California Code, Public Resources Code - PRC § 21092.3

The notices required pursuant to Sections 21080.4 and 21092 for an environmental impact report shall be posted in the office and on the internet website of the county clerk of each county in which the project will be located and shall remain posted for a period of 30 days.  The notice required pursuant to Section 21092 for a negative declaration shall be so posted for a period of 20 days, unless otherwise required by law to be posted for 30 days.  The county clerk shall post the notices within 24 hours of receipt.