EFFECTS OF SURFACE COAL MINING AND RECLAMATION ON GROUND WATER IN SMALL WATERSHEDS IN THE ALLEGHENY PLATEAU, OHIO By Michael Eberle and Allan C. Razem U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 85-4205 Columbus, Ohio 1985 UNITED STATES DEPARTMENT OF THE INTERIOR DONALD PAUL HODEL, Secretary GEOLOGICAL SURVEY Dallas L. Peck, Director For additional information Copies of this report can write to: be purchased from: District Chief Open-File Services Section Water Resources Division Western Distribution Branch U.S. Geological Survey U.S. Geological Survey 975 West Third Avenue Box 25425, Federal Center Columbus, Ohio 43212 Denver, Colorado 80225 (Telephone: (303) 236-7476) CONTENTS Page Abstract - 1 Introduction - 1 Background 1 Purpose and scope - 3 Hydrogeologic setting of Ohio's coal region- 3 Data coll ection 5 Ground-water conditions at the study watersheds- 6 Conditions before mining and reclamation 6 Physical characteristics and hydrology- 6 Ground-water quality 6 Conditions after mining and reclamation - 8 Physical characteristics and hydrology- 8 Ground-water quality - 8 Significance of results - 8 Selected references - - 12 Glossary - 13 ILLUSTRATIONS Figure 1-2 Maps showing locations of: 1. The Eastern Coal Province and the unglaciated Allegheny Plateau - 2 2. Study watersheds and Ohio's coal region 4 3 Generalized stratigraphic column of sedi­ mentary rocks between coal beds 6 4 Conceptual diagram of the ground-water flow system typically found in Ohio's coal region 7 5. Hydrogeologic section showing changes re­ sulting from surface mining at watershed Jll - 9 6. Graphs showing median values for .selected physical properties and chemical constit­ uents before mining and after reclama­ tion of the study watersheds - 11 TABLES Tables 1. Summary of selected physical characteristics and historical data for watersheds M09 f C06, and Jll 5 2. Comparison of water quality before and after mining and reclamation at watersheds M09, COG, and Jll 10 Hi CONVERSION FACTORS For the convenience of readers who prefer to use metric (International System) units, conversion factors for inch-pound units used in this report are listed below: Multiply Inch-Pound units By To Obtain Metric Units foot (ft) 0.3048 meter (m) acre 0.4047 square hectometer (hm2 ) To convert hardness from milligrams per liter to grains per gallon, multiply by 0.05841. ABBREVIATIONS mg/L milligram per liter jug/L microgram per liter juS/cm microsiemen per centimeter (at 25° C) iv EFFECTS OF SURFACE COAL MINING AND RECLAMATION ON GROUND WATER IN SMALL WATERSHEDS IN THE ALLEGHENY PLATEAU, OHIO By Michael Eberle and Allan C Razem ABSTRACT The hydrologic effects of surface coal in the middle aquifers were about the same mining in unmined areas is difficult to after reclamation as before mining, al­ predict, partly because of a lack of ade­ though levels rose in a few places. It ap­ quate data collected before and after min­ pears that the underclay at the base of the ing and reclamation. In order to help new top aquifers at all three sites pre­ provide data to assess the effects of sur­ vents significant downward leakage from the face mining on the hydrology of small ba­ top aquifer to lower aquifers except in sins in the coal fields of the eastern places where the layer may have been dam­ United States, the U.S. Bureau of Mines aged during mining. sponsored a comprehensive hydrologic study at three sites in the Ohio part of the Water in the new top aquifers is a Eastern Coal Province. These sites are calcium sulfate type, whereas calcium bi­ within the unglaciated part of the Alle­ carbonate type water predominated before gheny Plateau, and are representative of mining. The median specific conductance of similar coal-producing areas in Kentucky, water in the new top aquifers was about 5 West Virginia, and Pennsylvania. The U.S. times greater than that of the original top Geological Survey was responsible for the aquifers in two of the watersheds, and ground-water phase of the study. 1 1/2 times the level of the original top aquifer in the third. Concentrations of The aquifer system at each watershed dissolved sulfate, iron, and manganese in consisted of two localized perched aquifers the top aquifers before mining generally (top and middle) above a deeper, more re­ did not exceed U.S. and Ohio Environmental gional aquifer. The premining top aquifer Protection Agency drinking-water limits, was destroyed by mining in each case, and but generally exceeded these limits after was replaced by spoils during reclamation. reclamation. Water-quality changes in the middle aquifers were minor by comparison. The spoils formed new top aquifers Water levels and water quality in the that were slowly becoming resaturated at deeper, regional aquifers were unaffected the end of the study period. Water levels by mining. INTRODUCTION Background The Eastern Coal Province of the coal province depend on ground water for United States (fig. 1) has been one of the