Frequently Asked Questions

What is this all about?

Bottom line is safe drinking water.  90% of water contamination is caused by us!

What is Backflow and Cross Connection?

Backflow is the reversal of water from its intended direction of flow.  Backflow occurs all the time.  Water always flows to the lowest pressure in a system so it “backflows” from the direction it was going when there is a loss of pressure or backpressure.  Normally this isn’t a problem. 

Plumbing is engineered to be safe but a “cross connection” is created when an undrinkable substance is connected which can contaminate the drinking water.  Examples are underground landscape sprinkler systems, fire lines, post mix soda machines, and equipment that boost pressure or use chemicals.  By law, these cross connections have to be protected with an approved testable backflow prevention assembly.  The State of Washington Department of Health WAC 246-290-490 is the governing code that requires water providers to enforce protection of public water systems from contamination and pollution due to cross connections.

Backflow assemblies are considered the second line of defense in protecting the drinking water downstream of the water providers.

What is a Backflow Assembly?


A backflow prevention assembly is a mechanical device that allows water to flow only in the intended direction.  By preventing water from backflowing, it keeps the contamination where it belongs and not in the water you drink.  Backflow assemblies vary in type, model and size depending on the need of protection determined by the severity of the hazard.  They must be installed properly to allow testing and maintenance.

Why do I need to have the Backflow Assembly tested?

A backflow assembly has internal parts that move when water is flowing so they can and will fail at some point due to debris, freezing, or just normal wear and tear.  By law, upon installation of a new assembly it must be tested to make sure it is working properly and then it has to be tested every year by a certified backflow assembly tester.  Annual tests are a vital necessity to ensure the drinking water supplied to your home or business is safe from contamination.

What is a Backflow test?

A backflow assembly tester uses a calibrated pressure differential gauge that attaches to the test ports on the device and moves water to verify proper operation.  The test has specific procedures that all certified testers MUST follow.  The results are then required by DOH to be supplied to the water purveyor and the customer.  Per L & I, certified testers must be licensed, bonded and insured registered contractors to do any cleaning or repairs to a backflow assembly.

*Please note that water must be on to the assembly and all water downstream of the backflow assembly is shut off during the test.

Do I need to be at my home/business when my backflow assembly is tested?

Only if it is located inside or there is no safe access due to a locked gate or guard dog.

What do I do after the test?

Not a thing!  I take care of everything.  I send the results to your water provider quickly and email an invoice with a copy of the test results to you.  I offer online payments or simply mail a check.