Upon motion filed within ten days of the conclusion of the hearing, any party may seek leave from the Presiding Officer to supplement the record with additional relevant material evidence. Where the party shows to the satisfaction of the Presiding Officer that there were reasonable grounds for failure to adduce the evidence in the hearing, the Presiding Officer may allow the evidence to be heard in such manner and upon such conditions as the Presiding Officer considers proper.
6 Del. Admin. Code § 200-B-250