Reconnaissance of mine drainage in the coal fields of eastern Pennsylvania

Abstract

Anthracite has been extensively mined in four areas of eastern Pennsylvania. Almost all underground mining in the four areas, the Northern, Eastern Middle, Western Middle, and Southern Fields, has been discontinued and many mines are abandoned and flooded. Precipitation on much of the 408 square miles of coal fields infiltrates to the underground mine complexes, and Is discharged as mine drainage from tunnels, mine entrances, and boreholes.Mine drainage was measured and sampled at 251 sites that had a total discharge of 918 cubic feet per second, a total sulfate load of 1,470 tons per day, and a total iron discharge of 79 tons per day. The largest sulfate yield was 5.4 tons per day per square mile from the Western Middle Field. The yields from the Northern, Eastern Middle, and Southern Fields were 4.6, 3.6, and 1.4 tons per day per square mile, respectively. Methods of StudyLocations of mine-water discharges were compiled from published reports and from information obtained from State and Federal agencies, and were verified in the field prior to sampling. Generally, sites having discharges of less than 0.1 ft 3 /s were not included in the 251 sites sampled during the study. Water-quality data were determined from unfiltered samples; except for dissolved iron, which was determined from filtered samples. Samples for laboratory analyses were collected and preserved following standard Geological Survey procedures. To supplement the sampling program, flow and water-quality data were collected monthly at 12 sites. The U.S. Bureau of Mines in Wilkes-Barre and Schuylkill Haven, and the Pennsylvania Department of Environmental Resources assisted with the data collection. DESCRIPTION OF THE STUDY AREA Coal FieldsThe term "anthracite region" as used in this report includes the four anthracite fields and surrounding areas, as shown in figure 1. Anthracite has been extensively mined in four separate coal fields in east-central Pennsylvania the Northern, Eastern Middle, Western Middle, and Southern. The coal fields underlie parts of 10 counties and extend from 20 mi northeast of Harrisburg to 20 mi northeast of Scranton. Their combined area is about 408 mi 2 .