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​Washington On-Site Sewage Association


WOSSA Pumper / O&M Technician Academy


I-202 Basics of Installation 


"Voice of the Industry" for Members, Consumers, Our Communities & the Environment"

Washington State has approximately 1.5 million decentralized wastewater systems in use, it is our mission as an Association, with the help of our members, consumers and local government; to ensure that we put the water back into our communities the way we found it. Helping to replenish nature’s support system with a long term sustainable approach to wastewater disposal and treatment.

Voice of the INDUSTRY

WOSSA Scholarship


Top News

We look forward to announcing the recipients soon!

Oct 10-11


For over 20 years WOSSA's goal has been to promote professional excellence through education, advocacy...

Whether you’re an employer or someone looking to get hired on, having the skills, attitude and knowledge...

Upcoming Training Classes


O&M Cert. for Proprietary Devices


Thank You for submitting your 2018 WOSSA Scholarship Applications!

Sept 24th-27th / Oct 1st-4th

Calendar of Events

In a deliberate effort to raise awareness and reduce workplace injuries related to

Pathogen Exposure, Confined Space Entry, OSHA Construction Focus Four: Falls, Caught-in or between, Struck by and Electrocution

WOSSA has developed new training resources that focus on workers in the On-Site industry. This training delivers both knowledge and practical skills to address the numerous hazards that are unique to our industry.

These videos were developed by WOSSA as an integral part of these safety training classes.

Sept 20th


It is always a challenge to find a quality service provider within any trade...

Washington On-Site Sewage Association MembershipRecently, Jerry Stonebridge, John Thomas...