* NO PDH CREDIT*- January 2025 Meeting: Amanda Campbell (SUNY Oswego)

Regulatory agencies routinely assess the presence of stray gas released from unconventional HVHF gas wells by sampling for methane in nearby groundwater after the well is drilled or if citizens complain about methane in their water. We studied whether methane concentrations in groundwater naturally varies through time in NY to test the assumption that pre-drilling observations of well water quality can be reliable measures for assessing impacts of later gas drilling. This presentation focuses on our findings for 11 domestic water wells in southern NY and recommendations for pre-production water sampling. Further, some water wells are not tested pre-drilling. We trained decision tree models on observational data and found they can predict which wells have high dissolved methane concentrations. These models can be used as a simple screening tool to identify domestic groundwater wells that are likely to contain high baseline methane concentrations.