Neb. Rev. Stat. § 25-21,260

A person performing a voluntary self-evaluation may disclose in writing a possible violation of an environmental requirement to an agency having regulatory authority showing: (1) A description of the possible violation; (2) The date of discovery of the possible violation and, if known, the date the possible violation occurred; and (3) Actions taken to correct the possible violation and, if applicable, a schedule to achieve compliance.