Water systems depend on water pressure to keep water flowing in the proper direction through the pipes. However, a sudden or unexpected change in water pressure can cause an undesirable reversal in the normal flow of water. This is called backflow. During a backflow event, water runs backwards from the consumer’s water system and returns to the public water distribution system. The reversal of flow can allow potentially contaminated water to flow back into the public water supply, creating a possible health risk. For example, soapy water or other cleaning compounds can backflow through a hose submerged in a laundry basin or lawn chemicals can backflow through submerged irrigation nozzles.
Backflow is caused by two hydraulic principals: back siphonage and back pressure. Both occur when a pressure differential exists in the piping system causing lower pressure in the public water distribution system and a higher pressure in the consumer’s water system. Back siphonage occurs when there is unusual drop in pressure within the public water distribution system due to extreme water demand such as a water main break, hydrant flushing or fighting a fire. Back pressure occurs when there is an increase in pressure within the consumer’s water system due to elevation or mechanical pumping above the pressure of the public water distribution system. In both cases, water will flow from the high pressure system to the low pressure system; potentially allowing drinking water to become contaminated and unusable within the public water distribution system.
RESIDENTIAL IRRIGATION SYSTEM FAQS
WHAT IS BACKFLOW?
Water systems depend on water pressure to keep water flowing in the proper direction through the pipes. However, a sudden or unexpected change in water pressure can cause an undesirable reversal in the normal flow of water. This is called backflow.
WHAT HAPPENS DURING A BACKFLOW EVENT?
During a backflow event, potentially non-potable water flows backwards from the consumer’s internal plumbing system and returns to the public water supply, creating a possible health risk. For example, soapy water or other cleaning compounds can backflow through a hose submerged in a laundry basin.
WHAT IS A CROSS CONNECTION?
Cross connections are locations within the consumer’s internal plumbing system where possible backflow can occur if a pressure differential exists. It is a point where non-potable water from the consumer’s internal plumbing system can potentially enter the public water supply.
WHAT ARE COMMON TYPES OF CROSS CONNECTIONS?
Common cross connections for residential properties include lawn irrigation systems, garden hose connections to chemical solution aspirators, hose bibs, swimming pools and private wells. Common cross connections for commercial properties include fire sprinklers, boilers, chillers, chemical mixing tanks, pressure pumps as well as lawn irrigation systems.
WHAT IS A BACKFLOW DEVICE?
A backflow device is a mechanical assembly installed in the water line to prevent backflow from occurring at cross connections. It ensures that a one-way system of flow is maintained and thus protects the public water supply. Backflow devices on residential properties are installed right after the water meter and before the first branch line in their private plumbing.
IS A BACKFLOW DEVICE REQUIRED ON ALL RESIDENTIAL IRRIGATION SYSTEMS?
Yes. Per City Code, a backflow device must be installed on any cross connection which includes any residential irrigation system.
WHY DO BACKFLOW DEVICES NEED TO BE TESTED?
Regular testing of a backflow device ensures that it is working properly. Ultimately it protects your internal plumbing system and the public water supply from potential health risks.
HOW OFTEN DOES A BACKFLOW DEVICE NEED TO BE TESTED?
Each backflow device must be tested once every twelve (12) months after the previous test date. For example, if your device was tested in May, it must be tested by the last day of May the following year.
CAN ANYONE TEST A BACKFLOW DEVICE?
No. A backflow device must be tested by an Ohio Department of Commerce certified backflow tester. If you need a list of certified testers, please contact the Department of Public Service and Engineering at 614-342-4005.
WHAT HAPPENS AFTER THE BACKFLOW DEVICE HAS BEEN TESTED?
The backflow tester should give you a copy of the test report. It is your responsibility to keep records of all tests and maintenance performed on your backflow device. The backflow testing company will also submit a copy of the test report to the City once the tester has returned to the office and logged the report.
