The EPA has its headquarters in Washington, D.C., regional offices for each of the agency's ten regions, and 27 laboratories. The agency conducts environmental assessment, research, and education. It has the responsibility of maintaining and enforcing national standards under a variety of environmental laws, in consultation with state, tribal, and local governments. It delegates some permitting, monitoring, and enforcement responsibility to U.S. states and the federally recognized tribes. EPA enforcement powers include fines, sanctions, and other measures. The agency also works with industries and all levels of government in a wide variety of voluntary pollution prevention programs and energy conservation efforts.
In 2016, the agency had 15,376 full-time employees. More than half of EPA's employees are engineers, scientists, and environmental protection specialists; other employees include legal, public affairs, financial, and information technologists. In 2017 the Trump administration proposed a 31% cut to the EPA's budget to $5.7 billion from $8.1 billion and to eliminate a quarter of the agency jobs.
Beginning in the late 1950s and through the 1960s, Congress reacted to increasing public concern about the impact that human activity could have on the environment. Senator James E. Murray introduced a bill, the Resources and Conservation Act of 1959, in the 86th Congress. The 1962 publication of Silent Spring by Rachel Carson alerted the public about the detrimental effects on the environment of the indiscriminate use of pesticides. In the years following, similar bills were introduced and hearings were held to discuss the state of the environment and Congress's potential responses. In 1968, a joint House–Senate colloquium was convened by the chairmen of the Senate Committee on Interior and Insular Affairs, Senator Henry M. Jackson, and the House Committee on Science and Astronautics, Representative George Miller, to discuss the need for and means of implementing a national environmental policy. In the colloquium, some members of Congress expressed a continuing concern over federal agency actions affecting the environment.
The National Environmental Policy Act of 1969 (NEPA) was modeled on RCA. That bill would have established a Council on Environmental Quality in the office of the President, declared a national environmental policy, and required the preparation of an annual environmental report. President Nixon signed NEPA into law on January 1, 1970. The law created the Council on Environmental Quality (CEQ) in the Executive Office of the President. NEPA required that a detailed statement of environmental impacts be prepared for all major federal actions significantly affecting the environment. The "detailed statement" would ultimately be referred to as an environmental impact statement (EIS).
On July 9, 1970, Nixon proposed an executive reorganization that consolidated many environmental responsibilities of the federal government under one agency, a new Environmental Protection Agency. After conducting hearings during that summer, the House and Senate approved the proposal. The agency’s first Administrator, William Ruckelshaus, took the oath of office on December 4, 1970.
EPA staff recall that in the early days there was "an enormous sense of purpose and excitement" and the expectation that “there was this agency which was going to do something about a problem that clearly was on the minds of a lot of people in this country,” leading to tens of thousands of resumes from those eager to participate in the mighty effort to clean up America’s environment.
When EPA first began operation, members of the private sector felt strongly that the environmental protection movement was a passing fad. Ruckelshaus stated that he felt pressure to show a public which was deeply skeptical about government’s effectiveness, that EPA could respond effectively to widespread concerns about pollution.