Roger MarzullaUnclear environmental laws and vague regulations defeat their stated purpose—environmental protection. The success of our framework of environmental laws and regulations depends on how well people follow the regulations’ mandates and prohibitions. But if no one can understand them, and no one knows what is required or prohibited, these laws will not achieve their intended result. The more complex the regulatory regime, the less clear the laws and regulations, and the more difficult it is for the most well-intentioned individual to comply because he or she cannot ascertain what is expected. Imprisoning people for unintentional violation of ambiguous laws and regulations undermines the principles of fairness, due process, and respect for the law—all of which underlie the legal rule called “lenity.”

The Rule of Lenity

The rule of lenity is a judicial doctrine that requires ambiguous criminal laws to be interpreted in favor of persons subjected to them.

This venerable rule not only vindicates the fundamental principle that no citizen should be held accountable for a violation of a statute whose commands are uncertain, or subjected to punishment that is not clearly prescribed. It also places the weight of inertia upon the party that can best induce Congress to speak more clearly and keeps courts from making criminal law in Congress’s stead.1

Reasons for the Rule of Lenity

• Due process: It is unfair to convict a person who cannot determine what the law requires.

• Deterrence: A person cannot act in accordance with a statute that is unclear; therefore, the statute will not have the desired deterrent effect.

• Separation of powers: Congress, and not the courts, must decide what conduct is criminal under our constitutional system.

The Rule of Lenity and Environmental Crimes

Some aspects of important environmental statutes are ambiguous. Consider, for example, the statutory definitions of “wetlands,” “take” (of endangered species), or “hazardous waste,” all of which have been repeatedly defined by regulations, agency interpretative memoranda, as well as often- conflicting court decisions. Consider the example given by leading environmental criminal attorney, Judson Starr:

If [a] solvent is poured first on the machinery and then wiped with a clean rag, the rag is a hazardous waste. However, if the solvent is poured first on the rag and then is used to wipe the machinery clean, the rag is not a hazardous waste. Go figure.2

According to Don R. Clay, former Assistant Administrator for the EPA Office of Solid Waste and Emergency Response, only about five people in the agency actually know what a hazardous waste is.3

Environmental issues, which are often contentious in Congress, can result in a compromise statute that is less than clear. For example, the Supreme Court has twice re-defined “navigable waters” in the Clean Water Act,4 yet Congress has not yet mustered the support to adopt a definition.

Environmental law is often aspirational. The Clean Water Act, for example, prohibits discharge of all pollutants (even water that is cleaner than the stream it is discharged into) and required the cessation of all discharges by 1985.5 But as of the date of this article, discharges are still occurring. This physical inability of entities to comply with certain environmental statutes and regulations breeds a level of disregard and even disrespect for environmental regulatory regimes.

Environmental protection, which requires clarity in prescribing conduct, is lost when regulated companies and individuals are convicted of acts that they could not know were criminal—or even against the law. As one federal judge stated:

In a reversal of terms that is worthy of Alice in Wonderland, the regulatory hydra which emerged from the Clean Water Act mandates in this case that a land owner who places clean fill dirt on a plot of subdivided dry land may be imprisoned for the statutory felony offense of “discharging pollutants into the navigable waters of the United States.”6

The Prosecution of Ambiguity

In the 1980s Congress passed laws making violation of many environmental statutes and regulations felonies, punishable by hard prison time. These crimes do not require any damage to people or the environment. In turn, EPA created its Office of Criminal Enforcement and the Justice Department created its Environmental Crimes Section, both dedicated exclusively to prosecuting such felonies. The success of these environmental crimes programs is generally measured by the number of convictions, the years in jail, and the fines that they collect.

Those who intentionally violate environmental statutes and endanger others or destroy valuable natural resources should be criminally prosecuted. But some proportion of environmental criminal prosecutions are for paperwork violations of ambiguous regulations. Although these prosecutions give the illusion of protecting the environment, they violate the rule of lenity while fostering disrespect for environmental protection. As one federal judge who wrestled with EPA’s hazardous waste regulations finally stated: “The people who wrote this ought to go to jail. They ought not to be indicted, that’s not enough.”7



The rule of lenity is violated when people go to prison for breaking ambiguous laws and regulations. The imposition of fines and penalties upon those who are unable to comply with unclear regulations undermines the legitimacy of the very program it is intended to advance. This problem is particularly acute in the environmental realm.

Such prosecutions of ambiguous laws and regulations undermine the clarity and due process requirements of the rule of lenity and actually discourage citizens from complying by making it virtually impossible for them to do so.




1  United States v. Santos, 128 S. Ct. 2020, 2025 (2008).

2  Judson W. Starr, Joseph G. Block & John F. Cooney, Prosecuting Pollution,, Legal Times, May 31, 1993, at 8-10.

3  Timothy Lynch, Polluting Our Principles: Environmental Prosecutions and the Bill of Rights, Cato Institute, Policy Analysis #223, Apr. 20, 1995, n.31.

4  SWANCC v. Army Corps of Engineers, 531 U.S. 159 (2001); Rapanos v. United States, 547 U.S. 715 (2006).

5  33 U.S.C. 1251 (a)(1).

6  United States v. Mills, No.89-3325, slip op. at 1 (11th Cir. May 15, 1990).

7  Judge Adrian Duplantier, quoted in a press release from Marine Shale Processors Inc., itself quoted in Judge Critical of Both Parties in Marine Shale Case, Pesticide & Toxic Chemical News, Sept. 7, 1994, at 20.