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​Washington On-Site Sewage Association

Upcoming Training Events

"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

Training Classes

​Dec. 13th

Top News

​Dec. 20th

Nov. 29th

Safety Mgmt. &

First Aid/CPR


22nd Annual WOSSA Conference

January 26th - 27th, 2018

I-202 Install


Design, Install and O&M of Mounds 

(Mt. Vernon)

WOSSA's Quarterly Board Meeting

Date: January 25, 2018

Time: TBD

Location: Tacoma Convention Center

1500 Commerce St

Tacoma, WA 98402

All current WOSSA members are invited to attend.

Confined Space

Entry Training



Design/Install SSD


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...


Calendar of Events

​Jan. 3rd

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.

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

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

Dec. 6th