their domestic water supplies. Moreover, world's leading coal-producing areas in the hydrologic effects of surface mining recent years. In 1981, the amount of coal are of particular concern to mine operators produced in Ohio, Kentucky, Pennsylvania, and regulatory officials because the Sur­ an.d West Virginia alone was 47 percent of face Mining Control and Reclamation Act of the total production in the United States 1977 (Public Law 95-87) requires that every and more than 9 percent of the total world application for a surf.ace-mining permit production (U.S. Bureau of the Census, contain a determination of the "probable 1984). Much of the coal in the Eastern hydrologic consequences" of the mining Coal Province is surface mined. operation both on and off the mine site. The effects of surface mining on Unfortunately, the relations between ground water have been a matter of concern surface mining and the impacts on ground ever since surface mining became widespread water are not understood well enough to be around the middle of the twentieth century. adequately predicted in many cases. An Ground-water quality is of major concern example of this is the lack of data docu­ because it is a primary determinant of the menting ground-water quality before and water quality of base flow in streams, and after surface mining and reclamation at because many rural residents in the eastern specific sites. '^MARYLAND NORTH CAROMNA EXPLANATION I___[Eastern Coal Province SOUTH CAROLINA Approximate boundary of the unglaciated Allegheny Plateau (Fenneman. 1938) 0 100 MILES 0 100 KILOMETERS \ Base from ' U.S.GeologJcal Survey Figure 1. Location of Eastern Coal Province and the unglaciated Allegheny Plateau. In order to obtain data necessary for shale strata. The coal beds in watershed understanding relations between surface M09 were in limestone and shale strata. mining and the effects on hydrologic sys­ The watersheds were mined beginning with tems, the U.S. Bureau of Mines sponsored a C06 in November 1976. Reclamation was com­ comprehensive study to assess the effects pleted at M09, C06, and Jll in that order of surface mining and reclamation on the (table 1). hydrology of small watersheds (30-50 acres) in Muskingum, Coshocton, and Jefferson This summary, which is not solely for Counties in Ohio (fig. 2). The geology of a technical audience, is based primarily the study watersheds (referred to as water­ on reports by Razem (1983, 1984) and on sheds M09, C06, and Jll, respectively) is data from the U.S. Department of Agricul­ similar to that in the coal-producing areas ture, Agricultural Research Service. De­ in much of eastern Ohio, eastern Kentucky, tailed information on these watersheds can West Virginia, and western Pennsylvania be found in these and other works listed in (Brant and DeLong, 1960, p. 21). This re­ tne selected references. The information gion is in the unglaciated Allegheny Pla­ presented in this report should be useful teau section of the Appalachian Plateaus to .coal-mine operators, government offi­ physiographic province (Fenneman, 1938; cials, residents of the Eastern Coal Prov­ fig. 1). ince, and others who are interested in issues related to coal production, land Four agencies the U.S. Department of reclamation, and ground water. Agriculture, Agricultural Research Service; The Ohio State University, Ohio Agricultur­ al Research and Development Center; the U.S. Soil Conservation Service; and the Hydrogeologic Setting of Ohio's Coal Region U.S. Geological Survey were responsible for the design of the study and for the collection and analysis of data. Topics of Coal-bearing strata of eastern Ohio study included erosion and sedimentation, (fig. 2) consist of sedimentary rocks that surface-water quantity and quality, ground- range in age from the Mississippian Period water quantity and quality, and the econom­ (360-330 million years ago) to the Permian ics of mining and reclamation. The U.S. Period (290-240 million years ago). Most Geological Survey was responsible for the of the rocks cropping out in the study ground-water phase of the study. area, however, were deposited during the Pennsylvanian Period (330-290 million years ago). Purpose and-Scope The Pennsylvanian rocks of Ohio con­ sist of cyclical sequences of shale, sand­ stone, thin limestone', coal, and clay (fig. The purpose of this report is to pro­ 3). Water-bearing characteristics differ vide an overview of the effects of surface considerably among these strata, owing pri­ coal mining and reclamation on ground-water marily to differences in tne size and num­ systems of small watersheds in order to il­ ber of pores and fractures in the rocks. lustrate some typical hydrologic systems in Clay and shale layers, which commonly un­ the Eastern Coal Province. The report pre­ derlie the coal beds, considerably restrict sents background information on geology in the downward movement of ground water Ohio's coal region, and summarizes data on (Norris, 1969, p.