Relationship between pH and Dissolved Methane Concentrations in Groundwater from Water Wells in Northeastern Pennsylvania

Coleman, Nancy Pees

Relationship between pH and Dissolved Methane Concentrations in Groundwater from Water Wells in Northeastern Pennsylvania

Wednesday, June 19, 2013: 3:55 p.m.

Nancy Pees Coleman, Ph.D. , Environmental Consultants, Oklahoma City, OK

Debby Yost McElreath , Chesapeake Energy Corp., Oklahoma City, OK

Charles Olmsted, PG, CPG , Chesapeake Energy Corp., Harrisburg, PA

Dissolved methane has been found in the groundwater from domestic water wells in many locations in northeastern Pennsylvania. The dissolved methane can be naturally occurring thermogenic, diagnetic, or biogenic, or sourced from anthropogenic activities. The presence of dissolved methane has been reported to be associated with changes in geochemistry including increases in pH. The relationship between temporal changes in the dissolved methane concentrations and the pH level were examined within individual domestic water wells.

Dissolved methane has been found to be variable in domestic water wells. These variations are attributed to several factors, including changes in atmospheric conditions, physical disturbances, anthropogenic sources, the action of water well pumping, etc. Sampling and laboratory analysis for dissolved methane requires specialized sampling and analytical techniques. Identification of a surrogate parameter that is amendable to direct measurement in the field, such as pH, would be highly desirable for use in screening and identification of domestic water wells requiring further evaluation. It has been suggested that changes in pH may be an appropriate surrogate.

Comprehensive and frequent monitoring data for dissolved methane, pH, and other water-quality parameters were available for four groups of domestic water wells: (1) wells with no known impact from oil and natural gas drilling activities (approximately 28 wells), (2) wells with known perturbation of natural gas from a natural gas production well, (3) domestic wells sampled prior to the initiation of oil and natural gas drilling activity (predrill samples), and (4) wells under investigation for complaints related to the presence of increased levels of dissolved methane (18 wells). Analytical data for these domestic water wells were evaluated for short-term temporal variability in dissolved methane and pH. The data were evaluated to determine if any consistent predictive relationship exists between dissolved methane and pH and other water-quality parameters in groundwater in northeastern Pennsylvania.

Nancy Pees Coleman, Ph.D., Environmental Consultants, Oklahoma City, OK

Nancy Pees Coleman is environmental toxicologist with Environmental Consultants in Oklahoma City, Oklahoma. She has over 30 years experience as an environmental toxicologist and public health professional. She has a B.S. from Old Dominion University and graduate degrees from the University of Oklahoma Health Sciences Center.

Debby Yost McElreath, Chesapeake Energy Corp., Oklahoma City, OK

Debby Yost McElreath is a senior environmental specialist with Chesapeake Energy in Oklahoma City, Oklahoma. Formerly, she was the quality assurance/quality control manager for a large multioffice environmental consulting firm. She has bachelors and master’s degrees from Oklahoma State University.

Charles Olmsted, PG, CPG, Chesapeake Energy Corp., Harrisburg, PA

Charles Olmsted is an environmental supervisor and hydrogeologist with Chesapeake Energy in Harrisburg, Pennsylvania. He has over 24 years experience as an environmental hydrogeologist. He has bachelor’s and master’s degrees from Utah State University.