A written petition for a referendum on the local law may be filed during the 45 days following the final enactment of the local law. A petition filed under this section must be signed by: at least 20% of the residents of the area to be annexed under the local law; and owners of at least 20% of the assessed valuation of the real property located in the area to be annexed. The signers of a petition filed under this section must be: registered as voters in county elections; or if there are fewer than 20 individuals living in the area proposed to be annexed who are eligible to sign a petition under this subsection, any person owning real property in the area proposed to be annexed. When a written petition for referendum on a local law is submitted to the chair of the County Council, the chair shall verify: the signatures on the written petition; and that the petition meets the requirements of this section. On verifying that the requirements of this section have been met, the chair of the County Council shall suspend the effectiveness of the local law contingent on the results of the referendum. The chair of the County Council shall set a date for the referendum on the local law and publish notice of the referendum on the local law. The date of the referendum on the local law shall be between 15 and 90 days after the published notice of the referendum. The notice of the referendum on the local law shall: be published twice at not less than weekly intervals in a newspaper of general circulation in the area to be annexed; and specify the time and place at which the referendum will be held. The place where the referendum is held shall be within the area to be annexed under the local law. On the date and at the place specified, the local law proposing to annex an area to the regional district shall be submitted to a referendum election of the qualified voters who reside in the area to be annexed and who are registered as voters in county elections. If there are fewer than 20 individuals living in the area proposed to be annexed who are eligible to participate in a referendum election, any person owning real property in the area proposed to be annexed may participate in the referendum election. The ballots or voting machines for the referendum election shall contain a summary of the local law with suitable provisions for the voter to indicate a choice for or against it. If a majority of the persons voting on the local law in the referendum vote in favor of the local law, the local law shall become effective on the 14th day following the referendum. The County Council may enact local laws or adopt regulations that provide for conducting a referendum held under this section and tabulating the results of the referendum. The county shall pay in full for the expenses of a referendum held under this section.