Environmental policy encompasses a huge field, ranging from the disposal of household refuse and toxic waste to the protection of endangered species, from clean air and clean water to the control of vehicle emissions, from soil erosion to desertification to wetlands-to name but a few issues. Legislation abounds at both federal and state levels: the federal environmental legislation alone encompasses over a hundred statutes which have been passed during the last sixty years. More than a dozen federal agencies have major environmental responsibilities, and every state has an administrative organization for environmental protection. Any comprehensive account clearly has to be highly selective. The academic writer has the luxury, denied to the policy-maker, of being able to omit important relevant matters, and to choose those which are thought to illustrate adequately the nature and problems of environmental policy. The state level can also be largely ignored, ostensibly on the ground that state laws mirror or supplement federal provision. The states are, however, vital to the implementation of federal policies. In fact, the implementation of environmental policy operates in an intergovernmental and intragovernmental context with each level of government playing a role.