Ohio State University Extension

Food, Agricultural and Biological Engineering

590 Woody Hayes Dr., Columbus, Ohio 43210

Auglaize County Ground-Water Resources

AEX-490.06

John M. Smith
A. Wayne Jones
Larry C. Brown
Karen T. Ricker

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 Auglaize 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 Water Resources of Auglaize County, AEX-480.06.

Much of the water resource and water quality terminology used in this publication is described in Extension Fact Sheets AEX 460 and 465. Ohio Extension publications are available through the Auglaize County office of Ohio State University Extension.

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 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 regional carbonate aquifer, which is composed of layers of limestone and dolomite, is the principal source of ground water in west-central Ohio, including Auglaize County. Limestone is consolidated limy mud or calcareous sand, sometimes with fossil shells and shell fragments. The main mineral in limestone is calcium carbonate, CaCO₃. Dolomite is similar to limestone; its main mineral is calcium magnesium carbonate, (Ca,Mg)CO₃. Limestone and dolomite are technically referred to as carbonate rocks, though they are both commonly called limestone. The limestone and dolomite formations, which underlie most of the western portion of Ohio, were deposited about 400 to 500 million years ago. These formations are covered by a layer of glacial till, which is an unsorted mixture of clay, silt, sand, gravel and boulders, deposited by glacial processes that occurred approximately 10,000 to 20,000 years ago.

Limestone formations are usually adequate sources of ground water because of their naturally formed joints, fractures, and 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. Ground water also occurs in lenses (or pockets) of sand and gravel deposited by glacial processes. These deposits occur above the carbonate bedrock and may be imbedded in the glacial till or deposited in stratified layers. Glacial till generally does not provide enough water to support a well. Contact the Ohio Department of Natural Resources (ODNR), Division of Geological Survey, for information on Ohio's geologic formations (Fountain Square, Columbus, OH 43224-1362).

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, 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

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 Auglaize County (adapted from map by R. J. Kostelnick, 1983). This illustration is based on a hydrogeologic interpretation of the well-log data from Auglaize County and surrounding areas. It should be used only as a guide to understanding the ground-water resources in the county. The section below provides a brief description of the types of aquifers illustrated on the map in Figure 1.

Figure 1. Ground-water resources of Auglaize County, Ohio (modified from J.J. Schmidt, ODNR Division of Water, by R.A. Roberts).

AREA A: Limestone and Dolomite, High-Yield Potential

Area A in Figure 1 delineates the primary and most productive aquifer, which encompasses a large part of Auglaize County. Yields of 500 gpm or more may be obtained at depths ranging from 260 to 380 feet. Farm and domestic supplies of 10 to 25 gpm are usually encountered at depths of less than 125 feet. However, lenses of sand and gravel interbedded with clayey till, overlying the limestone and dolomite, may serve as a source of domestic water supply at depths ranging from 50 to 100 feet.

AREA B: Sand and Gravel in Ancestral Valley

The ancestral Teays Valley drainage channel, denoted as Area B, provides thick sand and gravel lenses interbedded with glacial till. These deposits lie in portions of an eroded ancestral drainage channel that are remnants of an ancient drainage system that cut a valley into the shale before the area was glaciated. Later, with the coming of the glaciers, the valleys were filled with glacial deposits, composed mainly of sand and gravel. These sand and gravel deposits are capable of producing adequate yields for several purposes. Yields sufficient for domestic supplies of 10 to 20 gpm are common at shallow depths, but properly screened wells may yield as much as 400 gpm at depths over 150 feet. Drilling through the valley fill material into the underlying shale is not recommended.

Figure 2 is a generalized cross section (referenced in Figure 1 as the line X-X') that shows the relationship between the ancestral Teays valley and the underlying bedrock in Auglaize County. This cross section crosses the Auglaize River at two points in the vicinity of Wapakoneta, and thus illustrates the variation in the thickness of the fill material over the bedrock in the river valley.

Figure 2. Generalized cross section of Auglaize County, Ohio (adapted from Underground Water Resources map A-3. ODNR Division of Water; illustration prepared by R. Roberts).

The descriptions above provide a general representation of the water-bearing formations underlying the county. However, a few other localized ground-water conditions are worth noting. For instance, as a result of the difference in the elevation of the water level and ground surface between two points, water pressure causes some wells to continually flow once drilled. These are called artesian flowing wells, and this condition has been observed in the vicinity of Washington Township. Another condition that may be of interest is wells that may yield water containing hydrogen sulfide (i.e., rotten egg or sulfur odor). This condition sometimes occurs in wells constructed in the limestone/dolomite aquifer. Shallower wells are often drilled to secure sulfur-free water from the sand, gravel and limestone which lie above the limestone/dolomite formation. Lastly, there are a few locations in the county where well water may contain oil that has seeped from old oil wells in close proximity to the water well. Well drillers that are familiar with the county, and hydrogeologists at ODNR Division of Water, may be able to provide specific information on these localized ground-water conditions.

Ground-Water Levels

The water level in any well does not remain constant, but changes in response to several factors. Rainfall distribution and amount may affect ground-water recharge and discharge, and subsequently may affect the water level in area wells. Also, wells that are hydraulically connected to a stream may show fluctuations in the water level as the stream level changes. 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 one well in Auglaize County. Located in Goshen Township, this well is noted as Observation Well AU-3 on Figure 1. This well, along with other wells throughout west-central Ohio, is used to monitor the natural seasonal fluctuation of water levels in the regional carbonate aquifer.

