The state of Illinois requires that backflow prevention devices (RPZs) to be tested and certified yearly.   The plumbers of A-Archer Sewer & Plumbing are backflow preventer specialists providing inspection, installation, repair, and certification of all types of backflow devices. Let A-Archer Sewer & Plumbing safeguard your drinking water from contamination by testing and certifying you backflow device in compliance with local and state laws.