To prevent substance abuse (alcohol and illicit drugs) among its municipal employees, the city of Nantes has implemented a comprehensive prevention plan: creation of a peer support group to raise staff awareness, information sessions led by addiction specialists and other professionals, provision of breathalyzers, limiting opportunities for substance use in the workplace, support and treatment for individuals with substance use disorders, and training for management. Three thousand employees have been educated on the issue, and three hundred fifty managers have been trained.