What can we learn about the use of the criminal negligence provisions of the federal Clean Water Act (CWA) by reviewing prior environmental crimes cases brought by the federal government? In an effort to answer that question, the authors have completed the first ever statistical analysis of all federal criminal negligence prosecutions brought since the CWA Amendments of 1987 created separate felony and negligence provisions. The results of that analysis are described below. It reveals clear patterns to past charging decisions of federal prosecutors, and suggests likely future trends.

Virtually all federal pollution control statutes contain criminal enforcement provisions.¹ Generally, the mental state that the government must prove for a conviction is that the defendant acted "knowingly," that is, the violative acts must be voluntary and intentional and not the result of an accident or mistake of fact.² However, in addition to crimes based on knowing conduct, the CWA also makes certain violations a crime if committed negligently.³ The potential reach of these criminal negligence provisions is extremely broad.⁴ For example, any violation of a national pollutant discharge elimination system (NPDES) permit, or spill of a pollutant into waters of the United States attributable to negligent operation, training, or supervision, may theoretically meet the elements of the crime. The government has not applied these provisions that broadly, and the question therefore becomes: why are certain negligent violations of the CWA selected for criminal prosecution and others not?