Environmental law draws from and is influenced by principles of environmentalism, including ecology, conservation, stewardship, responsibility and sustainability. Pollution control laws generally are intended (often with varying degrees of emphasis) to protect and preserve both the natural environment and human health. Resource conservation and management laws generally balance (again, often with varying degrees of emphasis) the benefits of preservation and economic exploitation of resources. From an economic perspective environmental laws may be understood as concerned with the prevention of present and future externalities, and preservation of common resources from individual exhaustion. The limitations and expenses that such laws may impose on commerce, and the often unquantifiable (non-monetized) benefit of environmental protection, have generated and continue to generate significant controversy.

Given the broad scope of environmental law, no fully definitive list of environmental laws is possible. The following discussion and resources give an indication of the breadth of law that falls within the "environmental" metric.

Laws from every stratum of the laws of the United States pertain to environmental issues. The United States Congress has passed a number of landmark environmental regulatory regimes, but many other federal laws are equally important, if less comprehensive. Concurrently, the legislatures of the fifty states have passed innumerable comparable sets of laws.[2] These state and federal systems are foliated with layer upon layer of administrative regulation. Meanwhile, the U.S. judicial system reviews not only the legislative enactments, but also the administrative decisions of the many agencies dealing with environmental issues. Where the statutes and regulations end, the common law begins.[3]

Sources

Federal statutes

Federal regulation

Consistent with the federal statutes that they administer, U.S. federal agencies promulgate regulations in the Code of Federal Regulations that fill out the broad programs enacted by Congress. Primary among these is Title 40 of the Code of Federal Regulations, containing the regulations of the Environmental Protection Agency. Other import CFR sections include Title 10 (energy), Title 18 (Conservation of Power and Water Resources), Title 21 (Food and Drugs), Title 33 (Navigable Waters), Title 36 (Parks, Forests and Public Property), Title 43 (Public Lands: Interior) and Title 50 (Wildlife and Fisheries).

Judicial decisions

The federal and state judiciaries have played an important role in the development of environmental law in the United States, in many cases resolving significant controversy regarding the application of federal environmental laws in favor of environmental interests. The decisions of the Supreme Court in cases such as Calvert Cliffs Coordinating Committee v. U.S. Atomic Energy Commission (broadly reading the procedural requirements of the National Environmental Policy Act), Tennessee Valley Authority v. Hill (broadly reading the Endangered Species Act), and, much more recently, Massachusetts v. EPA (requiring EPA to reconsider regulation of greenhouse gases under the Clean Air Act) have had policy impacts far beyond the facts of the particular case.

Common law

The common law of tort is an important tool for the resolution of environmental disputes that fall beyond the confines of regulated activity. Prior to the modern proliferation of environmental regulation, the doctrines of nuisance (public or private), trespass, negligence, and strict liability apportioned harm and assigned liability for activities that today would be considered pollution and likely governed by regulatory regimes.[4] These doctrines remain relevant, and most recently have been used by plaintiffs seeking to impose liability for the consequences of global climate change.[5]

The common law also continues to play a leading role in American water law, in the doctrines of riparian rights and prior appropriation.

Administration

In the United States, responsibilities for the administration of environmental laws are divided between numerous federal and state agencies with varying, overlapping and sometimes conflicting missions. The U.S. Environmental Protection Agency‎ (EPA) is the most well-known federal agency, with jurisdiction over many of the country's national air, water and waste and hazardous substance programs.[6] Other federal agencies, such as the U.S. Fish and Wildlife Service and National Park Service pursue primarily conservation missions,[7] while still others, such as the United States Forest Service and the Bureau of Land Management, tend to focus more on beneficial use of natural resources.[8]

Federal agencies operate within the limits of federal jurisdiction. For example, EPA's jurisdiction under the Clean Water Act is limited to "waters of the United States". Furthermore in many cases federal laws allow for more stringent regulation by states, and of transfer of certain federally mandated responsibilities from federal to state control. U.S. state governments, therefore, administering state law adopted under state police powers or federal law by delegation, uniformly include environmental agencies.[9] The extent to which state environmental laws are based on or depart from federal law varies from jurisdiction to jurisdiction.

Thus, while a permit to fill non-federal wetlands might require a permit from a single state agency, larger and more complex endeavors - for example, the construction of a coal-fired power plant - might require approvals from numerous federal and state agencies.

Enforcement

In the United States, violations of environmental laws are generally civil offenses, resulting in monetary penalties and, perhaps, civil sanctions such as injunction. Many environmental laws also provide for criminal penalties for egregious violations. Environmental agencies often include separate enforcement offices, with duties including monitoring permitted activities, performing compliance inspections, issuing citations and prosecuting wrongdoing (civilly or criminally, depending on the violation). EPA's Office of Enforcement and Compliance Assurance is one such agency. Others, such as the United States Park Police, carry out more traditional law enforcement activities.

Adjudicatory proceedings for environmental violations are often handled by the agencies themselves under the strictures of administrative law. In some cases, appeals are also handled internally (for example, EPA's Environmental Appeals Board). Generally, final agency determinations may subsequently be appealed to the appropriate court.

Other environmental law enforcement agencies include:

• Força Verde, a branch of the Brazilian Armed Forces which was established decades ago to protect against environmental crimes. [10]
• Green Police - an environmental task force in New Jersey.[11]
• Veteran Environmental Patrol of Israel - started fielding uniformed officers in 2001.[11]