breaking topical featured 5 THINGS TO KNOW: Who issues precautionary boil advisories and when would a mandatory order be issued? --Adrian O'Hanlon III Feb 23, 2021 Erin Hatfield, communications director with the Oklahoma Department of Environmental Quality, answers questions about boil orders and advisories. 1. What is the difference between a precautionary boil advisory and a mandatory boil order? A precautionary boil advisory is issued by a water system and is a recommendation to boil water prior to consumption. A mandatory boil order is issued by the Oklahoma Department of Environmental Quality for various reasons when drinking water is contaminated. 2. Why would a precautionary boil advisory be issued?