Ohio State University Extension

Food, Agricultural and Biological Engineering

590 Woody Hayes Dr., Columbus, Ohio 43210

Brown County Ground-Water Resources

AEX-490.08

John F. Grimes
James M. Raab
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 Brown 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 Brown County, AEX-480.08.

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 Brown 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 two geological formations that yield ground water in Brown County are: consolidated bedrock consisting of thinly interbedded gray shales and limestones; and unconsolidated deposits of sand and gravel. The bedrock aquifer, which was deposited during the Ordovician age, is covered by a thin layer of material primarily of clay. In general, the bedrock aquifer provides very low yields of ground water, usually less than 3 gallons per minute (gpm), due to its impermeable nature. Even though well yields typically are small, the bedrock formation is an important, and often, the only source of domestic water supply in most of Brown County.

The unconsolidated deposits of sand and gravel adjacent to the Ohio River have the highest yield potential in the county. The yield depends on the thickness of the sand and gravel deposit, and its proximity to the Ohio River. Wells located next to the Ohio River can cause induced infiltration through the permeable river bottom during prolonged pumping periods. Yields as great as 700 gpm have been reported where recharge is available from the river. 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, 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 Brown County (adapted from map by D. J. Sugar, 1989). This illustration is based on a hydrogeologic interpretation of the well-log data from Brown 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 Brown County, Ohio (adapted from Brown County map, D.J. Sugar, 1989, ODNR Division of Water; illustration prepared by J Humphreys).

AREA A: Coarse-Grained Sand and Gravel

Area A of Figure 1 shows the location of permeable sand and gravel deposits adjacent to the Ohio River. These small areas, in which yields greater than 100 gpm may be developed, constitutes the best ground- water areas in Brown County. Yields of as much as 700 gpm have been reported near Higginsport where induced infiltration is available from the river. Other high-yielding wells are located near Ripley and Aberdeen.

AREA B: Thick Valley Sand and Gravel Lenses

Delineated as Area B, small areas of thick local deposits of sand and gravel are present adjacent to the villages of Higginsport, Ripley, and Aberdeen. Wells in these locations encountering permeable deposits may yield as much as 100 gpm.

AREA C: Clay, Sand and Gravel

Area C denotes locations of variable thicknesses of clay with thin lenses of sand and gravel yielding less than 10 gpm. Wells in this area that do not encounter the sand and gravel deposits produce less than 3 gpm from the underlying limestone and shale bedrock. These sand and gravel deposits can be found along much of Eagle Creek and at the lower end of Straight Creek and Whiteoak Creek near the Ohio River.

AREA D: Shale and Limestone

The bedrock aquifer consisting of interbedded limestones and shales, delineated as Area D, underlies the vast majority of Brown County. This aquifer is a poor source of water and it is found in all of the county's townships. Wells constructed in the bedrock seldom produce more than 3 gpm. Dry wells are not uncommon. Alternate supplies of water are often sought.

Figure 2 is a generalized cross section (referenced in Figure 1 as the line X- X') of a portion of Brown County. This cross section shows the geological formations of alternating beds of shale and limestone in the upper part of the Eagle Creek and Straight Creek basins running from just east of Georgetown to Adams County. Within this basin is the highest point in Brown County which is located near Ash Ridge (elevation of 1091 feet).

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

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.

Currently, the ODNR Division of Water does not monitor any wells in Brown County. However, from 1955 through 1974, one well was monitored by ODNR. It was located at Georgetown. This well, along with other wells throughout southwestern Ohio, was used to monitor the natural seasonal fluctuation of water levels in the bedrock aquifer. The Brown County Observation Well, BR-1, was 170 feet deep (no depth to bedrock was recorded). Continuous water level measurements were recorded at BR-1 from 1955 to 1974. The lowest level recorded at BR-1 during that period of record was 13 feet below land surface in September of 1970; the highest level was 10.5 feet below land surface in April of 1958. The Brown County Rural Water Association reported water levels in their wells remained constant during the recent drought period in 1987 and 1988.

A new observation well was established in Brown County in 1993. Observation Well BR-20 is located near Fincastle. More data will be forthcoming.

Ground-Water Quality

Various state and federal agencies have participated in programs to determine the ground-water quality in Ohio. For four wells in Brown 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. These sites are municipal and private wells.

The results from some of the chemical tests performed on these Brown County wells are given in Table 1. The chemical constituents listed are total dissolved solids, hardness (as CaCO₃), calcium, magnesium, iron, manganese, chloride, sulfate, fluoride, and sodium. 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 iron concentrations 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 or sulfur odor). In general, the probability of obtaining sulfur in objectionable amounts increases with the depth drilled into the bedrock formations.

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 these wells were developed in the sand and gravel underlying Brown County, and these wells are in the range of 71 to 121 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 Brown County wells1.
Well No.	1	2	3	4	WQ Std2
Well Depth (feet)	100	78	121	71
Capacity (gpm)	-3	-	30	700
Depth to Bedrock (feet)	100	ne4	120	ne
Water-Bearing Formation5	SG	SG	SG	SG
Chemical Constituents6
Total Dissolved Solids	312	355	309	344	500
Hardness (as CaCO3)	295	315	280	269	none7
Calcium	nt8	nt	98	86	none
Magnesium	nt	nt	9	23.5	none
Iron	0.05	0.05	0	-	0.3
Manganese	nt	nt	0	0.06	0.05
Chloride	9.0	6.0	5.8	16	250
Sulfate	nt	nt	84	27	250
Fluoride	nt	nt	0.1	0.26	2
Sodium	nt	nt	3.2	5	none
1. Data on well 1 taken from Underground Water Resources map L-3; well 2 from Underground Water Resources map L-1; wells 3 and 4 from map by D. J. Sugar, 1989; general location of each well is shown on Figure 1.
2. USEPA Secondary Water Quality Standard.
3. Data not available.
4. ne = well constructed in this formation did not encounter bedrock.
5. SG-Sand and Gravel.
6. 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. Iron and Manganese: Iron concentrations greater than 0.3 ppm and manganese concentrations greater than 0.03 may cause brown or black stains on laundry, plumbing fixtures and sinks. Metallic taste may be present which may affect the taste of beverages made from the water. Chloride: High concentrations 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. Sodium: Major component of brine. May impart a soda taste and be a dietary concern.
7 No USEPA Secondary Standard.
8 nt = not tested.

Summary

Brown 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 a small portion of Brown 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 Brown County office of Ohio State University Extension can provide other publications on the county's water resources. Your Extension agent, the Brown 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 the map, Ground-Water Resources of Brown 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 Brown County. 1989. D. J. Sugar. 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.

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 State University Extension.

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

Water Resources of Brown County. 1994. J. F. Grimes, K. T. Ricker and L. C. Brown. AEX-480.08. 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, Brown County; Brown County Rural Water Association, Brown 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: Delmar G. Pullins (Brown County Rural Water Association); Ed Campbell (USDA-Soil Conservation Service, Brown County); Scott Golden (Environmental Health, ODH); and Steve Hindall (USGS, Ohio District).

A special thanks to 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.