What is a Chip Seal?

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.

Show All Answers

1. What are Area of Benefit (AOB) funds used for?
2. What are Best Management Practices (BMPs)?
3. What are Pollutants of Concern (POCs)?
4. What are the Public Works Counter hours of service, phone numbers, and location?
5. What can property owners do to help the County's maintenance efforts of private trees and other vegetation?
6. What can property owners do to prevent fallen leaves from creating blockages in the drainage system?
7. What do I do if my neighbor informed me that I am encroaching on his property?
8. What information should I provide when reporting a streetlight outage?
9. What is a cape seal?
10. What is a micro-surface seal?
11. What is a slurry seal?
12. What is a traffic Area of Benefit (AOB)?
13. What is a Watershed?
14. What is an illicit discharge and who do I call to report it?
15. What is an NOI and what permits does it cover?
16. What is C.3?
17. What is IPM and what are some ways I can try it?
18. What is NPDES and who oversees it?
19. What is the Adopt-A-Road Program?
20. What is the construction work occurring on a County Road or Flood Control Facility?
21. What is the CRIPP?
22. What is the design storm for my project?
23. What is the difference between a Stormwater Pollution Prevention Plan (SWPPP) and a Stormwater Control Plan (SWCP)?
24. What is the difference between point source and non-point source?
25. What is the difference between the County Watershed Program and the Contra Costa Clean Water Program?
26. What is the difference between the storm drain system and the sanitary sewer?
27. What is the Public Works Budget?
28. What projects are upcoming or currently advertised?
29. What should I do if I see someone dumping garbage on private or public property?
30. What is a Chip Seal?
31. What is the basis of the Area of Benefit (AOB) Program?
32. What is the County's responsibility in maintaining private drainage systems?
33. What is the drainage easement across my property? Can I build on it? What can I do on it?