FAQs
Cross Connection Control Program
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Backflow is the undesirable reversal of flow of non-potable water or other substances through a cross-connection and into the piping of a public water system or consumer’s potable water system. This reversal of flow or “backflow” can allow contaminated water to flow backward, drawing a contaminant into the water supply.
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Backflow can be caused when an unforeseen change in water pressure allows the water to flow backwards within the water supply piping system from a contaminated source to a drinking water supply. A drop in pressure could be caused by a variety of things including a water main break or the need to fight a fire.
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City of Pendleton requires installation of specific backflow prevention assemblies to be installed and tested annually according to currently adopted uniform plumbing code and Oregon Health Authority rules.
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Backflow assemblies must be tested at the time of installation, annually after installation, after repairs and after relocating. Testing in Oregon must be done by Oregon Health Authority-certified backflow testers.
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Water which is safe for human consumption, free from harmful or objectionable materials, as described by the Oregon Health Authority.
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Any water, other liquid, gas, or other substance that is not safe for human consumption, or is not a part of the public potable water supply as described by the Oregon Health Authority.
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Backsiphonage is a type of backflow caused by negative pressure in the supply piping. Some common causes of backsiphonage are:
- High velocities in pipe lines.
- Line repair or break that is lower than a service point.
- Lowered main pressure due to high water withdrawal rate, such as fire\fighting or water main flushing.
- Reduced supply pressure on the suction side of the booster pump.
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Backpressure is a backflow that is the reverse from normal flow direction within a piping system that is the result of the “downstream pressure” being higher than the supply pressure.