The proliferation of unconventional oil and gas development over the last two decades has raised concerns about impacts to surface and ground waters. Contamination associated with hydraulic fracturing introduces hydrocarbons and other harmful pollutants to drinking water sources. In this study, we evaluated the impact of a well communication event (frac-out) that occurred on June 19, 2022, in New Freeport, Pennsylvania. Over two years, 75 residential well and surface water samples were collected from surrounding areas and analyzed for anions, cations, and light hydrocarbons. Each sample was then assigned a Multi-component Contamination Index (MCI) (on a scale of 0–6) based on mass ratio space analysis (Ca/Sr, Br/SO4, SO4/Cl, Mg/Na, Mg/Li) and presence of light hydrocarbons (i.e., methane, ethane, and propane) to assess the level of impact. Results revealed evidence for oil and gas brine contributions to water chemistries as well as fugitive methane with 62% of the well water samples having an MCI greater than 4. 71% had methane, with 19% above 10 ppm. Geospatial analysis determined the extent of the contamination was wider than initially reported. Our results verify that unintended communication events can result in widespread contamination of subsurface water sources broader than current regulatory specified impact zones.
Cantlay et al. (2025) studied this question.