N.D. Cent. Code § 23.1-12-19

An owner or operator that is a first-party claimant and that proposes to take corrective action or has undertaken corrective action in response to a release, the time of the release being unknown, may apply to the department for partial or full reimbursement under section 23.1-12-18. An owner or operator who is a first-party claimant may be reimbursed only for costs incurred after July 1, 1989, even if the releases were discovered before July 1, 1989, up to the maximum of twenty-five thousand dollars per location.