Water Issues and Marcellus Shale Gas Development in New York

Science Center Objects

The Marcellus Shale of the Appalachian Basin is one of the largest unconventional gas plays in the United States. 

(grey-colored rock) Cherry Valley shale
Exposure of the Marcellus shale in central New York showing the Cherry Valley limestone (grey-colored rock) between the Union Springs and Oatka Creek shales of the Marcellus. (Credit: John Williams, USGS. Public domain.)

The Marcellus Shale is the most extensive of a series of Appalachian black-shale formations deposited in sediment-starved subsiding foreland basins during the Devonian Period. The targeted black shales in the Marcellus, which are delineated on geophysical logs by their elevated gamma radiation and low density, are organic rich and pyritic.

The Marcellus play is being developed in Pennsylvania, West Virginia, and Ohio at depths between 5,000 and 9,000 feet below land surface. Typically, six horizontal legs 4,000 feet long are drilled in the basal Marcellus per multi-well pad and 3 to 5 million gallons of water are used to hydraulically fracture each leg.

Water-resource issues associated with development of the Marcellus play include the 1) impact of surface-water and groundwater withdrawals for hydraulic fracturing during low-flow periods, 2) disposal of black-shale drill cuttings that may produce acidic, metals-rich drainage with elevated radioisotopes, and 3) treatment of hydraulic-fracturing flowback that contains elevated dissolved solids and radioisotopes. Surface spills of hydraulic-fracturing fluids and flowback and problems with casing and grout seals that allow migration of gas to freshwater aquifers pose the greatest threats to the water resources. 

well tower rig
Typical well drilling tower with associated equipment (Credit: John WIlliams, USGS. Public domain.)

Related Links:

Survey of Low-Flow Stream Water Specific Conductance in the Southern Tier of New York State

Water issues and the Marcellus Shale gas development in NY (NYWSC News Release)

The Marcellus Shale Gas Play - Geology, Development, and Water-Resource Impact Mitigation (Presentation)

Water-Supply Considerations within the Marcellus Shale Gas-Play Area of New York State (Handout)

Considerations for Protection of Water Resources in the Marcellus Shale Gas-Play Area of New York State (Poster)

Upstate New York Unconsolidated Aquifer Mapping Program (GIS Coverages)

Hydrogeology of Selected Valley-Fill Aquifers in the Marcellus Shale Gas-Play Area in the Southern Tier of New York State (Project Description)

Delineation of the Spatial Extent of Valley-Fill Aquifers in Five Counties in South-Central New York State (Project Proposal)

Natural Methane Occurrence in Water Wells of South-Central New York State - Evaluation of Topographic and Hydrogeologic Setting (Project Description)

Baseline Groundwater Quality in National Park Units Within the Marcellus and Utica Shale Gas Plays, New York, Pennsylvania, and West Virginia, 2011

 

 

backhoe loading big green tank with drill cuttings
Mixing of drill cuttings with absorbent polymer prior to shipping and disposal in a​​​​​​​ secured landfill. (Credit: John Williams, USGS. Public domain.)