Backflow preventers are required in Ohio to protect public water systems from contamination, requiring installation for hazards like irrigation systems, commercial boilers, or chemical processes. These devices must be installed by a licensed plumber and tested annually (every 12 months) by a certified backflow assembly tester, with results submitted to local water authorities. 

• Backflow Recertification in Ohio, require renewal every three years, involving an 8-hour refresher course to stay updated on regulations and techniques.
• Passage of the required practical test per the Backflow Prevention & Cross-Connection Control Manual.