Cross Connection Program


It is a logical assumption that because water is always under pressure, it can only flow in one direction.  However, can it flow the opposite way from its intended direction?  The answer is YES, and when it does it can cause disastrous results.  Water will always flow toward the point of lowest pressure.

If a water main in the public water system should break, or if a fire occurred and the fire department opened several hydrants, the pressure in the water mains could drop dramatically, causing a reversal of flow.  The potential for this reversal of flow is why the Philomath Public Works Department is concerned about the possibility of contaminants or pollutants being siphoned back into the water system.

When the plumbing at a residence is connected to the potable water supply, and it is connected to piping carrying another fluid or gas, such as an air conditioner containing chemicals to kill algae, the contaminant could be drawn back into our water mains.  A garden hose submerged into a hot tub or swimming pool, or inserted into your car’s radiator to flush out antifreeze, or attached to a fertilizer sprayer, could siphon these contaminants back into our water mains.  Incidents such as these have been documented throughout the country and have happened all too often.

The following is only a partial list of the types of fixtures that can have cross-connections and could pose a hazard to the public drinking water supply:

  • Agricultural mixing tanks
  • Auxiliary water supply (wells)
  • Dialysis equipment
  • Dishwashers
  • Garden hoses
  • Fire protection systems
  • Lawn irrigation systems
  • Photographic developers
  • Sinks
  • Solar energy systems
  • Swimming pools
  • Toilet flush valves
  • Watering troughs
  • Water softeners

If cross-connection potentials exist and are identified resulting from any hazardous condition, the source of the cross-connection must be eliminated.

This is why state regulations require water systems to have a Cross Connection Control Program in place and a Cross Connection Control Specialist on staff for preventing backflow incidents.  An active program consists of inspections to identify actual or potential cross connections, elimination of those cross connections where possible by installing the appropriate backflow assembly commensurate with the degree of hazard where the cross connection cannot be avoided.  This program also requires yearly testing of assemblies by a Certified Backflow Assembly Tester.

Cross Connection Control Inspectors can help the water user identify hazards associated with backflow and suggest ways to eliminate them or recommend the proper backflow prevention assembly that the state requires.  The City of Philomath, as well as other water districts, has a program to identify potential cross connections and oversee the installation of backflow prevention assemblies.  While our goal is to always provide you with safe, dependable drinking water, we cannot do it alone.  We need the public’s assistance to help prevent contamination through backflow and to keep our water safe throughout the system.

Should you have questions or concerns and desire more information, please feel free to contact the Public Works Department at 929-3579.

Garry Black
City of Philomath/Public Works
Cross Connection Control Specialist