Formed in 1990 in response to a lawsuit challenging the right of local health departments to certify licensed designers, the Washington On-Site Sewage Association now provides education and representation to the entire decentralized wastewater industry. The state’s pumper organization merged with WOSSA in 1998 to round out the membership, led by Executive Director John Thomas since 2002.How is licensing done in Washington?Thomas: Designers have a limited practice engineering license from the state Department of Health. Installers, pumpers, and those who maintain and inspect septic systems have specialty contractor licenses from local health jurisdictions on a county-by-county basis.For the installers, pumpers
