Quantifying the success or failure of states in effectively and safely managing natural gas development is important for regulators, elected officials, and citizens to engage in productive dialog around natural gas development and the process of hydraulic fracturing. Accordingly, this study provides a detailed analysis of notices of violations from the Pennsylvania Department of Environmental Protection from January 2008 to August 2011, categorizing each violation for 3533 wells drilled. Of the 2988 violations, 1844, or 62%, were for administrative or preventative reasons. The remaining 38%, or 1144 notices of violations, were for environmental violations, which were associated with 845 unique environmental events. These events were classified into major and nonmajor categories based on the level and severity of the pollution. Blowouts, uncontrolled venting, and gas migration are considered as severe and, hence, are classified as major. The top quartile of water contamination and land spills is 400 gal and provides the threshold in this study for major events in these two categories. Of these major events, less than 1% or 25 involved these major impacts. In all but six of these cases, the resulting environmental impacts have been completely mitigated. The 820 nonmajor environmental events concern site restoration, water contamination, land spills, and cement and casing events, which do not involve what is classified as having major environmental impact. The number of polluting environmental events per well drilled declined by 60% between 2008 and August 2011, from 52.9% of all wells drilled in 2008 to 20.8% to August 2011. The regulatory data evaluated in this study may serve as an appropriate litmus test for neighboring states as they move forward with regulating shale energy development. In particular, we find that each of the underlying causes associated with these specific events could have been either entirely avoided or mitigated under the proposed regulatory framework of the New York State.