Ohio State University Extension

Food, Agricultural and Biological Engineering

590 Woody Hayes Dr., Columbus, Ohio 43210

Warren County Ground-Water Resources

AEX-490.83

Ed Winkle
A. Wayne Jones
Kristina M. Boone
Larry C. Brown

Water stored under the earth's surface is a plentiful, yet precious, resource in most areas of Ohio. Humans greatly affect ground water. However, the availability and quality of this resource are influenced directly by the properties of the geologic formation that holds 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 Warren County. Its purpose is to help the reader better understand the factors that influence the quantity and quality of ground water. Water resources terminology used in this publication is included in Surface and Ground Water Terminology, fact sheet AEX-460, which provides a listing of generally accepted water resource definitions. Fact sheet AEX-460 and the publication Warren County Water Resources, AEX-480.83, are available through your county Extension office.

Aquifers

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 types of geologic material from which the formation originally was made influence its ability to store and transmit water. For example, sands and gravels 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 though it, unless the shale is highly fractured.

Ground water is stored in the pore spaces between grains of sediment or rock, and transmitted through tiny channels connecting these pore spaces. The ability to transmit water is called permeability, and a measure of the amount of pore space is called porosity. The most productive aquifers have both high porosity and high permeability.

The Great Miami and Little Miami basins cover most of southwestern Ohio. The aquifers in these basins consist of shale and limestone bedrock, and glacial materials like glacial outwash, sand and gravel. The bedrock aquifer in Warren County consists of interbedded limestone and shale, which is composed of compacted particles that have very low porosity and permeability. Some wells drilled into the bedrock produce dry holes, or at best very small quantities of water.

Buried valleys in the county are pre-glacial stream valleys that have been filled with unconsolidated sediment deposited during or between glacial epoches. These aquifers contain outwash sediments that were deposited in front of the glacier by melt water rushing away from the ice as it melted. Water sorts the particles by size, washing finer materials downstream, and leaving coarser materials as stream bed load. These sorted sand and gravel outwash deposits help make buried valley aquifers very productive.

Glacial till is an unsorted mixture of sand, gravel, silt and clay deposited by glacial action. No washing or sorting of the sediment occurs, so till is mostly clay with some silt, sand, gravel and boulders. The permeability of till is low, but lenses of sand and gravel may occur within the till. These lenses are a main source of ground water in Warren County.

Well Yield

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 techniques, 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.

Ground-Water Availability

The Ohio Department of Natural Resources (ODNR), Division of Water, maintains a statewide data base of more than 700,000 well logs. The Ground-Water Resources Section of the Division manages this valuable data base, 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, and 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 ground-water resource map. The map presented in Figure 1 is a generalized representation of the water-bearing formations underlying Warren County (adapted from map by Walker, 1986). This illustration is based on a hydrogeologic interpretation of the well log data from Warren County and surrounding areas. It 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 Warren County, Ohio (modified from A.C. Walker, ODNR Division of Water, by R.A. Roberts).

AREA A: Buried Valley

The Great Miami River buried valley aquifer illustrated in Figure 1 as Area A is part of a water-rich formation that runs through the southwest part of the state and the northwest tip of Warren County. If properly constructed and of large diameter, wells within this buried valley may yield more than 1,000 gpm. Large industrial well-field developments are possible. Ground water obtained from buried valleys has generally high quality because of neutral pH, moderate hardness, and low concentrations of sulfates and dissolved solids.

AREA B: Sand and Gravel

Area B contains generally well-sorted sand and gravels that can yield 100 to 500 gpm. Highest yields of water are reported where recharge is available from nearby streams. Exploratory drilling may be necessary to locate coarser materials for the greatest yields. The water has an almost neutral pH and an acceptable level of hardness.

AREA C: Valley Fill

A portion of the county, shown as Area C, is underlain with thick deposits of sand and gravel, known as valley fill. Wells drilled into these permeable deposits may yield as much as 100 gpm. Small-diameter domestic wells may only produce 15 to 25 gpm. Wells drilled deeper into the shale bedrock yield very limited supplies.

AREA D and D1: Shallow Sand and Gravel, and End Moraines

Areas D and D1 illustrate two similar geologic formations that may yield 10 to 25 gpm. One formation, Area D, is valley fill containing sand and gravel layers of limited thickness and extent. The thicker deposits of sand and gravel can yield up to 25 gpm. Wells drilled into the underlying bedrock may yield less than 3 gpm.

Area D1 is very similar to Area D in terms of yield and well depth. However, this formation is glacial end moraine consisting of clay interbedded with layers of sand and gravel. Depth to bedrock may range from 100 to 200 feet within the morainal area. Wells may encounter coarse sands and gravels which may yield from 10 to 15 gpm if properly screened. Shale bedrock below the moraine is a poor water source.

AREA E: Thin Sand and Gravel over Shale

The formations identified as Area E contain thin lenses of sand and gravel interbedded with glacial till. These areas may produce up to 10 gpm to properly screened wells. Depth to bedrock is seldom greater than 100 feet. Shale bedrock is low yielding, and most often non-water-bearing.

AREA F and F1: Limestone and Shale, Till over Shale

Area F is a poor source of ground water. The bedrock consists of interbedded plastic shales and thin limestone layers. If water is present in the bedrock, it usually occurs in the upper few feet where the strata have been weathered and fractured. The overlying glacial till is generally less than 50 feet thick, and consists largely of clay. Occasional lenses of sand and gravel will supply small yields, but wells seldom produce more than 3 gpm. In Area F1, little or no ground water is available from thick silt and clay deposits overlying shale bedrock. Depth to bedrock may exceed 200 feet.

