Yes. Before applying for reimbursement from EPA, you must try to recover your costs from all known potentially responsible parties (PRPs). After you ask them for payment, you should give PRPs 60 days either to pay you, express their intent to pay you, or indicate willingness to negotiate. You must also try to get reimbursed by other sources (for example, your insurance company or your state). If you are not successful, you must certify on your reimbursement application that you made a good-faith, reasonable effort to recover your costs from other sources before applying to EPA. If you recover any portion of the costs from these sources after you receive reimbursement from us, you must return the recovered amount to EPA.