Resources for Professionals

"NEW January 2018" - Jefferson County Website and GIS Mapping Tool Class

Washington State On-Site Sewage Association


The Washington On-Site Sewage Association (WOSSA) is a professional organization representing all professions in the siting, design, installation, use and regulation of on-site wastewater systems that will treat and dispose of sewage in a safe, reliable and cost-effective way. WOSSA operates the Northwest On-Site Waste Water Training Center to serve as a resource center and to promote professional excellence. A schedule of classes is available at the WOSSA website.


Washington State Department of Health Standards & Guidance


The Washington State Department of Health Wastewater Management Program is designed to protect public health by promoting the safe treatment and disposal of domestic and other non-industrial wastewater in areas of Washington not served by municipal sewage treatment works.


They provide assistance to local health jurisdictions regarding on-site wastewater issues and review and approve plans for large on-site sewage systems.


View a more detailed listing of standards and guidance.


Jefferson County Development Resources

The Jefferson County environmentally sensitive areas (ESA) mapping site project has been created to allow project proponents to get some idea of what issues might be involved on their land before they apply for a permit. View maps.


Access database tools for information about permits and cases, recorded and scanned documents, special reports and other pertinent data.

Useful Tables & Forms

On-Site Wastewater Designer Licensing & Inspector Certification Program

For more information on the certification and licensing program, go to the Washington State Department of Licensing website.