Water Division
Cross Connection Plan
The Key to Safe, Clean Drinking Water
Maintain the Water Quality
State and Federal regulations impose provisions on water supply systems, which are intended to insure that the quality of water is not compromised as a result of its delivery through the distribution system. In order to assure safe water is supplied at the consumer’s tap, the City of Sunnyside maintains an active Cross Connection Control Program that has been authorized by Sunnyside Municipal Code (SMC) 13.18. The provisions of this SMC apply to all premises, which receive potable water provided by the City of Sunnyside. The owner or occupant of any premise covered by this SMC is required to comply with the provisions of this chapter.
The intent of the Cross Connection Control Program is to protect the City’s water system from coming in contact with any contaminate that may enter into the water distribution system. The most common form of system contamination is from cross connections.
Protecting our Water
Over the years, water treatment processes have become more complex in an effort to provide the highest quality water possible to the water utilities customers. The protection of the water sources, rivers, wells, and lakes, combined with new water treatment procedures, enable the water purveyor to achieve this goal.
A cross connection, as defined by the Cross Connection Control Committee of the Pacific Northwest Section or the American Water Works Association (AWWA), is "Any actual or potential physical connection between a potable water line and any pipe, vessel, or machine containing a non-potable fluid or has the possibility of containing a non-potable fluid, solid or gas, such that it is possible for the non-potable fluid, solid or gas to enter the potable water system by backflow."
Backflow incidents have been documented by the University of Southern California Foundation for Cross Connection Control & Hydraulic Research as early as 1903. Links to Pacific Northwest Section of AWWA backflow incidents are available here: http://www.abpa.org/incidents.htm.
From the Federal Safe Water Drinking Act, the Washington State Department of Health Drinking Water Regulations requires the purveyor of water to develop and implement a cross connection control program using the manual published by the PNW Section - AWWA. The scope and complexity of the program is directly related to the size of the system.
One of the tasks of the Cross Connect Program is to routinely inspect irrigation systems and commercial buildings to identify potential and actual cross connections. Another task of the program is to advise the owners on how to properly eliminate or control the cross connection using the most cost effective methods. The water customer is required to ensure that these devices are operated, maintained, and tested in accordance with the City’s Cross Connection Control Regulations.
Types of Backflow Prevention Assemblies
Each assembly has different features and purposes. Choose an assembly that meets your needs.
Double Check Valve Assembly (DCVA)
A DCVA is a mechanical backflow preventer that consists of two independently acting, spring-loaded check valves. It includes shutoff valves at each end of the assembly and is equipped with test cocks. A DCVA is effective against backpressure backflow and backsiphonage but should be used to isolate only nonhealth hazards.
Reduced Pressure Backflow Assembly (RPBA)
An RPBA is a mechanical backflow preventer that consists of two independently acting, spring-loaded check valves with a hydraulically operating, mechanically independent, spring-loaded pressure differential relief valve between the check valves and below the first check valve. It includes shutoff valves at each end of the assembly and is equipped with test cocks. An RPBA is effective against backpressure backflow and backsiphonage and may be used to isolate health or non-health hazards.
- Usually most expensive and complex
- Installed above ground
- Used at high-hazard sites such as hospitals, chemical plants, mortuaries
- Only device that allows for applying fertilizer or other chemicals into irrigation systems
- State requires annual testing by State-certified tester
Air Gap
An air gap is a vertical, physical separation between the end of a water supply outlet and the flood-level rim of a receiving vessel. This separation must be at least twice the diameter of the water supply outlet and never less than one inch. An air gap is considered the maximum protection available against backpressure backflow or backsiphonage but is not always practical and can easily be bypassed.
- Used for high health hazard situations.
- Not always practical.
- Vulnerable to bypass arrangements
- Use of an air gap often exposes water to dust, debris, airborne bacteria, and other contaminants and pollutants.
If you have any questions about cross connection control in the City of Sunnyside, you can contact:
Shane Fisher, Associate Engineer, (509) 837-5399
Municipal Code and Operating Procedures Sunnyside Municipal Code, Chapter 13.18, pertaining to Cross Connections for those served by the water system of the City of Sunnyside. View the Standard Operating Procedures Manual for Cross Connection Control (PDF, 527K).
