Large-sample evidence on the impact of unconventional oil and gas development on surface waters

Lightly salted surface waters Hydraulic fracturing uses a water-based mixture to open up tight oil and gas formations. The process is mostly contained, but concerns remain about the potential for water contamination. Bonetti et al . found small increase in certain ions associated with hydraulic across several locations United States (see Perspective by Hill Ma). These increases appeared 90 180 days after new wells were put suggest some magnitude appears may require that more attention be paid monitoring near-well waters. —BG