A Flux Based Approach for Monitoring Hydraulic Fracturing Constituents in Groundwater

A major challenge in documenting the presence or absence of compounds in groundwater related to hydraulic fracturing activities is the lack of high quality baseline data. While no method is capable of generating bassline data after hydraulic fracturing activities have begun in a region of interest, by switching to a flux based measurement approach, flux and mass discharge of constituents can be quantified using a simple mass balance framework to better assess the source of mass and proximity to activities. This allows for further characterization of a potential link to hydraulic fracturing activities. Some potential compounds of interest include benzene, phenanthrenes, naphthalene, 1-methylnapthalene, 2-methylnapthalene, fluorenes, aromatics, ethylene glycol, methanol and methane.

The passive flux meter (PFM) technique is ideally suited to enhance monitoring of compounds related to hydraulic fracturing. The PFM device uses sorbents to accumulate compounds of interest and alcohol tracers pre-equilibrated on a permeable sorbet to quantity groundwater flow. The PFM is placed in a monitoring well screen for a few weeks to characterize solute and water flux during the deployment duration. While most of the compounds listed above have been tested in previous applications, a sorbent for methane is currently being evaluated. Zeolites look like a promising sorbent for methane.