Ohio Groundwater Forum: Protecting and Managing Groundwater for the Future : Alphabetical Content Listing
2013 William A. McEllhiney Distinguished Lecture Series in Water Well Technology — Keeping the Pump Primed: Aquifer Sustainability
John Jansen, P.G., P.Gp., Ph.D.
Numerical Groundwater Flow Modeling of a Northern Appalachian Coal Basin Bedrock Valley Exhibiting Stress-Relief Fractures
Real-Time Monitoring System for Evaluating Long-Term Variability in Methane in Domestic Water Wells in Pennsylvania
Richard Wardrop, PG
Real-time remote monitoring and data trend analyses are being utilized to understand natural dissolved methane fluctuations in groundwater and correlations between methane headspace concentration in the well annulus and other physical and chemical parameters, which could correlate to changes in headspace concentration. Significant efforts were made to select, evaluate, and prepare the wells for the study including borehole geophysics, well equipment upgrades, and installation of water-treatment systems. Descriptions of the customized real-time remote monitoring equipment, array of well headspace and water-quality sensors utilized, and equipment setup will be presented, as well as the associated challenges and logistics. Barometric pressure, water use, water quality, well recharge, water-level fluctuations, and pump cycling are examples of the variables monitored.
The results from the study will be presented, including discussion of well construction, geologic settings, water quality, initial trends and findings, and real-time display of data. The usefulness of the data and the accuracy/precision of sensors will be discussed. The long-term study will provide further information to better understand the occurrence and potential causes of methane fluctuations in groundwater and associated water well quality issues in northeast Pennsylvania.
Groundwater Protection Within Shale Gas Areas: Examples from Pennsylvania Source Water Protection Technical Assistance Program
Alfred C. Guiseppe, PG
Water systems face many threats to the water quality of their supply. Taking a proactive approach to source water protection lessens the risk of a catastrophic loss of a water supply. The examples provided in this presentation illustrate the advantages to utilizing groundwater computer models for source water protection measures.
Relationship between pH and Dissolved Methane Concentrations in Groundwater from Water Wells in Northeastern Pennsylvania
Nancy Pees Coleman, Ph.D.
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.
Paul Wendel, Ph.D.
John Boulanger, PG
This presentation will explore the occurrence and distribution of methane in groundwater prior to unconventional gas development. GIS-based mapping and statistics will be used to evaluate the geographic distribution and relationship to bedrock geology. The relationships between methane and other parameters can also help explain methane occurrence, including parameters such as ethane and propane, alkalinity, TDS and major ions, barium, etc.
Better understanding of methane in shallow groundwater will lead to better decision-making when evaluating potential impacts of shale gas development on water supplies and stray gas occurrence.
E. Scott Bair, Ph.D.
Stuart A. Smith, CGWP
Hydrogeological Investigation of the Carbonate Bedrock Aquifer to Evaluate Impact High-Yielding Wells, Ottawa County, Ohio
Curtis J. Coe, CPG, PG
Previous work completed in this area confirms that the carbonate bedrock aquifer of northwestern Ohio contains a number of flow zones. The well completion diagram for the Luckey homestead farm well shows the extent to which the flow zones occur in the subsurface. Drilling data shows that the carbonate bedrock aquifer is anisotropic and heterogeneous in its configuration. This gives rise to a number of concerns that need to be considered before long-term pumping rates can be accurately calculated and the data used to design water supply systems.
Pumping test data shows that the transmissivity of the aquifer is not uniform throughout the aquifer. It can vary both in the vertical and horizontal directions, and may vary over short distances within the carbonate bedrock aquifer when there are significant variations in permeability as well as fracturing. This helps to explain major changes in yield over short distances in both the vertical and horizontal directions.
Field data obtained for this project shows that the pumping of the high-yielding water wells can have an impact on the local water supply wells. The degree of impact depends on the location of the water well relative to the pumping center and the pumping rate. It also depends on the flow zone from which the water well produces. A deeper high-yielding well can impact water supply wells completed in the upper flow zone in the carbonate bedrock aquifer.