Figure 1. Ground-water resources of Clinton County, Ohio (adapted from ODNR Division of Water map by J. Humphreys).
L. Tony Nye
A. Wayne Jones
Larry C. Brown
Kristina M. Boone
Water stored under the earth's surface is a plentiful, yet precious, resource in most areas of Ohio. Many human activities may affect the quality and quantity of this resource. However, the availability and quality of this resource are influenced directly by the properties of the geologic formations that hold water. The chemical and physical nature of these formations varies from area to area, creating a wide range of water yields and quality at different depths. This publication contains information about the ground-water resources underlying Clinton County. Its purpose is to help the reader better understand the factors that influence the quantity and quality of ground water. An overview of the county's water resources is provided in the publication Clinton County Water Resources, AEX-480.14.
Much of the water resource and water quality terminology used in this publication is described in Extension Facts Sheets AEX 460 and 465. Ohio Extension publications are available through the Clinton County office of Ohio State University Extension.
Geologic formations (e.g. sand, gravel, limestone, sandstone) have the ability to receive, store and transmit water. In general, if a formation is capable of yielding enough water to support a well or spring, it is called an aquifer. The material from which the formation originally was made influences its ability to store and transmit water. For example, sand and gravel allow water to flow through easily. By comparison, shale, which originated from compacted layers of mud and clay, generally allows very little water to flow through it unless the shale is highly fractured.
The Silurian-aged, carbonate aquifer, which is composed of layers of limestone and dolomite, is the main source of ground water in north-eastern Clinton County. Limestone consists of fossilized sea shells, shell fragments, calcareous sand and consolidated limy mud. Its main mineral is calcium carbonate, CaCO3. Dolomite is similar to limestone, but has few recognizable fossils; its main mineral is calcium, magnesium carbonate, (Ca,Mg)CO3. Both limestone and dolomite are commonly referred to as limestone. The limestone and dolomite formations were deposited between about 400 and 500 million years ago.
The Ordovician-aged, shaley-carbonate aquifer, which is composed of interbedded shales and thin limestones, is a poor source of ground water in southern and western Clinton County. The low yielding nature of this bedrock formation results in a large number of non-producing wells, sometimes called "dry holes." Unconsolidated deposits in Clinton County consist of glacial till, sand, gravel, silt and clay, all of which were deposited by glacial processes. Glacial till, which is an unsorted mixture of clay, sand, gravel and silt, is not considered a water-bearing formation. However, lenses of sand and gravel, which occur above the carbonate bedrock in some parts of the county and may be imbedded in the glacial till or deposited in layers, are capable of yielding adequate quantities of water for many uses.
Limestone formations usually are adequate sources of ground water because of joints and fractures, and naturally formed solution channels, which provide water storage capacity and pathways for water movement. The number of fractures and other openings in limestone varies greatly from one location to another, and affects the amount of water that may be encountered when drilling a well. The position of such openings rarely can be determined from the land surface; therefore, there is always some uncertainty as to the production capability of a proposed well.
The actual yield of a well, in gallons per minute (gpm), will vary considerably depending on the age and depth of the well, the diameter of the casing, well construction, pump capacity and age, and most importantly, properties of the geologic formation. The exact yield and depth of each well will depend on the properties of the geologic formation at the specific location of the well.
To support the development of ground-water availability assessments in Ohio, the Ohio Department of Natural Resources (ODNR), Division of Water, maintains a statewide database of more than 700,000 well logs. The Ground-Water Resources Section of the Division manages this valuable database, which includes some information collected by the U.S. Geological Survey (USGS) and the Ohio Environmental Protection Agency (Ohio EPA). Since 1948, well-log information has been collected to increase the understanding of the ground-water resources in Ohio. Geologists and hydrogeologists continue to study the state's ground-water resources. As a result, Ohio is one of only a few states that has been completely mapped for ground-water availability (mapped by river basin, from 1959 to 1962).
