulaski, Richland, Saline, Union, Wabash, Wayne, White, Williamson

Regional Laboratories Illinois Department of Public Health 1800 West Fillmore Chicago, Illinois 60612 Illinois Department of Public Health P. O. Box 2467 Carbondale, Illinois 62901 Illinois Department of Public Health 134 North Ninth Street Springfield, Illinois 62706