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.
Joe Hall
City of Philomath/Public Works
Cross Connection Control Specialist |
