Contrary to what recent snow flurries might indicate, warmer weather means irrigation season is nearly upon us.

For those with lawns, that means it’s almost time to turn on the sprinklers and watch those non-native grasses turn green.

It also means people in cities like Bend and Redmond must get their backflow prevention devices tested to make sure they’re not contaminating local drinking water supplies with substances such as fertilizers, dirt and animal feces.

But depending on where you live and who provides your water, the cost and responsibility of backflow testing can vary.

There’s also a difference in whose water you could potentially contaminate if your backflow device fails. It could only be you, or it could be your neighbors as well.

“This is very serious,” said Steven Vieira, who heads the city of Bend’s Safe Drinking Water Program. “It only takes one event for customers to get sick.”

For the most part, water is pressurized to flow in one direction, meaning it goes from a city water main into a resident’s tap. But certain circumstances — a water main break or turning on a fire hydrant, for example — can cause the pressure to dip and force the water to siphon backward into the system.

In some instances, this can be hazardous, particularly in locations where drinkable water has the possibility of coming in contact with contaminants. These places, called cross connections, can be anything from a garden hose that is filling up a swimming pool or hot tub to landscape irrigation systems.

In June 1989, an air conditioning system broke at Redmond High School and pumped toxic antifreeze into the water there. Although it was summer break and no students were on campus, eight school employees who drank the water reported getting sick.

Backflow prevention devices, however, are designed to prevent these sorts of scenarios from happening. State and local laws now require the mechanisms to be installed on all homes with irrigation systems, and to be tested at least once year to make sure they’re operating effectively.

Different towns, different rules

In Bend, that responsibility falls on homeowners and can cost upwards of $35 for a single test. It doesn’t matter if the water provider is the city, or one of the two private purveyors, Avion Water Co. or Roats Water Supply, Inc.

But in Redmond the cost of residential backflow testing is much less, mainly because it’s spread out among all water customers regardless of whether they have an irrigation system.

According to Dustan Campbell, the manager for Redmond’s Water Division, the city hires a private contractor to test all the residential backflow devices. He said the monthly charge for residents breaks down to about 28 cents, or just under $4 a year.

“Everybody benefits from the program and we’re protecting the water supply that everybody receives,” Campbell said. “What it really comes down to is what is the most cost-effective system for your area.”

For some Bend residents, they’d prefer if the city provided the same backflow testing service as Redmond. They say it not only would make it more convenient, but it would also help to ensure everybody is testing their backflow assemblies to keep bad water out of the taps.

Jim Calice is one of those people. He’s a construction worker who lives in Northeast Bend and gets city water. With the way the system is set up in Bend today, there’s nothing that prevents someone defrauding the system, such as by paying someone to sign off on a test that was never performed.

“If they want it tested they should come out and test it themselves,” Calice said. “That’s good for everybody because everybody is getting good water and there’s no cheating.”

According to 2010 statistics from the Oregon Health Authority’s Cross Connection and Backflow Prevention Program, of Bend’s 20,558 backflow assemblies, 18,684, or about 91 percent, were tested. In Redmond, there were 6,305 backflow tests reported, which equates to about a 94 percent compliance rate.

Statewide figures from 2009 — the most recent statewide statistics available — show Oregon’s compliance rate for testing a total of 279,000 known backflow assemblies was 85 percent.

But even though officials consider those local compliance rates to be on the high end, Bend residents Amy and Greg Broderick believe there should be measures in place to make people get their backflow assemblies tested.

“It’s not fair for one person not to do it,” Amy Broderick said. “It’s a responsibility of being a homeowner.”

As it stands today, the city of Bend sends out reminders to homeowners every year to get their devices tested. Many of these people also likely receive some sort of door-hanger or notice from the certified private backflow testers advertising their services.

Honor system for tests

But the enforcement of backflow testing — at least in Bend where the onus is on homeowners — is relatively mild. If city officials notice a test hasn’t been performed they will send additional notices to those residents who haven’t complied. These can be followed up by phone calls and then site visits.

