California Onsite Water Association unifies and integrates California’s onsite water resources using environmentally sound and resilient practices through education, partnership, and policy change.


COWA Promotes Best Management Practices for Onsite Water Technologies


COWA serves both the public and private sectors of its membership by providing technical updates, training, networking opportunities, and advocacy for best management and industry practices.

From the very beginning, our philosophy has been that onsite water is a technical industry and that best decisions are made when based on sound science, facts, and education. Training is a key ingredient that is in short supply within this industry.

COWA sets out to fill the void.