<Li> A section 104 (e) letter is a request by the government for information about a site . It may include general notice to a potentially responsible party that CERCLA - related action may be undertaken at a site for which the recipient may be responsible. <42 U.S.C. 9604 (e)>. This section also authorizes the EPA to enter facilities and obtain information relating to PRPs, hazardous substances releases, and liability, and to order access for CERCLA activities . The 104 (e) letter information - gathering resembles written interrogatories in civil litigation . </Li> <Li> A section 106 order is a unilateral administrative order issued by EPA to PRP (s) to perform remedial actions at a Superfund site when the EPA determines there may be an imminent and substantial endangerment to the public health or welfare or the environment because of an actual or threatened release of a hazardous substance from a facility, subject to treble damages and daily fines if the order is not obeyed . </Li> <Li> A remedial response is a long - term action that stops or substantially reduces a release of a hazardous substance that could affect public health or the environment . The term remediation, or cleanup, is sometimes used interchangeably with the terms remedial action, removal action, response action, remedy, or corrective action . <Ul> <Li> A nonbinding allocation of responsibility (NBAR) is a device, established in the Superfund Amendments and Reauthorization Act, that allows the EPA to make a nonbinding estimate of the proportional share that each of the various responsible parties at a Superfund site should pay toward the costs of cleanup . </Li> </Ul> </Li> <Ul> <Li> A nonbinding allocation of responsibility (NBAR) is a device, established in the Superfund Amendments and Reauthorization Act, that allows the EPA to make a nonbinding estimate of the proportional share that each of the various responsible parties at a Superfund site should pay toward the costs of cleanup . </Li> </Ul>

Who pays for the cleanup of toxic sites on the superfund national priorities list