Although criminal provisions vary among the statutes, the basic elements of environmental criminal violations are an act that violates a statute's provisions and the intent to so violate the statute. Criminal violations that the acts have in common are making false statements, failing to file required reports, failing to pay required fees, operating without a permit, and violating the limits or conditions of a permit. To be convicted of a violation, the environmental criminal provisions generally require the mental state of "knowing" the actions at issue if the charge were occurring. The courts have declined to interpret "knowing" as having to include knowledge that the conduct is unlawful. The article discusses the elements of an offense, defenses, and penalties under the Clean Air Act, whose general purpose is to protect and enhance the quality of the Nation's air resources. Also discussed are the purpose, elements, defenses, and penalties of the Rivers and Harbors Act of 1899, whose purpose is to protect the integrity of navigable waters and the viability of commercial shipping activity by regulating deposits of refuse matter. The same features are discussed for the Clean Water Act, which is intended to restore and maintain the chemical, physical, and biological integrity of the Nation's waters by minimizing the effects of water pollution. Other statutes profiled are the Safe Drinking Water Act; the Comprehensive Environmental Response, Compensation, and Liability Act; the Resource Conservation and Recovery Act; the Toxic Substances Control Act; the Federal Insecticide, Fungicide, and Rodenticide Act; and the Endangered Species Act. 605 footnotes