On-site sewage system designers
These licenses are provided through the Washington State Department of Licensing. For more information,
Visit the Board of Registration for Professional Engineers & Land Surveyors
Certifications offered by King County
Associate/master installer
Learn about the on-site sewage associate and master installer certifications.
On-site system maintainer
Find information about the on-site sewage system maintainer certification.
Liquid waste pumper/hauler
Learn about the liquid waste pumper/hauler certification.