Observation Well AU-3 is 380 feet deep and is constructed in the limestone/dolomite bedrock. The depth to bedrock is 52 feet. It is representative of many wells constructed in the limestone/dolomite bedrock throughout the region. Continuous water-level measurements were made at AU-3 from December 1974 to September 1982, and periodic measurements since 1982. The lowest level recorded at AU-3 was 11.9 feet below land surface in February 1977; the highest level recorded was 4.3 feet below land surface in April 1991.

Ground-Water Quality

Various state and federal agencies have participated in programs to determine the ground-water quality in Ohio. For the five wells in Auglaize County, water-quality data were available from the ODNR Division of Water. In Figure 1, these wells are noted as Chemical Analysis Sites 1 through 4, and Observation Well AU-3. These sites are municipal and private wells.

The results from some of the chemical tests performed on these Auglaize County wells are given in Table 1. The chemical constituents listed are total dissolved solids, hardness (as CaCO₃), calcium, magnesium, chloride, sulfate, fluoride, hydrogen sulfide, and pH. 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. 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.

Ground water, whether obtained from bedrock or glacial deposits, may require some treatment. In some areas, water containing calcium carbonate (CaCO₃, i.e. hard water), and other constituents 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 or sulfur odor). In general, the probability of obtaining sulfur in objectionable amounts increases with the depth drilled.

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 all of these wells were developed in the limestone underlying Auglaize County, and these wells are in the range of 228-380 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 Auglaize County wells.1
Well No.	1	2	3	4	AU-3	WQ Std2
Well Depth (feet)	260	228	280	300	380
Capacity (gpm)	60	800	275	500	480
Depth to Bedrock (feet)	72	24	55	45	52
Water-Bearing Formation3	LS	LS	LS	LS	LS
Chemical Constituents4
Total Dissolved Solids	nt5	1020	726	429	605	500
Hardness (as CaCO3)	513	783	554	350	450	none6
Calcium	nt	172	128	81	110	none
Magnesium	nt	86	57	36	43	none
Chloride	nt	8	48	4	6	250
Sulfate	nt	389	246	94	240	250
Fluoride	nt	1.5	1.1	1.9	1.1	2.0
Hydrogen Sulfide (H2S)	0	nt	2.0	1.7	2.6	none
pH	8.0	7.2	7.4	7.6	7.4	none
1 Data on these wells taken from map by R. J. Kostelnick, 1983; general location of each well is shown on Figure 1.
2 USEPA Secondary Water Quality Standard.
3 LS-Limestone.
4 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. Calcium and Magnesium: Main constituents of hardness. Primary concerns with hardness 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: 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. Hydrogen Sulfide: Presence of this unpleasant smelling gas is difficult to measure but not difficult to detect, even in small concentrations. Highly corrosive to pump parts and plumbing fixtures, but has no known harmful effects in humans. pH: Is expressed on a scale of 1 (acidic) to 14 (basic). A pH of 7.0 is neutral.
5 nt = not tested.
6 No USEPA Secondary Standard.

Summary

Auglaize 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 productive formations that underlay much of Auglaize County have the potential to provide excellent water adequate for domestic and agricultural uses, and many municipal 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 provides 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 Auglaize County office of Ohio State University Extension can provide other publications on the county's water resources. Your Extension agent, the Auglaize County Health Department, and Ohio EPA (NWDO, 347 North Dunbridge Rd., Bowling Green, OH 43404) 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 the map, Ground-Water Resources of Auglaize 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

Ground-Water Resources of Auglaize County. 1983. R. J. Kostelnick. 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 Resources of Auglaize County. 1994. J. M. Smith, K. T. Ricker and L. C. Brown. AEX-480.06. Ohio State University Extension.

Water Testing. 1988. K. Mancl. AEX 314. Ohio State University Extension.

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 Karen T. Ricker. Partial support for this publication was provided by these cooperating agencies and programs: Ohio State University Extension, Auglaize County; Auglaize County Farm Bureau; Ruth Arnold Steva Endowment Fund for Auglaize Extension; Auglaize Soil and Water Conservation District; Overholt Drainage Education and Research Program; and the Ohio Management Systems Evaluation Area Project (USDA Extension Service Grant No. 90-EWQI-1-9018).

The project leaders acknowledge the following reviewers: Steve McDevitt (USDA-Soil Conservation Service, Auglaize County); Marvin L. Selhorst (Auglaize County Health Department); Jim Tester (Well Driller); Doug Reinhart (Auglaize County Engineer); Scott Golden (Environmental Health, ODH); Steve Hindall (USGS, Ohio District); and (Tim Fishbaugh, Ohio EPA, NWDO).

A special thanks to Donna Mann (Auglaize County Extension Office), Michelle Roby, Ross Roberts, and John Humphreys (Agricultural Engineering Undergraduate Assistants) for help in graphic and manuscript preparation, and Kim Wintringham and Ted Hattemer, Associate Editors (Section of Communications and Technology, Ohio State University Extension), for editorial and graphic production.