Barry W. Ward
James M. Raab
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 Richland 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 Richland County Water Resources, AEX-480.70, are available through your county Extension office.
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 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.
Sandstone, and coarse sand and gravel aquifers are the principal sources of ground water in northeast Ohio, including Richland County. The sandstone aquifer in the county is made up of massive to thin-bedded formations of fine-grained to conglomerate sandstone, mostly quartz cemented by calcite, silica, iron and clay. The coarse-grained unconsolidated aquifers are composed of coarse sand and gravel with mixtures of clay and silt.
Sandstone formations are good sources of ground water because they have naturally formed openings that permit water to move through the bedrock readily. Most water in consolidated sandstone formations occurs in the spaces between the sand grains. The number of naturally formed fractures and openings in the sandstone and the depth of the deposit vary from one location to another. This fact affects the amount of water that may be encountered when drilling a well. The position of such openings and formations rarely can be determined from the land surface. Therefore, there is always some uncertainty as to the production capacity of a proposed well.
The unconsolidated aquifers in Richland County include glacial materials deposited in both valley and upland areas. The thickness and extent of the sand and gravel deposits determine the amount of storage space available for water. These deposits, which yield the highest quantity of water to wells in the county, are located mainly in the valleys of the Clear, Rocky and Black Fork rivers. The unconsolidated glacial deposits that cover most of the upland areas in these river basins include thick deposits of glacial till containing only occasional thin lenses of sand and gravel, and yield less water than the coarse-grained aquifers. 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.
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 map. The map presented in Figure 1 is a generalized representation of the water-bearing formations underlying Richland County (adapted from map by Schmidt, 1979). This illustration is based on a hydrogeologic interpretation of the well log data from Richland 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 Richland County, Ohio
(modified from J.J. Schmidt, ODNR Division of Water, by R.A. Roberts).
The sand and gravel aquifer illustrated in Figure 1 as area A underlies the Clear Fork River as it flows from the Clear Fork Reservoir south and east towards the Pleasant Hill Reservoir. The coarse materials in the buried valley of the Clear Fork ranges in thickness from 46 to 185 feet. A generalized cross section of this valley and two others within Richland county is illustrated in Figure 2 (referenced in Figure 1 as line X-X'), which shows the thickness of the unconsolidated material above the sandstone and shale bedrock.
Figure 2. Generalized cross section of Richland County, Ohio
(modified from Underground Water Resources map, P-1, ODNR Division of Water).
Wells in this area are normally drilled into thick layers of sand and gravel to take advantage of high well yields. This area has the highest potential for development of municipal and industrial ground-water supplies. The thick permeable deposits of sand and gravel yield 400 to more than 1,000 gpm, yields, which are normally encountered at depths of 65 to 145 feet.
Water quality in this area is generally good, although the hardness of the water is much greater in this aquifer than the sandstone aquifers. However, the iron content of the water from the sand and gravel aquifer may be high enough to require treatment.
Area B illustrates unconsolidated material covered by thick deposits of glacial till, which contains numerous thick lenses of water-bearing sand and gravel. Yields ranging from 200 to more than 500 gpm are developed from the permeable sand and gravel encountered at depths of about 120 to 275 feet. Test drilling may be necessary to locate the more permeable deposits which partially fill these ancestral drainage channels.
The aquifer shown as Area C is characterized by moderately permeable sand and gravel deposits interbedded with clayey till. These aquifers follow closely along the Black Fork, Cedar Fork and parts of the Clear Fork river basins. Water-bearing deposits of sand and gravel may be encountered at depths of 105 to 130 feet. Yields for farm and household supplies are readily available. Extensive drilling may be necessary to develop small public supplies. Yields of 25 to 100 gpm are possible from this aquifer. Deep drilling through as much as 335 feet of sandy clay may only encounter small domestic supplies from the underlying shaley-sandstone bedrock.
Area D is part of the regional sandstone aquifer of northeast Ohio. An average of 50 feet of glacial till covers these sandstone and shale formations. The alternating sandstone and shale of the Cuyahoga Group are the principal sources of ground-water supplies in this area. Yields of 5 to more than 20 gpm are readily available. Drilling contractors may encounter thick deposits of clayey till interbedded with lenses of permeable sand and gravel in the morainal areas. Small supplies for domestic use are available from these unconsolidated formations, although most wells are developed in the bedrock at depths of 50 to 275 feet. Industrial and municipal supplies of more than 150 gpm have been reported for properly constructed, large-diameter wells at depths of 350 feet.
Interbedded with Clayey Till Thin lenses of sand and gravel interbedded in thick clayey till deposited in buried valleys are shown as Area E. These thin lenses may yield up to 9 gpm at depths of less than 150 feet. If water-bearing deposits are not encountered, wells may be developed in the underlying shaley-sandstone bedrock, although dry wells do occur.
