Investigation of De-Watering at Byesville No. 1 Well Field
Ohio Division of Mineral Resources Management, Columbus, OH
The Village of Byesville has two water well fields, one on the western side of the village in the Chapman Run Valley, and one field to the east. Four of the water wells in the western well field had a severe decline in yield beginning in December 2001. An investigation into the cause of the decline identified dewatering operations at a surface coal mine located approximately 1.9 miles to the southwest of the western well field as the probable cause.
Byesville’s No. 1 well field included seven wells capable of production from 1988 through 2001. Four wells produce from the Upper Freeport coal seam, which locally is a fresh water bedrock aquifer, and three wells produce from unconsolidated fluvial sediments. In the period December 2001 – February 2002, two of the bedrock wells were taken off-line.
The Upper Freeport coal seam was being strip-mined approximately 1.9 miles to the southwest of the water well field. Because the Upper Freeport seam is below local drainage level at the surface mine, dewatering of the mine was necessary.
The elevation of the Upper Freeport seam is approximately 15 to 25 feet lower at the coal mine than at the village well field. There are several underground mines in the Upper Freeport seam in the area beneath and extending to the west and south of Byesville. The mines as shown on a common base map have very thin barrier pillars or boundary zones of coal between the mines.
Dewatering operations at the surface mine affected water levels in the connected abandoned underground mine complexes that extend to the Byesville water well field. This resulted in lower water levels in the municipal wells and reduced yield in the water well field.
AAPG Search and Discovery Article #90031©2004 AAPG Eastern Section Meeting, Columbus, Ohio, October 3-5, 2004