Cross-Connection Control Survey Work

Cross-connection control survey work should only be performed by personnel knowledgeable about commercial and industrial potential cross-connections as well as general industrial uses for both potable and process water. If “containment” is the prime objective of the survey, then only sufficient time need be spent in the facility to determine the degree of hazard inherent within the facility or operation. Once this is determined, a judgment can be made by the cross-connection control inspector as to what type of backflow protective device will be needed at the potable supply entrance, or immediately downstream of the water meter. In the event that the cross-connection control program requires “total” protection to the last free flowing outlet, then the survey must be conducted in depth to visually inspect for all crossconnections within the facility and make recommendations and requirements for fixture outlet protective devices, internal protective devices, and containment devices.

It is recommended that consideration be given to the following objectives when performing a cross-connection control survey:

1. Determine if the survey will be conducted with a prearranged appointment or unannounced.
2. Upon entry, identify yourself and the purpose of the visitation and request to see the plant manager, owner, or maintenance supervisor in order to explain the purpose of the visit and why the cross-connection survey will be of benefit to him.
3. Ask what processes are involved within the facility and for what purpose potable water is used, i.e., do the boilers have chemical additives? Are air conditioning cooling towers in use with chemical additives? Do they use water savers with chemical additives? Do they have a second source of water (raw water from wells, etc.) in addition to the potable water supply? Does the process water cross-connect with potentially hazardous chemical etching tanks, etc.?
4. Request “as-built” engineering drawings of the potable water supply in order to trace out internal potable lines and potential areas of crossconnections.
5. Initiate the survey by starting at the potable entrance supply (the water meter in most cases) and then proceed with the internal survey in the event that total internal protective devices and fixture outlet protective devices are desired.
6. Survey the plant facilities with the objective of looking for cross-connections at all potable water outlets such as:
   • Hose bibbs
   • Slop sinks
   • Wash room facilities
   • Cafeteria and kitchens
   • Fire protection and
     
     • Siamese outlets
   • Irrigation outlets
   • Boiler rooms
   • Mechanical room
   • Laundry facilities
     
     • (hospitals)
   • Production floor
7. Make a sketch of all areas requiring backflow protection devices.
8. Review with the host what you have found and explain the findings to him. Inform him that he will receive a written report documenting the findings together with a written recommendation for corrective action. Attempt to answer all questions at this time. Review the findings with the owner or manager if time and circumstances permit.
9. Document all findings and recommendations prior to preparing the written report. Include as many sketches or photos with the final report as possible. If the located cross connection(s) cannot be eliminated, state the generic type of backflow preventer required at each cross connection found.
10. Consider requiring or recommending compliance of the survey findings within a definitive time frame. (if appropriate authority is in effect).