- World Plumbing Day is an international event on March 11 initiated by the World Plumbing Council celebrating the important role plumbing plays in the health and safety of modern society. WPD also brings attention to the importance of preserving and protecting our most precious resource - clean, fresh drinking water! SSI supports these initiatives every day by providing high quality products that support CONSERVATION WITHOUT COMPROMISE! Happy World Plumbing Day! Thank you to plumbing professional everywhere who support and maintain this vital industry! For more information visit the World Plumbing site.