WHAT IS THE DIFFERENCE BETWEEN A SPRING STARTUP SERVICE AND A BACKFLOW TEST?
A spring startup service is performed on the irrigation system as whole to check for leaks, clogs, etc. A backflow test is specifically performed on the device itself to ensure that is working properly.
WHAT IF MY BACKFLOW DEVICE IS DUE TO BE TESTED BEFORE I WANT TO TURN ON MY IRRIGATION SYSTEM FOR THE SEASON OR HAVE THE SPRING STARTUP SERVICE PERFORMED?
Each backflow device must be tested once every twelve (12) months after the previous test date, regardless of when the irrigation system is planned to be turned on or the startup service will be performed. For example, if your device was tested in May, it must be tested by the last day of May the following year. It is your responsibility to coordinate the device test and spring startup service with your irrigation company to ensure EPA regulations and testing timelines are met each year. The date of the spring startup may vary from year to year due to the weather but unfortunately the backflow test cannot. Testing the device once every twelve (12) months after the previous test date is a firm deadline.
If your irrigation company will be turning on the system earlier than normal, it is recommended that you coordinate with them to have the spring startup performed but delay the backflow test until the month it is actually due to be tested. That way you can ensure your testing month remains the same each year regardless of when your system is turned on. For example, if your device was tested in May the previous year, but your system is turned on in March; you will want to instruct your irrigation company to perform the spring startup in March and then come back in May to test the backflow.
CAN I HAVE MY BACKFLOW DEVICE TESTED AT THE SAME TIME THAT THE SPRING STARTUP SERVICE IS PERFORMED?
Yes, as long as the spring startup service falls within the testing timeline for the backflow device. Depending on the maintenance plan you have with your irrigation company, the backflow testing may or may not be included with the spring startup service. You will need to confirm this with your irrigation company. If the backflow test is not included in your maintenance plan, you will need to specifically state to your irrigation company that a backflow test needs to be done in addition to the spring startup service.
WHY DID TWO PEOPLE COME OUT TO PERFORM MY SPRING STARTUP SERVICE AND BACKFLOW TEST?
Since the backflow device must be tested by a certified tester, the irrigation company may send two employees to perform maintenance on your irrigation system. One employee may not be a certified tester; therefore, he or she will only perform the spring startup service. The other employee that is a certified tester will test the backflow device. These services may occur on the same day or possibly on different days.
AM I STILL REQUIRED TO HAVE THE BACKFLOW DEVICE TESTED EVEN IF I DO NOT USE MY IRRIGATION SYSTEM?
Yes. Since the irrigation system is still physically connected to the public water supply, there is a potential for backflow to occur. Due to this reason, the backflow device must be tested once every twelve (12) months after the previous test date regardless if you use the irrigation system or not.
WHAT ARE MY OPTIONS IF I DO NOT WANT TO HAVE MY BACKFLOW DEVICE TESTED EVERY YEAR?
The only option to be exempt from backflow testing requirements is to hire a contractor to “cut and cap” the physical water line extending to the irrigation system. This process disconnects the irrigation system and creates a physical break in the water pipe. Since there is no potential for the water to flow backwards into the public water supply, you would not be required to have the backflow device tested. The City must inspect the cut and cap once it is complete to make sure everything was done properly. There is no charge for this inspection. Upon inspection approval, the irrigation system is marked as inactive in the backflow compliance system.
WHAT ARE SOME CONSIDERATIONS BEFORE HAVING MY IRRIGATION SYSTEM CUT AND CAPPED?
Hiring a contractor to cut and cap the irrigation system may be initially more expensive than having the backflow device tested. However, if you plan to own the property for an extended period of time while never using the irrigation system, then this may be a good option for you. Keep in mind that a cut and cap is a more permanent solution. If you change your mind and want to use the system in the future, you would need to hire a contractor to come back out and reconnect the system. In addition, you must notify the City since the backflow device would require annual testing once the irrigation system is reconnected.