Can I install my own OSS after I obtain an OSS permit?

Whatcom County code requires that all OSS be installed by a licensed OSS installer; however, if you are the property owner and you will live in the home the OSS will serve, you can request an exemption from certification requirements. The request will be reviewed and if approved, you can install the OSS. We recommend that you hire a Licensed OSS Installer for complex systems, e.g. pressure systems or alternative systems.


Developers must hire a Licensed OSS Installer or obtain an OSS Installer's License through the Health Department to install OSS on properties they plan to develop and then sell.

Exemption From Certification Requirements (PDF)

Show All Answers

1. Can I use my septic system during or after a flood?
2. How do I know if my septic system was damaged by flooding, and how can I get it fixed?
3. Should I use an additive in my septic tank?
4. When is an OSS permit needed?
5. Can I design my own OSS?
6. Can I install my own OSS after I obtain an OSS permit?
7. Do you have a copy of my OSS permit?
8. How do I clean up sewage that has backed up into my house?
9. What are some signs that my OSS is failing?
10. How can I find my septic tank?
11. What is the reserve area?