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Wed, Oct. 16

Prescott presses homeowners to add backflow valve

I have had numerous phone calls from homeowners, home inspectors and realtors about the "official notice" sent out from the City of Prescott regarding sewer backflow valves. The notice said Prescott has passed a resolution and ordinance to amend the 2006 International Plumbing Code that was already adopted by the city.

The City of Prescott added the following to the plumbing code:

"Section 715.1.1: Sewage backflow retrofit requirements. All structures connected to the City of Prescott sewer system prior to the adoption of this ordinance shall be protected by an approved backwater valve when additions, alterations, or repairs to existing structures are done."

I hear you asking: What is a backflow valve? This is a one-way valve installed in a home sewer line. It allows wastewater to flow away from the home to the sewer, but not backwards. So if the city sewer line becomes obstructed, the sewage cannot flow backwards into your home.

Prescott Valley has required these for about 10 years. In most Prescott Valley homes there are three black pipes in the front yard, usually near the home. Two of these are the waste- line cleanouts (for the Roto-Rooter guy when your kids flush their toys down the toilets.) The third pipe is a little larger and contains the backflow valve.

The letter from Prescott infers that every homeowner in Prescott needs to rush out and have a backflow valve installed. This is not my interpretation; this is why people are calling me. I don't believe the city can require someone to install a backflow valve immediately. The amendment says a backflow valve is required "when additions, alterations or repairs to existing structures are done."

If you read the letter from the city, it says you will install a valve or sign a "hold harmless and indemnification agreement." I will refer to this simply as the "agreement." I read the agreement online. It basically says if the city sewer line fails and causes sewage to back up into your home, you will have no claim with the city. It says other stuff that I did not reread enough times to fully understand; I'm pretty sure it was written by an attorney.

So here is what I tell homeowners about this letter. The city cannot require you to have a backflow valve installed; you can sign the agreement instead. A backflow valve is not a bad idea, but some homes may not really need them. If your home is the highest one on the street, a backflow valve is much less important. (If a backflow occurs, it will likely be in your lower neighbor's bathtub and not reach yours.) If your home is the lowest on a hilly street, a backflow valve is a good idea. You need to consult with a plumber regarding cost. If your waste lines are accessible in a crawlspace, it may be possible to install the backflow valve here. This would be much less expensive than if the plumber has to install the valve in an underground waste line. And make sure you get a permit so the city knows you had the backflow valve installed.

I tell real estate agents that, as a home inspector, I will not mention the absence of backflow valves in my inspection report. Home inspectors report on the visual condition of the home at the time of the inspection. We do not report on code compliance; an inspection like that requires much more time and research. If there is not a backflow valve, we cannot determine if the current owner has signed the agreement. This may be a disclosure situation for real estate agents, which is beyond my knowledge.

I tell other home inspectors that I will not report on the existence or absence of a backflow valve. There may be one that is not visible. There may be one that is visible but is not installed correctly or is defective. However, the indemnification agreement has clauses that state the agreement will be recorded and will "run with the land." I interpret this as meaning that subsequent owners of the home will be bound by this agreement. Frankly, I have never heard of a municipality requiring such an agreement. I can't say it has not been done; I've just never heard of it. I will be adding a disclaimer in my inspection reports that briefly explains backflow valves and the city requirements. I will state that determining the existence or proper operation of a backflow valve is beyond the scope of a home inspection, as is determining if an indemnification agreement on this property has been executed.

I've always told homeowners that they are not required to upgrade their home every three years when a new building code is issued (or more accurately, when a new building code is adopted by your municipality.) It would be impossible for municipalities to enforce this and to inspect every home every three years. It would be expensive for every homeowner. It could be extremely expensive for owners of old homes.

I have told clients and homeowners that a municipality will usually require compliance with newer codes if a building permit is obtained. For example, if you remodel your kitchen, you will need to upgrade to current safety devices, such as GFCI outlets, anti-tip brackets on ranges, etc. I have no problem with this. If you are remodeling your kitchen anyway, these upgrades are a good idea and will be little additional cost.

In the future, I will be careful what I tell clients about code compliance and future building permits. Apparently, Prescott can require you to get a backflow valve before granting a permit of any kind, even if the permit is for work that has nothing to do with the plumbing system. Knowing this, I cannot say for sure what any municipality may require for obtaining permits.

Randy West owns Professional Building Consultants in Prescott. He is a state-certified home inspector and has performed almost 6,000 home inspections in the Prescott area. West is past president of the Arizona chapter of the American Society of Home Inspectors, and currently serves on the Home Inspector Rules and Standards Committee for the Arizona Board of Technical Registration. Contact him at

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