Water/Sediment Interactions with Coalbed Methane Discharge Water in an Ephemeral Stream Channel.
(A05-patz227430-oral)
Authors:
M.J. Patz* - Univ. Of Wyoming K.J. Reddy - Univ. of Wyoming Q.D. Skinner - Univ. of Wyoming
Abstract:
Extraction of methane (natural gas) from coal deposits is facilitated by pumping of associated aquifer water. Coalbed methane (CBM) product water, produced from pumping of ground water, is
discharged into associated unlined holding ponds or downstream stream channels. The objective of this study was to examine the interaction of CBM product water with ephemeral stream channel sediment in the Powder River Basin, Wyoming. Water samples were collected bimonthly on seven channel flow locations and three discharge wells. Before sample collection, the pH, electrical conductivity (EC), temperature, dissolved oxygen (DO), and turbidity were measured in the field. Samples were analyzed for alkalinity, major cations and anions, and trace elements. Results suggest that Ca2+ concentrations decreased significantly in downstream flow due to the precipitation of calcium carbonate, which increased the sodium adsorption ratio (SAR). Dissolved concentration of iron (Fe) and manganese (Mn) concentrations decreased, while dissolved arsenic (As) and selenium (Se) concentrations increased in the channel flow. High SAR values recorded in tributary flow of CBM product water suggest further monitoring is needed to evaluate the buffering capacity of receiving streams and rivers in the Powder River Basin.
Speaker Information: Marji Patz, Univ. Of Wyoming, USDA - NRCS % Marji Patz PO Box 569, Ogallala, NE 69153; Phone: 308-284-2048 ext.3; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 1:25 PM-2:45 PM Presentation Start: 2:00 PM