Events like those in Flint, Michigan, where improper maintenance caused lead to leak into the public water supply, have awakened the American public to the issue of cross-connection and backf low.
While much needs to be repaired at a state and national level, there is plent y of work to be done at a local level, too. Contractors with irrigation experience will have a lot of work in the years to come.
Water mains aren’t the only thing that can put poison into the water supply. There are many instances of cross-connection hazards. Potable water can also be polluted when used water is accidentally flushed back into the mains through a process called backflow, bringing all sorts of contaminants with it.
Backflow comes in one of two forms: backsiphonage or backpressure. In backsiphonage, water is pulled from a system’s pipes by suction from the public lines. In backpressure, water is pushed out of a system’s pipes by a system’s water pressure rising above that of the public lines. One is pushing, one is pulling, but the effect is still the same: backflow.
Last year in Corpus Christi, Texas, an E. coli contamination scare caused a city-wide notice, advising residents to boil water prior to use. It resulted in the installation of new backflow prevention devices at 112 homes. In Jacksonville, North Carolina, all the pools in the city had their water tested after a resident of Arlington West Apartments reported that their tap water had a salty taste. The building’s backflow preventer had failed, and the tenants were unwittingly drinking pool water.
Those are actually fairly mild examples, compared to the real nightmares that can happen with backflow. Fertigation, chemigation and graywater reuse also pose dangers, and should never reach into a property’s potable water.
Backflow prevention devices prevent these catastrophes, but they need regular testing and occasionally, repair. So by becoming a certified backflow inspector, not only are you opening up a new revenue stream, you’re also safeguarding your clients and the neighborhoods in which they live from a hidden threat.
Testing of backflow preventers is required at least once every 12 months by the International Plumbing Code and the International Residential Code. It is also required when the devices are first installed, so irrigation systems installers who don’t have an inspector on staff are forced to subcontract out that work.
Because it concerns public safety, there are rules in place to ensure that inspectors are capable and using the proper equipment. Every backflow inspector must pass a test to become certified, and then recertify every three years.
Furthermore, there are a few startup costs. “The gauges are typically the most important and most costly piece of testing equipment,” said Thomas Schaub, owner of Planscape Inc. in Dover, Florida. “They typically run between $600 and $1,000.” The testing gauges need to be tested themselves, annually, and the results sent off to the relevant authorities.
That’s where things can get a bit tricky. Backflow testing can require documentation from the city, county or state government in which the property is located, the water provider for that property, or some combination of those four. It’s not always clear who has a stake, and who needs a copy of what documents.
That confusion often falls on the contractor to sort out, so it’s important to keep good records, and be clear in your communications. “I’ve actually had customers call and tell us that, even though they had their backflows tested, they got a nasty note from some enforcement organization,” said Lindsey Denson, office manager at Everflow Irrigation in Mount Vernon, Washington.
Sometimes, Denson’s company tests a system in the fall, but the county that the property is in wants all their backflow testing done in the spring instead, and insists on a second testing. That’s when she has to go to bat for their clients. “I’ve had to call the county and say, ‘It was done last fall. Washington state law says it’s good for 12 months; we’re not going to redo it now and charge our customer a second time,” she said.
Still, Denson says the situation usually isn’t so grim. There can be hundreds of water purveyors in a single county, and she’s found them quite friendly and understanding about the misfiling that can result. You may find that your own service areas have a more organized system in place.
A clear-cut system would certainly be more fitting, as the world of backflow looks at potential accidents in a fairly black-and-white fashion. All accidental additions to the water supply are divided into two categories. Pollutants, which don’t pose a risk to health and safety and have a low degree of hazard, and contaminants, which can cause illness or death, and have a high degree of hazard.
As a result, different systems need different backflow devices, depending on what might be getting through if backflow were to occur. In some areas, the rules will declare irrigation systems to have a low degree of hazard, assuming that they are only being used to transport water. In most areas, however, they are considered ‘high hazard’.
In these cases, a backflow device that only prevents backsiphonage will probably be all that the rules require. “The pressure vacuum breaker, or PVB, is good for backsiphonage,” said Schaub. “It’s an antisiphon device which introduces air into the system. The air breaks the vacuum and keeps material from getting siphoned back into the system.”
If a municipality is concerned about potential contamination from irrigation systems, it’s likely to require that any backflow devices be able to prevent backpressure as well as backsiphonage. In that case, a PVB won’t be enough. It might ac cept a double-check valve assembly (DCVA), which relies on two oneway valves to prevent any backflow.
If that isn’t enough, you’ll probably need to install a reduced pressure principle (RP) backflow device, also referred to as a reduced pressure zone device (RPZ). The RPZ bears a lot of similarities to the DCVA: two one-way valves in sequence, each theoretically strong enough to prevent backflow on its own. What makes the RPZ a better bet at preventing backflow is an additional assembly that opens up an overflow pipe when water isn’t flowing in the right direction.
“If a property has a pond on it and the irrigation system draws from that pond, then the county will normally require an RP,” said Schaub.
“Because they want to make sure that there’s no cross-connection between what might be pumped out of the pond, and what might possibly get into the potable supply.”
Being able to assess the degree of hazard a backflow device must meet on your own is a valuable skill, because once you start looking with an eye towards backflow, you’ll see it everywhere. “Let’s say you’ve got a client with a sprinkler head that’s in a depression, but uphill from the backflow device,” Schaub said. “If a puddle forms in that depression, then anything that could be in there—dog feces, motor oil, anything—could all get into the potable water supply if the water pressure was cut off.”
Given the pressure our water infrastructure is under right now, more pressure problems are likely to occur. We hear reports of water main breaks and pump failures on a regular basis, and millions of feet of lead piping that needs to be replaced. Even when things are running smoothly, cities often have to cut pressure in order to perform regular maintenance. Are your clients prepared?
Even if they are, the real power in doing backflow testing is its potential to bring in new clients. Think of it like this: If your municipality required a yearly irrigation audit on every property, wouldn’t you start offering that service?
Aquaturf Irrigation Systems in Elmsford, New York, started offering backflow testing about 18 months ago, and Tony Dilluvio, managing partner, says that it opened up a stream of new customers. “People needing a backflow inspection who weren’t our customers have become our customers,” he said. “It’s really given us a Swiss Army knife approach to the business, because we offer all the services they could need.”
Another component of backflow to keep in mind is that these fairly valuable devices are gleaming targets for scrap metal thieves. Their solid brass construction means that even relatively small residential units can easily fetch $20 a pop at the local scrapyard. Thieves aren’t terribly likely to take care to remove them properly either; if breaking the pipe off gets the job done quicker, they’ll do it.
Should one of your clients be struck, they could be facing a significant repair bill. The replacement device costs an order of magnitude more than its scrap value, and if the thieves broke off pipes underground in their haste, the labor costs won’t be trivial either. If you think some of the properties you service are at risk, you may want to look into security cages for your clients’ backflow devices.
Ensuring that those “just-in-case” measures are functioning properly is what backflow testing is all about. Decaying infrastructure issues are going to make this even more pressing in the years to come, and if you aren’t offering this service in your area, someone else might.
Landscape contractors wear so many hats. They mow, they install, they irrigate, they fertilize, they weed, they spray and they light. All of which makes their clients’ lives happier and less stressful. Each time you add a service, you gain new skills and become a better landscape expert for your clients.
Backflow is a real danger, and one that many people aren’t aware of yet. If you offer irrigation services, you can already look at a landscape and judge precipitation rates, slopes and pressures. By getting certified, you can employ that expertise for the public good. There’s a lot at stake. Are you up for the challenge?