Ground-Water Levels

The water level in any well typically does not remain constant, but changes depending upon the proximity of adjacent wells and surface streams, and natural rainfall. Ground-water discharge and recharge greatly affect water levels in wells. The ODNR Division of Water monitors ground-water levels in one well in Warren County. This well, located near Monroe, is designated as W-5 on Figure 1, and is one of a number of wells throughout southwest Ohio used to monitor the natural seasonal fluctuation or the effect of nearby pumping on water levels.

Observation well W-5 is 121 feet deep. Continuous water level measurements have been recorded since 1972. The lowest level recorded at W-5 was 47.6 feet below land surface in January 1989; the highest level recorded was 17.7 feet below land surface in April 1975.

Ground-Water Quality

Various state and federal agencies participate in programs to determine ground-water quality in Ohio. Chemical analyses are available from ODNR Division of Water for three wells in Warren County. These wells are public water supplies located in the buried valley aquifer system, and are noted in Figure 1 as Chemical Analysis Sites 1, 2 and 3.

The results of some of the chemical tests performed on these Warren County wells are given in Table 1. The chemical constituents listed are hardness (as CaCO₃), chloride, fluoride, iron, sulfate and manganese. All concentrations are given in parts-per-million (ppm). For comparison purposes, secondary drinking water-quality standards for these chemical constituents are also 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. These chemical constituents do not pose a risk to human health (see notes in Table 1). There are no drinking water-quality standards for private wells.

The information in Table 1 can be used as a guide to what one might expect from an existing or new well. Even though all three of these wells were developed in the sand and gravel underlying Warren County, and all are in the range of 75 to 129 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.

Table 1. Chemical constituents of selected Warren County wells.
Well No.	1	2	3	WQ Std1
Well Depth (feet)	90	129	75
Capacity (gpm)	1,500	750	200
Depth to Bedrock (feet)	NE2	NE	67
Water-Bearing-Formation3	SG	SG	SG
Chemical Constituents4
Hardness (as CACO3)	292	400	360	None5
Chloride	1.7	30	44	250
Fluoride	0.23	0.56	0.14	2
Iron	0.29	2.82	0.15	0.3
Sulfate	38	15	54	250
Manganese	0.15	0.03	0.03	None
1 USEPA Secondary Water Quality Standard.
2 Well constructed in this formation did not encounter bedrock.
3 SG - Sand and Gravel.
4 Units are parts-per-million, ppm; Comments as per Interpreting Your Water Test Report (1988); 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. Chloride: High concentrations may result in an objectionable, salty taste to water and corrosion of plumbing in the hot water systems. Fluoride: At concentrations greater than 1.5 ppm, fluorosis (mottling) of teeth may occur. USEPA Primary Standard is 4 ppm. Iron and Manganese: Concentrations greater than 0.3 ppm iron, or 0.03 ppm manganese, may cause brown or black stains on laundry, plumbing fixtures and sinks. Metallic taste may be present and may affect the taste of beverages made from the water. 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.
5 No USEPA secondary standard.

Summary

Warren 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. By understanding the physical and chemical nature of these resources, better decisions can be made about ground-water protection, management and use. This publication was designed to provide the reader with 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.

Where to Get More Information

The Warren County Extension office can provide other publications about the county's water resources. Your Extension agent, the Warren County Department of Health, and Ohio EPA Division of Drinking and Ground Water (1800 WaterMark Drive, Columbus, OH 43266) can provide information on well-water testing and drinking-water quality. The ODNR Division of Water -- Ground-Water Resources Section (Fountain Square, Columbus, Ohio, OH 43224) is an excellent source of information on ground water. Some of the information in this publication was summarized from the map, Ground-Water Resources of Warren County, and other information available through the Division of Water. This map is much more detailed than that given in Figure 1, and the Ground-Water Resources Section can provide detailed information on ground-water availability and wells. The USGS, Ohio District (975 W. Third Ave., Columbus, OH 43212), also provides information concerning ground water in Ohio.

Bibliography

Aquifer Update. October 1991. The Miami Conservancy District. (newsletter).

Ground-Water Resources of Warren County. 1986. A.C. Walker. 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.

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.

Southwest Ohio Water Plan. 1976. ODNR Division of Water. Surface and Ground Water Terminology. 1990. L.C. Brown and L.P. Black. AEX-460. Ohio Cooperative Extension Service, The Ohio State University.

Underground Water Resources (maps of various river basins). 1958-1962. ODNR Division of Water.

Warren County Water Resources. 1992. E. Winkle, K.M. Boone and L.C. Brown. AEX-480.83. Ohio Cooperative Extension Service, The Ohio State University.

Water Testing. 1988. K. Mancl. AEX-314. Ohio Cooperative Extension Service, The Ohio State University.

Acknowledgments

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; Warren County Extension office; Warren County Commissioners; Overholt Drainage Education and Research Program; and USDA Extension Service Grant No. 90-EWQI-1-9018. The project leaders acknowledge the following reviewers: John Tkatschenko (USDA-Soil Conservation Service); David Cashell (ODNR Division of Water); Scott Golden (Environmental Health, ODH); Tom Bean (Agricultural Engineering, OSU); Steve Hindall (USGS, Ohio District); and Rich Bendula (Ohio EPA Division of Drinking and Ground Water).

A special thanks to Michelle Roby and Ross A. Roberts (Agricultural Engineering Undergraduate Assistants) for help in manuscript and graphics preparation, and Judy Kauffeld and Tonya Ewing (Section of Information and Applied Communications, OSU Extension) for editorial and graphic production.