In order to ensure the proper operation of a backflow prevention assembly, it must be tested and certified upon initial installation and at least once a year thereafter by a licensed backflow tester.    

Proper permits must be acquired from a city's Building Department.

A cross-connection is any temporary or permanent connection between a public water system or the customer’s potable water system and any source or system containing non-potable water or other substances.

Common cross-connections:

Private Wells – where the private well connection is connected to a service line receiving water from a public water supply.  The untreated water could be pumped into the potable water supply which serves the home and the public water system.

Lawn sprinkler systems – where the stagnant/contaminated water from the sprinkler system could be drawn into the drinkable water supply for your home.

A backflow prevention assembly is a means or mechanism to prevent backflow.  The basic means for preventing backflow is an air gap, which either eliminates a cross-connection or provides a barrier from backflow.  The basic mechanism for preventing backflow is a mechanical backflow preventer, which provides a physical barrier to backflow.  The principal types of backflow preventers are the reduced-pressure principle assembly, the pressure vacuum breaker assembly and the double check valve assembly.

Back-siphonage is backflow caused by negative pressure (i.e. vacuum or partial vacuum) in a public water system or customer’s potable water system.  The effect is similar to drinking water through a straw.  Back-siphonage can occur when there is a stoppage of water supply due to nearby firefighting, a break in a water main, etc.

Backflow refers to the reverse flow of non-potable water, or other substances, through a cross-connection and into the piping of a public water system or customer’s potable water system.  Two types of backflow are backpressure backflow and back-siphonage. 

Backpressure backflow occurs when the downstream side of the piping system is greater than the supply pressure in a public system or customer’s potable water system.  Backpressure can result from an increase in downstream pressure, a reduction in the potable water supply pressure or a combination of both.  Pumps can create increases in downstream pressure; temperature increases in boilers, etc.  Reductions in potable water supply pressure occur whenever the amount of after being used exceeds the amount of water being supplied, such as during waterline flushing, firefighting or breaks in the water mains.

These programs safeguard the public drinking water and protect the health of its residents.  They do thus by helping to ensure that any contaminants that could backflow into the public water supply system are isolated within the internal distribution system.  

No. cities will continue to review all permits and utility drawings to ensure compliance with backflow prevention requirements.  They will continue to oversee the installation and testing of the assemblies.

Yes.  Section 608.16.5, of the International Plumbing Code and Section P2902.5.3 of the International Residential Code (connections to lawn irrigation systems), states that the potable water supply to lawn irrigation systems shall be protected against backflow by a pressure-type vacuum breaker, a double-check valve assembly or a reduced pressure principle backflow preventer – depending on the degree of the site hazard. 

A potential hazard is defined as any possibility of pollutants or contaminants entering the system.  For example, fire protection systems, irrigation systems, gasoline refineries and stations, restaurants, hospitals and manufacturers are typical locations requiring backflow devices.

Fees can differ depending on the testing company, quantity of backflow prevention assemblies to be tested, number of locations, etc.  In general, expect between $50-$200 per assembly.

With proper maintenance and annual testing, backflow prevention assemblies have been known to last for many years.

Mechanical backflow prevention assemblies have internal seals, springs, and moving parts that are subject to fouling, wear or fatigue.  Also, mechanical backflow preventers and air gaps can be bypassed.  Therefore, all backflow prevention assemblies have to be tested periodically to ensure that they are functioning correctly.  Mechanical backflow prevention assemblies have to be tested with properly calibrated gauge equipment.    

Yes.  Section 608.16.5, of the International Plumbing Code and Section P2902.5.3 of the International Residential Code (connections to lawn irrigation systems), states that the potable water supply to lawn irrigation systems shall be protected against backflow by a pressure-type vacuum breaker, a double-check valve assembly or a reduced pressure principle backflow preventer – depending on the degree of the site hazard. 

Only ASSE-Licensed testers are authorized to test backflow prevention assemblies.  

Go to www.safewatercommission.com, under the Property Owner tab select Backflow Device Test Status, ender your property address and hit Submit to verify whether your test results have been submitted.

Each state has different requirements.  You should review your state's plumbing code to determine what is in or out of scope.

For instance, the State of MN requires all High Hazard devices (RPZ) to be tested annually, regardless of the date of install. Regarding all other testable devices (PVB, SVB, and double check), these devices need to be tested annually if they were installed after January 23^rd, 2016. Water municipalities do have the choice to go above and beyond the State’s requirement to test all testable devices regardless of the date they were installed.

For cities that leverage Safe Water Commission, the licensed tester will input the approved backflow testing report via the Safe Water Commission testing portal.  SWC will notify the City upon completion.  If the customer’s backflow testing report is not inputted into SWC database on or by the due date, SWC will mail a non-compliance notice to the customer.  Failure to comply with annual testing could result in the city disconnecting the water service until backflow device is tested. 

No, the installation, repair, replacement and/or testing of in-scope testable backflow assemblies must be performed by an ASSE licensed contractor.  Other un-related plumbing tasks can be performed by a homeowner, but not activities relating to backflow prevention devices.

Fees are determined by the backflow tester or testing company.  They can range from $70 - $200 depending on location and quantity, but please verify costs when you are trying to schedule with a tester.

Review the 2015 Minnesota Plumbing Code Fact Sheet HERE!

A list of licensed testers can be found here.