Estimates of the size, shape, geologic make-up and yields of aquifers are being mapped county by county. Most of Ohio's counties have a completed map. The map presented in Figure 1 is a generalized representation of the water-bearing formations underlying Clinton County (adapted from map by J.J. Schmidt, 1993). This illustration is based on a hydrogeologic interpretation of the well-log data from Clinton County and surrounding areas. Figure 2 presents a generalized cross section of Clinton County (referenced in Figure 1 as the line X-X') illustrating the valley fill in the Wilmington and Cowan Lake areas. The information in these figures should be used only as a guide to understanding the ground-water resources in the county. The remainder of this section provides a brief description of the types of aquifers illustrated on the map in Figure 1.
Figure 1. Ground-water resources of Clinton County, Ohio
(adapted from ODNR Division of Water map by J. Humphreys).
Figure 2. Generalized cross section of Clinton County, Ohio
(adapted from ODNR Division of Water map by R. Roberts).
Area A in Figure 1 is part of the regional carbonate aquifer of western Ohio. Yields of as much as 75 gpm may be developed in the limestone beneath the glacial till. Yields of 60 gpm may be developed from this aquifer at depths of less 120 feet in larger diameter wells. This is considered adequate for industrial and municipal water supplies. Domestic and farm water supplies can usually be developed at depths of 40 to 95 feet.
Area B also is part of the regional carbonate aquifer. However, the basal carbonates are encountered at a shallower depth compared to that of Area A. Well yields of up to 25 gpm can be expected at depths of less than 100 feet. Deeper drilling, which may encounter lesser yields at depths greater than 135 feet, is not advised.
The limestone aquifer illustrated as Area C is part of the regional carbonate aquifer which underlies much of western Ohio. This area consists of massive thin-bedded limestone, and calcareous shale, which is overlain by glacial till. Wells developed in the Silurian limestone bedrock at average depths of 50 to 75 feet yield from 3 to 10 gpm. Farm and domestic supplies may be available from sand and gravel deposits where these deposits are present. Drilling deeper than 100 feet is not advisable, since the well may encounter the Ordovician-aged, non-water-bearing soft shale and hard limestone bedrock formations. Cisterns and/or storage may be necessary for peak periods of domestic demand.
Thick unconsolidated deposits of clay, with some interbedded sand and gravel make up the aquifer in area D. In some places, these deposits can be from 50 to 290 feet thick overlying the shale and thin limestone bedrock. Water-bearing deposits may be encountered at depths ranging from 35 to more than 290 feet. Well yields of 3 to 10 gpm from sand and gravel interbedded in the glacial till can provide supplies adequate for farm and domestic use. In a few limited areas, wells may yield as much as 135 gpm to properly screened, drilled wells. However, cautious drilling is advised.
The poorest producing area of the county is Area E. Clayey glacial till from 30 to 70 feet thick above non-water-bearing shale and limestone bedrock yields on average less than 3 gpm. Dry wells are common. If water is present in the interbedded shale and limestone bedrock, it usually occurs in the upper few feet where the rock is weathered and fractured. Occasional lenses of sand and gravel may supply small domestic needs. Homeowners often rely upon cisterns and/or storage to provide for daily water demand.
Ground water, whether obtained from bedrock or glacial deposits, may require some treatment. In some areas, water containing concentrations of calcium carbonate (CaCO3, i.e., hard water) and iron (greater than 0.3 ppm) may require treatment for some uses (see notes in Table 1). Wells drilled into shale or limestone may produce water that contains objectionable quantities of hydrogen sulfide (rotten egg odor). In general, the probability of obtaining sulfur in objectionable amounts increases with the depth drilled.
The water level in any well usually does not remain constant, but may change depending upon several factors. Rainfall distribution and amount, and fluctuating water level in a stream that is hydraulically connected to an aquifer, may affect ground-water recharge and discharge, and subsequently may affect the water level in area wells. Also, in some cases, depending upon the hydraulic properties of the geologic formation, the intense pumping of a well, or number of wells, may cause the water level in some nearby wells to be lowered.
The ODNR Division of Water monitors ground-water levels in many wells throughout southwestern Ohio. No observation wells are located in Clinton County, but observation wells are located in neighboring Fayette, Green and Warren counties. These wells are located in formations that are similar to those in Clinton County, and may provide general information about aquifers in the area.