And while there aren’t any fines for not getting a backflow device tested, the city can shut off water service to the home, something that rarely, if ever, happens.

Greg Broderick said this means people are relying on the “honor system” to keep Bend’s water supply safe, which to him doesn’t do service to the people who actually test their systems.

“It’s definitely a safety concern,” he said. “And since it’s a safety concern there should be checks and balances in place because if they’re not then there’s no reason to have backflow testing.”

This shouldn’t suggest there aren’t fail-safes in place to protect the integrity of the entire water system. The city of Bend, Avion and Roats are all in the process of installing what are known as premise isolation devices on their water meters to prevent contaminants from leaving a household and entering their entire water supply.

These premise isolation assemblies act as a second backflow device, though it only protects the integrity of the system and not the individuals living in a residence. This means if there’s a backflow of contaminated water at one home, only the people there risk getting sick instead of the people on the entire block.

Redmond does not rely upon premise isolation devices since it performs the backflow testing itself.

Not all Bend homes have these devices either. Avion and Roats representatives said most of their customers have the assemblies in place, but not all. Those companies also charge their customers to test and maintain those devices.

There are about 7,000 city of Bend residential connections that have yet to be installed with premise isolation controls, though not all of them have irrigation systems. Of the ones that have been installed, the city owns, maintains and tests them itself. New connections also receive the premise isolation assemblies.

Retrofitting under way

Steven Vieira, of Bend’s Safe Drinking Water Program, said it will likely take the city about five years to get all its connections retrofitted with premise isolation backflow devices, and that work is under way now.

It’s a priority of his, he said, because if there is a backflow event at a residence, it could impact the entire water system and potentially threaten the health of a large group of people.

For this reason, he said the city pays special attention to the individuals with irrigation systems who don’t have premise isolation controls on their property and send them at least three notices throughout the year telling them to get backflow devices tested.

“These are our big concern,” Vieira said. “These folks we really encourage that they get tested.”

Even though it seems there are a lot of variations on how backflow testing is performed locally, all the state really cares about is whether it’s done effectively.

Michael Perry is the coordinator of Oregon’s Cross Connection and Backflow Prevention Program. He said about 80 percent of water providers in the state make homeowners with irrigation systems take care of their own backflow testing, and it tends to be smaller entities, like Redmond, that do it differently.

“You’re talking Fords and Chevys,” Perry said. “They both have good points. They both have bad points. I wouldn’t say one is better than the other. They’re just different.”

He said a lot providers also are implementing premise isolation as part of their backflow prevention efforts. This is particularly common, he said, for water users who have high hazard risks, such as large commercial operations that use lots of potential contaminants.

When comparing premise isolation to what he calls “point-of-use” isolation, which would be homeowner’s backflow device for an irrigation system, he said there’s really no difference in protection as long as the assembly keeps people and their water supply safe.

“There isn’t one that’s that much better or that much worse,” Perry said. “They all can be done properly and they all can be done poorly.”

Backflow happens, and depending on what contaminants are in the water, the results can be serious if there’s nothing to prevent it.

In June 1989, Redmond High School experienced such an event when an air conditioning unit broke and sent ethylene glycol antifreeze into the water piping.

Even though school was out, eight teachers were sent to the hospital after drinking water that had been contaminated with the highly toxic coolant.

“As far as cross-connection events are concerned, it was pretty infamous,” said Casey Roats, who is the vice president of Roats Water System in Bend.

His company provides water service to about 1,600 customers in the city, and he said the Redmond contamination event serves as a reminder for why annual backflow testing is important. Roats even has a link on its main website under the title “Safe Water” that tells the story of the Redmond incident.

According to that account, the backflow event caused the city of Redmond to isolate the school from the rest of the water system. The school was also ordered to flush all the water lines, turn off its water fountains and supply bottled water until receiving approval to do otherwise from the state.

Since then, Oregon Cross Connection and Backflow Prevention Coordinator Michael Perry said there have been no major backflow incidents of that magnitude reported in Central Oregon.

— Nick Grube, The Bulletin