N.J. Stat. Ann. § 40:41A-107

All petition papers comprising an initiative or referendum petition shall be assembled and filed with the county clerk as one instrument. Within 20 days after a petition is filed, the county clerk shall determine whether each paper of the petition has a proper statement of the circulator and whether the petition is signed by a sufficient number of qualified voters. After completing his examination of the petition, the county clerk shall certify the result thereof to the board at its next regular meeting. If he shall certify that the petition is insufficient he shall set forth in his certificate the particulars in which it is defective and shall at once notify at least two members of the committee of the petitioners of his findings.