Various state and federal agencies have participated in programs to determine the ground-water quality in Ohio. In Clinton County, water-quality data for five wells were available from the ODNR Division of Water. In Figure 1, these wells are noted as Chemical Analysis Sites 1 through 5, and are either industrial, public or domestic wells.
The results from some of the chemical tests performed on these Clinton County wells are given in Table 1. The chemical constituents listed are total dissolved solids, hardness (as CaCO3), iron, chloride, sulfate and fluoride. All concentrations are given as parts-per-million (ppm). For comparison purposes, secondary drinking water-quality standards for these chemical constituents also are shown. These standards are established by the U.S. Environmental Protection Agency (USEPA) for public water systems for aesthetic reasons (taste, odor, appearance, etc.), and are not enforceable. Except for fluoride concentrations greater than 4.0 ppm, these chemical constituents do not pose a risk to human health (see notes in Table 1). For private wells, there are no legally enforceable drinking water-quality standards other than total coliform, which is an indicator of bacteriological quality.
The information in Table 1 can be used as a guide to what one might expect from an existing or new well developed in similar geologic material in the county. This information provides a general representation of the quality of the water at the time of sampling, which was not the same for all wells. In most cases, the data provided in Table 1 was taken from a water sample obtained just after the well was put into operation. Even though three of the five wells were developed in sand and gravel, or gravel deposits underlying Clinton County, and all are in the range of 55 to 145 feet deep, some variation exists in the concentrations of each of these chemical constituents. Just as well yields differ, water quality will vary depending on aquifer properties at the specific location of each well. One should not forget that many human activities also affect the quality of ground water (see AEX 465).
| Table 1. Chemical constituents of selected Clinton County wells1. | ||||||
|---|---|---|---|---|---|---|
| Well No. | 1 | 2 | 3 | 4 | 5 | WQ Std2 |
| Well Depth (feet) | 115 | 65 | 145 | 67 | 55 | |
| Capacity (gpm) | 10 | 4 | 10 | 20 | 15 | |
| Depth to Bedrock(feet) | 56 | 40 | NE3 | NE | NE | |
| Water-Bearing Formation4 | LS | LS | SG | SG | G | |
| Chemical Constituents5 | ||||||
| Total Dissolved Solids | 619 | 567 | 1350 | 551 | 506 | 500 |
| Hardness (as CaCO3) | 420 | 469 | 315 | 390 | 397 | none6 |
| Iron | 0.2 | 0.47 | 2.2 | 1.8 | 1.8 | 0.3 |
| Chloride | 5 | 118 | 690 | 12 | 5 | 250 |
| Sulfate | -7 | 38 | 5.2 | 22 | 94 | 250 |
| Fluoride | 1.1 | 0.2 | 1.8 | 0.8 | 0.6 | 2 |
| 1. Data on these wells from map by Schmidt, 1993; General location of each well is shown on Figure 1. | ||||||
| 2. USEPA Secondary Water Quality Standard. | ||||||
| 3. Well constructed in this formation did not encounter bedrock. | ||||||
| 4. G -Gravel; LS - Limestone; SG - Sand and Gravel. | ||||||
| 5. Units are parts-per-million, ppm;
Comments as per "Interpreting Your Water Test Report" (1988); Total Dissolved Solids: Concentrations above 500 ppm may cause adverse taste and deteriorate domestic plumbing and appliances. Use of water containing 500 ppm is common. Hardness: Primary concerns are that more soap is required for effective cleaning, a film may form on fixtures, fabrics may yellow and scales may form in boilers, water heaters and cooking utensils. Iron: Concentrations greater than 0.3 ppm may cause rust-colored stains on laundry, plumbing fixtures and sinks. Metallic taste may be present, which may affect the taste of beverages made from the water. Chloride: Concentrations greater than 250 ppm may result in an objectionable, salty taste to water and the corrosion of plumbing in the hot water system. Sulfate: Concentrations in excess of 250 ppm may have laxative effect on persons unaccustomed to the water. Also affects the taste of water and will form a hard scale in boilers and heat exchangers. Fluoride: At concentrations greater than 1.5 ppm, fluorosis (mottling) of teeth may occur. USEPA Primary Standard is 4 ppm. | ||||||
| 6. No USEPA Secondary Standard. | ||||||
| 7. Data not available. | ||||||
Clinton County's ground-water resources are valuable assets to the county's citizens and industry. The availability and quality of these resources are directly influenced by the properties of the geologic formations underlying the county. The limestone, and sand and gravel formations underlying Clinton County have the potential to supply water adequate for many domestic and agricultural uses. By understanding the physical and chemical nature of these resources, better decisions can be made about ground-water protection, management and use. This publication provided an overview of the county's ground-water resources. It should be used as a guide, and not as a substitute for detailed information and professional advice when drilling a well.
