A cross-connection is an actual or potential connection between any part of a potable water system and any other environment that contains other substances that would allow such substances to enter the potable water system. Cross-connection control programs are intended to reduce the risk of contamination or pollution of the public water system. This fourth edition of AWWA Manual M14, Backflow Prevention and Cross-Connection Control, provides both technical and general guidance on the recommended procedures and practices for developing, operating, and maintaining a cross-connection control and backflow prevention program.

This edition includes a new chapter on conducting a cross-connection control survey and expands the discussions on assessing the risks and preventing backflow. A greatly expanded appendix details how to test most backflow-prevention devices. Other issues covered include backflow prevention principles, assembly, application, installation, and maintenance; health and legal concerns; and detailed information on potential and real hazards.

This manual is intended for use by all professionals charged with protecting the public water supply with proper backflow prevention and cross-connection control programs.

Cross-connection control is one of the most important barriers in the multiple-barrier approach drinking water suppliers use to protect public health. Contamination of a drinking water distribution system through a cross-connection often results in immediate adverse health effects – illness or even death.

Reduce the chances of cross-connections and backflow into your potable water system. Manual M14 provides a total cross-connection control program for your water system. The manual explains how cross-connections and backflow can occur and tells you how to choose, install, and maintain backflow prevention devices.

Manual M14 provides complete guidance for establishing a cross-connection/backflow prevention program for a water utility. You?ll learn the water purveyor?s legal responsibilities, as well as the customer?s responsibilities in backflow prevention. The manual covers risk assessment, types of programs to consider, and program administration. Until the cross connection control program is fully developed, the water purveyor is at maximum risk of potential liability.

M14 also explains the hydraulics of backflow, the two types of backflow ? backsiphonage and backpressure, and the conditions that can cause backflow and a potential cross-connection (such as a water main break).

You?ll get expert guidance in selecting and installing backflow prevention equipment. You?ll learn the 10 main types of backflow prevention devices or assemblies (yes, they are different), and the relative effectiveness of each type against backsiphonage, backpressure, and low and high hazards. The manual describes each device or assembly, its application in a water system, installation requirements. Detailed assembly test procedures are included for the different types of devices and assemblies.

Manual M14 recommends backflow prevention equipment for installation in the water distribution system, as well as raw water-storage reservoirs, chemical feed pumps and injectors, filters, surface washers, saturators and dry chemical solution tanks, sampling lines, hose bib connections, and membrane systems.