The County Public Works Department Maintenance crews perform two types of chip seal:
• A single chip seal involves spraying liquid asphalt on the pavement followed by the spreading of a layer of small aggregate (chips) that is embedded into the oil.
• A double-chip seal is a single chip seal with a second application (layer) of liquid asphalt and small aggregate.
Single and double-chip seals are typically used on arterial and collector roads that have a significant amount of wear and high traffic volume. Schedule information regarding the chip seal application can be obtained by calling the Public Works Department Maintenance Division at (925) 313-7000, or you can visit our Pavement Management Program page.