Coalbed Methane Groundwater Model

Background and Purpose

Groundwater withdrawal during coalbed-methane production, upgradient from where the produced coal seam subcrops to streams, has the potential to reduce baseflow to those streams. Isotopes such as carbon and strontium have been shown to effectively fingerprint the groundwater contribution to surface water in the Powder River Basin. Geochemical parameters will be combined with traditional in-stream flow measurements to identify – and perhaps quantify – the contribution to Powder River Basin streams from coal aquifer baseflow. The ability to quantify the impact to surface water from upgradient energy development will aid in the acquisition of the necessary permits that will allow the energy producers to use the coproduced water for beneficial purposes, rather than treat it as a waste product.

Project Scope

This GWIP study examines the contribution from coal aquifers to streams in the Powder River Basin, including the Tongue River and Hanging Woman Creek, through the following tasks:

  • Determine the location of major coal outcrops
  • Monitor the water-level elevation for coal and alluvial aquifers, as compared to the elevation of the streambed, using wells near the coal outcrop
  • Measure stream gain or loss across the coal outcrop 
  • Geochemically characterize the coal aquifers and look for chemical signatures from the coal in the streams
  • Using geochemical mixing equations, compare calculated contributions to the stream from the coal aquifers to the measured gain in flow rate across the coal aquifer
Knoblock outcrop

Knoblock Outcrop

Project Duration:
Duration: July 2012 to June 2013

GWIP Personnel Assigned:

Elizabeth Meredith – Team Leader/Hydrogeologist
406.272.1601 (office)
Email Liddy

Simon Bierbach – Field Technician
406.272.1604 (office)
email Simon

Project Fact Sheet (pdf file)

Publications and Reports:

Coal aquifer contribution to streams in the Powder River Basin, Montana —21 March 2016, Journal of Hydrology, Elizabeth Brinck Meredith

Project data available here: /v11/menus/menuProject.asp?mygroup =GWIP&myroot=BWIPPRB&ord=1&

Contact information :