Neb. Rev. Stat. § 81-15,140

(1) The director shall provide for reciprocal certification agreements with other states, territories, and countries if the requirements for certification by such other states, territories, and countries do not conflict with the Wastewater Treatment Operator Certification Act and are as stringent as those required by this state. (2) In making determinations pursuant to subsection (1) of this section, the director may consider any generally applicable criteria and guidelines developed by a nationally recognized association of certification authorities.