Why are the potentially responsible parties at the site allowed to help design the cleanup plan?

EPA has a longstanding policy to pursue "enforcement first" throughout the Superfund cleanup process. Existing EPA guidance emphasizes that a major component of the "enforcement first" policy is that potentially responsible parties should conduct remedial actions whenever possible. Under the existing Consent Decree, the potentially responsible parties (PRPs) are required to carry out the remedial design, remedial action, operation and maintenance and emergency response actions.