Area F is characterized by wells developed in the glacial deposits at depths of 35 to 80 feet. Wells in this area generally yield 3 to 8 gpm, and dry wells are common. Deeper drilling into the underlying shale and shaley-sandstone bedrock yields meager supplies of brackish water.
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 effect water levels in wells. The ODNR Division of Water monitors ground-water levels in two wells in Richland County: one located in Shiloh is designated as R-3 on Figure 1; the other located in Mansfield is designated as R-4. These are two of a number of wells throughout northeast Ohio used to monitor the natural seasonal fluctuation, or the effects of nearby pumping, on water levels in the regional sandstone, or sand and gravel aquifers.
Observation wells R-3 and R-4 are 150 and 127 feet deep, respectively, and both are completed in sand and gravel. They are representative of many wells in the region. Continuous water-level measurements have been recorded at R-3 since April 1946 and at R-4 since May 1942. The lowest level recorded on R-3 (Shiloh) was 35.9 feet below land surface in February 1981; the highest level recorded was 23.7 feet below land surface in June 1947. The lowest level recorded from R-4 (Mansfield) was 60.1 feet below land surface in October 1962; the highest level recorded was 15.5 feet below land surface in July 1987.
Various state and federal agencies participate in programs to determine ground-water quality in Ohio. For Richland County, water-quality data were available from the ODNR Division of Water and the Ohio EPA Division of Drinking and Ground Water for six wells. In Figure 1, these wells are noted as Chemical Analysis Sites 1 through 6, and are either municipal or commercial supplies.
The results of some of the chemical tests performed on these Richland County wells are given in Table 1. The chemical constituents listed are total dissolved solids, hardness (as CaCO3), iron, sulfate and chloride. 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 six of these wells were developed in sandstone, or a sand and gravel formation underlying Richland County, and all are in the range of 44 to 303 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 Richland County wells. | |||||||
---|---|---|---|---|---|---|---|
Well No. | 1 | 2 | 3 | 4 | 5 | 6 | WQ Std1 |
Well Depth (feet) | 90 | 44 | 303 | 240 | 200 | 200 | |
Capacity (gpm) | 300 | -2 | 185 | 100 | 200 | 600 | |
Depth to Bedrock (feet) | NE3 | NE | 30 | 5 | 95 | - | |
Water-Bearing Formation4 | SG | S | SS | SS | SS | SG | |
Chemical Constituents5 | |||||||
Total Dissolved Solids | 448 | 1,314 | 226 | 200 | 406 | 252 | 500 |
Hardness (as CaCO3) | 321 | 883 | 145 | 157 | 338 | 213 | None6 |
Iron | 0.4 | 15 | 0.05 | 0.05 | 0.94 | 4.8 | 0.3 |
Sulfate | - | - | - | - | 47 | 17 | 250 |
Chloride | 6 | 10 | 2 | 4 | - | - | 250 |
1 USEPA Secondary Water Quality Standard. | |||||||
2 Data not available. | |||||||
3 Well constructed in this formation did not encounter bedrock. | |||||||
4 SG-Sand and Gravel; S-Sand; SS-Sandstone. | |||||||
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. 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 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; may also affect the taste of water and form a hard scale in boilers and heat exchangers. Chloride: High concentrations may result in an objectionable, salty taste to water and the corrosion of plumbing in the hot water system. | |||||||
6. No USEPA Secondary Standard. |
Richland 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.
The Richland County Extension office can provide other publications on the county's water resources. Your Extension agent, the Richland County Health Department 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, 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 Richland County, and other information available through the Division of Water. This map is much more detailed than that given in Figure 1. Personnel in the Ground-Water Resources Section can provide detailed information on ground-water availability and wells. The USGS, Ohio District (975 West Third Ave., Columbus, OH 43212), also provides information about ground water in Ohio.
Ground-Water Resources of Richland County. 1979. 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.
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.
Richland County Water Resources. 1992. B.W. Ward, K.M. Boone and L.C. Brown. AEX-480.70. Ohio Cooperative Extension Service, The Ohio State University.
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, Black and Clear Fork Basins, Map P-1. 1962. ODNR Division of Water.
Water Testing. 1988. K. Mancl. AEX-314. Ohio Cooperative Extension Service, The Ohio State University.
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; Richland County Extension office; Richland 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: David Cashell (ODNR Division of Water); Scott Golden (Environmental Health, ODH); Tom Bean (Agricultural Engineering, OSU); Steve Hindall (USGS, Ohio District); and Tim Fishbaugh (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 Communications & Technology, OSU Extension) 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