When all required performance has been completed, the obligor shall notify the Township Committee, in writing, by certified or registered mail of the completion thereof and shall send a copy thereof to the Township Engineer. The Township Committee shall authorize the Township Engineer to inspect the site to determine that all requirements of the approved plan have been carried out. The Township Engineer shall thereupon file a report, in writing, with the Township Committee, which shall be detailed and shall recommend approval, partial approval or rejection. If the work covered by the bond or performance guaranty or any portion thereof shall not be approved, or shall be rejected by the Township Engineer, said report shall contain a statement of reasons for such nonapproval or rejection. Where said rejection indicates partial approval of said improvements of works, it shall indicate the costs of the work for which approval is denied. The Township Committee shall accept or reject the work, grant partial approval or withhold approval on the basis of such report and shall notify the obligor, in writing, by certified or registered mail, of the contents of said report and the action of the Township Committee with relation thereto not later than 90 days after receipt of notice from the obligor of the completion of the work. Where partial approval is granted, the obligor shall be released from all liability pursuant to his performance guaranty bond, except for that portion sufficient to secure the work not yet approved.