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​Washington On-Site Sewage Association

About the Washington Onsite Sewage Association
Founded in 1990, the Washington On-Site Sewage Association is a non-profit trade association serving the on-site wastewater industry. Today the organization has grown to encompass all disciplines of the industry, has continued to expand its impact, and supports improvement in all of the industry's professions. These professional areas include regulators, designers, installers, operations and maintenance support, and manufacturers/suppliers operating in the state of Washington. WOSSA has since been a leading onsite professional membership association for the onsite septic industry with key consideration to the Consumer, Public Health and the Environment.

Mission Statement
“WOSSA exists to represent our diverse industry through education, certification, legislative involvement, ethical standards and technical advancement to elevate the professionalism within all segments of our Onsite Waste Water Community.”

With more than 300 industry professional members and member companies in the state of Washington, WOSSA serves as the voice of the on-site industry and the resource for our members in service to our communities.

We carry out our mission through education, advocacy, information, and our community. Each year WOSSA;

  • Serves as an advocate of the onsite profession in our communities through involvement in our state legislation and local governments
  • Sponsors numerous continuing education experiences to help onsite professionals maintain or achieve their mandatory licensure / certification
  • Provides Web-based resources for continuing education and emerging industry professionals
  • Hosts the annual WOSSA Conference
  • Helps support and give back to our on-site community through the annual WOSSA Scholarship Program
  • Champions the onsite industry’s future by enhancing public belief in the value of long term decentralized wastewater strategies
  • Promotes industry excellence and development with the publication of the WOSSA quarterly magazine, the “Pipeline”


Not a member yet? We invite you to learn more about membership in WOSSA and join our community.

History of the Washington Onsite Sewage Association
WOSSA was formed in 1990 to provide a united defense against a lawsuit that impacted non engineering designers in the State of Washington as affected third parties.

The legal right of local health jurisdictions to certify licensed engineering designers was challenged in court. WOSSA was able to make a reasonable defense and participate in the process, which has allowed non-engineers to continue to practice.

This effort helped lead to the current statewide designer licensing program currently being developed and administered by the Department of Licensing.

From that beginning, the organization has grown to encompass all disciplines within the industry, from regulators to pumpers. In about 1998, the state Pumpers organization merged with WOSSA adding their voice.

WOSSA Presidents
Bill Stuth Sr., was WOSSA’s first President, serving from 1990 to 1992. He is also one of the two original founders of WOSSA. Jerry Stonebridge was the other founding member of WOSSA and served as WOSSA President from 1995 to 1997.


Past Presidents

The Code of Ethics and Professional Conduct
The preamble to WOSSA’s Code of Ethics describes the principles upon which the Code of Ethics is based. It provides that members of the Washington On-Site Sewage Association shall uphold and advance the integrity, honor, and dignity of the on-site wastewater profession. This Code states guidelines for the conduct of members in fulfilling those obligations. The Code is arranged in two tiers of statements: Canons, and Guidelines for use with the Fundamental Canons of Ethics. Canons are broad principles of conduct while the Guidelines are more specific goals toward which members should aspire in professional performance and behavior.


Code Of Ethics

Organizational Structure

The Washington On-Site Sewage Association is governed by a Board of Directors, a statewide elected governing body that provides long-range strategic leadership. The Board is composed of elected WOSSA officers, including the president, vice president, past president, secretary, and treasurer; elected representatives from each of WOSSA’s 4 regions; a supplier’s and manufacturer’s representative; an operations and maintenance representative; a pumper’s representative; a designer’s representative; an installer’s representative; and a public regulator’s representative from one of the local health jurisdictions.


Board Of Directors
Visit the Board of Directors Directory for Leadership information and member profiles. If you’re a WOSSA member, request approved minutes from past board meetings.


WOSSA Board Directory

About WOSSA