1. If the petition substantially meets the requirements of section 357H.2, the public hearing required in section 357H.2 shall be held within sixty days of the presentation of the petition. Notice of hearing shall be given by publication as provided in section 331.305. Holding a public hearing pursuant to this section is not dispositive of the approval or denial of a petition by the board under this chapter.
 2. If the board determines that the petition or the engineer’s report does not substantially meet the requirements of section 357H.2, the board may, within thirty days of presentation of the petition, request additional information from the petitioners. The board’s request for additional information shall be limited to the information required under section 357H.2 that was not contained in the petition or the accompanying engineer’s report. The board shall be limited to one request for additional information under this section. The public hearing required in section 357H.2 shall be held within sixty days of receiving the additional information. Notice of hearing shall be given in the same manner as required under subsection 1.