Charleston Water System’s Cross Connection Control Program Manual on Backflow Prevention (Adobe PDF) provides detailed, illustrated installation guidelines, a list of approved assemblies, and Charleston Water System’s requirements for backflow prevention.

Backflow prevention requirements are determined by an actual or potential degree of hazard. To assess this degree of hazard, the customer must complete a questionnaire when applying for water service. If the questionnaire is incomplete or vague on how water will be used, a Charleston Water System Compliance Inspector will call or visit the customer to determine the degree of hazard. When the required backflow prevention assembly has been installed correctly and inspected by Charleston Water System, the water service will be activated.