The Clinton County office of Ohio State University Extension can provide other publications on the county's water resources. Your Extension agent, the Clinton County Health Department, and Ohio EPA Southwest District Office - SWDO (40 South Main St., Dayton, OH 45402) can provide information on well-water testing and drinking-water quality. The ODNR Division of Water - Ground-Water Resources Section (Fountain Square, Columbus, OH 43224) is an excellent source of information on ground water. Some of the information in this publication was summarized from a map titled Ground-Water Resources of Clinton County, and other information available through the Division of Water. This map is much more detailed than that given in Figure 1 of this publication. In addition, personnel in the Ground-Water Resources Section can provide you with more detailed information about ground-water availability and wells. The USGS, Ohio District (975 W. Third Ave. Columbus, OH 43212), also provides information concerning ground water in Ohio.
Clinton County Water Resources. 1993. L.T. Nye, K.M. Boone and L.C. Brown. AEX-480.14. Ohio State University Extension.
Ground-Water Resources of Clinton County. 1993. J.J. Schmidt. ODNR Division of Water. (map).
Interpreting Your Water Test Report. 1988. D. Lundstrom and S. Fundingsland. AE-937, No. 13-AENG-10. North Dakota State University Extension Service.
Nonpoint Source Pollution: Water Primer. 1993. R. Leeds and L.C. Brown. AEX 465. Ohio State University Extension.
Ohio Ground-Water Quality. USGS National Water Summary - Ohio. 1986. U.S. Geological Survey Water-Supply Paper 2325.
Ohio Ground-Water Resources. USGS National Water Summary - Ohio. 1984. U.S. Geological Survey Water-Supply Paper 2275.
Surface and Ground Water Terminology. 1990. L.C . Brown and L.P. Black. AEX 460. Ohio State University Extension.
Underground Water Resources (maps of various river basins). 1958-1962. ODNR Division of Water.
Water Inventory of the Little Miami and Mill Creek Basins and Adjacent Ohio River Tributaries. 1964. Report 18. ODNR Division of Water.
Water Testing. 1988. K. Mancl. AEX 314. Ohio State University Extension.
This publication was produced through the Ohio Water Resources Education Project, in cooperation with: ODNR Division of Water; Ohio EPA; USGS, Ohio District; and Ohio Department of Health (ODH). Project leaders are Larry C. Brown and Kristina M. Boone. Support for this publication was provided, in part, by: cooperating agencies; the Clinton County office of Ohio State University Extension; Clinton County Commissioners; Clinton County Farm Bureau; Clinton Soil and Water Conservation District; Overholt Drainage Education and Research Program; and USDA Extension Service Grant No. 90-EWQI-1-9018. The project leaders acknowledge the following reviewers: Kenneth Schaublin (Clinton County Regional Planning Commission); Lizbeth White (Clinton County Health Department); Robert Coblenz (USDA Soil Conservation Service); Scott Golden (Environmental Health, ODH); Steve Hindall (USGS, Ohio District); and Rich Bendula (Ohio EPA, SWDO).
A special thanks to Michelle Roby, Ross Roberts, and John Humphreys (Agricultural Engineering Undergraduate Assistants) for help in graphic and manuscript preparation, and Judy Kauffeld, Publications Editor (Section of Communications and Technology, Ohio State University), for editorial and graphic production.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
TDD No. 800-589-8292 (Ohio only) or 614-292-1868