Resources for Backflow Testing Individual City ResourcesAlameda County Backflow Testing InformationDublin San Ramon Services District Backflow Testing InformationCity of Pleastanton Backflow Testing InformationCity of Livermore Backflow Prevention ServicesCity of Los Angeles Backflow Testing InformationMarin Municipal Water District – Backflow Testing InformationRedwood City Backflow Testing InformationSan Francisco Cross Connection Control ProgramSan Mateo County Backflow Testing Information Frequently Asked QuestionsBackflow FAQsWhat is Backflow Testing?What is a Cross Connection?