Backflow is the flow of water or other liquids, mixtures or substances, under positive or reduced pressure into the distribution pipes of a potable water supply from any source other than its intended source. Backflow is caused by either backsiphonage or backpressure. Backsiphonage occurs when a flow of used, contaminated, or polluted water from a plumbing fixture or vessel enters into the public water system, often due to negative pressure in a pipe. Backpressure occurs due to a drop in pressure from the water system. It is important to note that drop in pressure is out of your control and can occur at any time.
Backflow Prevention Frequently Asked Questions
Cross Connection is any connection between the public water supply and a source of contamination or pollution. Examples of cross connections include a hose connection to a chemical solution, lawn irrigation systems, water softeners, hose connections, and swimming pools.
What are some examples of cross connection?
Examples of cross connections include a hose connection to a chemical solution, water service connection, boilers, lawn irrigation systems and swimming pools.
What is a backflow preventer and why are they needed?
A backflow prevention assembly is an approved, testable assembly, which uses valves to prevent potential contaminants from flowing into the drinking water system. Common assemblies are the Double Check Valve (DCV), Reduced Pressure Zone (RPZ), Pressure Vacuum Breakers (PVB), and Spill Resistant Vacuum Breakers (SVB).
Who needs a backflow preventer?
All commercial and industrial RPU water customers are required to have backflow protection at the water service entrance.
Do residential RPU water customers need backflow preventers?
Residential water customers are required to have an approved backflow preventer if they have an irrigation system and/or a boiler at their home.
How often does my backflow preventer need to be tested?
The current Minnesota Plumbing Code requires all testable backflow assemblies to be tested annually, which include; RPZ’s, DCV’s, PVB’s, and SVB’s.
Who is responsible for the testing and maintenance of the backflow preventers?
The owner is responsible to ensure that the backflow prevention assembly is in proper operating condition at all times.
Who can install a backflow preventer?
Installation of a backflow preventer can only be done by a licensed plumber.
Does the installing of the backflow device require a permit?
Yes. Permits can be obtained by your licensed plumber through the City of Rochester Building Safety Department.
Who can test backflow preventers?
American Society of Sanitary Engineers (ASSE) certified plumber or tester of your choice.
How much will a backflow test cost?
The cost of having a device tested varies among testers. The cost is also dependent on several factors, including the size of the device, where the device is located, the type of device, etc.
What happens if my backflow test fails?
Any backflow preventer which fails during an annual test shall be immediately repaired or replaced.
What happens if I don’t have my assembly tested?
RPU will send a notice of violation when the test is thirty (30) days past due. RPU will send a final notice of violation when the test is sixty (60) days past due. After the final notice, the Owner will have thirty (30) days to become compliant or face possible termination of water service to their premise and may be subject to a reconnection charge. In the event the Owner informs RPU of extenuating circumstances as to why the test has not been made, a time extension may be granted by RPU, but in no case will exceed an additional thirty (30) days.
Contact RPU’s Business Services Dept. at 507-280-1544 or email: backflowtesting@rpu.org