Backflow FAQs

Q: What is a backflow?
A: Backflow occurs when the flow of water changes directions, usually because of a change in pressure. This is a potentially dangerous situation because untreated or nonpotable (not safe for human consumption) water can be sucked back into the drinking water system and contaminate it. For example, backflow can happen if the flow from a hose in a bucket of water containing soap or household chemicals reverses because of a change in pressure, pulling the water from the bucket into your home's drinking water system.
Q: What is a cross-connection?
A: A cross-connection is any connection (whether temporary or permanent) between Columbus Water Work's water distribution system and any source or system containing water or other substances that may not be suitable for drinking. An example of a cross-connection would be an irrigation system connected to a customer's drinking water system.
Q: How does backflow affect me?
A: Backflow can potentially contaminate your drinking water. Because of this, CWW requires that all meters come equipped with a backflow prevention device to protect all customers from contaminants being introduced, either intentionally or accidentally, into the water system. A backflow prevention device prevents the "flowing back" of water into the water main. It is usually installed at the water meter.
Q: Is there a law requiring that I have a backflow prevention device?
A: Yes. Federal law requires CWW as the provider of the municipal water system to protect the system from being compromised by backflow once the water has passed through a customer's meter. Therefore, CWW requires a backflow prevention device be in place for its customers before we will provide service.
Q: Does everyone have to comply with these regulations?
A: Yes, because of the federal mandate CWW is under regarding backflow prevention and because it serves as a way of protecting the water supply, it is imperative that all customers have backflow prevention devices.
Q: Why do backflow devices need to be tested and by whom?
A: Backflow devices need to be tested to ensure no contamination has entered CWW's distribution system or residents' homes or businesses. A certified backflow tester typically performs these tests.
Q: What is thermal expansion?
A: Whenever water is heated it expands and this is called thermal expansion. Thermal expansion can cause the pressure to increase in a plumbing system where a backflow device has been installed. To prevent this problem a thermal expansion device is installed on the cold water side of interior plumbing to allow for this pressure relief. The fix can be an inexpensive one. CWW offers a thermal expansion device at our cost of $25 that may be obtained at our business office. It comes with simple instructions on how to connect the device to your washing machine's cold water line. If you prefer, you may consult with your plumber for alternate protection devices and installation.
Q: My water system was in place before this regulation - why isn't my system "grandfathered in" on regulatory requirements?
A: Because backflow can lead to serious public-health issues, "grandfathering" older homes and businesses into the system is not an option. The regulations are not in place to put a burden on residents but to ensure that Columbus' drinking water is safe for everyone.
Q: Who is going to pay for these regulatory requirements?
A: The regulations are included in the plumbing code which affects anyone that is installing or upgrading plumbing. It is up to the homeowner to make sure they are in compliance with the regulations.
Q: We've been here all these years and never had to do anything about backflow before. Why do I have to do this now?
A: As state and federal regulations protecting drinking water grow more stringent, it is imperative that water systems keep up. Because the end-users, which are the customers, can individually impact the drinking water system, they must be a part of the solution in preventing backflow.