Most environmental regulations follow a similar evolutionary path. A law is passed in Washington, DC., outlining the requirements of the law and assigning, typically to the federal Environmental Protection Agency (EPA), the authority to promulgate federal regulations for implementing those requirements. These regulations take a minimum of two years to navigate the regulatory promulgation process. When finalized, the regulations provide the basis for "how to comply" with the law. Federal laws and regulations often require the states to develop programs that are "at least as stringent" as the federal version. States require another minimum of two years to promulgate their state-specific "least as stringent" programs for which they may then receive approval from the EPA to implement and enforce. This approval may be for an entire program, such as the RCRA Hazardous Waste Program, or for a portion of a program, such as the Clean Water Act. In all cases, the federal EPA retains oversight and enforcement capabilities.